Ard Biesheuvel [Wed, 30 Mar 2016 15:43:07 +0000 (17:43 +0200)]
arm64: move early boot code to the .init segment
Apart from the arm64/linux and EFI header data structures, there is nothing
in the .head.text section that must reside at the beginning of the Image.
So let's move it to the .init section where it belongs.
Note that this involves some minor tweaking of the EFI header, primarily
because the address of 'stext' no longer coincides with the start of the
.text section. It also requires a couple of relocated symbol references
to be slightly rewritten or their definition moved to the linker script.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
546c8c44f092b2f23291fe499c221efc8cabbb67)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Ard Biesheuvel [Wed, 30 Mar 2016 15:43:06 +0000 (17:43 +0200)]
arm64: use 'segment' rather than 'chunk' to describe mapped kernel regions
Replace the poorly defined term chunk with segment, which is a term that is
already used by the ELF spec to describe contiguous mappings with the same
permission attributes of statically allocated ranges of an executable.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
2c09ec06bc39fc85a2b3856524348c301def27af)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Jeremy Linton [Fri, 19 Feb 2016 17:50:32 +0000 (11:50 -0600)]
arm64: mm: Mark .rodata as RO
Currently the .rodata section is actually still executable when DEBUG_RODATA
is enabled. This changes that so the .rodata is actually read only, no execute.
It also adds the .rodata section to the mem_init banner.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
[catalin.marinas@arm.com: added vm_struct vmlinux_rodata in map_kernel()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
2f39b5f91eb4bccd786d194e70db1dccad784755)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Helge Deller [Wed, 23 Mar 2016 15:00:46 +0000 (16:00 +0100)]
parisc: Use generic extable search and sort routines
Switch to the generic extable search and sort routines which were introduced
with commit
a272858 from Ard Biesheuvel. This saves quite some memory in the
vmlinux binary with the 64bit kernel.
Signed-off-by: Helge Deller <deller@gmx.de>
(cherry picked from commit
0de798584bdedfdad19db21e3c7aec84f252f4f3)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Catalin Marinas [Thu, 10 Mar 2016 18:30:56 +0000 (18:30 +0000)]
arm64: kasan: Use actual memory node when populating the kernel image shadow
With the 16KB or 64KB page configurations, the generic
vmemmap_populate() implementation warns on potential offnode
page_structs via vmemmap_verify() because the arm64 kasan_init() passes
NUMA_NO_NODE instead of the actual node for the kernel image memory.
Fixes: f9040773b7bb ("arm64: move kernel image to base of vmalloc area")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: James Morse <james.morse@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
(cherry picked from commit
2f76969f2eef051bdd63d38b08d78e790440b0ad)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Fri, 26 Feb 2016 16:57:14 +0000 (17:57 +0100)]
arm64: mm: treat memstart_addr as a signed quantity
Commit
c031a4213c11 ("arm64: kaslr: randomize the linear region")
implements randomization of the linear region, by subtracting a random
multiple of PUD_SIZE from memstart_addr. This causes the virtual mapping
of system RAM to move upwards in the linear region, and at the same time
causes memstart_addr to assume a value which may be negative if the offset
of system RAM in the physical space is smaller than its offset relative to
PAGE_OFFSET in the virtual space.
Since memstart_addr is effectively an offset now, redefine its type as s64
so that expressions involving shifting or division preserve its sign.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
020d044f66874eba058ce8264fc550f3eca67879)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Thu, 25 Feb 2016 19:48:53 +0000 (20:48 +0100)]
arm64: lse: deal with clobbered IP registers after branch via PLT
The LSE atomics implementation uses runtime patching to patch in calls
to out of line non-LSE atomics implementations on cores that lack hardware
support for LSE. To avoid paying the overhead cost of a function call even
if no call ends up being made, the bl instruction is kept invisible to the
compiler, and the out of line implementations preserve all registers, not
just the ones that they are required to preserve as per the AAPCS64.
However, commit
fd045f6cd98e ("arm64: add support for module PLTs") added
support for routing branch instructions via veneers if the branch target
offset exceeds the range of the ordinary relative branch instructions.
Since this deals with jump and call instructions that are exposed to ELF
relocations, the PLT code uses x16 to hold the address of the branch target
when it performs an indirect branch-to-register, something which is
explicitly allowed by the AAPCS64 (and ordinary compiler generated code
does not expect register x16 or x17 to retain their values across a bl
instruction).
Since the lse runtime patched bl instructions don't adhere to the AAPCS64,
they don't deal with this clobbering of registers x16 and x17. So add them
to the clobber list of the asm() statements that perform the call
instructions, and drop x16 and x17 from the list of registers that are
callee saved in the out of line non-LSE implementations.
In addition, since we have given these functions two scratch registers,
they no longer need to stack/unstack temp registers.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: factored clobber list into #define, updated Makefile comment]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
5be8b70af1ca78cefb8b756d157532360a5fd663)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Wed, 2 Mar 2016 08:47:13 +0000 (09:47 +0100)]
arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly
Commit
8439e62a1561 ("arm64: mm: use bit ops rather than arithmetic in
pa/va translations") changed the boundary check against PAGE_OFFSET from
an arithmetic comparison to a bit test. This means we now silently assume
that PAGE_OFFSET is a power of 2 that divides the kernel virtual address
space into two equal halves. So make that assumption explicit.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
6d2aa549de1fc998581d216de3853aa131aa4446)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Catalin Marinas [Thu, 10 Mar 2016 18:41:16 +0000 (18:41 +0000)]
arm64: kasan: Fix zero shadow mapping overriding kernel image shadow
With the 16KB and 64KB page size configurations, SWAPPER_BLOCK_SIZE is
PAGE_SIZE and ARM64_SWAPPER_USES_SECTION_MAPS is 0. Since
kimg_shadow_end is not page aligned (_end shifted by
KASAN_SHADOW_SCALE_SHIFT), the edges of previously mapped kernel image
shadow via vmemmap_populate() may be overridden by subsequent calls to
kasan_populate_zero_shadow(), leading to kernel panics like below:
------------------------------------------------------------------------------
Unable to handle kernel paging request at virtual address
fffffc100135068c
pgd =
fffffc8009ac0000
[
fffffc100135068c] *pgd=
00000009ffee0003, *pud=
00000009ffee0003, *pmd=
00000009ffee0003, *pte=
00e0000081a00793
Internal error: Oops:
9600004f [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.5.0-rc4+ #1984
Hardware name: Juno (DT)
task:
fffffe09001a0000 ti:
fffffe0900200000 task.ti:
fffffe0900200000
PC is at __memset+0x4c/0x200
LR is at kasan_unpoison_shadow+0x34/0x50
pc : [<
fffffc800846f1cc>] lr : [<
fffffc800821ff54>] pstate:
00000245
sp :
fffffe0900203db0
x29:
fffffe0900203db0 x28:
0000000000000000
x27:
0000000000000000 x26:
0000000000000000
x25:
fffffc80099b69d0 x24:
0000000000000001
x23:
0000000000000000 x22:
0000000000002000
x21:
dffffc8000000000 x20:
1fffff9001350a8c
x19:
0000000000002000 x18:
0000000000000008
x17:
0000000000000147 x16:
ffffffffffffffff
x15:
79746972100e041d x14:
ffffff0000000000
x13:
ffff000000000000 x12:
0000000000000000
x11:
0101010101010101 x10:
1fffffc11c000000
x9 :
0000000000000000 x8 :
fffffc100135068c
x7 :
0000000000000000 x6 :
000000000000003f
x5 :
0000000000000040 x4 :
0000000000000004
x3 :
fffffc100134f651 x2 :
0000000000000400
x1 :
0000000000000000 x0 :
fffffc100135068c
Process swapper/0 (pid: 1, stack limit = 0xfffffe0900200020)
Call trace:
[<
fffffc800846f1cc>] __memset+0x4c/0x200
[<
fffffc8008220044>] __asan_register_globals+0x5c/0xb0
[<
fffffc8008a09d34>] _GLOBAL__sub_I_65535_1_sunrpc_cache_lookup+0x1c/0x28
[<
fffffc8008f20d28>] kernel_init_freeable+0x104/0x274
[<
fffffc80089e1948>] kernel_init+0x10/0xf8
[<
fffffc8008093a00>] ret_from_fork+0x10/0x50
------------------------------------------------------------------------------
This patch aligns kimg_shadow_start and kimg_shadow_end to
SWAPPER_BLOCK_SIZE in all configurations.
Fixes: f9040773b7bb ("arm64: move kernel image to base of vmalloc area")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
(cherry picked from commit
2776e0e8ef683a42fe3e9a5facf576b73579700e)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Tue, 22 Mar 2016 10:11:45 +0000 (10:11 +0000)]
arm64: consistently use p?d_set_huge
Commit
324420bf91f60582 ("arm64: add support for ioremap() block
mappings") added new p?d_set_huge functions which do the hard work to
generate and set a correct block entry.
These differ from open-coded huge page creation in the early page table
code by explicitly setting the P?D_TYPE_SECT bits (which are implicitly
retained by mk_sect_prot() for any valid prot), but are otherwise
identical (and cannot fail on arm64).
For simplicity and consistency, make use of these in the initial page
table creation code.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
c661cb1c537e2364bfdabb298fb934fd77445e98)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Tue, 15 Mar 2016 11:22:57 +0000 (11:22 +0000)]
arm64: fix KASLR boot-time I-cache maintenance
Commit
f80fb3a3d50843a4 ("arm64: add support for kernel ASLR") missed a
DSB necessary to complete I-cache maintenance in the primary boot path,
and hence stale instructions may still be present in the I-cache and may
be executed until the I-cache maintenance naturally completes.
Since commit
8ec41987436d566f ("arm64: mm: ensure patched kernel text is
fetched from PoU"), all CPUs invalidate their I-caches after their MMU
is enabled. Prior a CPU's MMU having been enabled, arbitrary lines may
have been fetched from the PoC into I-caches. We never patch text
expected to be executed with the MMU off. Thus, it is unnecessary to
perform broadcast I-cache maintenance in the primary boot path.
This patch reduces the scope of the I-cache maintenance to the local
CPU, and adds the missing DSB with similar scope, matching prior
maintenance in the primary boot path.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesehvuel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
b90b4a608ea2401cc491828f7a385edd2e236e37)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Will Deacon [Wed, 9 Mar 2016 15:22:55 +0000 (15:22 +0000)]
arm64: hugetlb: partial revert of
66b3923a1a0f
Commit
66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")
introduced support for huge pages using the contiguous bit in the PTE
as opposed to block mappings, which may be slightly unwieldy (512M) in
64k page configurations.
Unfortunately, this support has resulted in some late regressions when
running the libhugetlbfs test suite with 64k pages and CONFIG_DEBUG_VM
as a result of a BUG:
| readback (2M: 64): ------------[ cut here ]------------
| kernel BUG at fs/hugetlbfs/inode.c:446!
| Internal error: Oops - BUG: 0 [#1] SMP
| Modules linked in:
| CPU: 7 PID: 1448 Comm: readback Not tainted 4.5.0-rc7 #148
| Hardware name: linux,dummy-virt (DT)
| task:
fffffe0040964b00 ti:
fffffe00c2668000 task.ti:
fffffe00c2668000
| PC is at remove_inode_hugepages+0x44c/0x480
| LR is at remove_inode_hugepages+0x264/0x480
Rather than revert the entire patch, simply avoid advertising the
contiguous huge page sizes for now while people are actively working on
a fix. This patch can then be reverted once things have been sorted out.
Cc: David Woods <dwoods@ezchip.com>
Reported-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
ff7925848b50050732ac0401e0acf27e8b241d7b)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Yang Shi [Thu, 11 Feb 2016 21:53:10 +0000 (13:53 -0800)]
arm64: make irq_stack_ptr more robust
Switching between stacks is only valid if we are tracing ourselves while on the
irq_stack, so it is only valid when in current and non-preemptible context,
otherwise is is just zeroed off.
Fixes: 132cd887b5c5 ("arm64: Modify stack trace and dump for use with irq_stack")
Acked-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
a80a0eb70c358f8c7dda4bb62b2278dc6285217b)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 26 Jan 2016 13:48:29 +0000 (14:48 +0100)]
arm64: efi: invoke EFI_RNG_PROTOCOL to supply KASLR randomness
Since arm64 does not use a decompressor that supplies an execution
environment where it is feasible to some extent to provide a source of
randomness, the arm64 KASLR kernel depends on the bootloader to supply
some random bits in the /chosen/kaslr-seed DT property upon kernel entry.
On UEFI systems, we can use the EFI_RNG_PROTOCOL, if supplied, to obtain
some random bits. At the same time, use it to randomize the offset of the
kernel Image in physical memory.
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
2b5fe07a78a09a32002642b8a823428ade611f16)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Mon, 11 Jan 2016 10:47:49 +0000 (11:47 +0100)]
efi: stub: use high allocation for converted command line
Before we can move the command line processing before the allocation
of the kernel, which is required for detecting the 'nokaslr' option
which controls that allocation, move the converted command line higher
up in memory, to prevent it from interfering with the kernel itself.
Since x86 needs the address to fit in 32 bits, use UINT_MAX as the upper
bound there. Otherwise, use ULONG_MAX (i.e., no limit)
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
48fcb2d0216103d15306caa4814e2381104df6d8)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Mon, 11 Jan 2016 09:43:16 +0000 (10:43 +0100)]
efi: stub: add implementation of efi_random_alloc()
This implements efi_random_alloc(), which allocates a chunk of memory of
a certain size at a certain alignment, and uses the random_seed argument
it receives to randomize the address of the allocation.
This is implemented by iterating over the UEFI memory map, counting the
number of suitable slots (aligned offsets) within each region, and picking
a random number between 0 and 'number of slots - 1' to select the slot,
This should guarantee that each possible offset is chosen equally likely.
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
2ddbfc81eac84a299cb4747a8764bc43f23e9008)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Sun, 10 Jan 2016 10:29:07 +0000 (11:29 +0100)]
efi: stub: implement efi_get_random_bytes() based on EFI_RNG_PROTOCOL
This exposes the firmware's implementation of EFI_RNG_PROTOCOL via a new
function efi_get_random_bytes().
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
e4fbf4767440472f9d23b0f25a2b905e1c63b6a8)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Fri, 29 Jan 2016 10:59:03 +0000 (11:59 +0100)]
arm64: kaslr: randomize the linear region
When KASLR is enabled (CONFIG_RANDOMIZE_BASE=y), and entropy has been
provided by the bootloader, randomize the placement of RAM inside the
linear region if sufficient space is available. For instance, on a 4KB
granule/3 levels kernel, the linear region is 256 GB in size, and we can
choose any 1 GB aligned offset that is far enough from the top of the
address space to fit the distance between the start of the lowest memblock
and the top of the highest memblock.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
c031a4213c11a5db475f528c182f7b3858df11db)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 26 Jan 2016 13:12:01 +0000 (14:12 +0100)]
arm64: add support for kernel ASLR
This adds support for KASLR is implemented, based on entropy provided by
the bootloader in the /chosen/kaslr-seed DT property. Depending on the size
of the address space (VA_BITS) and the page size, the entropy in the
virtual displacement is up to 13 bits (16k/2 levels) and up to 25 bits (all
4 levels), with the sidenote that displacements that result in the kernel
image straddling a 1GB/32MB/512MB alignment boundary (for 4KB/16KB/64KB
granule kernels, respectively) are not allowed, and will be rounded up to
an acceptable value.
If CONFIG_RANDOMIZE_MODULE_REGION_FULL is enabled, the module region is
randomized independently from the core kernel. This makes it less likely
that the location of core kernel data structures can be determined by an
adversary, but causes all function calls from modules into the core kernel
to be resolved via entries in the module PLTs.
If CONFIG_RANDOMIZE_MODULE_REGION_FULL is not enabled, the module region is
randomized by choosing a page aligned 128 MB region inside the interval
[_etext - 128 MB, _stext + 128 MB). This gives between 10 and 14 bits of
entropy (depending on page size), independently of the kernel randomization,
but still guarantees that modules are within the range of relative branch
and jump instructions (with the caveat that, since the module region is
shared with other uses of the vmalloc area, modules may need to be loaded
further away if the module region is exhausted)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
f80fb3a3d50843a401dac4b566b3b131da8077a2)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 26 Jan 2016 08:13:44 +0000 (09:13 +0100)]
arm64: add support for building vmlinux as a relocatable PIE binary
This implements CONFIG_RELOCATABLE, which links the final vmlinux
image with a dynamic relocation section, allowing the early boot code
to perform a relocation to a different virtual address at runtime.
This is a prerequisite for KASLR (CONFIG_RANDOMIZE_BASE).
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
1e48ef7fcc374051730381a2a05da77eb4eafdb0)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Fri, 1 Jan 2016 14:02:12 +0000 (15:02 +0100)]
arm64: switch to relative exception tables
Instead of using absolute addresses for both the exception location
and the fixup, use offsets relative to the exception table entry values.
Not only does this cut the size of the exception table in half, it is
also a prerequisite for KASLR, since absolute exception table entries
are subject to dynamic relocation, which is incompatible with the sorting
of the exception table that occurs at build time.
This patch also introduces the _ASM_EXTABLE preprocessor macro (which
exists on x86 as well) and its _asm_extable assembly counterpart, as
shorthands to emit exception table entries.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
6c94f27ac847ff8ef15b3da5b200574923bd6287)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Fri, 1 Jan 2016 11:39:09 +0000 (12:39 +0100)]
extable: add support for relative extables to search and sort routines
This adds support to the generic search_extable() and sort_extable()
implementations for dealing with exception table entries whose fields
contain relative offsets rather than absolute addresses.
Acked-by: Helge Deller <deller@gmx.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
a272858a3c1ecd4a935ba23c66668f81214bd110)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Sun, 10 Jan 2016 10:42:28 +0000 (11:42 +0100)]
scripts/sortextable: add support for ET_DYN binaries
Add support to scripts/sortextable for handling relocatable (PIE)
executables, whose ELF type is ET_DYN, not ET_EXEC. Other than adding
support for the new type, no changes are needed.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
7b957b6e603623ef8b2e8222fa94b976df613fa2)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
James Morse [Tue, 2 Feb 2016 15:53:59 +0000 (15:53 +0000)]
arm64: futex.h: Add missing PAN toggling
futex.h's futex_atomic_cmpxchg_inatomic() does not use the
__futex_atomic_op() macro and needs its own PAN toggling. This was missed
when the feature was implemented.
Fixes: 338d4f49d6f ("arm64: kernel: Add support for Privileged Access Never")
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
811d61e384e24759372bb3f01772f3744b0a8327)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Mon, 11 Jan 2016 16:08:26 +0000 (17:08 +0100)]
arm64: make asm/elf.h available to asm files
This reshuffles some code in asm/elf.h and puts a #ifndef __ASSEMBLY__
around its C definitions so that the CPP defines can be used in asm
source files as well.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
4a2e034e5cdadde4c712f79bdd57d1455c76a3db)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Sat, 26 Dec 2015 11:46:40 +0000 (12:46 +0100)]
arm64: avoid dynamic relocations in early boot code
Before implementing KASLR for arm64 by building a self-relocating PIE
executable, we have to ensure that values we use before the relocation
routine is executed are not subject to dynamic relocation themselves.
This applies not only to virtual addresses, but also to values that are
supplied by the linker at build time and relocated using R_AARCH64_ABS64
relocations.
So instead, use assemble time constants, or force the use of static
relocations by folding the constants into the instructions.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
2bf31a4a05f5b00f37d65ba029d36a0230286cb7)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Sat, 26 Dec 2015 12:48:02 +0000 (13:48 +0100)]
arm64: avoid R_AARCH64_ABS64 relocations for Image header fields
Unfortunately, the current way of using the linker to emit build time
constants into the Image header will no longer work once we switch to
the use of PIE executables. The reason is that such constants are emitted
into the binary using R_AARCH64_ABS64 relocations, which are resolved at
runtime, not at build time, and the places targeted by those relocations
will contain zeroes before that.
So refactor the endian swapping linker script constant generation code so
that it emits the upper and lower 32-bit words separately.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
6ad1fe5d9077a1ab40bf74b61994d2e770b00b14)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 24 Nov 2015 11:37:35 +0000 (12:37 +0100)]
arm64: add support for module PLTs
This adds support for emitting PLTs at module load time for relative
branches that are out of range. This is a prerequisite for KASLR, which
may place the kernel and the modules anywhere in the vmalloc area,
making it more likely that branch target offsets exceed the maximum
range of +/- 128 MB.
In this version, I removed the distinction between relocations against
.init executable sections and ordinary executable sections. The reason
is that it is hardly worth the trouble, given that .init.text usually
does not contain that many far branches, and this version now only
reserves PLT entry space for jump and call relocations against undefined
symbols (since symbols defined in the same module can be assumed to be
within +/- 128 MB)
For example, the mac80211.ko module (which is fairly sizable at ~400 KB)
built with -mcmodel=large gives the following relocation counts:
relocs branches unique !local
.text 3925 3347 518 219
.init.text 11 8 7 1
.exit.text 4 4 4 1
.text.unlikely 81 67 36 17
('unique' means branches to unique type/symbol/addend combos, of which
!local is the subset referring to undefined symbols)
IOW, we are only emitting a single PLT entry for the .init sections, and
we are better off just adding it to the core PLT section instead.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
fd045f6cd98ec4953147b318418bd45e441e52a3)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 23 Feb 2016 07:56:45 +0000 (08:56 +0100)]
arm64: move brk immediate argument definitions to separate header
Instead of reversing the header dependency between asm/bug.h and
asm/debug-monitors.h, split off the brk instruction immediate value
defines into a new header asm/brk-imm.h, and include it from both.
This solves the circular dependency issue that prevents BUG() from
being used in some header files, and keeps the definitions together.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
f98deee9a9f8c47d05a0f64d86440882dca772ff)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Mon, 22 Feb 2016 17:46:04 +0000 (18:46 +0100)]
arm64: mm: use bit ops rather than arithmetic in pa/va translations
Since PAGE_OFFSET is chosen such that it cuts the kernel VA space right
in half, and since the size of the kernel VA space itself is always a
power of 2, we can treat PAGE_OFFSET as a bitmask and replace the
additions/subtractions with 'or' and 'and-not' operations.
For the comparison against PAGE_OFFSET, a mov/cmp/branch sequence ends
up getting replaced with a single tbz instruction. For the additions and
subtractions, we save a mov instruction since the mask is folded into the
instruction's immediate field.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
8439e62a15614e8fcd43835d57b7245cd9870dc5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Mon, 22 Feb 2016 17:46:03 +0000 (18:46 +0100)]
arm64: mm: only perform memstart_addr sanity check if DEBUG_VM
Checking whether memstart_addr has been assigned every time it is
referenced adds a branch instruction that may hurt performance if
the reference in question occurs on a hot path. So only perform the
check if CONFIG_DEBUG_VM=y.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[catalin.marinas@arm.com: replaced #ifdef with VM_BUG_ON]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
a92405f082d43267575444a6927085e4c8a69e4e)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Catalin Marinas [Fri, 19 Feb 2016 14:28:58 +0000 (14:28 +0000)]
arm64: User die() instead of panic() in do_page_fault()
The former gives better error reporting on unhandled permission faults
(introduced by the UAO patches).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
70c8abc28762d04e36c92e07eee2ce6ab41049cb)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:42 +0000 (13:52 +0100)]
arm64: allow kernel Image to be loaded anywhere in physical memory
This relaxes the kernel Image placement requirements, so that it
may be placed at any 2 MB aligned offset in physical memory.
This is accomplished by ignoring PHYS_OFFSET when installing
memblocks, and accounting for the apparent virtual offset of
the kernel Image. As a result, virtual address references
below PAGE_OFFSET are correctly mapped onto physical references
into the kernel Image regardless of where it sits in memory.
Special care needs to be taken for dealing with memory limits passed
via mem=, since the generic implementation clips memory top down, which
may clip the kernel image itself if it is loaded high up in memory. To
deal with this case, we simply add back the memory covering the kernel
image, which may result in more memory to be retained than was passed
as a mem= parameter.
Since mem= should not be considered a production feature, a panic notifier
handler is installed that dumps the memory limit at panic time if one was
set.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
a7f8de168ace487fa7b88cb154e413cf40e87fc6)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:41 +0000 (13:52 +0100)]
arm64: defer __va translation of initrd_start and initrd_end
Before deferring the assignment of memstart_addr in a subsequent patch, to
the moment where all memory has been discovered and possibly clipped based
on the size of the linear region and the presence of a mem= command line
parameter, we need to ensure that memstart_addr is not used to perform __va
translations before it is assigned.
One such use is in the generic early DT discovery of the initrd location,
which is recorded as a virtual address in the globals initrd_start and
initrd_end. So wire up the generic support to declare the initrd addresses,
and implement it without __va() translations, and perform the translation
after memstart_addr has been assigned.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
a89dea585371a9d5d85499db47c93f129be8e0c4)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:40 +0000 (13:52 +0100)]
arm64: move kernel image to base of vmalloc area
This moves the module area to right before the vmalloc area, and moves
the kernel image to the base of the vmalloc area. This is an intermediate
step towards implementing KASLR, which allows the kernel image to be
located anywhere in the vmalloc area.
Since other subsystems such as hibernate may still need to refer to the
kernel text or data segments via their linears addresses, both are mapped
in the linear region as well. The linear alias of the text region is
mapped read-only/non-executable to prevent inadvertent modification or
execution.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
f9040773b7bbbd9e98eb6184a263512a7cfc133f)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:39 +0000 (13:52 +0100)]
arm64: kvm: deal with kernel symbols outside of linear mapping
KVM on arm64 uses a fixed offset between the linear mapping at EL1 and
the HYP mapping at EL2. Before we can move the kernel virtual mapping
out of the linear mapping, we have to make sure that references to kernel
symbols that are accessed via the HYP mapping are translated to their
linear equivalent.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
a0bf9776cd0be4490d4675d4108e13379849fc7f)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
skip new funcs create_hyp_mappings(__start_rodata,
in arch/arm/kvm/arm.c and keep funcs in arch/arm64/kvm/hyp.S
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:38 +0000 (13:52 +0100)]
arm64: decouple early fixmap init from linear mapping
Since the early fixmap page tables are populated using pages that are
part of the static footprint of the kernel, they are covered by the
initial kernel mapping, and we can refer to them without using __va/__pa
translations, which are tied to the linear mapping.
Since the fixmap page tables are disjoint from the kernel mapping up
to the top level pgd entry, we can refer to bm_pte[] directly, and there
is no need to walk the page tables and perform __pa()/__va() translations
at each step.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
157962f5a8f236cab898b68bdaa69ce68922f0bf)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:37 +0000 (13:52 +0100)]
arm64: pgtable: implement static [pte|pmd|pud]_offset variants
The page table accessors pte_offset(), pud_offset() and pmd_offset()
rely on __va translations, so they can only be used after the linear
mapping has been installed. For the early fixmap and kasan init routines,
whose page tables are allocated statically in the kernel image, these
functions will return bogus values. So implement pte_offset_kimg(),
pmd_offset_kimg() and pud_offset_kimg(), which can be used instead
before any page tables have been allocated dynamically.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
6533945a32c762c5db70d7a3ec251a040b2d9661)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:36 +0000 (13:52 +0100)]
arm64: introduce KIMAGE_VADDR as the virtual base of the kernel region
This introduces the preprocessor symbol KIMAGE_VADDR which will serve as
the symbolic virtual base of the kernel region, i.e., the kernel's virtual
offset will be KIMAGE_VADDR + TEXT_OFFSET. For now, we define it as being
equal to PAGE_OFFSET, but in the future, it will be moved below it once
we move the kernel virtual mapping out of the linear mapping.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
ab893fb9f1b17f02139bce547bb4b69e96b9ae16)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:35 +0000 (13:52 +0100)]
arm64: add support for ioremap() block mappings
This wires up the existing generic huge-vmap feature, which allows
ioremap() to use PMD or PUD sized block mappings. It also adds support
to the unmap path for dealing with block mappings, which will allow us
to unmap the __init region using unmap_kernel_range() in a subsequent
patch.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
324420bf91f60582bb481133db9547111768ef17)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:34 +0000 (13:52 +0100)]
arm64: prevent potential circular header dependencies in asm/bug.h
Currently, using BUG_ON() in header files is cumbersome, due to the fact
that asm/bug.h transitively includes a lot of other header files, resulting
in the actual BUG_ON() invocation appearing before its definition in the
preprocessor input. So let's reverse the #include dependency between
asm/bug.h and asm/debug-monitors.h, by moving the definition of BUG_BRK_IMM
from the latter to the former. Also fix up one user of asm/debug-monitors.h
which relied on a transitive include.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
03336b1df9929e5d9c28fd9768948b6151cb046c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
skip arch/arm64/kvm/hyp/debug-sr.c
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:33 +0000 (13:52 +0100)]
of/fdt: factor out assignment of initrd_start/initrd_end
Since architectures may not yet have their linear mapping up and running
when the initrd address is discovered from the DT, factor out the
assignment of initrd_start and initrd_end, so that an architecture can
override it and use the translation it needs.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
369bc9abf22bf026e8645a4dd746b90649a2f6ee)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 16 Feb 2016 12:52:32 +0000 (13:52 +0100)]
of/fdt: make memblock minimum physical address arch configurable
By default, early_init_dt_add_memory_arch() ignores memory below
the base of the kernel image since it won't be addressable via the
linear mapping. However, this is not appropriate anymore once we
decouple the kernel text mapping from the linear mapping, so archs
may want to drop the low limit entirely. So allow the minimum to be
overridden by setting MIN_MEMBLOCK_ADDR.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
270522a04f7a9911983878fa37da467f9ff1c938)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Catalin Marinas [Thu, 18 Feb 2016 15:50:04 +0000 (15:50 +0000)]
arm64: Remove the get_thread_info() function
This function was introduced by previous commits implementing UAO.
However, it can be replaced with task_thread_info() in
uao_thread_switch() or get_fs() in do_page_fault() (the latter being
called only on the current context, so no need for using the saved
pt_regs).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
e950631e84e7e38892ffbeee5e1816b270026b0e)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
James Morse [Fri, 5 Feb 2016 14:58:50 +0000 (14:58 +0000)]
arm64: kernel: Don't toggle PAN on systems with UAO
If a CPU supports both Privileged Access Never (PAN) and User Access
Override (UAO), we don't need to disable/re-enable PAN round all
copy_to_user() like calls.
UAO alternatives cause these calls to use the 'unprivileged' load/store
instructions, which are overridden to be the privileged kind when
fs==KERNEL_DS.
This patch changes the copy_to_user() calls to have their PAN toggling
depend on a new composite 'feature' ARM64_ALT_PAN_NOT_UAO.
If both features are detected, PAN will be enabled, but the copy_to_user()
alternatives will not be applied. This means PAN will be enabled all the
time for these functions. If only PAN is detected, the toggling will be
enabled as normal.
This will save the time taken to disable/re-enable PAN, and allow us to
catch copy_to_user() accesses that occur with fs==KERNEL_DS.
Futex and swp-emulation code continue to hang their PAN toggling code on
ARM64_HAS_PAN.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
705441960033e66b63524521f153fbb28c99ddbd)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
James Morse [Fri, 5 Feb 2016 14:58:49 +0000 (14:58 +0000)]
arm64: cpufeature: Test 'matches' pointer to find the end of the list
CPU feature code uses the desc field as a test to find the end of the list,
this means every entry must have a description. This generates noise for
entries in the list that aren't really features, but combinations of them.
e.g.
> CPU features: detected feature: Privileged Access Never
> CPU features: detected feature: PAN and not UAO
These combination features are needed for corner cases with alternatives,
where cpu features interact.
Change all walkers of the arm64_features[] and arm64_hwcaps[] lists to test
'matches' not 'desc', and only print 'desc' if it is non-NULL.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
644c2ae198412c956700e55a2acf80b2541f6aa5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
James Morse [Fri, 5 Feb 2016 14:58:48 +0000 (14:58 +0000)]
arm64: kernel: Add support for User Access Override
'User Access Override' is a new ARMv8.2 feature which allows the
unprivileged load and store instructions to be overridden to behave in
the normal way.
This patch converts {get,put}_user() and friends to use ldtr*/sttr*
instructions - so that they can only access EL0 memory, then enables
UAO when fs==KERNEL_DS so that these functions can access kernel memory.
This allows user space's read/write permissions to be checked against the
page tables, instead of testing addr<USER_DS, then using the kernel's
read/write permissions.
Signed-off-by: James Morse <james.morse@arm.com>
[catalin.marinas@arm.com: move uao_thread_switch() above dsb()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
57f4959bad0a154aeca125b7d38d1d9471a12422)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
James Morse [Fri, 5 Feb 2016 14:58:47 +0000 (14:58 +0000)]
arm64: add ARMv8.2 id_aa64mmfr2 boiler plate
ARMv8.2 adds a new feature register id_aa64mmfr2. This patch adds the
cpu feature boiler plate used by the actual features in later patches.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
406e308770a92bd33995b2e5b681e86358328bb0)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
James Morse [Fri, 5 Feb 2016 14:58:46 +0000 (14:58 +0000)]
arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macro
Older assemblers may not have support for newer feature registers. To get
round this, sysreg.h provides a 'mrs_s' macro that takes a register
encoding and generates the raw instruction.
Change read_cpuid() to use mrs_s in all cases so that new registers
don't have to be a special case. Including sysreg.h means we need to move
the include and definition of read_cpuid() after the #ifndef __ASSEMBLY__
to avoid syntax errors in vmlinux.lds.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
0f54b14e76f5302afe164dc911b049b5df836ff5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Mon, 15 Feb 2016 08:51:49 +0000 (09:51 +0100)]
arm64: use local label prefixes for __reg_num symbols
The __reg_num_xNN symbols that are used to implement the msr_s and
mrs_s macros are recorded in the ELF metadata of each object file.
This does not affect the size of the final binary, but it does clutter
the output of tools like readelf, i.e.,
$ readelf -a vmlinux |grep -c __reg_num_x
50976
So let's use symbols with the .L prefix, these are strictly local,
and don't end up in the object files.
$ readelf -a vmlinux |grep -c __reg_num_x
0
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
7abc7d833c9eb16efc8a59239d3771a6e30be367)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
David Brown [Wed, 10 Feb 2016 21:52:22 +0000 (13:52 -0800)]
arm64: vdso: Mark vDSO code as read-only
Although the arm64 vDSO is cleanly separated by code/data with the
code being read-only in userspace mappings, the code page is still
writable from the kernel. There have been exploits (such as
http://itszn.com/blog/?p=21) that take advantage of this on x86 to go
from a bad kernel write to full root.
Prevent this specific exploit on arm64 by putting the vDSO code page
in read-only memory as well.
Before the change:
[ 3.138366] vdso: 2 pages (1 code @
ffffffc000a71000, 1 data @
ffffffc000a70000)
---[ Kernel Mapping ]---
0xffffffc000000000-0xffffffc000082000 520K RW NX SHD AF UXN MEM/NORMAL
0xffffffc000082000-0xffffffc000200000 1528K ro x SHD AF UXN MEM/NORMAL
0xffffffc000200000-0xffffffc000800000 6M ro x SHD AF BLK UXN MEM/NORMAL
0xffffffc000800000-0xffffffc0009b6000 1752K ro x SHD AF UXN MEM/NORMAL
0xffffffc0009b6000-0xffffffc000c00000 2344K RW NX SHD AF UXN MEM/NORMAL
0xffffffc000c00000-0xffffffc008000000 116M RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc00c000000-0xffffffc07f000000 1840M RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc800000000-0xffffffc840000000 1G RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc840000000-0xffffffc87ae00000 942M RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc87ae00000-0xffffffc87ae70000 448K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87af80000-0xffffffc87af8a000 40K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87af8b000-0xffffffc87b000000 468K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87b000000-0xffffffc87fe00000 78M RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc87fe00000-0xffffffc87ff50000 1344K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87ff90000-0xffffffc87ffa0000 64K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87fff0000-0xffffffc880000000 64K RW NX SHD AF UXN MEM/NORMAL
After:
[ 3.138368] vdso: 2 pages (1 code @
ffffffc0006de000, 1 data @
ffffffc000a74000)
---[ Kernel Mapping ]---
0xffffffc000000000-0xffffffc000082000 520K RW NX SHD AF UXN MEM/NORMAL
0xffffffc000082000-0xffffffc000200000 1528K ro x SHD AF UXN MEM/NORMAL
0xffffffc000200000-0xffffffc000800000 6M ro x SHD AF BLK UXN MEM/NORMAL
0xffffffc000800000-0xffffffc0009b8000 1760K ro x SHD AF UXN MEM/NORMAL
0xffffffc0009b8000-0xffffffc000c00000 2336K RW NX SHD AF UXN MEM/NORMAL
0xffffffc000c00000-0xffffffc008000000 116M RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc00c000000-0xffffffc07f000000 1840M RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc800000000-0xffffffc840000000 1G RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc840000000-0xffffffc87ae00000 942M RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc87ae00000-0xffffffc87ae70000 448K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87af80000-0xffffffc87af8a000 40K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87af8b000-0xffffffc87b000000 468K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87b000000-0xffffffc87fe00000 78M RW NX SHD AF BLK UXN MEM/NORMAL
0xffffffc87fe00000-0xffffffc87ff50000 1344K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87ff90000-0xffffffc87ffa0000 64K RW NX SHD AF UXN MEM/NORMAL
0xffffffc87fff0000-0xffffffc880000000 64K RW NX SHD AF UXN MEM/NORMAL
Inspired by https://lkml.org/lkml/2016/1/19/494 based on work by the
PaX Team, Brad Spengler, and Kees Cook.
Signed-off-by: David Brown <david.brown@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[catalin.marinas@arm.com: removed superfluous __PAGE_ALIGNED_DATA]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
88d8a7994e564d209d4b2583496631c2357d386b)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Yang Shi [Fri, 5 Feb 2016 23:50:18 +0000 (15:50 -0800)]
arm64: ubsan: select ARCH_HAS_UBSAN_SANITIZE_ALL
To enable UBSAN on arm64, ARCH_HAS_UBSAN_SANITIZE_ALL need to be selected.
Basic kernel bootup test is passed on arm64 with CONFIG_UBSAN_SANITIZE_ALL
enabled.
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
f0b7f8a4b44657386273a67179dd901c81cd11a6)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Laura Abbott [Sat, 6 Feb 2016 00:24:48 +0000 (16:24 -0800)]
arm64: ptdump: Indicate whether memory should be faulting
With CONFIG_DEBUG_PAGEALLOC, pages do not have the valid bit
set when free in the buddy allocator. Add an indiciation to
the page table dumping code that the valid bit is not set,
'F' for fault, to make this easier to understand.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
d7e9d59494a9a5d83274f5af2148b82ca22dff3f)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Laura Abbott [Sat, 6 Feb 2016 00:24:47 +0000 (16:24 -0800)]
arm64: Add support for ARCH_SUPPORTS_DEBUG_PAGEALLOC
ARCH_SUPPORTS_DEBUG_PAGEALLOC provides a hook to map and unmap
pages for debugging purposes. This requires memory be mapped
with PAGE_SIZE mappings since breaking down larger mappings
at runtime will lead to TLB conflicts. Check if debug_pagealloc
is enabled at runtime and if so, map everyting with PAGE_SIZE
pages. Implement the functions to actually map/unmap the
pages at runtime.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
[catalin.marinas@arm.com: static annotation block_mappings_allowed() and #ifdef]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
83863f25e4b8214e994ef8b5647aad614d74b45d)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Laura Abbott [Sat, 6 Feb 2016 00:24:46 +0000 (16:24 -0800)]
arm64: Drop alloc function from create_mapping
create_mapping is only used in fixmap_remap_fdt. All the create_mapping
calls need to happen on existing translation table pages without
additional allocations. Rather than have an alloc function be called
and fail, just set it to NULL and catch its use. Also change
the name to create_mapping_noalloc to better capture what exactly is
going on.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
132233a759580f5ce9b1bfaac9073e47d03c460d)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Will Deacon [Wed, 10 Feb 2016 10:07:30 +0000 (10:07 +0000)]
arm64: prefetch: add missing #include for spin_lock_prefetch
As of
52e662326e1e ("arm64: prefetch: don't provide spin_lock_prefetch
with LSE"), spin_lock_prefetch is patched at runtime when the LSE atomics
are in use. This relies on the ARM64_LSE_ATOMIC_INSN macro to drive
the alternatives framework, but that macro is only available via
asm/lse.h, which isn't explicitly included in processor.h. Consequently,
drivers can run into build failures such as:
In file included from include/linux/prefetch.h:14:0,
from drivers/net/ethernet/intel/i40e/i40e_txrx.c:27:
arch/arm64/include/asm/processor.h: In function 'spin_lock_prefetch':
arch/arm64/include/asm/processor.h:183:15: error: expected string literal before 'ARM64_LSE_ATOMIC_INSN'
asm volatile(ARM64_LSE_ATOMIC_INSN(
This patch add the missing include and gets things building again.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
afb83cc3f0e4f86ea0e1cc3db7a90f58f1abd4d5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Andrew Pinski [Tue, 2 Feb 2016 12:46:26 +0000 (12:46 +0000)]
arm64: lib: patch in prfm for copy_page if requested
On ThunderX T88 pass 1 and pass 2, there is no hardware prefetching so
we need to patch in explicit software prefetching instructions
Prefetching improves this code by 60% over the original code and 2x
over the code without prefetching for the affected hardware using the
benchmark code at https://github.com/apinski-cavium/copy_page_benchmark
Signed-off-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
60e0a09db24adc8809696307e5d97cc4ba7cb3e0)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Will Deacon [Tue, 2 Feb 2016 12:46:25 +0000 (12:46 +0000)]
arm64: lib: improve copy_page to deal with 128 bytes at a time
We want to avoid lots of different copy_page implementations, settling
for something that is "good enough" everywhere and hopefully easy to
understand and maintain whilst we're at it.
This patch reworks our copy_page implementation based on discussions
with Cavium on the list and benchmarking on Cortex-A processors so that:
- The loop is unrolled to copy 128 bytes per iteration
- The reads are offset so that we read from the next 128-byte block
in the same iteration that we store the previous block
- Explicit prefetch instructions are removed for now, since they hurt
performance on CPUs with hardware prefetching
- The loop exit condition is calculated at the start of the loop
Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
223e23e8aa26b0bb62c597637e77295e14f6a62c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Will Deacon [Tue, 2 Feb 2016 12:46:24 +0000 (12:46 +0000)]
arm64: prefetch: add alternative pattern for CPUs without a prefetcher
Most CPUs have a hardware prefetcher which generally performs better
without explicit prefetch instructions issued by software, however
some CPUs (e.g. Cavium ThunderX) rely solely on explicit prefetch
instructions.
This patch adds an alternative pattern (ARM64_HAS_NO_HW_PREFETCH) to
allow our library code to make use of explicit prefetch instructions
during things like copy routines only when the CPU does not have the
capability to perform the prefetching itself.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
d5370f754875460662abe8561388e019d90dd0c4)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Will Deacon [Tue, 2 Feb 2016 12:46:23 +0000 (12:46 +0000)]
arm64: prefetch: don't provide spin_lock_prefetch with LSE
The LSE atomics rely on us not dirtying data at L1 if we can avoid it,
otherwise many of the potential scalability benefits are lost.
This patch replaces spin_lock_prefetch with a nop when the LSE atomics
are in use, so that users don't shoot themselves in the foot by causing
needless coherence traffic at L1.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
cd5e10bdf3795d22f10787bb1991c43798c885d5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Wed, 27 Jan 2016 09:50:19 +0000 (10:50 +0100)]
arm64: allow vmalloc regions to be set with set_memory_*
The range of set_memory_* is currently restricted to the module address
range because of difficulties in breaking down larger block sizes.
vmalloc maps PAGE_SIZE pages so it is safe to use as well. Update the
function ranges and add a comment explaining why the range is restricted
the way it is.
Suggested-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
95f5c80050ad723163aa80dc8bffd48ef4afc6d5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Lorenzo Pieralisi [Tue, 26 Jan 2016 11:10:38 +0000 (11:10 +0000)]
arm64: kernel: implement ACPI parking protocol
The SBBR and ACPI specifications allow ACPI based systems that do not
implement PSCI (eg systems with no EL3) to boot through the ACPI parking
protocol specification[1].
This patch implements the ACPI parking protocol CPU operations, and adds
code that eases parsing the parking protocol data structures to the
ARM64 SMP initializion carried out at the same time as cpus enumeration.
To wake-up the CPUs from the parked state, this patch implements a
wakeup IPI for ARM64 (ie arch_send_wakeup_ipi_mask()) that mirrors the
ARM one, so that a specific IPI is sent for wake-up purpose in order
to distinguish it from other IPI sources.
Given the current ACPI MADT parsing API, the patch implements a glue
layer that helps passing MADT GICC data structure from SMP initialization
code to the parking protocol implementation somewhat overriding the CPU
operations interfaces. This to avoid creating a completely trasparent
DT/ACPI CPU operations layer that would require creating opaque
structure handling for CPUs data (DT represents CPU through DT nodes, ACPI
through static MADT table entries), which seems overkill given that ACPI
on ARM64 mandates only two booting protocols (PSCI and parking protocol),
so there is no need for further protocol additions.
Based on the original work by Mark Salter <msalter@redhat.com>
[1] https://acpica.org/sites/acpica/files/MP%20Startup%20for%20ARM%20platforms.docx
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Loc Ho <lho@apm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Al Stone <ahs3@redhat.com>
[catalin.marinas@arm.com: Added WARN_ONCE(!acpi_parking_protocol_valid() on the IPI]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
5e89c55e4ed81d7abb1ce8828db35fa389dc0e90)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:12 +0000 (11:45 +0000)]
arm64: mm: create new fine-grained mappings at boot
At boot we may change the granularity of the tables mapping the kernel
(by splitting or making sections). This may happen when we create the
linear mapping (in __map_memblock), or at any point we try to apply
fine-grained permissions to the kernel (e.g. fixup_executable,
mark_rodata_ro, fixup_init).
Changing the active page tables in this manner may result in multiple
entries for the same address being allocated into TLBs, risking problems
such as TLB conflict aborts or issues derived from the amalgamation of
TLB entries. Generally, a break-before-make (BBM) approach is necessary
to avoid conflicts, but we cannot do this for the kernel tables as it
risks unmapping text or data being used to do so.
Instead, we can create a new set of tables from scratch in the safety of
the existing mappings, and subsequently migrate over to these using the
new cpu_replace_ttbr1 helper, which avoids the two sets of tables being
active simultaneously.
To avoid issues when we later modify permissions of the page tables
(e.g. in fixup_init), we must create the page tables at a granularity
such that later modification does not result in splitting of tables.
This patch applies this strategy, creating a new set of fine-grained
page tables from scratch, and safely migrating to them. The existing
fixmap and kasan shadow page tables are reused in the new fine-grained
tables.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
068a17a5805dfbca4bbf03e664ca6b19709cc7a8)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:11 +0000 (11:45 +0000)]
arm64: ensure _stext and _etext are page-aligned
Currently we have separate ALIGN_DEBUG_RO{,_MIN} directives to align
_etext and __init_begin. While we ensure that __init_begin is
page-aligned, we do not provide the same guarantee for _etext. This is
not problematic currently as the alignment of __init_begin is sufficient
to prevent issues when we modify permissions.
Subsequent patches will assume page alignment of segments of the kernel
we wish to map with different permissions. To ensure this, move _etext
after the ALIGN_DEBUG_RO_MIN for the init section. This renders the
prior ALIGN_DEBUG_RO irrelevant, and hence it is removed. Likewise,
upgrade to ALIGN_DEBUG_RO_MIN(PAGE_SIZE) for _stext.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
fca082bfb543ccaaff864fc0892379ccaa1711cd)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:10 +0000 (11:45 +0000)]
arm64: mm: allow passing a pgdir to alloc_init_*
To allow us to initialise pgdirs which are fixmapped, allow explicitly
passing a pgdir rather than an mm. A new __create_pgd_mapping function
is added for this, with existing __create_mapping callers migrated to
this.
The mm argument was previously only used at the top level. Now that it
is redundant at all levels, it is removed. To indicate its new found
similarity to alloc_init_{pud,pmd,pte}, __create_mapping is renamed to
init_pgd.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
11509a306bb6ea595878b2d246d2d56b1783e040)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:09 +0000 (11:45 +0000)]
arm64: mm: allocate pagetables anywhere
Now that create_mapping uses fixmap slots to modify pte, pmd, and pud
entries, we can access page tables anywhere in physical memory,
regardless of the extent of the linear mapping.
Given that, we no longer need to limit memblock allocations during page
table creation, and can leave the limit as its default
MEMBLOCK_ALLOC_ANYWHERE.
We never add memory which will fall outside of the linear map range
given phys_offset and MAX_MEMBLOCK_ADDR are configured appropriately, so
any tables we create will fall in the linear map of the final tables.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
cdef5f6e9e0e5ee397759b664a9f875ff59ccf01)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:08 +0000 (11:45 +0000)]
arm64: mm: use fixmap when creating page tables
As a preparatory step to allow us to allocate early page tables from
unmapped memory using memblock_alloc, modify the __create_mapping
callees to map and unmap the tables they modify using fixmap entries.
All but the top-level pgd initialisation is performed via the fixmap.
Subsequent patches will inject the pgd physical address, and migrate to
using the FIX_PGD slot.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
f4710445458c0a1bd1c3c014ada2e7d7dc7b882f)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:07 +0000 (11:45 +0000)]
arm64: mm: add functions to walk tables in fixmap
As a preparatory step to allow us to allocate early page tables from
unmapped memory using memblock_alloc, add new p??_{set,clear}_fixmap*
functions which can be used to walk page tables outside of the linear
mapping by using fixmap slots.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
961faac114819a01e627fe9c9c82b830bb3849d4)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:06 +0000 (11:45 +0000)]
arm64: mm: add __{pud,pgd}_populate
We currently have __pmd_populate for creating a pmd table entry given
the physical address of a pte, but don't have equivalents for the pud or
pgd levels of table.
To enable us to manipulate tables which are mapped outside of the linear
mapping (where we have a PA, but not a linear map VA), it is useful to
have these functions.
This patch adds __{pud,pgd}_populate. As these should not be called when
the kernel uses folded {pmd,pud}s, in these cases they expand to
BUILD_BUG(). So long as the appropriate checks are made on the {pud,pgd}
entry prior to attempting population, these should be optimized out at
compile time.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
1e531cce68c92b46c7d29f36a72f9a3e5886678f)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:05 +0000 (11:45 +0000)]
arm64: mm: avoid redundant __pa(__va(x))
When we "upgrade" to a section mapping, we free any table we made
redundant by giving it back to memblock. To get the PA, we acquire the
physical address and convert this to a VA, then subsequently convert
this back to a PA.
This works currently, but will not work if the tables are not accessed
via linear map VAs (e.g. is we use fixmap slots).
This patch uses {pmd,pud}_page_paddr to acquire the PA. This avoids the
__pa(__va()) round trip, saving some work and avoiding reliance on the
linear mapping.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
316b39db06718d59d82736df9fc65cf05b467cc7)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:04 +0000 (11:45 +0000)]
arm64: mm: add functions to walk page tables by PA
To allow us to walk tables allocated into the fixmap, we need to acquire
the physical address of a page, rather than the virtual address in the
linear map.
This patch adds new p??_page_paddr and p??_offset_phys functions to
acquire the physical address of a next-level table, and changes
p??_offset* into macros which simply convert this to a linear map VA.
This renders p??_page_vaddr unused, and hence they are removed.
At the pgd level, a new pgd_offset_raw function is added to find the
relevant PGD entry given the base of a PGD and a virtual address.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
dca56dca7124709f3dfca81afe61b4d98eb9cacf)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:03 +0000 (11:45 +0000)]
arm64: mm: move pte_* macros
For pmd, pud, and pgd levels of table, functions including p?d_index and
p?d_offset are defined after the p?d_page_vaddr function for the
immediately higher level of table.
The pte functions however are defined much earlier, even though several
rely on the later definition of pmd_page_vaddr. While this isn't
currently a problem as these are macros, it prevents the logical
grouping of later C functions (which cannot rely on prototypes for
functions not yet defined).
Move these definitions after pmd_page_vaddr, for consistency with the
placement of these functions for other levels of table.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
053520f7d3923cc6d37afb28f9887cb1e7d77454)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:02 +0000 (11:45 +0000)]
arm64: kasan: avoid TLB conflicts
The page table modification performed during the KASAN init risks the
allocation of conflicting TLB entries, as it swaps a set of valid global
entries for another without suitable TLB maintenance.
The presence of conflicting TLB entries can result in the delivery of
synchronous TLB conflict aborts, or may result in the use of erroneous
data being returned in response to a TLB lookup. This can affect
explicit data accesses from software as well as translations performed
asynchronously (e.g. as part of page table walks or speculative I-cache
fetches), and can therefore result in a wide variety of problems.
To avoid this, use cpu_replace_ttbr1 to swap the page tables. This
ensures that when the new tables are installed there are no stale
entries from the old tables which may conflict. As all updates are made
to the tables while they are not active, the updates themselves are
safe.
At the same time, add the missing barrier to ensure that the tmp_pg_dir
entries updated via memcpy are visible to the page table walkers at the
point the tmp_pg_dir is installed. All other page table updates made as
part of KASAN initialisation have the requisite barriers due to the use
of the standard page table accessors.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
c1a88e9124a499939ebd8069d5e4d3937f019157)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:01 +0000 (11:45 +0000)]
arm64: mm: add code to safely replace TTBR1_EL1
If page tables are modified without suitable TLB maintenance, the ARM
architecture permits multiple TLB entries to be allocated for the same
VA. When this occurs, it is permitted that TLB conflict aborts are
raised in response to synchronous data/instruction accesses, and/or and
amalgamation of the TLB entries may be used as a result of a TLB lookup.
The presence of conflicting TLB entries may result in a variety of
behaviours detrimental to the system (e.g. erroneous physical addresses
may be used by I-cache fetches and/or page table walks). Some of these
cases may result in unexpected changes of hardware state, and/or result
in the (asynchronous) delivery of SError.
To avoid these issues, we must avoid situations where conflicting
entries may be allocated into TLBs. For user and module mappings we can
follow a strict break-before-make approach, but this cannot work for
modifications to the swapper page tables that cover the kernel text and
data.
Instead, this patch adds code which is intended to be executed from the
idmap, which can safely unmap the swapper page tables as it only
requires the idmap to be active. This enables us to uninstall the active
TTBR1_EL1 entry, invalidate TLBs, then install a new TTBR1_EL1 entry
without potentially unmapping code or data required for the sequence.
This avoids the risk of conflict, but requires that updates are staged
in a copy of the swapper page tables prior to being installed.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
50e1881ddde2a986c7d0d2150985239e5e3d7d96)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:45:00 +0000 (11:45 +0000)]
arm64: add function to install the idmap
In some cases (e.g. when making invasive changes to the kernel page
tables) we will need to execute code from the idmap.
Add a new helper which may be used to install the idmap, complementing
the existing cpu_uninstall_idmap.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
609116d202a8c5fd3fe393eb85373cbee906df68)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:44:59 +0000 (11:44 +0000)]
arm64: unmap idmap earlier
During boot we leave the idmap in place until paging_init, as we
previously had to wait for the zero page to become allocated and
accessible.
Now that we have a statically-allocated zero page, we can uninstall the
idmap much earlier in the boot process, making it far easier to spot
accidental use of physical addresses. This also brings the cold boot
path in line with the secondary boot path.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
86ccce896cb0aa800a7a6dcd29b41ffc4eeb1a75)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:44:58 +0000 (11:44 +0000)]
arm64: unify idmap removal
We currently open-code the removal of the idmap and restoration of the
current task's MMU state in a few places.
Before introducing yet more copies of this sequence, unify these to call
a new helper, cpu_uninstall_idmap.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
9e8e865bbe294a69666a1996bda3e87825b258c0)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:44:57 +0000 (11:44 +0000)]
arm64: mm: place empty_zero_page in bss
Currently the zero page is set up in paging_init, and thus we cannot use
the zero page earlier. We use the zero page as a reserved TTBR value
from which no TLB entries may be allocated (e.g. when uninstalling the
idmap). To enable such usage earlier (as may be required for invasive
changes to the kernel page tables), and to minimise the time that the
idmap is active, we need to be able to use the zero page before
paging_init.
This patch follows the example set by x86, by allocating the zero page
at compile time, in .bss. This means that the zero page itself is
available immediately upon entry to start_kernel (as we zero .bss before
this), and also means that the zero page takes up no space in the raw
Image binary. The associated struct page is allocated in bootmem_init,
and remains unavailable until this time.
Outside of arch code, the only users of empty_zero_page assume that the
empty_zero_page symbol refers to the zeroed memory itself, and that
ZERO_PAGE(x) must be used to acquire the associated struct page,
following the example of x86. This patch also brings arm64 inline with
these assumptions.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
5227cfa71f9e8574373f4d0e9e754942d76cdf67)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:44:56 +0000 (11:44 +0000)]
arm64: mm: specialise pagetable allocators
We pass a size parameter to early_alloc and late_alloc, but these are
only ever used to allocate single pages. In late_alloc we always
allocate a single page.
Both allocators provide us with zeroed pages (such that all entries are
invalid), but we have no barriers between allocating a page and adding
that page to existing (live) tables. A concurrent page table walk may
see stale data, leading to a number of issues.
This patch specialises the two allocators for page tables. The size
parameter is removed and the necessary dsb(ishst) is folded into each.
To make it clear that the functions are intended for use for page table
allocation, they are renamed to {early,late}_pgtable_alloc, with the
related function pointed renamed to pgtable_alloc.
As the dsb(ishst) is now in the allocator, the existing barrier for the
zero page is redundant and thus is removed. The previously missing
include of barrier.h is added.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
21ab99c289d350f4ae454bc069870009db6df20e)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Mon, 25 Jan 2016 11:44:55 +0000 (11:44 +0000)]
asm-generic: Fix local variable shadow in __set_fixmap_offset
Currently __set_fixmap_offset is a macro function which has a local
variable called 'addr'. If a caller passes a 'phys' parameter which is
derived from a variable also called 'addr', the local variable will
shadow this, and the compiler will complain about the use of an
uninitialized variable. To avoid the issue with namespace clashes,
'addr' is prefixed with a liberal sprinkling of underscores.
Turning __set_fixmap_offset into a static inline breaks the build for
several architectures. Fixing this properly requires updates to a number
of architectures to make them agree on the prototype of __set_fixmap (it
could be done as a subsequent patch series).
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
[catalin.marinas@arm.com: squashed the original function patch and macro fixup]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit
3694bd76781b76c4f8d2ecd85018feeb1609f0e5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
William Cohen [Fri, 22 Jan 2016 03:56:26 +0000 (22:56 -0500)]
Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modules
By default the aarch64 gcc generates .eh_frame sections. Unlike
.debug_frame sections, the .eh_frame sections are loaded into memory
when the associated code is loaded. On an example kernel being built
with this default the .eh_frame section in vmlinux used an extra 1.7MB
of memory. The x86 disables the creation of the .eh_frame section.
The aarch64 should probably do the same to save some memory.
Signed-off-by: William Cohen <wcohen@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
728dabd6d1751cf5e0f8e0535891393da62396e9)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
pick
67dfa1751 arm64: errata: Add -mpc-relative-literal-loads
in arch/arm64/Makefile
Masanari Iida [Sun, 24 Jan 2016 06:24:12 +0000 (15:24 +0900)]
arm64: Fix an enum typo in mm/dump.c
This patch fixes a typo in mm/dump.c:
"MODUELS_END_NR" should be "MODULES_END_NR".
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
b3122023df935cf14bf951da98ca598d71b9f826)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Mon, 11 Jan 2016 13:50:21 +0000 (14:50 +0100)]
arm64: kasan: ensure that the KASAN zero page is mapped read-only
When switching from the early KASAN shadow region, which maps the
entire shadow space read-write, to the permanent KASAN shadow region,
which uses a zero page to shadow regions that are not subject to
instrumentation, the lowest level table kasan_zero_pte[] may be
reused unmodified, which means that the mappings of the zero page
that it contains will still be read-write.
So update it explicitly to map the zero page read only when we
activate the permanent mapping.
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
7b1af9795773d745c2a8c7d4ca5f2936e8b6adfb)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Minchan Kim [Sat, 16 Jan 2016 00:55:37 +0000 (16:55 -0800)]
arch/arm64/include/asm/pgtable.h: add pmd_mkclean for THP
MADV_FREE needs pmd_dirty and pmd_mkclean for detecting recent overwrite
of the contents since MADV_FREE syscall is called for THP page.
This patch adds pmd_mkclean for THP page MADV_FREE support.
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Shaohua Li <shli@kernel.org>
Cc: <yalin.wang2010@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Helge Deller <deller@gmx.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jason Evans <je@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttil <mika.penttila@nextfour.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Shaohua Li <shli@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit
05ee26d9e7e29ab026995eab79be3c6e8351908c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Fri, 15 Jan 2016 12:28:57 +0000 (13:28 +0100)]
arm64: hide __efistub_ aliases from kallsyms
Commit
e8f3010f7326 ("arm64/efi: isolate EFI stub from the kernel
proper") isolated the EFI stub code from the kernel proper by prefixing
all of its symbols with __efistub_, and selectively allowing access to
core kernel symbols from the stub by emitting __efistub_ aliases for
functions and variables that the stub can access legally.
As an unintended side effect, these aliases are emitted into the
kallsyms symbol table, which means they may turn up in backtraces,
e.g.,
...
PC is at __efistub_memset+0x108/0x200
LR is at fixup_init+0x3c/0x48
...
[<
ffffff8008328608>] __efistub_memset+0x108/0x200
[<
ffffff8008094dcc>] free_initmem+0x2c/0x40
[<
ffffff8008645198>] kernel_init+0x20/0xe0
[<
ffffff8008085cd0>] ret_from_fork+0x10/0x40
The backtrace in question has nothing to do with the EFI stub, but
simply returns one of the several aliases of memset() that have been
recorded in the kallsyms table. This is undesirable, since it may
suggest to people who are not aware of this that the issue they are
seeing is somehow EFI related.
So hide the __efistub_ aliases from kallsyms, by emitting them as
absolute linker symbols explicitly. The distinction between those
and section relative symbols is completely irrelevant to these
definitions, and to the final link we are performing when these
definitions are being taken into account (the distinction is only
relevant to symbols defined inside a section definition when performing
a partial link), and so the resulting values are identical to the
original ones. Since absolute symbols are ignored by kallsyms, this
will result in these values to be omitted from its symbol table.
After this patch, the backtrace generated from the same address looks
like this:
...
PC is at __memset+0x108/0x200
LR is at fixup_init+0x3c/0x48
...
[<
ffffff8008328608>] __memset+0x108/0x200
[<
ffffff8008094dcc>] free_initmem+0x2c/0x40
[<
ffffff8008645198>] kernel_init+0x20/0xe0
[<
ffffff8008085cd0>] ret_from_fork+0x10/0x40
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
75feee3d9d51775072d3a04f47d4a439a4c4590e)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Wed, 6 Jan 2016 11:05:27 +0000 (11:05 +0000)]
arm64: head.S: use memset to clear BSS
Currently we use an open-coded memzero to clear the BSS. As it is a
trivial implementation, it is sub-optimal.
Our optimised memset doesn't use the stack, is position-independent, and
for the memzero case can use of DC ZVA to clear large blocks
efficiently. In __mmap_switched the MMU is on and there are no live
caller-saved registers, so we can safely call an uninstrumented memset.
This patch changes __mmap_switched to use memset when clearing the BSS.
We use the __pi_memset alias so as to avoid any instrumentation in all
kernel configurations.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
2a803c4db615d85126c5c7afd5849a3cfde71422)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Wed, 23 Dec 2015 09:29:28 +0000 (10:29 +0100)]
efi: stub: define DISABLE_BRANCH_PROFILING for all architectures
This moves the DISABLE_BRANCH_PROFILING define from the x86 specific
to the general CFLAGS definition for the stub. This fixes build errors
when building for arm64 with CONFIG_PROFILE_ALL_BRANCHES_ENABLED.
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
b523e185bba36164ca48a190f5468c140d815414)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Mark Rutland [Tue, 5 Jan 2016 17:33:34 +0000 (17:33 +0000)]
arm64: entry: remove pointless SPSR mode check
In work_pending, we may skip work if the stacked SPSR value represents
anything other than an EL0 context. We then immediately invoke the
kernel_exit 0 macro as part of ret_to_user, assuming a return to EL0.
This is somewhat confusing.
We use work_pending as part of the ret_to_user/ret_fast_syscall state
machine. We only use ret_fast_syscall in the return from an SVC issued
from EL0. We use ret_to_user for return from EL0 exception handlers and
also for return from ret_from_fork in the case the task was not a kernel
thread (i.e. it is a user task).
Thus in all cases the stacked SPSR value must represent an EL0 context,
and the check is redundant. This patch removes it, along with the now
unused no_work_pending label.
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
ee03353bc04f8e460cc4e3da80d9721d9ecb89f1)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Will Deacon [Tue, 5 Jan 2016 15:36:59 +0000 (15:36 +0000)]
arm64: mm: move pgd_cache initialisation to pgtable_cache_init
Initialising the suppport for EFI runtime services requires us to
allocate a pgd off the back of an early_initcall. On systems where the
PGD_SIZE is smaller than PAGE_SIZE (e.g. 64k pages and 48-bit VA), the
pgd_cache isn't initialised at this stage, and we panic with a NULL
dereference during boot:
Unable to handle kernel NULL pointer dereference at virtual address
00000000
__create_mapping.isra.5+0x84/0x350
create_pgd_mapping+0x20/0x28
efi_create_mapping+0x5c/0x6c
arm_enable_runtime_services+0x154/0x1e4
do_one_initcall+0x8c/0x190
kernel_init_freeable+0x84/0x1ec
kernel_init+0x10/0xe0
ret_from_fork+0x10/0x50
This patch fixes the problem by initialising the pgd_cache earlier, in
the pgtable_cache_init callback, which sounds suspiciously like what it
was intended for.
Reported-by: Dennis Chen <dennis.chen@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
39b5be9b4233a9f212b98242bddf008f379b5122)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 5 Jan 2016 09:18:52 +0000 (10:18 +0100)]
arm64: module: avoid undefined shift behavior in reloc_data()
Compilers may engage the improbability drive when encountering shifts
by a distance that is a multiple of the size of the operand type. Since
the required bounds check is very simple here, we can get rid of all the
fuzzy masking, shifting and comparing, and use the documented bounds
directly.
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
f930896967fa3f9ab16a6f87267b92798308d48f)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ard Biesheuvel [Tue, 5 Jan 2016 09:18:51 +0000 (10:18 +0100)]
arm64: module: fix relocation of movz instruction with negative immediate
The test whether a movz instruction with a signed immediate should be
turned into a movn instruction (i.e., when the immediate is negative)
is flawed, since the value of imm is always positive. Also, the
subsequent bounds check is incorrect since the limit update never
executes, due to the fact that the imm_type comparison will always be
false for negative signed immediates.
Let's fix this by performing the sign test on sval directly, and
replacing the bounds check with a simple comparison against U16_MAX.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: tidied up use of sval, renamed MOVK enum value to MOVKZ]
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
b24a557527f97ad88619d5bd4c8017c635056d69)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Will Deacon [Mon, 21 Dec 2015 16:44:27 +0000 (16:44 +0000)]
arm64: traps: address fallout from printk -> pr_* conversion
Commit
ac7b406c1a9d ("arm64: Use pr_* instead of printk") was a fairly
mindless s/printk/pr_*/ change driven by a complaint from checkpatch.
As is usual with such changes, this has led to some odd behaviour on
arm64:
* syslog now picks up the "pr_emerg" line from dump_backtrace, but not
the actual trace, which leads to a bunch of "kernel:Call trace:"
lines in the log
* __{pte,pmd,pgd}_error print at KERN_CRIT, as opposed to KERN_ERR
which is used by other architectures.
This patch restores the original printk behaviour for dump_backtrace
and downgrade the pgtable error macros to KERN_ERR.
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
c9cd0ed925c0b927283d4739bfe689eb9d1e9dfd)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
AKASHI Takahiro [Tue, 15 Dec 2015 08:33:41 +0000 (17:33 +0900)]
arm64: ftrace: fix a stack tracer's output under function graph tracer
Function graph tracer modifies a return address (LR) in a stack frame
to hook a function return. This will result in many useless entries
(return_to_handler) showing up in
a) a stack tracer's output
b) perf call graph (with perf record -g)
c) dump_backtrace (at panic et al.)
For example, in case of a),
$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
$ echo 1 > /proc/sys/kernel/stack_trace_enabled
$ cat /sys/kernel/debug/tracing/stack_trace
Depth Size Location (54 entries)
----- ---- --------
0) 4504 16 gic_raise_softirq+0x28/0x150
1) 4488 80 smp_cross_call+0x38/0xb8
2) 4408 48 return_to_handler+0x0/0x40
3) 4360 32 return_to_handler+0x0/0x40
...
In case of b),
$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
$ perf record -e mem:XXX:x -ag -- sleep 10
$ perf report
...
| | |--0.22%-- 0x550f8
| | | 0x10888
| | | el0_svc_naked
| | | sys_openat
| | | return_to_handler
| | | return_to_handler
...
In case of c),
$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
$ echo c > /proc/sysrq-trigger
...
Call trace:
[<
ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30
[<
ffffffc000092250>] return_to_handler+0x0/0x40
[<
ffffffc000092250>] return_to_handler+0x0/0x40
...
This patch replaces such entries with real addresses preserved in
current->ret_stack[] at unwind_frame(). This way, we can cover all
the cases.
Reviewed-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
[will: fixed minor context changes conflicting with irq stack bits]
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
20380bb390a443b2c5c8800cec59743faf8151b4)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
AKASHI Takahiro [Tue, 15 Dec 2015 08:33:40 +0000 (17:33 +0900)]
arm64: pass a task parameter to unwind_frame()
Function graph tracer modifies a return address (LR) in a stack frame
to hook a function's return. This will result in many useless entries
(return_to_handler) showing up in a call stack list.
We will fix this problem in a later patch ("arm64: ftrace: fix a stack
tracer's output under function graph tracer"). But since real return
addresses are saved in ret_stack[] array in struct task_struct,
unwind functions need to be notified of, in addition to a stack pointer
address, which task is being traced in order to find out real return
addresses.
This patch extends unwind functions' interfaces by adding an extra
argument of a pointer to task_struct.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
fe13f95b720075327a761fe6ddb45b0c90cab504)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
AKASHI Takahiro [Tue, 15 Dec 2015 08:33:39 +0000 (17:33 +0900)]
arm64: ftrace: modify a stack frame in a safe way
Function graph tracer modifies a return address (LR) in a stack frame by
calling ftrace_prepare_return() in a traced function's function prologue.
The current code does this modification before preserving an original
address at ftrace_push_return_trace() and there is always a small window
of inconsistency when an interrupt occurs.
This doesn't matter, as far as an interrupt stack is introduced, because
stack tracer won't be invoked in an interrupt context. But it would be
better to proactively minimize such a window by moving the LR modification
after ftrace_push_return_trace().
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
79fdee9b6355c9720f14717e1ad66af51bb331b5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
James Morse [Fri, 18 Dec 2015 16:01:47 +0000 (16:01 +0000)]
arm64: remove irq_count and do_softirq_own_stack()
sysrq_handle_reboot() re-enables interrupts while on the irq stack. The
irq_stack implementation wrongly assumed this would only ever happen
via the softirq path, allowing it to update irq_count late, in
do_softirq_own_stack().
This means if an irq occurs in sysrq_handle_reboot(), during
emergency_restart() the stack will be corrupted, as irq_count wasn't
updated.
Lose the optimisation, and instead of moving the adding/subtracting of
irq_count into irq_stack_entry/irq_stack_exit, remove it, and compare
sp_el0 (struct thread_info) with sp & ~(THREAD_SIZE - 1). This tells us
if we are on a task stack, if so, we can safely switch to the irq stack.
Finally, remove do_softirq_own_stack(), we don't need it anymore.
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
[will: use get_thread_info macro]
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
d224a69e3d80fe08f285d1f41d21b590bae4fa9f)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
David Woods [Thu, 17 Dec 2015 19:31:26 +0000 (14:31 -0500)]
arm64: hugetlb: add support for PTE contiguous bit
The arm64 MMU supports a Contiguous bit which is a hint that the TTE
is one of a set of contiguous entries which can be cached in a single
TLB entry. Supporting this bit adds new intermediate huge page sizes.
The set of huge page sizes available depends on the base page size.
Without using contiguous pages the huge page sizes are as follows.
4KB: 2MB 1GB
64KB: 512MB
With a 4KB granule, the contiguous bit groups together sets of 16 pages
and with a 64KB granule it groups sets of 32 pages. This enables two new
huge page sizes in each case, so that the full set of available sizes
is as follows.
4KB: 64KB 2MB 32MB 1GB
64KB: 2MB 512MB 16GB
If a 16KB granule is used then the contiguous bit groups 128 pages
at the PTE level and 32 pages at the PMD level.
If the base page size is set to 64KB then 2MB pages are enabled by
default. It is possible in the future to make 2MB the default huge
page size for both 4KB and 64KB granules.
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Reviewed-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: David Woods <dwoods@ezchip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
66b3923a1a0f77a563b43f43f6ad091354abbfe9)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Ashok Kumar [Thu, 17 Dec 2015 09:38:32 +0000 (01:38 -0800)]
arm64: Use PoU cache instr for I/D coherency
In systems with three levels of cache(PoU at L1 and PoC at L3),
PoC cache flush instructions flushes L2 and L3 caches which could affect
performance.
For cache flushes for I and D coherency, PoU should suffice.
So changing all I and D coherency related cache flushes to PoU.
Introduced a new __clean_dcache_area_pou API for dcache flush till PoU
and provided a common macro for __flush_dcache_area and
__clean_dcache_area_pou.
Also, now in __sync_icache_dcache, icache invalidation for non-aliasing
VIPT icache is done only for that particular page instead of the earlier
__flush_icache_all.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ashok Kumar <ashoks@broadcom.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
0a28714c53fd4f7aea709be7577dfbe0095c8c3e)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
included reset_pmuserenr_el0 in arch/arm64/mm/proc-macros.S
Ashok Kumar [Thu, 17 Dec 2015 09:38:31 +0000 (01:38 -0800)]
arm64: Defer dcache flush in __cpu_copy_user_page
Defer dcache flushing to __sync_icache_dcache by calling
flush_dcache_page which clears PG_dcache_clean flag.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ashok Kumar <ashoks@broadcom.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
e6b1185f77351aa154e63bd54b05d07ff99d4ffa)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
James Morse [Tue, 15 Dec 2015 11:21:25 +0000 (11:21 +0000)]
arm64: reduce stack use in irq_handler
The code for switching to irq_stack stores three pieces of information on
the stack, fp+lr, as a fake stack frame (that lets us walk back onto the
interrupted tasks stack frame), and the address of the struct pt_regs that
contains the register values from kernel entry. (which dump_backtrace()
will print in any stack trace).
To reduce this, we store fp, and the pointer to the struct pt_regs.
unwind_frame() can recognise this as the irq_stack dummy frame, (as it only
appears at the top of the irq_stack), and use the struct pt_regs values
to find the missing interrupted link-register.
Suggested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit
971c67ce37cfeeaf560e792a2c3bc21d8b67163a)
Signed-off-by: Alex Shi <alex.shi@linaro.org>