From: Sami Tolvanen Date: Wed, 14 Dec 2016 20:32:37 +0000 (-0800) Subject: Revert "FROMLIST: arm64: Introduce uaccess_{disable,enable} functionality based on... X-Git-Tag: firefly_0821_release~176^2~25 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4d05e13fb0757aee4f6d143e1f7ac7c01bfe2787;p=firefly-linux-kernel-4.4.55.git Revert "FROMLIST: arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1" This reverts commit 1911d36b27ba58ee18592df25b7ee636d4d4c41d. Bug: 31432001 Change-Id: Iee77eed8454f379b948dbbaf65c105952ea30bef Signed-off-by: Sami Tolvanen --- diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index aeb4554b3af3..9d3e77a5cf07 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -53,15 +53,6 @@ msr daifclr, #2 .endm - .macro save_and_disable_irq, flags - mrs \flags, daif - msr daifset, #2 - .endm - - .macro restore_irq, flags - msr daif, \flags - .endm - /* * Enable and disable debug exceptions. */ @@ -371,13 +362,6 @@ alternative_endif movk \reg, :abs_g0_nc:\val .endm -/* - * Return the current thread_info. - */ - .macro get_thread_info, rd - mrs \rd, sp_el0 - .endm - /* * Errata workaround post TTBR0_EL1 update. */ diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 8e1f826caf99..1695f77d8bf2 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -189,12 +189,6 @@ static inline bool system_supports_mixed_endian_el0(void) return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1)); } -static inline bool system_uses_ttbr0_pan(void) -{ - return IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN) && - !cpus_have_cap(ARM64_HAS_PAN); -} - #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h index 7803343e5881..7e51d1b57c0c 100644 --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -19,7 +19,6 @@ #ifndef __ASM_KERNEL_PGTABLE_H #define __ASM_KERNEL_PGTABLE_H -#include #include /* @@ -55,12 +54,6 @@ #define SWAPPER_DIR_SIZE (SWAPPER_PGTABLE_LEVELS * PAGE_SIZE) #define IDMAP_DIR_SIZE (IDMAP_PGTABLE_LEVELS * PAGE_SIZE) -#ifdef CONFIG_ARM64_SW_TTBR0_PAN -#define RESERVED_TTBR0_SIZE (PAGE_SIZE) -#else -#define RESERVED_TTBR0_SIZE (0) -#endif - /* Initial memory map size */ #if ARM64_SWAPPER_USES_SECTION_MAPS #define SWAPPER_BLOCK_SHIFT SECTION_SHIFT diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index b3325a9cb90f..abd64bd1f6d9 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -47,9 +47,6 @@ typedef unsigned long mm_segment_t; struct thread_info { unsigned long flags; /* low level flags */ mm_segment_t addr_limit; /* address limit */ -#ifdef CONFIG_ARM64_SW_TTBR0_PAN - u64 ttbr0; /* saved TTBR0_EL1 */ -#endif struct task_struct *task; /* main task structure */ int preempt_count; /* 0 => preemptable, <0 => bug */ int cpu; /* cpu */ diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index c37c064d7cdd..c8ef22a9a83b 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -28,7 +28,6 @@ #include #include -#include #include #include #include @@ -129,57 +128,16 @@ static inline void set_fs(mm_segment_t fs) /* * User access enabling/disabling. */ -#ifdef CONFIG_ARM64_SW_TTBR0_PAN -static inline void uaccess_ttbr0_disable(void) -{ - unsigned long ttbr; - - /* reserved_ttbr0 placed at the end of swapper_pg_dir */ - ttbr = read_sysreg(ttbr1_el1) + SWAPPER_DIR_SIZE; - write_sysreg(ttbr, ttbr0_el1); - isb(); -} - -static inline void uaccess_ttbr0_enable(void) -{ - unsigned long flags; - - /* - * Disable interrupts to avoid preemption between reading the 'ttbr0' - * variable and the MSR. A context switch could trigger an ASID - * roll-over and an update of 'ttbr0'. - */ - local_irq_save(flags); - write_sysreg(current_thread_info()->ttbr0, ttbr0_el1); - isb(); - local_irq_restore(flags); -} -#else -static inline void uaccess_ttbr0_disable(void) -{ -} - -static inline void uaccess_ttbr0_enable(void) -{ -} -#endif - #define __uaccess_disable(alt) \ do { \ - if (system_uses_ttbr0_pan()) \ - uaccess_ttbr0_disable(); \ - else \ - asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), alt, \ - CONFIG_ARM64_PAN)); \ + asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), alt, \ + CONFIG_ARM64_PAN)); \ } while (0) #define __uaccess_enable(alt) \ do { \ - if (system_uses_ttbr0_pan()) \ - uaccess_ttbr0_enable(); \ - else \ - asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt, \ - CONFIG_ARM64_PAN)); \ + asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt, \ + CONFIG_ARM64_PAN)); \ } while (0) static inline void uaccess_disable(void) @@ -409,39 +367,12 @@ extern __must_check long strnlen_user(const char __user *str, long n); #include #include -#include - -/* - * User access enabling/disabling macros. - */ - .macro uaccess_ttbr0_disable, tmp1 - mrs \tmp1, ttbr1_el1 // swapper_pg_dir - add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir - msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 - isb - .endm - - .macro uaccess_ttbr0_enable, tmp1 - get_thread_info \tmp1 - ldr \tmp1, [\tmp1, #TI_TTBR0] // load saved TTBR0_EL1 - msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1 - isb - .endm /* - * These macros are no-ops when UAO is present. + * User access enabling/disabling macros. These are no-ops when UAO is + * present. */ .macro uaccess_disable_not_uao, tmp1 -#ifdef CONFIG_ARM64_SW_TTBR0_PAN -alternative_if_not ARM64_HAS_PAN - uaccess_ttbr0_disable \tmp1 -alternative_else - nop - nop - nop - nop -alternative_endif -#endif alternative_if_not ARM64_ALT_PAN_NOT_UAO nop alternative_else @@ -450,21 +381,6 @@ alternative_endif .endm .macro uaccess_enable_not_uao, tmp1, tmp2 -#ifdef CONFIG_ARM64_SW_TTBR0_PAN -alternative_if_not ARM64_HAS_PAN - save_and_disable_irq \tmp2 // avoid preemption - uaccess_ttbr0_enable \tmp1 - restore_irq \tmp2 -alternative_else - nop - nop - nop - nop - nop - nop - nop -alternative_endif -#endif alternative_if_not ARM64_ALT_PAN_NOT_UAO nop alternative_else diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index dac70c160289..2bb17bd556f8 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -38,9 +38,6 @@ int main(void) DEFINE(TI_FLAGS, offsetof(struct thread_info, flags)); DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count)); DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit)); -#ifdef CONFIG_ARM64_SW_TTBR0_PAN - DEFINE(TI_TTBR0, offsetof(struct thread_info, ttbr0)); -#endif DEFINE(TI_TASK, offsetof(struct thread_info, task)); DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); BLANK(); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index cdf1dca64133..eda7d5915fbb 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -46,7 +46,6 @@ unsigned int compat_elf_hwcap2 __read_mostly; #endif DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); -EXPORT_SYMBOL(cpu_hwcaps); #define __ARM64_FTR_BITS(SIGNED, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ { \ diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 8aa564f58b61..367e850ece4d 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -187,6 +187,10 @@ alternative_endif eret // return to kernel .endm + .macro get_thread_info, rd + mrs \rd, sp_el0 + .endm + .macro irq_stack_entry mov x19, sp // preserve the original sp diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 8cfd5ab37743..0ea9a97467a6 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -318,14 +318,14 @@ __create_page_tables: * dirty cache lines being evicted. */ mov x0, x25 - add x1, x26, #SWAPPER_DIR_SIZE + RESERVED_TTBR0_SIZE + add x1, x26, #SWAPPER_DIR_SIZE bl __inval_cache_range /* * Clear the idmap and swapper page tables. */ mov x0, x25 - add x6, x26, #SWAPPER_DIR_SIZE + RESERVED_TTBR0_SIZE + add x6, x26, #SWAPPER_DIR_SIZE 1: stp xzr, xzr, [x0], #16 stp xzr, xzr, [x0], #16 stp xzr, xzr, [x0], #16 @@ -404,7 +404,7 @@ __create_page_tables: * tables again to remove any speculatively loaded cache lines. */ mov x0, x25 - add x1, x26, #SWAPPER_DIR_SIZE + RESERVED_TTBR0_SIZE + add x1, x26, #SWAPPER_DIR_SIZE dmb sy bl __inval_cache_range diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 7a5228c7abdd..9442a51d3540 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -194,11 +194,6 @@ SECTIONS swapper_pg_dir = .; . += SWAPPER_DIR_SIZE; -#ifdef CONFIG_ARM64_SW_TTBR0_PAN - reserved_ttbr0 = .; - . += RESERVED_TTBR0_SIZE; -#endif - _end = .; STABS_DEBUG