From 45db1c6176c8171d9ae6fa6d82e07d115a5950ca Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 5 Dec 2011 16:08:49 -0800 Subject: [PATCH] x86, um: Use the same style generated syscall tables as native Now when the native kernel uses a single style of generated system call table, follow suite for UML and implement the same style, all in C. This requires __NR_syscall_max and NR_syscalls to be generated; on native this is done in asm-headers.h but that file is common to all UML architectures; therefore put it in user-headers.h instead which already have accommodations for architecture-specific values. Signed-off-by: H. Peter Anvin --- arch/x86/um/Makefile | 3 +- arch/x86/um/sys_call_table_32.S | 26 ---------------- arch/x86/um/sys_call_table_32.c | 55 +++++++++++++++++++++++++++++++++ arch/x86/um/sys_call_table_64.c | 31 +++++++------------ arch/x86/um/user-offsets.c | 15 +++++++++ 5 files changed, 84 insertions(+), 46 deletions(-) delete mode 100644 arch/x86/um/sys_call_table_32.S create mode 100644 arch/x86/um/sys_call_table_32.c diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile index 8fb58400e415..5d065b2222d3 100644 --- a/arch/x86/um/Makefile +++ b/arch/x86/um/Makefile @@ -37,7 +37,8 @@ subarch-$(CONFIG_MODULES) += ../kernel/module.o USER_OBJS := bugs_$(BITS).o ptrace_user.o fault.o extra-y += user-offsets.s -$(obj)/user-offsets.s: c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) +$(obj)/user-offsets.s: c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) \ + -Iarch/x86/include/generated UNPROFILE_OBJS := stub_segv.o CFLAGS_stub_segv.o := $(CFLAGS_NO_HARDENING) diff --git a/arch/x86/um/sys_call_table_32.S b/arch/x86/um/sys_call_table_32.S deleted file mode 100644 index a7ca80d2dceb..000000000000 --- a/arch/x86/um/sys_call_table_32.S +++ /dev/null @@ -1,26 +0,0 @@ -#include -/* Steal i386 syscall table for our purposes, but with some slight changes.*/ - -#define sys_iopl sys_ni_syscall -#define sys_ioperm sys_ni_syscall - -#define sys_vm86old sys_ni_syscall -#define sys_vm86 sys_ni_syscall - -#define old_mmap sys_old_mmap - -#define ptregs_fork sys_fork -#define ptregs_execve sys_execve -#define ptregs_iopl sys_iopl -#define ptregs_vm86old sys_vm86old -#define ptregs_clone sys_clone -#define ptregs_vm86 sys_vm86 -#define ptregs_sigaltstack sys_sigaltstack -#define ptregs_vfork sys_vfork - -.section .rodata,"a" - -#include "../kernel/syscall_table_32.S" - -ENTRY(syscall_table_size) -.long .-sys_call_table diff --git a/arch/x86/um/sys_call_table_32.c b/arch/x86/um/sys_call_table_32.c new file mode 100644 index 000000000000..b897fcae6205 --- /dev/null +++ b/arch/x86/um/sys_call_table_32.c @@ -0,0 +1,55 @@ +/* + * System call table for UML/i386, copied from arch/x86/kernel/syscall_*.c + * with some changes for UML. + */ + +#include +#include +#include +#include + +#define __NO_STUBS + +/* + * Below you can see, in terms of #define's, the differences between the x86-64 + * and the UML syscall table. + */ + +/* Not going to be implemented by UML, since we have no hardware. */ +#define stub_iopl sys_ni_syscall +#define sys_ioperm sys_ni_syscall + +#define sys_vm86old sys_ni_syscall +#define sys_vm86 sys_ni_syscall + +#define old_mmap sys_old_mmap + +#define ptregs_fork sys_fork +#define ptregs_execve sys_execve +#define ptregs_iopl sys_iopl +#define ptregs_vm86old sys_vm86old +#define ptregs_clone sys_clone +#define ptregs_vm86 sys_vm86 +#define ptregs_sigaltstack sys_sigaltstack +#define ptregs_vfork sys_vfork + +#define __SYSCALL_I386(nr, sym, compat) extern asmlinkage void sym(void) ; +#include + +#undef __SYSCALL_I386 +#define __SYSCALL_I386(nr, sym, compat) [ nr ] = sym, + +typedef void (*sys_call_ptr_t)(void); + +extern void sys_ni_syscall(void); + +sys_call_ptr_t sys_call_table[] __cacheline_aligned = { + /* + * Smells like a compiler bug -- it doesn't work + * when the & below is removed. + */ + [0 ... __NR_syscall_max] = &sys_ni_syscall, +#include +}; + +int syscall_table_size = sizeof(sys_call_table); diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c index 99522f78b162..797a639bcca5 100644 --- a/arch/x86/um/sys_call_table_64.c +++ b/arch/x86/um/sys_call_table_64.c @@ -1,11 +1,12 @@ /* - * System call table for UML/x86-64, copied from arch/x86_64/kernel/syscall.c + * System call table for UML/x86-64, copied from arch/x86/kernel/syscall_*.c * with some changes for UML. */ #include #include #include +#include #define __NO_STUBS @@ -34,31 +35,23 @@ #define stub_sigaltstack sys_sigaltstack #define stub_rt_sigreturn sys_rt_sigreturn -#define __SYSCALL(nr, sym) extern asmlinkage void sym(void) ; -#undef _ASM_X86_UNISTD_64_H -#include "../../x86/include/asm/unistd_64.h" +#define __SYSCALL_64(nr, sym, compat) extern asmlinkage void sym(void) ; +#include -#undef __SYSCALL -#define __SYSCALL(nr, sym) [ nr ] = sym, -#undef _ASM_X86_UNISTD_64_H +#undef __SYSCALL_64 +#define __SYSCALL_64(nr, sym, compat) [ nr ] = sym, typedef void (*sys_call_ptr_t)(void); extern void sys_ni_syscall(void); -/* - * We used to have a trick here which made sure that holes in the - * x86_64 table were filled in with sys_ni_syscall, but a comment in - * unistd_64.h says that holes aren't allowed, so the trick was - * removed. - * The trick looked like this - * [0 ... UM_NR_syscall_max] = &sys_ni_syscall - * before including unistd_64.h - the later initializations overwrote - * the sys_ni_syscall filler. - */ - sys_call_ptr_t sys_call_table[] __cacheline_aligned = { -#include + /* + * Smells like a compiler bug -- it doesn't work + * when the & below is removed. + */ + [0 ... __NR_syscall_max] = &sys_ni_syscall, +#include }; int syscall_table_size = sizeof(sys_call_table); diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c index ca49be8ddd0c..5edf4f4bbf53 100644 --- a/arch/x86/um/user-offsets.c +++ b/arch/x86/um/user-offsets.c @@ -8,6 +8,18 @@ #include #include +#ifdef __i386__ +#define __SYSCALL_I386(nr, sym, compat) [nr] = 1, +static char syscalls[] = { +#include +}; +#else +#define __SYSCALL_64(nr, sym, compat) [nr] = 1, +static char syscalls[] = { +#include +}; +#endif + #define DEFINE(sym, val) \ asm volatile("\n->" #sym " %0 " #val : : "i" (val)) @@ -77,4 +89,7 @@ void foo(void) DEFINE(UM_PROT_READ, PROT_READ); DEFINE(UM_PROT_WRITE, PROT_WRITE); DEFINE(UM_PROT_EXEC, PROT_EXEC); + + DEFINE(__NR_syscall_max, sizeof(syscalls) - 1); + DEFINE(NR_syscalls, sizeof(syscalls)); } -- 2.34.1