From 3ae36655b97a03fa1decf72f04078ef945647c1a Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 10 Aug 2011 11:15:32 -0400 Subject: x86-64: Rework vsyscall emulation and add vsyscall= parameter There are three choices: vsyscall=native: Vsyscalls are native code that issues the corresponding syscalls. vsyscall=emulate (default): Vsyscalls are emulated by instruction fault traps, tested in the bad_area path. The actual contents of the vsyscall page is the same as the vsyscall=native case except that it's marked NX. This way programs that make assumptions about what the code in the page does will not be confused when they read that code. vsyscall=none: Trying to execute a vsyscall will segfault. Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/8449fb3abf89851fd6b2260972666a6f82542284.1312988155.git.luto@mit.edu Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/irq_vectors.h | 4 ---- arch/x86/include/asm/traps.h | 2 -- arch/x86/include/asm/vsyscall.h | 6 ++++++ 3 files changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h index a563c509edcb..2c224e183b52 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -17,7 +17,6 @@ * Vectors 0 ... 31 : system traps and exceptions - hardcoded events * Vectors 32 ... 127 : device interrupts * Vector 128 : legacy int80 syscall interface - * Vector 204 : legacy x86_64 vsyscall emulation * Vectors 129 ... INVALIDATE_TLB_VECTOR_START-1 except 204 : device interrupts * Vectors INVALIDATE_TLB_VECTOR_START ... 255 : special interrupts * @@ -51,9 +50,6 @@ #ifdef CONFIG_X86_32 # define SYSCALL_VECTOR 0x80 #endif -#ifdef CONFIG_X86_64 -# define VSYSCALL_EMU_VECTOR 0xcc -#endif /* * Vectors 0x30-0x3f are used for ISA interrupts. diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 2bae0a513b40..0012d0902c5f 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -40,7 +40,6 @@ asmlinkage void alignment_check(void); asmlinkage void machine_check(void); #endif /* CONFIG_X86_MCE */ asmlinkage void simd_coprocessor_error(void); -asmlinkage void emulate_vsyscall(void); dotraplinkage void do_divide_error(struct pt_regs *, long); dotraplinkage void do_debug(struct pt_regs *, long); @@ -67,7 +66,6 @@ dotraplinkage void do_alignment_check(struct pt_regs *, long); dotraplinkage void do_machine_check(struct pt_regs *, long); #endif dotraplinkage void do_simd_coprocessor_error(struct pt_regs *, long); -dotraplinkage void do_emulate_vsyscall(struct pt_regs *, long); #ifdef CONFIG_X86_32 dotraplinkage void do_iret_error(struct pt_regs *, long); #endif diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h index 60107072c28b..eaea1d31f753 100644 --- a/arch/x86/include/asm/vsyscall.h +++ b/arch/x86/include/asm/vsyscall.h @@ -27,6 +27,12 @@ extern struct timezone sys_tz; extern void map_vsyscall(void); +/* + * Called on instruction fetch fault in vsyscall page. + * Returns true if handled. + */ +extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address); + #endif /* __KERNEL__ */ #endif /* _ASM_X86_VSYSCALL_H */ -- cgit v1.2.1