diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/entry/vdso/vdso2c.c | 1 | ||||
| -rw-r--r-- | arch/x86/entry/vdso/vdso32/system_call.S | 25 | ||||
| -rw-r--r-- | arch/x86/include/asm/vdso.h | 1 |
3 files changed, 26 insertions, 1 deletions
diff --git a/arch/x86/entry/vdso/vdso2c.c b/arch/x86/entry/vdso/vdso2c.c index 2637eb1e3949..785d9922b106 100644 --- a/arch/x86/entry/vdso/vdso2c.c +++ b/arch/x86/entry/vdso/vdso2c.c @@ -101,6 +101,7 @@ struct vdso_sym required_syms[] = { {"__kernel_vsyscall", true}, {"__kernel_sigreturn", true}, {"__kernel_rt_sigreturn", true}, + {"int80_landing_pad", true}, }; __attribute__((format(printf, 1, 2))) __attribute__((noreturn)) diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S index b52cbfbe119e..d591fe93e93a 100644 --- a/arch/x86/entry/vdso/vdso32/system_call.S +++ b/arch/x86/entry/vdso/vdso32/system_call.S @@ -16,7 +16,30 @@ ALIGN __kernel_vsyscall: CFI_STARTPROC - int $0x80 + /* + * Reshuffle regs so that all of any of the entry instructions + * will preserve enough state. + */ + pushl %edx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET edx, 0 + pushl %ecx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ecx, 0 + movl %esp, %ecx + + /* Enter using int $0x80 */ + movl (%esp), %ecx + int $0x80 +GLOBAL(int80_landing_pad) + + /* Restore ECX and EDX in case they were clobbered. */ + popl %ecx + CFI_RESTORE ecx + CFI_ADJUST_CFA_OFFSET -4 + popl %edx + CFI_RESTORE edx + CFI_ADJUST_CFA_OFFSET -4 ret CFI_ENDPROC diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h index 5bcb1de8296e..756de9190aec 100644 --- a/arch/x86/include/asm/vdso.h +++ b/arch/x86/include/asm/vdso.h @@ -26,6 +26,7 @@ struct vdso_image { long sym___kernel_sigreturn; long sym___kernel_rt_sigreturn; long sym___kernel_vsyscall; + long sym_int80_landing_pad; }; #ifdef CONFIG_X86_64 |