diff options
| author | Andy Lutomirski <luto@kernel.org> | 2015-10-05 17:48:11 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-10-09 09:41:09 +0200 |
| commit | a474e67c913d3ebaf02ba9d7835d5299d226c3ed (patch) | |
| tree | 6b9ec92426db8a6e453c3748f34eda2f7cd070da /arch/x86/entry/vdso | |
| parent | 710246df58041106b7de645f4b45770f8a59a269 (diff) | |
x86/vdso/compat: Wire up SYSENTER and SYSCSALL for compat userspace
What, you didn't realize that SYSENTER and SYSCALL were actually
the same thing? :)
Unlike the old code, this actually passes the ptrace_syscall_32
test on AMD systems.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/b74615af58d785aa02d917213ec64e2022a2c796.1444091585.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry/vdso')
| -rw-r--r-- | arch/x86/entry/vdso/vdso32/system_call.S | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S index d591fe93e93a..00157cae71e0 100644 --- a/arch/x86/entry/vdso/vdso32/system_call.S +++ b/arch/x86/entry/vdso/vdso32/system_call.S @@ -3,6 +3,8 @@ */ #include <asm/dwarf2.h> +#include <asm/cpufeature.h> +#include <asm/alternative-asm.h> /* * First get the common code for the sigreturn entry points. @@ -28,6 +30,12 @@ __kernel_vsyscall: CFI_REL_OFFSET ecx, 0 movl %esp, %ecx +#ifdef CONFIG_X86_64 + /* If SYSENTER (Intel) or SYSCALL32 (AMD) is available, use it. */ + ALTERNATIVE_2 "", "sysenter", X86_FEATURE_SYSENTER32, \ + "syscall", X86_FEATURE_SYSCALL32 +#endif + /* Enter using int $0x80 */ movl (%esp), %ecx int $0x80 |