diff options
| author | Andy Lutomirski <luto@kernel.org> | 2018-01-28 19:38:49 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-01-30 15:30:36 +0100 |
| commit | 21d375b6b34ff511a507de27bf316b3dde6938d9 (patch) | |
| tree | b2b77e5b404afb963a62f51e456a2885022cc164 /arch/x86/entry/syscall_64.c | |
| parent | x86/spectre: Check CONFIG_RETPOLINE in command line parser (diff) | |
| download | linux-21d375b6b34ff511a507de27bf316b3dde6938d9.tar.xz linux-21d375b6b34ff511a507de27bf316b3dde6938d9.zip | |
x86/entry/64: Remove the SYSCALL64 fast path
The SYCALLL64 fast path was a nice, if small, optimization back in the good
old days when syscalls were actually reasonably fast. Now there is PTI to
slow everything down, and indirect branches are verboten, making everything
messier. The retpoline code in the fast path is particularly nasty.
Just get rid of the fast path. The slow path is barely slower.
[ tglx: Split out the 'push all extra regs' part ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Link: https://lkml.kernel.org/r/462dff8d4d64dfbfc851fbf3130641809d980ecd.1517164461.git.luto@kernel.org
Diffstat (limited to 'arch/x86/entry/syscall_64.c')
| -rw-r--r-- | arch/x86/entry/syscall_64.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c index 9c09775e589d..c176d2fab1da 100644 --- a/arch/x86/entry/syscall_64.c +++ b/arch/x86/entry/syscall_64.c @@ -7,14 +7,11 @@ #include <asm/asm-offsets.h> #include <asm/syscall.h> -#define __SYSCALL_64_QUAL_(sym) sym -#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_##sym - -#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long __SYSCALL_64_QUAL_##qual(sym)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); +#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); #include <asm/syscalls_64.h> #undef __SYSCALL_64 -#define __SYSCALL_64(nr, sym, qual) [nr] = __SYSCALL_64_QUAL_##qual(sym), +#define __SYSCALL_64(nr, sym, qual) [nr] = sym, extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); |