diff options
| author | Andy Lutomirski <luto@amacapital.net> | 2014-09-05 15:13:54 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2014-09-08 14:14:03 -0700 |
| commit | e0ffbaabc46db508b8717f023c0ce03b980eefac (patch) | |
| tree | 89ee63906648601f938b0e93655e1106c85e77b9 /arch/x86/include/asm/ptrace.h | |
| parent | fd143b210e685f0c4b37895f03fb79cd0555b00d (diff) | |
x86: Split syscall_trace_enter into two phases
This splits syscall_trace_enter into syscall_trace_enter_phase1 and
syscall_trace_enter_phase2. Only phase 2 has full pt_regs, and only
phase 2 is permitted to modify any of pt_regs except for orig_ax.
The intent is that phase 1 can be called from the syscall fast path.
In this implementation, phase1 can handle any combination of
TIF_NOHZ (RCU context tracking), TIF_SECCOMP, and TIF_SYSCALL_AUDIT,
unless seccomp requests a ptrace event, in which case phase2 is
forced.
In principle, this could yield a big speedup for TIF_NOHZ as well as
for TIF_SECCOMP if syscall exit work were similarly split up.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2df320a600020fda055fccf2b668145729dd0c04.1409954077.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/include/asm/ptrace.h')
| -rw-r--r-- | arch/x86/include/asm/ptrace.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 6205f0c434db..86fc2bb82287 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -75,6 +75,11 @@ convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs); extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code, int si_code); + +extern unsigned long syscall_trace_enter_phase1(struct pt_regs *, u32 arch); +extern long syscall_trace_enter_phase2(struct pt_regs *, u32 arch, + unsigned long phase1_result); + extern long syscall_trace_enter(struct pt_regs *); extern void syscall_trace_leave(struct pt_regs *); |