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| author |   Andy Lutomirski <luto@kernel.org> | 2015-10-05 17:48:22 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2015-10-09 09:41:12 +0200 |
| commit | dd636071c3d8044c802b7a365e9934724a929530 (patch) | |
| tree | 66106b8b51760d5bbb51bc0fa7d5b27202aa738b /arch/x86/entry | |
| parent | x86/entry: Hide two syscall entry assertions behind CONFIG_DEBUG_ENTRY (diff) | |
| download | linux-dev-dd636071c3d8044c802b7a365e9934724a929530.tar.xz linux-dev-dd636071c3d8044c802b7a365e9934724a929530.zip | |
x86/entry: Use pt_regs_to_thread_info() in syscall entry tracing
It generates simpler and faster code than current_thread_info().
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/a3b6633e7dcb9f673c1b619afae602d29d27d2cf.1444091585.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/common.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 778ca70c22dd..d0874210d5b5 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -30,6 +30,13 @@ #define CREATE_TRACE_POINTS #include <trace/events/syscalls.h> +static struct thread_info *pt_regs_to_thread_info(struct pt_regs *regs) +{ + unsigned long top_of_stack = + (unsigned long)(regs + 1) + TOP_OF_KERNEL_STACK_PADDING; + return (struct thread_info *)(top_of_stack - THREAD_SIZE); +} + #ifdef CONFIG_CONTEXT_TRACKING /* Called on entry from user mode with IRQs off. */ __visible void enter_from_user_mode(void) @@ -68,14 +75,14 @@ static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch) */ unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch) { + struct thread_info *ti = pt_regs_to_thread_info(regs); unsigned long ret = 0; u32 work; if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) BUG_ON(regs != task_pt_regs(current)); - work = ACCESS_ONCE(current_thread_info()->flags) & - _TIF_WORK_SYSCALL_ENTRY; + work = ACCESS_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY; #ifdef CONFIG_CONTEXT_TRACKING /* @@ -157,9 +164,9 @@ unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch) long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch, unsigned long phase1_result) { + struct thread_info *ti = pt_regs_to_thread_info(regs); long ret = 0; - u32 work = ACCESS_ONCE(current_thread_info()->flags) & - _TIF_WORK_SYSCALL_ENTRY; + u32 work = ACCESS_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY; if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) BUG_ON(regs != task_pt_regs(current)); @@ -211,13 +218,6 @@ long syscall_trace_enter(struct pt_regs *regs) return syscall_trace_enter_phase2(regs, arch, phase1_result); } -static struct thread_info *pt_regs_to_thread_info(struct pt_regs *regs) -{ - unsigned long top_of_stack = - (unsigned long)(regs + 1) + TOP_OF_KERNEL_STACK_PADDING; - return (struct thread_info *)(top_of_stack - THREAD_SIZE); -} - /* Called with IRQs disabled. */ __visible void prepare_exit_to_usermode(struct pt_regs *regs) { |