Commit-ID: dd636071c3d8044c802b7a365e9934724a929530
Gitweb: http://git.kernel.org/tip/dd636071c3d8044c802b7a365e9934724a929530
Author: Andy Lutomirski <luto@xxxxxxxxxx>
AuthorDate: Mon, 5 Oct 2015 17:48:22 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 9 Oct 2015 09:41:12 +0200
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@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/a3b6633e7dcb9f673c1b619afae602d29d27d2cf.1444091585.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/entry/common.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 778ca70..d087421 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)
{
--
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