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>
This commit is contained in:
Andy Lutomirski 2015-10-05 17:48:22 -07:00 committed by Ingo Molnar
parent 4aabd140f9
commit dd636071c3
1 changed files with 11 additions and 11 deletions

View File

@ -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)
{