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Groups > linux.kernel > #1483966
| From | tip-bot for Linus Torvalds <tipbot@zytor.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [tip:x86/asm] x86/entry: Get rid of pt_regs_to_thread_info() |
| Date | 2016-09-15 12:50 +0200 |
| Message-ID | <shCoW-5Sc-7@gated-at.bofh.it> (permalink) |
| References | <sh3AS-7tK-27@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Commit-ID: 97245d00585d82540f4538cf72d92a1e853c7b0e
Gitweb: http://git.kernel.org/tip/97245d00585d82540f4538cf72d92a1e853c7b0e
Author: Linus Torvalds <torvalds@linux-foundation.org>
AuthorDate: Tue, 13 Sep 2016 14:29:22 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 15 Sep 2016 08:25:12 +0200
x86/entry: Get rid of pt_regs_to_thread_info()
It was a nice optimization while it lasted, but thread_info is moving
and this optimization will no longer work.
Quoting Linus:
Oh Gods, Andy. That pt_regs_to_thread_info() thing made me want
to do unspeakable acts on a poor innocent wax figure that looked
_exactly_ like you.
[ Changelog written by Andy. ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
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: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/6376aa81c68798cc81631673f52bd91a3e078944.1473801993.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/entry/common.c | 20 ++++++--------------
1 file changed, 6 insertions(+), 14 deletions(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 871bbf9..bdd9cc5 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -31,13 +31,6 @@
#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 inline void enter_from_user_mode(void)
@@ -71,7 +64,7 @@ static long syscall_trace_enter(struct pt_regs *regs)
{
u32 arch = in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
unsigned long ret = 0;
bool emulated = false;
u32 work;
@@ -173,18 +166,17 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags)
/* Disable IRQs and retry */
local_irq_disable();
- cached_flags = READ_ONCE(pt_regs_to_thread_info(regs)->flags);
+ cached_flags = READ_ONCE(current_thread_info()->flags);
if (!(cached_flags & EXIT_TO_USERMODE_LOOP_FLAGS))
break;
-
}
}
/* Called with IRQs disabled. */
__visible inline void prepare_exit_to_usermode(struct pt_regs *regs)
{
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
u32 cached_flags;
if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled()))
@@ -247,7 +239,7 @@ static void syscall_slow_exit_work(struct pt_regs *regs, u32 cached_flags)
*/
__visible inline void syscall_return_slowpath(struct pt_regs *regs)
{
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
u32 cached_flags = READ_ONCE(ti->flags);
CT_WARN_ON(ct_state() != CONTEXT_KERNEL);
@@ -270,7 +262,7 @@ __visible inline void syscall_return_slowpath(struct pt_regs *regs)
#ifdef CONFIG_X86_64
__visible void do_syscall_64(struct pt_regs *regs)
{
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
unsigned long nr = regs->orig_ax;
enter_from_user_mode();
@@ -303,7 +295,7 @@ __visible void do_syscall_64(struct pt_regs *regs)
*/
static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
{
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
unsigned int nr = (unsigned int)regs->orig_ax;
#ifdef CONFIG_IA32_EMULATION
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH 00/12] thread_info cleanups and stack caching Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:30 +0200
[PATCH 03/12] um: Stop conflating task_struct::stack with thread_info Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:30 +0200
Re: [PATCH 03/12] um: Stop conflating task_struct::stack with thread_info Ingo Molnar <mingo@kernel.org> - 2016-09-15 08:30 +0200
[tip:x86/asm] um/Stop conflating task_struct::stack with thread_info tip-bot for Linus Torvalds <tipbot@zytor.com> - 2016-09-15 12:50 +0200
[PATCH 12/12] fork: Cache two thread stacks per cpu if CONFIG_VMAP_STACK is set Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
[PATCH 01/12] x86/asm: Move 'status' from struct thread_info to struct thread_struct Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
[tip:x86/asm] x86/asm: Move the thread_info::status field to thread_struct tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-09-15 12:50 +0200
[PATCH 10/12] lib/syscall: Pin the task stack in collect_syscall() Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
[PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-14 17:00 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Andy Lutomirski <luto@amacapital.net> - 2016-09-14 20:30 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-14 20:40 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Andy Lutomirski <luto@amacapital.net> - 2016-09-15 20:10 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-15 20:40 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Andy Lutomirski <luto@amacapital.net> - 2016-09-15 20:50 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-15 21:20 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Peter Zijlstra <peterz@infradead.org> - 2016-09-16 09:50 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Andy Lutomirski <luto@amacapital.net> - 2016-09-16 17:20 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Andy Lutomirski <luto@kernel.org> - 2016-09-16 17:40 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Peter Zijlstra <peterz@infradead.org> - 2016-09-16 18:40 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Peter Zijlstra <peterz@infradead.org> - 2016-09-16 17:40 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Ingo Molnar <mingo@kernel.org> - 2016-09-15 08:40 +0200
Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Ingo Molnar <mingo@kernel.org> - 2016-09-15 11:30 +0200
[PATCH 09/12] x86/process: Pin the target stack in get_wchan() Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
Re: [PATCH 09/12] x86/process: Pin the target stack in get_wchan() Jann Horn <jann@thejh.net> - 2016-09-17 04:10 +0200
Re: [PATCH 09/12] x86/process: Pin the target stack in get_wchan() Andy Lutomirski <luto@amacapital.net> - 2016-09-23 00:50 +0200
Re: [PATCH 09/12] x86/process: Pin the target stack in get_wchan() Andy Lutomirski <luto@amacapital.net> - 2016-09-23 01:00 +0200
Re: [PATCH 09/12] x86/process: Pin the target stack in get_wchan() Jann Horn <jann@thejh.net> - 2016-09-23 09:50 +0200
[PATCH 06/12] sched: Add try_get_task_stack() and put_task_stack() Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
[PATCH 02/12] x86/entry: Get rid of pt_regs_to_thread_info() Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
Re: [PATCH 02/12] x86/entry: Get rid of pt_regs_to_thread_info() Ingo Molnar <mingo@kernel.org> - 2016-09-15 08:30 +0200
[tip:x86/asm] x86/entry: Get rid of pt_regs_to_thread_info() tip-bot for Linus Torvalds <tipbot@zytor.com> - 2016-09-15 12:50 +0200
[PATCH 05/12] x86: Move thread_info into task_struct Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
[tip:x86/asm] x86: Move thread_info into task_struct tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-09-15 12:50 +0200
[PATCH 04/12] sched: Allow putting thread_info into task_struct Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
[tip:x86/asm] sched/core: Allow putting thread_info into task_struct tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-09-15 12:50 +0200
[PATCH 11/12] sched: Free the stack early if CONFIG_THREAD_INFO_IN_TASK Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
[PATCH 07/12] kthread: to_live_kthread() needs try_get_task_stack() Andy Lutomirski <luto@kernel.org> - 2016-09-13 23:40 +0200
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