diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-09-13 14:29:22 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-09-15 08:25:12 +0200 |
| commit | 97245d00585d82540f4538cf72d92a1e853c7b0e (patch) | |
| tree | 26054c5eba683abdb5163d60e85bf2c90997882c /arch/x86/entry | |
| parent | b9d989c7218ac922185d82ad46f3e58b27a4bea9 (diff) | |
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>
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/common.c | 20 |
1 files changed, 6 insertions, 14 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 871bbf975d4c..bdd9cc59d20f 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 |