diff options
| author | Andy Lutomirski <luto@kernel.org> | 2017-11-02 10:59:14 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-11-02 13:04:47 +0300 |
| commit | 46f5a10a721ce8dce8cc8fe55279b49e1c6b3288 (patch) | |
| tree | 4e6ca348b4ec0a7033f268399a1df3cb44b58c6b | |
| parent | 20bb83443ea79087b5e5f8dab4e9d80bb9bf7acb (diff) | |
| download | linux-46f5a10a721ce8dce8cc8fe55279b49e1c6b3288.tar.xz | |
x86/entry/64: Remove all remaining direct thread_struct::sp0 reads
The only remaining readers in context switch code or vm86(), and
they all just want to update TSS.sp0 to match the current task.
Replace them all with a new helper update_sp0().
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2d231687f4ff288c9d9e98d7861b7df374246ac3.1509609304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/include/asm/switch_to.h | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/process_32.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/vm86_32.c | 4 |
4 files changed, 10 insertions, 4 deletions
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index 7ae8caffbada..54e64d909725 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -84,4 +84,10 @@ static inline void refresh_sysenter_cs(struct thread_struct *thread) } #endif +/* This is used when switching tasks or entering/exiting vm86 mode. */ +static inline void update_sp0(struct task_struct *task) +{ + load_sp0(task->thread.sp0); +} + #endif /* _ASM_X86_SWITCH_TO_H */ diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 40b85870e429..45bf0c5f93e1 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -287,7 +287,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) * current_thread_info(). Refresh the SYSENTER configuration in * case prev or next is vm86. */ - load_sp0(next->sp0); + update_sp0(next_p); refresh_sysenter_cs(next); this_cpu_write(cpu_current_top_of_stack, (unsigned long)task_stack_page(next_p) + diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 2124304fb77a..45e380958392 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -465,7 +465,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) this_cpu_write(current_task, next_p); /* Reload sp0. */ - load_sp0(next->sp0); + update_sp0(next_p); /* * Now maybe reload the debug registers and handle I/O bitmaps diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index 0f1d92cd20ad..a7b44c75c642 100644 --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -148,7 +148,7 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval) preempt_disable(); tsk->thread.sp0 = vm86->saved_sp0; tsk->thread.sysenter_cs = __KERNEL_CS; - load_sp0(tsk->thread.sp0); + update_sp0(tsk); refresh_sysenter_cs(&tsk->thread); vm86->saved_sp0 = 0; preempt_enable(); @@ -373,7 +373,7 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus) refresh_sysenter_cs(&tsk->thread); } - load_sp0(tsk->thread.sp0); + update_sp0(tsk); preempt_enable(); if (vm86->flags & VM86_SCREEN_BITMAP) |