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authorAndy Lutomirski <luto@kernel.org>2017-11-02 00:59:10 -0700
committerIngo Molnar <mingo@kernel.org>2017-11-02 11:04:44 +0100
commitda51da189a24bb9b7e2d5a123be096e51a4695a5 (patch)
tree39b88e6bed96687f02eabe22ed211f7bc78c9c0b /arch/x86/kernel/vm86_32.c
parentbd7dc5a6afac719d8ce4092391eef2c7e83c2a75 (diff)
x86/entry/64: Pass SP0 directly to load_sp0()
load_sp0() had an odd signature: void load_sp0(struct tss_struct *tss, struct thread_struct *thread); Simplify it to: void load_sp0(unsigned long sp0); Also simplify a few get_cpu()/put_cpu() sequences to preempt_disable()/preempt_enable(). 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/2655d8b42ed940aa384fe18ee1129bbbcf730a08.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/vm86_32.c')
-rw-r--r--arch/x86/kernel/vm86_32.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 5bc1c3ab6287..0f1d92cd20ad 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -94,7 +94,6 @@
void save_v86_state(struct kernel_vm86_regs *regs, int retval)
{
- struct tss_struct *tss;
struct task_struct *tsk = current;
struct vm86plus_struct __user *user;
struct vm86 *vm86 = current->thread.vm86;
@@ -146,13 +145,13 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval)
do_exit(SIGSEGV);
}
- tss = &per_cpu(cpu_tss, get_cpu());
+ preempt_disable();
tsk->thread.sp0 = vm86->saved_sp0;
tsk->thread.sysenter_cs = __KERNEL_CS;
- load_sp0(tss, &tsk->thread);
+ load_sp0(tsk->thread.sp0);
refresh_sysenter_cs(&tsk->thread);
vm86->saved_sp0 = 0;
- put_cpu();
+ preempt_enable();
memcpy(&regs->pt, &vm86->regs32, sizeof(struct pt_regs));
@@ -238,7 +237,6 @@ SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg)
static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
{
- struct tss_struct *tss;
struct task_struct *tsk = current;
struct vm86 *vm86 = tsk->thread.vm86;
struct kernel_vm86_regs vm86regs;
@@ -366,8 +364,8 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
vm86->saved_sp0 = tsk->thread.sp0;
lazy_save_gs(vm86->regs32.gs);
- tss = &per_cpu(cpu_tss, get_cpu());
/* make room for real-mode segments */
+ preempt_disable();
tsk->thread.sp0 += 16;
if (static_cpu_has(X86_FEATURE_SEP)) {
@@ -375,8 +373,8 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
refresh_sysenter_cs(&tsk->thread);
}
- load_sp0(tss, &tsk->thread);
- put_cpu();
+ load_sp0(tsk->thread.sp0);
+ preempt_enable();
if (vm86->flags & VM86_SCREEN_BITMAP)
mark_screen_rdonly(tsk->mm);