Commit-ID: 0233606ce5cf12c1a0e27cb197066ea5bc2bb488
Gitweb: http://git.kernel.org/tip/0233606ce5cf12c1a0e27cb197066ea5bc2bb488
Author: Brian Gerst <brgerst@xxxxxxxxx>
AuthorDate: Sun, 19 Jul 2015 21:09:04 -0400
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 21 Jul 2015 09:12:23 +0200
x86/entry/vm86: Clean up saved_fs/gs
There is no need to save FS and non-lazy GS outside the 32-bit
regs. Lazy GS still needs to be saved because it wasn't saved
on syscall entry. Save it in the gs slot of regs32, which is
present but unused.
Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1437354550-25858-2-git-send-email-brgerst@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/processor.h | 2 --
arch/x86/kernel/vm86_32.c | 6 ++----
2 files changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 43e6519..f4e4e3f 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -410,8 +410,6 @@ struct thread_struct {
unsigned long v86flags;
unsigned long v86mask;
unsigned long saved_sp0;
- unsigned int saved_fs;
- unsigned int saved_gs;
#endif
/* IO permissions: */
unsigned long *io_bitmap_ptr;
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index fc9db6e..761a2f9 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -159,8 +159,7 @@ struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs)
ret = KVM86->regs32;
- ret->fs = current->thread.saved_fs;
- set_user_gs(ret, current->thread.saved_gs);
+ lazy_load_gs(ret->gs);
return ret;
}
@@ -315,8 +314,7 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
*/
info->regs32->ax = VM86_SIGNAL;
tsk->thread.saved_sp0 = tsk->thread.sp0;
- tsk->thread.saved_fs = info->regs32->fs;
- tsk->thread.saved_gs = get_user_gs(info->regs32);
+ lazy_save_gs(info->regs32->gs);
tss = &per_cpu(cpu_tss, get_cpu());
tsk->thread.sp0 = (unsigned long) &info->VM86_TSS_ESP0;
--
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