From 0233606ce5cf12c1a0e27cb197066ea5bc2bb488 Mon Sep 17 00:00:00 2001 From: Brian Gerst Date: Sun, 19 Jul 2015 21:09:04 -0400 Subject: [PATCH] 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 Cc: Andy Lutomirski Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1437354550-25858-2-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar --- 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 43e6519df0d5..f4e4e3ff753c 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 fc9db6ef2a95..761a2f9039a3 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; -- 2.34.1