Messages in this thread Patch in this message | | | From | Brian Gerst <> | Subject | [PATCH 1/7] x86/vm86: Clean up saved_fs/gs | Date | Thu, 16 Jul 2015 07:46:01 -0400 |
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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.
Signed-off-by: Brian Gerst <brgerst@gmail.com> --- arch/x86/include/asm/processor.h | 3 ++- arch/x86/kernel/vm86_32.c | 6 ++---- 2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 43e6519..a4b5c6a 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -410,9 +410,10 @@ struct thread_struct { unsigned long v86flags; unsigned long v86mask; unsigned long saved_sp0; - unsigned int saved_fs; +#ifdef CONFIG_X86_32_LAZY_GS unsigned int saved_gs; #endif +#endif /* IO permissions: */ unsigned long *io_bitmap_ptr; unsigned long iopl; diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index fc9db6e..75eab83 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(current->thread.saved_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(tsk->thread.saved_gs); tss = &per_cpu(cpu_tss, get_cpu()); tsk->thread.sp0 = (unsigned long) &info->VM86_TSS_ESP0; -- 2.4.3
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