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| author |   Brian Gerst <brgerst@gmail.com> | 2015-07-29 01:41:19 -0400 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2015-07-31 13:31:09 +0200 |
| commit | 5ed92a8ab71f8865ba07811429c988c72299b315 (patch) | |
| tree | 30e8cd33bd97ca0c0b7a835e11b6ab41657c7356 /arch/x86/kernel/signal.c | |
| parent | x86/vm86: Eliminate 'struct kernel_vm86_struct' (diff) | |
| download | linux-dev-5ed92a8ab71f8865ba07811429c988c72299b315.tar.xz linux-dev-5ed92a8ab71f8865ba07811429c988c72299b315.zip | |
x86/vm86: Use the normal pt_regs area for vm86
Change to use the normal pt_regs area to enter and exit vm86
mode. This is done by increasing the padding at the top of the
stack to make room for the extra vm86 segment slots in the IRET
frame. It then saves the 32-bit regs in the off-stack vm86
data, and copies in the vm86 regs. Exiting back to 32-bit mode
does the reverse. This allows removing the hacks to jump
directly into the exit asm code due to having to change the
stack pointer. Returning normally from the vm86 syscall and the
exception handlers allows things like ptrace and auditing to work properly.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.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/1438148483-11932-5-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/signal.c')
| -rw-r--r-- | arch/x86/kernel/signal.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 7e88cc782712..bfd736e80c89 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -635,6 +635,9 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs) bool stepping, failed; struct fpu *fpu = ¤t->thread.fpu; + if (v8086_mode(regs)) + save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL); + /* Are we from a system call? */ if (syscall_get_nr(current, regs) >= 0) { /* If so, check system call restarting.. */ |