Commit 3bd29515 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar

x86/entry/32: Fix FS and GS restore in opportunistic SYSEXIT

We either need to restore them before popping and thus changing
ESP, or we need to adjust the offsets.  The former is simpler.
Reported-and-tested-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
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>
Fixes: 5f310f73 x86/entry/32: ("Re-implement SYSENTER using the new C path")
Link: http://lkml.kernel.org/r/461e5c7d8fa3821529893a4893ac9c4bc37f9e17.1445035014.git.luto@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 657c1eea
...@@ -315,14 +315,14 @@ sysenter_past_esp: ...@@ -315,14 +315,14 @@ sysenter_past_esp:
TRACE_IRQS_ON /* User mode traces as IRQs on. */ TRACE_IRQS_ON /* User mode traces as IRQs on. */
movl PT_EIP(%esp), %edx /* pt_regs->ip */ movl PT_EIP(%esp), %edx /* pt_regs->ip */
movl PT_OLDESP(%esp), %ecx /* pt_regs->sp */ movl PT_OLDESP(%esp), %ecx /* pt_regs->sp */
1: mov PT_FS(%esp), %fs
PTGS_TO_GS
popl %ebx /* pt_regs->bx */ popl %ebx /* pt_regs->bx */
addl $2*4, %esp /* skip pt_regs->cx and pt_regs->dx */ addl $2*4, %esp /* skip pt_regs->cx and pt_regs->dx */
popl %esi /* pt_regs->si */ popl %esi /* pt_regs->si */
popl %edi /* pt_regs->di */ popl %edi /* pt_regs->di */
popl %ebp /* pt_regs->bp */ popl %ebp /* pt_regs->bp */
popl %eax /* pt_regs->ax */ popl %eax /* pt_regs->ax */
1: mov PT_FS(%esp), %fs
PTGS_TO_GS
/* /*
* Return back to the vDSO, which will pop ecx and edx. * Return back to the vDSO, which will pop ecx and edx.
......
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