From a57dae3aa4d00a000b5bac4238025438204c78b2 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 6 Feb 2008 22:39:45 +0100 Subject: [PATCH] x86: fix iret exception recovery on 64-bit This change broke recovery of exceptions in iret: commit 72fe4858544292ad64600765cb78bc02298c6b1c Author: Glauber de Oliveira Costa x86: replace privileged instructions with paravirt macros The ENTRY(native_iret) macro adds alignment padding before the iretq instruction, so "iret_label" no longer points exactly at the instruction. It was sloppy to leave the old "iret_label" label behind when replacing its nearby use. Removing it would have revealed the other use of the label later in the file, and upon noticing that use, anyone exercising the minimum of attention to detail expected of anyone touching this subtle code would realize it needed to change as well. Signed-off-by: Roland McGrath Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/entry_64.S | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index e518928114db..c7341e81941c 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -582,7 +582,6 @@ retint_restore_args: /* return to kernel space */ TRACE_IRQS_IRETQ restore_args: RESTORE_ARGS 0,8,0 -iret_label: #ifdef CONFIG_PARAVIRT INTERRUPT_RETURN #endif @@ -920,7 +919,7 @@ error_kernelspace: iret run with kernel gs again, so don't set the user space flag. B stepping K8s sometimes report an truncated RIP for IRET exceptions returning to compat mode. Check for these here too. */ - leaq iret_label(%rip),%rbp + leaq native_iret(%rip),%rbp cmpq %rbp,RIP(%rsp) je error_swapgs movl %ebp,%ebp /* zero extend */ -- 2.30.2