diff options
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index bea8474744ff..6be39a387c5a 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -581,25 +581,41 @@ retint_restore_args: /* return to kernel space */ */ TRACE_IRQS_IRETQ restore_args: - RESTORE_ARGS 0,8,0 -iret_label: -#ifdef CONFIG_PARAVIRT + RESTORE_ARGS 0,8,0 + +ENTRY(irq_return) INTERRUPT_RETURN -#endif + + .section __ex_table, "a" + .quad irq_return, bad_iret + .previous + +#ifdef CONFIG_PARAVIRT ENTRY(native_iret) iretq .section __ex_table,"a" .quad native_iret, bad_iret .previous +#endif + .section .fixup,"ax" - /* force a signal here? this matches i386 behaviour */ - /* running with kernel gs */ bad_iret: - movq $11,%rdi /* SIGSEGV */ - TRACE_IRQS_ON - ENABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI)) - jmp do_exit + /* + * The iret traps when the %cs or %ss being restored is bogus. + * We've lost the original trap vector and error code. + * #GPF is the most likely one to get for an invalid selector. + * So pretend we completed the iret and took the #GPF in user mode. + * + * We are now running with the kernel GS after exception recovery. + * But error_entry expects us to have user GS to match the user %cs, + * so swap back. + */ + pushq $0 + + SWAPGS + jmp general_protection + .previous /* edi: workmask, edx: work */ @@ -796,7 +812,7 @@ paranoid_swapgs\trace: SWAPGS_UNSAFE_STACK paranoid_restore\trace: RESTORE_ALL 8 - INTERRUPT_RETURN + jmp irq_return paranoid_userspace\trace: GET_THREAD_INFO(%rcx) movl threadinfo_flags(%rcx),%ebx @@ -911,7 +927,7 @@ 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 irq_return(%rip),%rbp cmpq %rbp,RIP(%rsp) je error_swapgs movl %ebp,%ebp /* zero extend */ |