From e88d974136dbb5d6962eeb63075900603e737a1e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 21 May 2020 22:05:30 +0200 Subject: [PATCH] x86/entry: Change exit path of xen_failsafe_callback xen_failsafe_callback() is invoked from XEN for two cases: 1. Fault while reloading DS, ES, FS or GS 2. Fault while executing IRET #1 retries the IRET after XEN has fixed up the segments. #2 injects a #GP which kills the task For #1 there is no reason to go through the full exception return path because the tasks TIF state is still the same. So just going straight to the IRET path is good enough. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Acked-by: Andy Lutomirski Link: https://lore.kernel.org/r/20200521202118.423224507@linutronix.de --- arch/x86/entry/entry_32.S | 2 +- arch/x86/entry/entry_64.S | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 6c6ae3a8c1fc..6fcdee9feba0 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1355,7 +1355,7 @@ SYM_FUNC_START(xen_failsafe_callback) 5: pushl $-1 /* orig_ax = -1 => not a system call */ SAVE_ALL ENCODE_FRAME_POINTER - jmp ret_from_exception + jmp handle_exception_return .section .fixup, "ax" 6: xorl %eax, %eax diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 2e476f488ace..a526fb57b65d 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1175,7 +1175,7 @@ SYM_CODE_START(xen_failsafe_callback) pushq $-1 /* orig_ax = -1 => not a system call */ PUSH_AND_CLEAR_REGS ENCODE_FRAME_POINTER - jmp error_exit + jmp error_return SYM_CODE_END(xen_failsafe_callback) #endif /* CONFIG_XEN_PV */ -- 2.50.1