From 657c1eea0019e80685a84cbb1919794243a187c9 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Fri, 16 Oct 2015 15:42:54 -0700 Subject: x86/entry/32: Fix entry_INT80_32() to expect interrupts to be on When I rewrote entry_INT80_32, I thought that int80 was an interrupt gate. It's a trap gate. *facepalm* Thanks to Brian Gerst for pointing out that it's better to change the entry code than to change the gate type. Suggested-by: Brian Gerst Reported-and-tested-by: Borislav Petkov Signed-off-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: 150ac78d63af ("x86/entry/32: Switch INT80 to the new C syscall path") Link: http://lkml.kernel.org/r/dc09d9b574a5c1dcca996847875c73f8341ce0ad.1445035014.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/entry/entry_32.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/x86/entry/entry_32.S') diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index c1c7c6364216..4f97f49261d3 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -345,13 +345,13 @@ ENTRY(entry_INT80_32) SAVE_ALL pt_regs_ax=$-ENOSYS /* save rest */ /* - * User mode is traced as though IRQs are on, and the interrupt gate - * turned them off. + * User mode is traced as though IRQs are on. Unlike the 64-bit + * case, INT80 is a trap gate on 32-bit kernels, so interrupts + * are already on (unless user code is messing around with iopl). */ - TRACE_IRQS_OFF movl %esp, %eax - call do_int80_syscall_32 + call do_syscall_32_irqs_on .Lsyscall_32_done: restore_all: -- cgit v1.2.3