From 8f77542c58133a79474b03dfb2338d5f1f28db4a Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 24 Feb 2016 12:18:49 -0800 Subject: [PATCH] x86/entry/compat: Add missing CLAC to entry_INT80_32 Orabug: 23331033 [ Upstream commit 3d44d51bd339766f0178f0cf2e8d048b4a4872aa ] This doesn't seem to fix a regression -- I don't think the CLAC was ever there. I double-checked in a debugger: entries through the int80 gate do not automatically clear AC. Stable maintainers: I can provide a backport to 4.3 and earlier if needed. This needs to be backported all the way to 3.10. Reported-by: Brian Gerst 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 Cc: # v3.10 and later Fixes: 63bcff2a307b ("x86, smap: Add STAC and CLAC instructions to control user space access") Link: http://lkml.kernel.org/r/b02b7e71ae54074be01fc171cbd4b72517055c0e.1456345086.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin (cherry picked from commit 1f9780e372264c0cd71571c94da08cc49ae327e3) Signed-off-by: Dan Duval --- arch/x86/ia32/ia32entry.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 72bf2680f819a..27e54946ef356 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -511,6 +511,7 @@ ENTRY(ia32_syscall) * it is too small to ever cause noticeable irq latency. */ PARAVIRT_ADJUST_EXCEPTION_FRAME + ASM_CLAC /* Do this early to minimize exposure */ SWAPGS ENABLE_INTERRUPTS(CLBR_NONE) -- 2.50.1