From 556b6723689694ac9134bcc36a07828168e057f4 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Tue, 23 Aug 2016 19:23:56 +0200 Subject: [PATCH] x86/entry: Remove outdated comment about SYSCALL targets The comment probably meant some old AMD64 incarnation which most likely never saw the light of day. STAR and LSTAR are two different registers and STAR sets CS/SS(DS) selectors for *all* modes, not only 32-bit. So simply remove that comment. Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20160823172356.15879-1-bp@alien8.de Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/common.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 6ef55e8..e374c19 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1305,11 +1305,6 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks /* May not be marked __init: used by software suspend */ void syscall_init(void) { - /* - * LSTAR and STAR live in a bit strange symbiosis. - * They both write to the same internal register. STAR allows to - * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip. - */ wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS); wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64); -- 2.7.4