[PATCH] x86/CPU: Remove outdated comment about SYSCALL targets

From: Borislav Petkov
Date: Tue Aug 23 2016 - 13:23:55 EST


From: Borislav Petkov <bp@xxxxxxx>

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 <bp@xxxxxxx>
---
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 ce7a4c17f1bc..06919427d451 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1310,11 +1310,6 @@ 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);

--
2.8.4