[tip:x86/asm] x86/entry: Remove outdated comment about SYSCALL targets

[tip-bot for Borislav Petkov]

Commit-ID:  556b6723689694ac9134bcc36a07828168e057f4
Gitweb: http://git.kernel.org/tip/556b6723689694ac9134bcc36a07828168e057f4
Author: Borislav Petkov 
AuthorDate: Tue, 23 Aug 2016 19:23:56 +0200
Committer:  Ingo Molnar 
CommitDate: Wed, 24 Aug 2016 11:20:31 +0200

x86/entry: Remove outdated comment about SYSCALL targets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...@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);
 

[tip:x86/asm] x86/entry: Remove outdated comment about SYSCALL targets

[tip-bot for Borislav Petkov]

Commit-ID:  556b6723689694ac9134bcc36a07828168e057f4
Gitweb: http://git.kernel.org/tip/556b6723689694ac9134bcc36a07828168e057f4
Author: Borislav Petkov 
AuthorDate: Tue, 23 Aug 2016 19:23:56 +0200
Committer:  Ingo Molnar 
CommitDate: Wed, 24 Aug 2016 11:20:31 +0200

x86/entry: Remove outdated comment about SYSCALL targets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...@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);