2023-07-21 16:53:37

by Brian Gerst

Subject: [PATCH v2 5/6] x86/entry/32: Remove SEP test for SYSEXIT

SEP must be already be present in order for do_fast_syscall_32() to be
called on native 32-bit, so checking it again is unnecessary.

Signed-off-by: Brian Gerst <[email protected]>
---
arch/x86/entry/common.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 5b3594457af3..4d7d6d25dda9 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -265,8 +265,7 @@ __visible noinstr bool do_fast_syscall_32(struct pt_regs *regs)
* We don't allow syscalls at all from VM86 mode, but we still
* need to check VM, because we might be returning from sys_vm86.
*/
- return static_cpu_has(X86_FEATURE_SEP) &&
- regs->cs == __USER_CS && regs->ss == __USER_DS &&
+ return regs->cs == __USER_CS && regs->ss == __USER_DS &&
regs->ip == landing_pad &&
(regs->flags & (X86_EFLAGS_RF | X86_EFLAGS_TF | X86_EFLAGS_VM)) == 0;
#endif
--
2.41.0

2023-10-05 14:26:23

by tip-bot2 for Alexey Makhalov

Subject: [tip: x86/entry] x86/entry/32: Remove SEP test for SYSEXIT

The following commit has been merged into the x86/entry branch of tip:

Commit-ID: bab9fa6dc5e4483749838877deebe038de3ce97e
Gitweb: https://git.kernel.org/tip/bab9fa6dc5e4483749838877deebe038de3ce97e
Author: Brian Gerst <[email protected]>
AuthorDate: Fri, 21 Jul 2023 12:10:16 -04:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Thu, 05 Oct 2023 10:06:43 +02:00

x86/entry/32: Remove SEP test for SYSEXIT

SEP must be already be present in order for do_fast_syscall_32() to be
called on native 32-bit, so checking it again is unnecessary.

Signed-off-by: Brian Gerst <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
arch/x86/entry/common.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index f1f3bf1..0551bcb 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -238,8 +238,7 @@ __visible noinstr bool do_fast_syscall_32(struct pt_regs *regs)
* We don't allow syscalls at all from VM86 mode, but we still
* need to check VM, because we might be returning from sys_vm86.
*/
- return static_cpu_has(X86_FEATURE_SEP) &&
- regs->cs == __USER_CS && regs->ss == __USER_DS &&
+ return regs->cs == __USER_CS && regs->ss == __USER_DS &&
regs->ip == landing_pad &&
(regs->flags & (X86_EFLAGS_RF | X86_EFLAGS_TF | X86_EFLAGS_VM)) == 0;
#endif