2023-07-18 13:57:19

by Brian Gerst

[permalink] [raw]
Subject: [PATCH 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 15660f936ede..fca6f2b7daf3 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -275,8 +275,7 @@ __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