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Message-ID: <20230721161018.50214-4-brgerst@gmail.com>
Date: Fri, 21 Jul 2023 12:10:14 -0400
From: Brian Gerst <brgerst@...il.com>
To: linux-kernel@...r.kernel.org, x86@...nel.org
Cc: Thomas Gleixner <tglx@...utronix.de>,
Borislav Petkov <bp@...en8.de>,
"H . Peter Anvin" <hpa@...or.com>,
Andy Lutomirski <luto@...nel.org>,
Mika Penttilä <mpenttil@...hat.com>,
Brian Gerst <brgerst@...il.com>
Subject: [PATCH v2 3/6] x86/entry/compat: Combine return value test from syscall handler
Move the sysret32_from_system_call label to remove a duplicate test of
the return value from the syscall handler.
Signed-off-by: Brian Gerst <brgerst@...il.com>
---
arch/x86/entry/entry_64_compat.S | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 70150298f8bd..b16272395f1a 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -118,9 +118,6 @@ SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL)
movq %rsp, %rdi
call do_SYSENTER_32
- /* XEN PV guests always use IRET path */
- ALTERNATIVE "testl %eax, %eax; jz swapgs_restore_regs_and_return_to_usermode", \
- "jmp swapgs_restore_regs_and_return_to_usermode", X86_FEATURE_XENPV
jmp sysret32_from_system_call
.Lsysenter_fix_flags:
@@ -212,13 +209,15 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_after_hwframe, SYM_L_GLOBAL)
movq %rsp, %rdi
call do_fast_syscall_32
+
+sysret32_from_system_call:
/* XEN PV guests always use IRET path */
ALTERNATIVE "testl %eax, %eax; jz swapgs_restore_regs_and_return_to_usermode", \
"jmp swapgs_restore_regs_and_return_to_usermode", X86_FEATURE_XENPV
- /* Opportunistic SYSRET */
-sysret32_from_system_call:
/*
+ * Opportunistic SYSRET
+ *
* We are not going to return to userspace from the trampoline
* stack. So let's erase the thread stack right now.
*/
--
2.41.0
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