2023-07-21 17:07:24

by Brian Gerst

Subject: [PATCH v2 4/6] x86/entry/32: Convert do_fast_syscall_32() to bool return type

Signed-off-by: Brian Gerst <[email protected]>
---
arch/x86/entry/common.c | 10 +++++-----
arch/x86/entry/entry_32.S | 2 +-
arch/x86/entry/entry_64_compat.S | 2 +-
arch/x86/include/asm/syscall.h | 4 ++--
4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index cccdd18c8304..5b3594457af3 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -220,8 +220,8 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs)
return true;
}

-/* Returns 0 to return using IRET or 1 to return using SYSEXIT/SYSRETL. */
-__visible noinstr long do_fast_syscall_32(struct pt_regs *regs)
+/* Returns true to return using SYSEXIT/SYSRETL, or false to use IRET */
+__visible noinstr bool do_fast_syscall_32(struct pt_regs *regs)
{
/*
* Called using the internal vDSO SYSENTER/SYSCALL32 calling
@@ -239,7 +239,7 @@ __visible noinstr long do_fast_syscall_32(struct pt_regs *regs)

/* Invoke the syscall. If it failed, keep it simple: use IRET. */
if (!__do_fast_syscall_32(regs))
- return 0;
+ return false;

#ifdef CONFIG_X86_64
/*
@@ -272,8 +272,8 @@ __visible noinstr long do_fast_syscall_32(struct pt_regs *regs)
#endif
}

-/* Returns 0 to return using IRET or 1 to return using SYSEXIT/SYSRETL. */
-__visible noinstr long do_SYSENTER_32(struct pt_regs *regs)
+/* Returns true to return using SYSEXIT/SYSRETL, or false to use IRET */
+__visible noinstr bool do_SYSENTER_32(struct pt_regs *regs)
{
/* SYSENTER loses RSP, but the vDSO saved it in RBP. */
regs->sp = regs->bp;
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 6e6af42e044a..c73047bf9f4b 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -837,7 +837,7 @@ SYM_FUNC_START(entry_SYSENTER_32)

movl %esp, %eax
call do_SYSENTER_32
- testl %eax, %eax
+ testb %al, %al
jz .Lsyscall_32_done

STACKLEAK_ERASE
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index b16272395f1a..27c05d08558a 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -212,7 +212,7 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_after_hwframe, SYM_L_GLOBAL)

sysret32_from_system_call:
/* XEN PV guests always use IRET path */
- ALTERNATIVE "testl %eax, %eax; jz swapgs_restore_regs_and_return_to_usermode", \
+ ALTERNATIVE "testb %al, %al; jz swapgs_restore_regs_and_return_to_usermode", \
"jmp swapgs_restore_regs_and_return_to_usermode", X86_FEATURE_XENPV

/*
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index be6c5515e0b9..f44e2f9ab65d 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -131,7 +131,7 @@ bool do_syscall_64(struct pt_regs *regs, int nr);
#endif /* CONFIG_X86_32 */

void do_int80_syscall_32(struct pt_regs *regs);
-long do_fast_syscall_32(struct pt_regs *regs);
-long do_SYSENTER_32(struct pt_regs *regs);
+bool do_fast_syscall_32(struct pt_regs *regs);
+bool do_SYSENTER_32(struct pt_regs *regs);

#endif /* _ASM_X86_SYSCALL_H */
--
2.41.0

2023-10-05 16:03:27

by tip-bot2 for Alexey Makhalov

Subject: [tip: x86/entry] x86/entry/32: Convert do_fast_syscall_32() to bool return type

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

Commit-ID: 0d3109ad2e6125add5b3c88e8de3fb7bfd4e8c49
Gitweb: https://git.kernel.org/tip/0d3109ad2e6125add5b3c88e8de3fb7bfd4e8c49
Author: Brian Gerst <[email protected]>
AuthorDate: Fri, 21 Jul 2023 12:10:15 -04:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Thu, 05 Oct 2023 10:06:42 +02:00

x86/entry/32: Convert do_fast_syscall_32() to bool return type

Doesn't have to be 'long' - this simplifies the code a bit.

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 | 10 +++++-----
arch/x86/entry/entry_32.S | 2 +-
arch/x86/entry/entry_64_compat.S | 2 +-
arch/x86/include/asm/syscall.h | 4 ++--
4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 328990d..f1f3bf1 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -193,8 +193,8 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs)
return true;
}

-/* Returns 0 to return using IRET or 1 to return using SYSEXIT/SYSRETL. */
-__visible noinstr long do_fast_syscall_32(struct pt_regs *regs)
+/* Returns true to return using SYSEXIT/SYSRETL, or false to use IRET */
+__visible noinstr bool do_fast_syscall_32(struct pt_regs *regs)
{
/*
* Called using the internal vDSO SYSENTER/SYSCALL32 calling
@@ -212,7 +212,7 @@ __visible noinstr long do_fast_syscall_32(struct pt_regs *regs)

/* Invoke the syscall. If it failed, keep it simple: use IRET. */
if (!__do_fast_syscall_32(regs))
- return 0;
+ return false;

#ifdef CONFIG_X86_64
/*
@@ -245,8 +245,8 @@ __visible noinstr long do_fast_syscall_32(struct pt_regs *regs)
#endif
}

-/* Returns 0 to return using IRET or 1 to return using SYSEXIT/SYSRETL. */
-__visible noinstr long do_SYSENTER_32(struct pt_regs *regs)
+/* Returns true to return using SYSEXIT/SYSRETL, or false to use IRET */
+__visible noinstr bool do_SYSENTER_32(struct pt_regs *regs)
{
/* SYSENTER loses RSP, but the vDSO saved it in RBP. */
regs->sp = regs->bp;
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 6e6af42..c73047b 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -837,7 +837,7 @@ SYM_FUNC_START(entry_SYSENTER_32)

movl %esp, %eax
call do_SYSENTER_32
- testl %eax, %eax
+ testb %al, %al
jz .Lsyscall_32_done

STACKLEAK_ERASE
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index b162723..27c05d0 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -212,7 +212,7 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_after_hwframe, SYM_L_GLOBAL)

sysret32_from_system_call:
/* XEN PV guests always use IRET path */
- ALTERNATIVE "testl %eax, %eax; jz swapgs_restore_regs_and_return_to_usermode", \
+ ALTERNATIVE "testb %al, %al; jz swapgs_restore_regs_and_return_to_usermode", \
"jmp swapgs_restore_regs_and_return_to_usermode", X86_FEATURE_XENPV

/*
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 4fb36fb..c7e25c9 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -131,7 +131,7 @@ void do_syscall_64(struct pt_regs *regs, int nr);
#endif /* CONFIG_X86_32 */

void do_int80_syscall_32(struct pt_regs *regs);
-long do_fast_syscall_32(struct pt_regs *regs);
-long do_SYSENTER_32(struct pt_regs *regs);
+bool do_fast_syscall_32(struct pt_regs *regs);
+bool do_SYSENTER_32(struct pt_regs *regs);

#endif /* _ASM_X86_SYSCALL_H */