From 2df1ad0d25803399056d439425e271802cd243f6 Mon Sep 17 00:00:00 2001
From: Brian Gerst <brgerst@gmail.com>
Date: Sun, 2 Feb 2025 15:23:22 -0500
Subject: [PATCH] x86/arch_prctl: Simplify sys_arch_prctl()
Use in_ia32_syscall() instead of a compat syscall entry.
No change in functionality intended.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20250202202323.422113-2-brgerst@gmail.com
---
arch/x86/entry/syscalls/syscall_32.tbl | 2 +-
arch/x86/include/asm/proto.h | 3 +--
arch/x86/kernel/process.c | 5 ++++-
arch/x86/kernel/process_32.c | 5 -----
arch/x86/kernel/process_64.c | 18 ------------------
5 files changed, 6 insertions(+), 27 deletions(-)
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 4d0fb2fba7e2..62283097a7cc 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -396,7 +396,7 @@
381 i386 pkey_alloc sys_pkey_alloc
382 i386 pkey_free sys_pkey_free
383 i386 statx sys_statx
-384 i386 arch_prctl sys_arch_prctl compat_sys_arch_prctl
+384 i386 arch_prctl sys_arch_prctl
385 i386 io_pgetevents sys_io_pgetevents_time32 compat_sys_io_pgetevents
386 i386 rseq sys_rseq
393 i386 semget sys_semget
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
index 484f4f0131a5..05224a695872 100644
--- a/arch/x86/include/asm/proto.h
+++ b/arch/x86/include/asm/proto.h
@@ -15,7 +15,6 @@ void entry_SYSCALL_64(void);
void entry_SYSCALL_64_safe_stack(void);
void entry_SYSRETQ_unsafe_stack(void);
void entry_SYSRETQ_end(void);
-long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2);
#endif
#ifdef CONFIG_X86_32
@@ -41,6 +40,6 @@ void x86_configure_nx(void);
extern int reboot_force;
-long do_arch_prctl_common(int option, unsigned long arg2);
+long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2);
#endif /* _ASM_X86_PROTO_H */
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 6da6769d7254..0f398a42c1e2 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -1043,7 +1043,7 @@ unsigned long __get_wchan(struct task_struct *p)
return addr;
}
-long do_arch_prctl_common(int option, unsigned long arg2)
+SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
{
switch (option) {
case ARCH_GET_CPUID:
@@ -1058,5 +1058,8 @@ long do_arch_prctl_common(int option, unsigned long arg2)
return fpu_xstate_prctl(option, arg2);
}
+ if (!in_ia32_syscall())
+ return do_arch_prctl_64(current, option, arg2);
+
return -EINVAL;
}
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 0917c7f25720..2bdab416298c 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -215,8 +215,3 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
return prev_p;
}
-
-SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
-{
- return do_arch_prctl_common(option, arg2);
-}
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 226472332a70..e067c61b5fca 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -980,24 +980,6 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2)
return ret;
}
-SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
-{
- long ret;
-
- ret = do_arch_prctl_64(current, option, arg2);
- if (ret == -EINVAL)
- ret = do_arch_prctl_common(option, arg2);
-
- return ret;
-}
-
-#ifdef CONFIG_IA32_EMULATION
-COMPAT_SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
-{
- return do_arch_prctl_common(option, arg2);
-}
-#endif
-
unsigned long KSTK_ESP(struct task_struct *task)
{
return task_pt_regs(task)->sp;
--
2.49.0