linux-kernel - [tip: core/rseq] entry: Remove syscall_enter_from_user_mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <176224424930.2601451.4022403110713858266.tip-bot2@tip-bot2>
Date: Tue, 04 Nov 2025 08:17:29 -0000
From: "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Thomas Gleixner <tglx@...utronix.de>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>,
 Ingo Molnar <mingo@...nel.org>,
 Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: core/rseq] entry: Remove syscall_enter_from_user_mode_prepare()

The following commit has been merged into the core/rseq branch of tip:

Commit-ID:     54a5ab56242f96555999aaa41228f77b4a76e386
Gitweb:        https://git.kernel.org/tip/54a5ab56242f96555999aaa41228f77b4a76e386
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Mon, 27 Oct 2025 09:44:38 +01:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Tue, 04 Nov 2025 08:31:37 +01:00

entry: Remove syscall_enter_from_user_mode_prepare()

Open code the only user in the x86 syscall code and reduce the zoo of
functions.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
Link: https://patch.msgid.link/20251027084306.652839989@linutronix.de
---
 arch/x86/entry/syscall_32.c   |  3 ++-
 include/linux/entry-common.h  | 26 +++++---------------------
 kernel/entry/syscall-common.c |  8 --------
 3 files changed, 7 insertions(+), 30 deletions(-)

diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 2b15ea1..a67a644 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -274,9 +274,10 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs)
 	 * fetch EBP before invoking any of the syscall entry work
 	 * functions.
 	 */
-	syscall_enter_from_user_mode_prepare(regs);
+	enter_from_user_mode(regs);
 
 	instrumentation_begin();
+	local_irq_enable();
 	/* Fetch EBP from where the vDSO stashed it. */
 	if (IS_ENABLED(CONFIG_X86_64)) {
 		/*
diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
index c585221..75b194c 100644
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@ -45,23 +45,6 @@
 				 SYSCALL_WORK_SYSCALL_EXIT_TRAP	|	\
 				 ARCH_SYSCALL_WORK_EXIT)
 
-/**
- * syscall_enter_from_user_mode_prepare - Establish state and enable interrupts
- * @regs:	Pointer to currents pt_regs
- *
- * Invoked from architecture specific syscall entry code with interrupts
- * disabled. The calling code has to be non-instrumentable. When the
- * function returns all state is correct, interrupts are enabled and the
- * subsequent functions can be instrumented.
- *
- * This handles lockdep, RCU (context tracking) and tracing state, i.e.
- * the functionality provided by enter_from_user_mode().
- *
- * This is invoked when there is extra architecture specific functionality
- * to be done between establishing state and handling user mode entry work.
- */
-void syscall_enter_from_user_mode_prepare(struct pt_regs *regs);
-
 long syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long work);
 
 /**
@@ -71,8 +54,8 @@ long syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long work)
  * @syscall:	The syscall number
  *
  * Invoked from architecture specific syscall entry code with interrupts
- * enabled after invoking syscall_enter_from_user_mode_prepare() and extra
- * architecture specific work.
+ * enabled after invoking enter_from_user_mode(), enabling interrupts and
+ * extra architecture specific work.
  *
  * Returns: The original or a modified syscall number
  *
@@ -108,8 +91,9 @@ static __always_inline long syscall_enter_from_user_mode_work(struct pt_regs *re
  * function returns all state is correct, interrupts are enabled and the
  * subsequent functions can be instrumented.
  *
- * This is combination of syscall_enter_from_user_mode_prepare() and
- * syscall_enter_from_user_mode_work().
+ * This is the combination of enter_from_user_mode() and
+ * syscall_enter_from_user_mode_work() to be used when there is no
+ * architecture specific work to be done between the two.
  *
  * Returns: The original or a modified syscall number. See
  * syscall_enter_from_user_mode_work() for further explanation.
diff --git a/kernel/entry/syscall-common.c b/kernel/entry/syscall-common.c
index 66e6ba7..940a597 100644
--- a/kernel/entry/syscall-common.c
+++ b/kernel/entry/syscall-common.c
@@ -63,14 +63,6 @@ long syscall_trace_enter(struct pt_regs *regs, long syscall,
 	return ret ? : syscall;
 }
 
-noinstr void syscall_enter_from_user_mode_prepare(struct pt_regs *regs)
-{
-	enter_from_user_mode(regs);
-	instrumentation_begin();
-	local_irq_enable();
-	instrumentation_end();
-}
-
 /*
  * If SYSCALL_EMU is set, then the only reason to report is when
  * SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP).  This syscall