From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- arch/arm/lib/memcpy.S | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 arch/arm/lib/memcpy.S (limited to 'arch/arm/lib/memcpy.S') diff --git a/arch/arm/lib/memcpy.S b/arch/arm/lib/memcpy.S new file mode 100644 index 000000000..90f2b645a --- /dev/null +++ b/arch/arm/lib/memcpy.S @@ -0,0 +1,66 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/memcpy.S + * + * Author: Nicolas Pitre + * Created: Sep 28, 2005 + * Copyright: MontaVista Software, Inc. + */ + +#include +#include +#include + +#define LDR1W_SHIFT 0 +#define STR1W_SHIFT 0 + + .macro ldr1w ptr reg abort + W(ldr) \reg, [\ptr], #4 + .endm + + .macro ldr4w ptr reg1 reg2 reg3 reg4 abort + ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4} + .endm + + .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort + ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8} + .endm + + .macro ldr1b ptr reg cond=al abort + ldrb\cond \reg, [\ptr], #1 + .endm + + .macro str1w ptr reg abort + W(str) \reg, [\ptr], #4 + .endm + + .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort + stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8} + .endm + + .macro str1b ptr reg cond=al abort + strb\cond \reg, [\ptr], #1 + .endm + + .macro enter regs:vararg +UNWIND( .save {r0, \regs} ) + stmdb sp!, {r0, \regs} + .endm + + .macro exit regs:vararg + ldmfd sp!, {r0, \regs} + .endm + + .text + +/* Prototype: void *memcpy(void *dest, const void *src, size_t n); */ + +ENTRY(__memcpy) +ENTRY(mmiocpy) +WEAK(memcpy) + +#include "copy_template.S" + +ENDPROC(memcpy) +ENDPROC(mmiocpy) +ENDPROC(__memcpy) -- cgit v1.3.1