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/microblaze/lib/memset.c | 94 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 arch/microblaze/lib/memset.c (limited to 'arch/microblaze/lib/memset.c') diff --git a/arch/microblaze/lib/memset.c b/arch/microblaze/lib/memset.c new file mode 100644 index 000000000..7c2352d56 --- /dev/null +++ b/arch/microblaze/lib/memset.c @@ -0,0 +1,94 @@ +/* + * Copyright (C) 2008-2009 Michal Simek + * Copyright (C) 2008-2009 PetaLogix + * Copyright (C) 2007 John Williams + * + * Reasonably optimised generic C-code for memset on Microblaze + * This is generic C code to do efficient, alignment-aware memcpy. + * + * It is based on demo code originally Copyright 2001 by Intel Corp, taken from + * http://www.embedded.com/showArticle.jhtml?articleID=19205567 + * + * Attempts were made, unsuccessfully, to contact the original + * author of this code (Michael Morrow, Intel). Below is the original + * copyright notice. + * + * This software has been developed by Intel Corporation. + * Intel specifically disclaims all warranties, express or + * implied, and all liability, including consequential and + * other indirect damages, for the use of this program, including + * liability for infringement of any proprietary rights, + * and including the warranties of merchantability and fitness + * for a particular purpose. Intel does not assume any + * responsibility for and errors which may appear in this program + * not any responsibility to update it. + */ + +#include +#include +#include +#include +#include + +#ifdef CONFIG_OPT_LIB_FUNCTION +void *memset(void *v_src, int c, __kernel_size_t n) +{ + char *src = v_src; + uint32_t *i_src; + uint32_t w32 = 0; + + /* Truncate c to 8 bits */ + c = (c & 0xFF); + + if (unlikely(c)) { + /* Make a repeating word out of it */ + w32 = c; + w32 |= w32 << 8; + w32 |= w32 << 16; + } + + if (likely(n >= 4)) { + /* Align the destination to a word boundary */ + /* This is done in an endian independent manner */ + switch ((unsigned) src & 3) { + case 1: + *src++ = c; + --n; + fallthrough; + case 2: + *src++ = c; + --n; + fallthrough; + case 3: + *src++ = c; + --n; + } + + i_src = (void *)src; + + /* Do as many full-word copies as we can */ + for (; n >= 4; n -= 4) + *i_src++ = w32; + + src = (void *)i_src; + } + + /* Simple, byte oriented memset or the rest of count. */ + switch (n) { + case 3: + *src++ = c; + fallthrough; + case 2: + *src++ = c; + fallthrough; + case 1: + *src++ = c; + break; + default: + break; + } + + return v_src; +} +EXPORT_SYMBOL(memset); +#endif /* CONFIG_OPT_LIB_FUNCTION */ -- cgit v1.3.1