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 --- tools/perf/util/block-range.h | 76 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 tools/perf/util/block-range.h (limited to 'tools/perf/util/block-range.h') diff --git a/tools/perf/util/block-range.h b/tools/perf/util/block-range.h new file mode 100644 index 000000000..ec0fb534b --- /dev/null +++ b/tools/perf/util/block-range.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_BLOCK_RANGE_H +#define __PERF_BLOCK_RANGE_H + +#include +#include +#include + +struct symbol; + +/* + * struct block_range - non-overlapping parts of basic blocks + * @node: treenode + * @start: inclusive start of range + * @end: inclusive end of range + * @is_target: @start is a jump target + * @is_branch: @end is a branch instruction + * @coverage: number of blocks that cover this range + * @taken: number of times the branch is taken (requires @is_branch) + * @pred: number of times the taken branch was predicted + */ +struct block_range { + struct rb_node node; + + struct symbol *sym; + + u64 start; + u64 end; + + int is_target, is_branch; + + u64 coverage; + u64 entry; + u64 taken; + u64 pred; +}; + +static inline struct block_range *block_range__next(struct block_range *br) +{ + struct rb_node *n = rb_next(&br->node); + if (!n) + return NULL; + return rb_entry(n, struct block_range, node); +} + +struct block_range_iter { + struct block_range *start; + struct block_range *end; +}; + +static inline struct block_range *block_range_iter(struct block_range_iter *iter) +{ + return iter->start; +} + +static inline bool block_range_iter__next(struct block_range_iter *iter) +{ + if (iter->start == iter->end) + return false; + + iter->start = block_range__next(iter->start); + return true; +} + +static inline bool block_range_iter__valid(struct block_range_iter *iter) +{ + if (!iter->start || !iter->end) + return false; + return true; +} + +extern struct block_range *block_range__find(u64 addr); +extern struct block_range_iter block_range__create(u64 start, u64 end); +extern double block_range__coverage(struct block_range *br); + +#endif /* __PERF_BLOCK_RANGE_H */ -- cgit v1.3.1