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/cputopo.h | 78 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 tools/perf/util/cputopo.h (limited to 'tools/perf/util/cputopo.h') diff --git a/tools/perf/util/cputopo.h b/tools/perf/util/cputopo.h new file mode 100644 index 000000000..8d42f6102 --- /dev/null +++ b/tools/perf/util/cputopo.h @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_CPUTOPO_H +#define __PERF_CPUTOPO_H + +#include + +struct cpu_topology { + /* The number of unique package_cpus_lists below. */ + u32 package_cpus_lists; + /* The number of unique die_cpu_lists below. */ + u32 die_cpus_lists; + /* The number of unique core_cpu_lists below. */ + u32 core_cpus_lists; + /* + * An array of strings where each string is unique and read from + * /sys/devices/system/cpu/cpuX/topology/package_cpus_list. From the ABI + * each of these is a human-readable list of CPUs sharing the same + * physical_package_id. The format is like 0-3, 8-11, 14,17. + */ + const char **package_cpus_list; + /* + * An array of string where each string is unique and from + * /sys/devices/system/cpu/cpuX/topology/die_cpus_list. From the ABI + * each of these is a human-readable list of CPUs within the same die. + * The format is like 0-3, 8-11, 14,17. + */ + const char **die_cpus_list; + /* + * An array of string where each string is unique and from + * /sys/devices/system/cpu/cpuX/topology/core_cpus_list. From the ABI + * each of these is a human-readable list of CPUs within the same + * core. The format is like 0-3, 8-11, 14,17. + */ + const char **core_cpus_list; +}; + +struct numa_topology_node { + char *cpus; + u32 node; + u64 mem_total; + u64 mem_free; +}; + +struct numa_topology { + u32 nr; + struct numa_topology_node nodes[]; +}; + +struct hybrid_topology_node { + char *pmu_name; + char *cpus; +}; + +struct hybrid_topology { + u32 nr; + struct hybrid_topology_node nodes[]; +}; + +/* + * The topology for online CPUs, lazily created. + */ +const struct cpu_topology *online_topology(void); + +struct cpu_topology *cpu_topology__new(void); +void cpu_topology__delete(struct cpu_topology *tp); +/* Determine from the core list whether SMT was enabled. */ +bool cpu_topology__smt_on(const struct cpu_topology *topology); +/* Are the sets of SMT siblings all enabled or all disabled in user_requested_cpus. */ +bool cpu_topology__core_wide(const struct cpu_topology *topology, + const char *user_requested_cpu_list); + +struct numa_topology *numa_topology__new(void); +void numa_topology__delete(struct numa_topology *tp); + +struct hybrid_topology *hybrid_topology__new(void); +void hybrid_topology__delete(struct hybrid_topology *tp); + +#endif /* __PERF_CPUTOPO_H */ -- cgit v1.3.1