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authorSteven Rostedt <rostedt@goodmis.org>2026-09-02 09:55:01 -0400
committerSteven Rostedt <rostedt@goodmis.org>2026-09-02 11:08:21 -0400
commit4617721c502b2ddaa4e324e86da4997edf738fa5 (patch)
tree350aa83b47da0b574a814795392b20b0bed83cbc /Documentation/features/locking
downloadlinux-stable-4617721c502b2ddaa4e324e86da4997edf738fa5.tar.gz
linux-stable-4617721c502b2ddaa4e324e86da4997edf738fa5.zip
ftrace: Synchronize the initialization of ftrace_opsgrafted
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 <rostedt@goodmis.org>
Diffstat (limited to 'Documentation/features/locking')
-rw-r--r--Documentation/features/locking/cmpxchg-local/arch-support.txt30
-rw-r--r--Documentation/features/locking/lockdep/arch-support.txt30
-rw-r--r--Documentation/features/locking/queued-rwlocks/arch-support.txt30
-rw-r--r--Documentation/features/locking/queued-spinlocks/arch-support.txt30
4 files changed, 120 insertions, 0 deletions
diff --git a/Documentation/features/locking/cmpxchg-local/arch-support.txt b/Documentation/features/locking/cmpxchg-local/arch-support.txt
new file mode 100644
index 000000000..2c3a4b91f
--- /dev/null
+++ b/Documentation/features/locking/cmpxchg-local/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name: cmpxchg-local
+# Kconfig: HAVE_CMPXCHG_LOCAL
+# description: arch supports the this_cpu_cmpxchg() API
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | TODO |
+ | arm: | TODO |
+ | arm64: | ok |
+ | csky: | TODO |
+ | hexagon: | TODO |
+ | loongarch: | TODO |
+ | m68k: | TODO |
+ | microblaze: | TODO |
+ | mips: | TODO |
+ | nios2: | TODO |
+ | openrisc: | TODO |
+ | parisc: | TODO |
+ | powerpc: | TODO |
+ | riscv: | TODO |
+ | s390: | ok |
+ | sh: | TODO |
+ | sparc: | TODO |
+ | um: | TODO |
+ | x86: | ok |
+ | xtensa: | TODO |
+ -----------------------
diff --git a/Documentation/features/locking/lockdep/arch-support.txt b/Documentation/features/locking/lockdep/arch-support.txt
new file mode 100644
index 000000000..87a534c89
--- /dev/null
+++ b/Documentation/features/locking/lockdep/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name: lockdep
+# Kconfig: LOCKDEP_SUPPORT
+# description: arch supports the runtime locking correctness debug facility
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | ok |
+ | arc: | ok |
+ | arm: | ok |
+ | arm64: | ok |
+ | csky: | ok |
+ | hexagon: | ok |
+ | loongarch: | ok |
+ | m68k: | TODO |
+ | microblaze: | ok |
+ | mips: | ok |
+ | nios2: | TODO |
+ | openrisc: | ok |
+ | parisc: | ok |
+ | powerpc: | ok |
+ | riscv: | ok |
+ | s390: | ok |
+ | sh: | ok |
+ | sparc: | ok |
+ | um: | ok |
+ | x86: | ok |
+ | xtensa: | ok |
+ -----------------------
diff --git a/Documentation/features/locking/queued-rwlocks/arch-support.txt b/Documentation/features/locking/queued-rwlocks/arch-support.txt
new file mode 100644
index 000000000..b286a5fff
--- /dev/null
+++ b/Documentation/features/locking/queued-rwlocks/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name: queued-rwlocks
+# Kconfig: ARCH_USE_QUEUED_RWLOCKS
+# description: arch supports queued rwlocks
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | TODO |
+ | arm: | TODO |
+ | arm64: | ok |
+ | csky: | ok |
+ | hexagon: | TODO |
+ | loongarch: | ok |
+ | m68k: | TODO |
+ | microblaze: | TODO |
+ | mips: | ok |
+ | nios2: | TODO |
+ | openrisc: | ok |
+ | parisc: | TODO |
+ | powerpc: | ok |
+ | riscv: | ok |
+ | s390: | TODO |
+ | sh: | TODO |
+ | sparc: | ok |
+ | um: | TODO |
+ | x86: | ok |
+ | xtensa: | ok |
+ -----------------------
diff --git a/Documentation/features/locking/queued-spinlocks/arch-support.txt b/Documentation/features/locking/queued-spinlocks/arch-support.txt
new file mode 100644
index 000000000..cf2604248
--- /dev/null
+++ b/Documentation/features/locking/queued-spinlocks/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name: queued-spinlocks
+# Kconfig: ARCH_USE_QUEUED_SPINLOCKS
+# description: arch supports queued spinlocks
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | TODO |
+ | arm: | TODO |
+ | arm64: | ok |
+ | csky: | ok |
+ | hexagon: | TODO |
+ | loongarch: | ok |
+ | m68k: | TODO |
+ | microblaze: | TODO |
+ | mips: | ok |
+ | nios2: | TODO |
+ | openrisc: | ok |
+ | parisc: | TODO |
+ | powerpc: | ok |
+ | riscv: | ok |
+ | s390: | TODO |
+ | sh: | TODO |
+ | sparc: | ok |
+ | um: | TODO |
+ | x86: | ok |
+ | xtensa: | ok |
+ -----------------------