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>

1 files changed, 57 insertions, 0 deletions

diff --git a/fs/unicode/README.utf8data b/fs/unicode/README.utf8data
new file mode 100644
index 000000000..f75567e28
--- /dev/null
+++ b/fs/unicode/README.utf8data
@@ -0,0 +1,57 @@
+The utf8data.c file in this directory is generated from the Unicode
+Character Database for version 12.1.0 of the Unicode standard.
+
+The full set of files can be found here:
+
+  http://www.unicode.org/Public/12.1.0/ucd/
+
+Individual source links:
+
+  https://www.unicode.org/Public/12.1.0/ucd/CaseFolding.txt
+  https://www.unicode.org/Public/12.1.0/ucd/DerivedAge.txt
+  https://www.unicode.org/Public/12.1.0/ucd/extracted/DerivedCombiningClass.txt
+  https://www.unicode.org/Public/12.1.0/ucd/DerivedCoreProperties.txt
+  https://www.unicode.org/Public/12.1.0/ucd/NormalizationCorrections.txt
+  https://www.unicode.org/Public/12.1.0/ucd/NormalizationTest.txt
+  https://www.unicode.org/Public/12.1.0/ucd/UnicodeData.txt
+
+md5sums (verify by running "md5sum -c README.utf8data"):
+
+  900e76da1d822a160fd6b8c0b1d70094  CaseFolding.txt
+  131256380bff4fea8ad4a851616f2f10  DerivedAge.txt
+  e731a4089b30002144e107e3d6f8d1fa  DerivedCombiningClass.txt
+  a47c9fbd7ff92a9b261ba9831e68778a  DerivedCoreProperties.txt
+  fcab6dad15e440879d92f315978f93d3  NormalizationCorrections.txt
+  f9ff1c55a60decf436100f791b44aa98  NormalizationTest.txt
+  755f6af699f8c8d2d958da411f78f6c6  UnicodeData.txt
+
+sha1sums (verify by running "sha1sum -c README.utf8data"):
+
+  dc9245f6803c4ac99555c361f5052e0b13eb779b  CaseFolding.txt
+  3281104f237184cdb5d869e86eb8573678ada7da  DerivedAge.txt
+  2f5f995ccb96e0fa84b15151b35d5e2681535175  DerivedCombiningClass.txt
+  5b8698a3fcd5018e1987f296b02e2c17e696415e  DerivedCoreProperties.txt
+  cd83935fbc012345d8792d2c704f69497e753835  NormalizationCorrections.txt
+  ea419aae505b337b0d99a83fa83fe58ddff7c19f  NormalizationTest.txt
+  dc973c0fc93d6f09d9ab9f70d1c9f89c447f0526  UnicodeData.txt
+
+
+To update to the newer version of the Unicode standard, the latest
+released version of the UCD can be found here:
+
+  http://www.unicode.org/Public/UCD/latest/
+
+Then, build under fs/unicode/ with REGENERATE_UTF8DATA=1:
+
+	make REGENERATE_UTF8DATA=1 fs/unicode/
+
+After sanity checking the newly generated utf8data.c file (the
+version generated from the 12.1.0 UCD should be 4,109 lines long, and
+have a total size of 324k) and/or comparing it with the older version
+of utf8data.c_shipped, rename it to utf8data.c_shipped.
+
+If you are a kernel developer updating to a newer version of the
+Unicode Character Database, please update this README.utf8data file
+with the version of the UCD that was used, the md5sum and sha1sums of
+the *.txt files, before checking in the new versions of the utf8data.c
+and README.utf8data files.