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>

22 files changed, 292 insertions, 0 deletions

diff --git a/scripts/atomic/kerneldoc/add b/scripts/atomic/kerneldoc/add
new file mode 100644
index 000000000..991f3dafc
--- /dev/null
+++ b/scripts/atomic/kerneldoc/add
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic add with ${desc_order} ordering
+ * @i: ${int} value to add
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v + @i) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/add_negative b/scripts/atomic/kerneldoc/add_negative
new file mode 100644
index 000000000..f4ca1f05d
--- /dev/null
+++ b/scripts/atomic/kerneldoc/add_negative
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic add and test if negative with ${desc_order} ordering
+ * @i: ${int} value to add
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v + @i) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: @true if the resulting value of @v is negative, @false otherwise.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/add_unless b/scripts/atomic/kerneldoc/add_unless
new file mode 100644
index 000000000..fbc2fadfb
--- /dev/null
+++ b/scripts/atomic/kerneldoc/add_unless
@@ -0,0 +1,19 @@
+if [ -z "${pfx}" ]; then
+	desc_return="Return: @true if @v was updated, @false otherwise."
+fi
+
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic add unless value with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ * @a: ${int} value to add
+ * @u: ${int} value to compare with
+ *
+ * If (@v != @u), atomically updates @v to (@v + @a) with ${desc_order} ordering.
+ * Otherwise, @v is not modified and relaxed ordering is provided.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/and b/scripts/atomic/kerneldoc/and
new file mode 100644
index 000000000..a92357435
--- /dev/null
+++ b/scripts/atomic/kerneldoc/and
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic bitwise AND with ${desc_order} ordering
+ * @i: ${int} value
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v & @i) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/andnot b/scripts/atomic/kerneldoc/andnot
new file mode 100644
index 000000000..64bb509f8
--- /dev/null
+++ b/scripts/atomic/kerneldoc/andnot
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic bitwise AND NOT with ${desc_order} ordering
+ * @i: ${int} value
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v & ~@i) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/cmpxchg b/scripts/atomic/kerneldoc/cmpxchg
new file mode 100644
index 000000000..02b24ee9d
--- /dev/null
+++ b/scripts/atomic/kerneldoc/cmpxchg
@@ -0,0 +1,15 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic compare and exchange with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ * @old: ${int} value to compare with
+ * @new: ${int} value to assign
+ *
+ * If (@v == @old), atomically updates @v to @new with ${desc_order} ordering.
+ * Otherwise, @v is not modified and relaxed ordering is provided.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: The original value of @v.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/dec b/scripts/atomic/kerneldoc/dec
new file mode 100644
index 000000000..bbeecbc4c
--- /dev/null
+++ b/scripts/atomic/kerneldoc/dec
@@ -0,0 +1,12 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic decrement with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v - 1) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/dec_and_test b/scripts/atomic/kerneldoc/dec_and_test
new file mode 100644
index 000000000..71bbd23ce
--- /dev/null
+++ b/scripts/atomic/kerneldoc/dec_and_test
@@ -0,0 +1,12 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic decrement and test if zero with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v - 1) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: @true if the resulting value of @v is zero, @false otherwise.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/dec_if_positive b/scripts/atomic/kerneldoc/dec_if_positive
new file mode 100644
index 000000000..9468b4a69
--- /dev/null
+++ b/scripts/atomic/kerneldoc/dec_if_positive
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic decrement if positive with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * If (@v > 0), atomically updates @v to (@v - 1) with ${desc_order} ordering.
+ * Otherwise, @v is not modified and relaxed ordering is provided.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: The old value of (@v - 1), regardless of whether @v was updated.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/dec_unless_positive b/scripts/atomic/kerneldoc/dec_unless_positive
new file mode 100644
index 000000000..06a678678
--- /dev/null
+++ b/scripts/atomic/kerneldoc/dec_unless_positive
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic decrement unless positive with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * If (@v <= 0), atomically updates @v to (@v - 1) with ${desc_order} ordering.
+ * Otherwise, @v is not modified and relaxed ordering is provided.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: @true if @v was updated, @false otherwise.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/inc b/scripts/atomic/kerneldoc/inc
new file mode 100644
index 000000000..9f14f1b3d
--- /dev/null
+++ b/scripts/atomic/kerneldoc/inc
@@ -0,0 +1,12 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic increment with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v + 1) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/inc_and_test b/scripts/atomic/kerneldoc/inc_and_test
new file mode 100644
index 000000000..971694d59
--- /dev/null
+++ b/scripts/atomic/kerneldoc/inc_and_test
@@ -0,0 +1,12 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic increment and test if zero with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v + 1) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: @true if the resulting value of @v is zero, @false otherwise.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/inc_not_zero b/scripts/atomic/kerneldoc/inc_not_zero
new file mode 100644
index 000000000..c1a30fc66
--- /dev/null
+++ b/scripts/atomic/kerneldoc/inc_not_zero
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic increment unless zero with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * If (@v != 0), atomically updates @v to (@v + 1) with ${desc_order} ordering.
+ * Otherwise, @v is not modified and relaxed ordering is provided.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: @true if @v was updated, @false otherwise.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/inc_unless_negative b/scripts/atomic/kerneldoc/inc_unless_negative
new file mode 100644
index 000000000..ece0d2c7b
--- /dev/null
+++ b/scripts/atomic/kerneldoc/inc_unless_negative
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic increment unless negative with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * If (@v >= 0), atomically updates @v to (@v + 1) with ${desc_order} ordering.
+ * Otherwise, @v is not modified and relaxed ordering is provided.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: @true if @v was updated, @false otherwise.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/or b/scripts/atomic/kerneldoc/or
new file mode 100644
index 000000000..55b33de50
--- /dev/null
+++ b/scripts/atomic/kerneldoc/or
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic bitwise OR with ${desc_order} ordering
+ * @i: ${int} value
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v | @i) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/read b/scripts/atomic/kerneldoc/read
new file mode 100644
index 000000000..89fe6147c
--- /dev/null
+++ b/scripts/atomic/kerneldoc/read
@@ -0,0 +1,12 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic load with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically loads the value of @v with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: The value loaded from @v.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/set b/scripts/atomic/kerneldoc/set
new file mode 100644
index 000000000..e82cb9ebb
--- /dev/null
+++ b/scripts/atomic/kerneldoc/set
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic set with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ * @i: ${int} value to assign
+ *
+ * Atomically sets @v to @i with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: Nothing.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/sub b/scripts/atomic/kerneldoc/sub
new file mode 100644
index 000000000..3ba642d04
--- /dev/null
+++ b/scripts/atomic/kerneldoc/sub
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic subtract with ${desc_order} ordering
+ * @i: ${int} value to subtract
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v - @i) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/sub_and_test b/scripts/atomic/kerneldoc/sub_and_test
new file mode 100644
index 000000000..96615e508
--- /dev/null
+++ b/scripts/atomic/kerneldoc/sub_and_test
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic subtract and test if zero with ${desc_order} ordering
+ * @i: ${int} value to subtract
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v - @i) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: @true if the resulting value of @v is zero, @false otherwise.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/try_cmpxchg b/scripts/atomic/kerneldoc/try_cmpxchg
new file mode 100644
index 000000000..4dfc7a167
--- /dev/null
+++ b/scripts/atomic/kerneldoc/try_cmpxchg
@@ -0,0 +1,16 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic compare and exchange with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ * @old: pointer to ${int} value to compare with
+ * @new: ${int} value to assign
+ *
+ * If (@v == @old), atomically updates @v to @new with ${desc_order} ordering.
+ * Otherwise, @v is not modified, @old is updated to the current value of @v,
+ * and relaxed ordering is provided.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: @true if the exchange occurred, @false otherwise.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/xchg b/scripts/atomic/kerneldoc/xchg
new file mode 100644
index 000000000..75f04c085
--- /dev/null
+++ b/scripts/atomic/kerneldoc/xchg
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic exchange with ${desc_order} ordering
+ * @v: pointer to ${atomic}_t
+ * @new: ${int} value to assign
+ *
+ * Atomically updates @v to @new with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * Return: The original value of @v.
+ */
+EOF
diff --git a/scripts/atomic/kerneldoc/xor b/scripts/atomic/kerneldoc/xor
new file mode 100644
index 000000000..8837270f2
--- /dev/null
+++ b/scripts/atomic/kerneldoc/xor
@@ -0,0 +1,13 @@
+cat <<EOF
+/**
+ * ${class}${atomicname}() - atomic bitwise XOR with ${desc_order} ordering
+ * @i: ${int} value
+ * @v: pointer to ${atomic}_t
+ *
+ * Atomically updates @v to (@v ^ @i) with ${desc_order} ordering.
+ *
+ * ${desc_noinstr}
+ *
+ * ${desc_return}
+ */
+EOF