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, 59 insertions, 0 deletions

diff --git a/rust/helpers/pci.c b/rust/helpers/pci.c
new file mode 100644
index 000000000..a714cc2bf
--- /dev/null
+++ b/rust/helpers/pci.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/pci.h>
+
+__rust_helper u16 rust_helper_pci_dev_id(struct pci_dev *dev)
+{
+	return PCI_DEVID(dev->bus->number, dev->devfn);
+}
+
+__rust_helper resource_size_t
+rust_helper_pci_resource_start(struct pci_dev *pdev, int bar)
+{
+	return pci_resource_start(pdev, bar);
+}
+
+__rust_helper resource_size_t rust_helper_pci_resource_len(struct pci_dev *pdev,
+							   int bar)
+{
+	return pci_resource_len(pdev, bar);
+}
+
+__rust_helper bool rust_helper_dev_is_pci(const struct device *dev)
+{
+	return dev_is_pci(dev);
+}
+
+__rust_helper unsigned int rust_helper_pci_irq_type(struct pci_dev *pdev)
+{
+	return pci_irq_type(pdev);
+}
+
+#ifndef CONFIG_PCI_IOV
+__rust_helper unsigned int
+rust_helper_pci_sriov_get_totalvfs(struct pci_dev *pdev)
+{
+	return pci_sriov_get_totalvfs(pdev);
+}
+#endif
+
+#ifndef CONFIG_PCI_MSI
+__rust_helper int rust_helper_pci_alloc_irq_vectors(struct pci_dev *dev,
+						    unsigned int min_vecs,
+						    unsigned int max_vecs,
+						    unsigned int flags)
+{
+	return pci_alloc_irq_vectors(dev, min_vecs, max_vecs, flags);
+}
+
+__rust_helper void rust_helper_pci_free_irq_vectors(struct pci_dev *dev)
+{
+	pci_free_irq_vectors(dev);
+}
+
+__rust_helper int rust_helper_pci_irq_vector(struct pci_dev *pdev,
+					     unsigned int nvec)
+{
+	return pci_irq_vector(pdev, nvec);
+}
+#endif