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, 215 insertions, 0 deletions

diff --git a/drivers/bcma/bcma_private.h b/drivers/bcma/bcma_private.h
new file mode 100644
index 000000000..6eded32d1
--- /dev/null
+++ b/drivers/bcma/bcma_private.h
@@ -0,0 +1,215 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LINUX_BCMA_PRIVATE_H_
+#define LINUX_BCMA_PRIVATE_H_
+
+#ifndef pr_fmt
+#define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt
+#endif
+
+#include <linux/bcma/bcma.h>
+#include <linux/delay.h>
+
+#define bcma_err(bus, fmt, ...) \
+	dev_err((bus)->dev, "bus%d: " fmt, (bus)->num, ##__VA_ARGS__)
+#define bcma_warn(bus, fmt, ...) \
+	dev_warn((bus)->dev, "bus%d: " fmt, (bus)->num, ##__VA_ARGS__)
+#define bcma_info(bus, fmt, ...) \
+	dev_info((bus)->dev, "bus%d: " fmt, (bus)->num, ##__VA_ARGS__)
+#define bcma_debug(bus, fmt, ...) \
+	dev_dbg((bus)->dev, "bus%d: " fmt, (bus)->num, ##__VA_ARGS__)
+
+struct bcma_bus;
+
+/* main.c */
+bool bcma_wait_value(struct bcma_device *core, u16 reg, u32 mask, u32 value,
+		     int timeout);
+void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core);
+void bcma_init_bus(struct bcma_bus *bus);
+void bcma_unregister_cores(struct bcma_bus *bus);
+int bcma_bus_register(struct bcma_bus *bus);
+void bcma_bus_unregister(struct bcma_bus *bus);
+int __init bcma_bus_early_register(struct bcma_bus *bus);
+#ifdef CONFIG_PM
+int bcma_bus_suspend(struct bcma_bus *bus);
+int bcma_bus_resume(struct bcma_bus *bus);
+#endif
+
+/* scan.c */
+void bcma_detect_chip(struct bcma_bus *bus);
+int bcma_bus_scan(struct bcma_bus *bus);
+
+/* sprom.c */
+int bcma_sprom_get(struct bcma_bus *bus);
+
+/* driver_chipcommon.c */
+void bcma_core_chipcommon_early_init(struct bcma_drv_cc *cc);
+void bcma_core_chipcommon_init(struct bcma_drv_cc *cc);
+void bcma_chipco_bcm4331_ext_pa_lines_ctl(struct bcma_drv_cc *cc, bool enable);
+#ifdef CONFIG_BCMA_DRIVER_MIPS
+void bcma_chipco_serial_init(struct bcma_drv_cc *cc);
+#endif /* CONFIG_BCMA_DRIVER_MIPS */
+
+/* driver_chipcommon_b.c */
+int bcma_core_chipcommon_b_init(struct bcma_drv_cc_b *ccb);
+void bcma_core_chipcommon_b_free(struct bcma_drv_cc_b *ccb);
+
+/* driver_chipcommon_pmu.c */
+void bcma_pmu_early_init(struct bcma_drv_cc *cc);
+void bcma_pmu_init(struct bcma_drv_cc *cc);
+u32 bcma_pmu_get_alp_clock(struct bcma_drv_cc *cc);
+u32 bcma_pmu_get_cpu_clock(struct bcma_drv_cc *cc);
+
+/**************************************************
+ * driver_chipcommon_sflash.c
+ **************************************************/
+
+#ifdef CONFIG_BCMA_PFLASH
+extern struct platform_device bcma_pflash_dev;
+int bcma_pflash_init(struct bcma_drv_cc *cc);
+#else
+static inline int bcma_pflash_init(struct bcma_drv_cc *cc)
+{
+	bcma_err(cc->core->bus, "Parallel flash not supported\n");
+	return 0;
+}
+#endif /* CONFIG_BCMA_PFLASH */
+
+#ifdef CONFIG_BCMA_SFLASH
+/* driver_chipcommon_sflash.c */
+int bcma_sflash_init(struct bcma_drv_cc *cc);
+extern struct platform_device bcma_sflash_dev;
+#else
+static inline int bcma_sflash_init(struct bcma_drv_cc *cc)
+{
+	bcma_err(cc->core->bus, "Serial flash not supported\n");
+	return 0;
+}
+#endif /* CONFIG_BCMA_SFLASH */
+
+#ifdef CONFIG_BCMA_NFLASH
+/* driver_chipcommon_nflash.c */
+int bcma_nflash_init(struct bcma_drv_cc *cc);
+extern struct platform_device bcma_nflash_dev;
+#else
+static inline int bcma_nflash_init(struct bcma_drv_cc *cc)
+{
+	bcma_err(cc->core->bus, "NAND flash not supported\n");
+	return 0;
+}
+#endif /* CONFIG_BCMA_NFLASH */
+
+#ifdef CONFIG_BCMA_HOST_PCI
+/* host_pci.c */
+extern int __init bcma_host_pci_init(void);
+extern void __exit bcma_host_pci_exit(void);
+#endif /* CONFIG_BCMA_HOST_PCI */
+
+/* host_soc.c */
+#if defined(CONFIG_BCMA_HOST_SOC) && defined(CONFIG_OF)
+extern int __init bcma_host_soc_register_driver(void);
+extern void __exit bcma_host_soc_unregister_driver(void);
+#else
+static inline int __init bcma_host_soc_register_driver(void)
+{
+	return 0;
+}
+static inline void __exit bcma_host_soc_unregister_driver(void)
+{
+}
+#endif /* CONFIG_BCMA_HOST_SOC && CONFIG_OF */
+
+/* driver_pci.c */
+#ifdef CONFIG_BCMA_DRIVER_PCI
+u32 bcma_pcie_read(struct bcma_drv_pci *pc, u32 address);
+void bcma_core_pci_early_init(struct bcma_drv_pci *pc);
+void bcma_core_pci_init(struct bcma_drv_pci *pc);
+void bcma_core_pci_up(struct bcma_drv_pci *pc);
+void bcma_core_pci_down(struct bcma_drv_pci *pc);
+#else
+static inline void bcma_core_pci_early_init(struct bcma_drv_pci *pc)
+{
+	WARN_ON(pc->core->bus->hosttype == BCMA_HOSTTYPE_PCI);
+}
+static inline void bcma_core_pci_init(struct bcma_drv_pci *pc)
+{
+	/* Initialization is required for PCI hosted bus */
+	WARN_ON(pc->core->bus->hosttype == BCMA_HOSTTYPE_PCI);
+}
+#endif
+
+/* driver_pcie2.c */
+#ifdef CONFIG_BCMA_DRIVER_PCI
+void bcma_core_pcie2_init(struct bcma_drv_pcie2 *pcie2);
+void bcma_core_pcie2_up(struct bcma_drv_pcie2 *pcie2);
+#else
+static inline void bcma_core_pcie2_init(struct bcma_drv_pcie2 *pcie2)
+{
+	/* Initialization is required for PCI hosted bus */
+	WARN_ON(pcie2->core->bus->hosttype == BCMA_HOSTTYPE_PCI);
+}
+#endif
+
+extern int bcma_chipco_watchdog_register(struct bcma_drv_cc *cc);
+
+#ifdef CONFIG_BCMA_DRIVER_PCI_HOSTMODE
+bool bcma_core_pci_is_in_hostmode(struct bcma_drv_pci *pc);
+void bcma_core_pci_hostmode_init(struct bcma_drv_pci *pc);
+#else
+static inline bool bcma_core_pci_is_in_hostmode(struct bcma_drv_pci *pc)
+{
+	return false;
+}
+static inline void bcma_core_pci_hostmode_init(struct bcma_drv_pci *pc)
+{
+}
+#endif /* CONFIG_BCMA_DRIVER_PCI_HOSTMODE */
+
+/**************************************************
+ * driver_mips.c
+ **************************************************/
+
+#ifdef CONFIG_BCMA_DRIVER_MIPS
+unsigned int bcma_core_mips_irq(struct bcma_device *dev);
+void bcma_core_mips_early_init(struct bcma_drv_mips *mcore);
+void bcma_core_mips_init(struct bcma_drv_mips *mcore);
+#else
+static inline unsigned int bcma_core_mips_irq(struct bcma_device *dev)
+{
+	return 0;
+}
+static inline void bcma_core_mips_early_init(struct bcma_drv_mips *mcore)
+{
+}
+static inline void bcma_core_mips_init(struct bcma_drv_mips *mcore)
+{
+}
+#endif
+
+/**************************************************
+ * driver_gmac_cmn.c
+ **************************************************/
+
+#ifdef CONFIG_BCMA_DRIVER_GMAC_CMN
+void bcma_core_gmac_cmn_init(struct bcma_drv_gmac_cmn *gc);
+#else
+static inline void bcma_core_gmac_cmn_init(struct bcma_drv_gmac_cmn *gc)
+{
+}
+#endif
+
+#ifdef CONFIG_BCMA_DRIVER_GPIO
+/* driver_gpio.c */
+int bcma_gpio_init(struct bcma_drv_cc *cc);
+int bcma_gpio_unregister(struct bcma_drv_cc *cc);
+#else
+static inline int bcma_gpio_init(struct bcma_drv_cc *cc)
+{
+	return -ENOTSUPP;
+}
+static inline int bcma_gpio_unregister(struct bcma_drv_cc *cc)
+{
+	return 0;
+}
+#endif /* CONFIG_BCMA_DRIVER_GPIO */
+
+#endif