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, 177 insertions, 0 deletions

diff --git a/arch/arm/mach-mvebu/system-controller.c b/arch/arm/mach-mvebu/system-controller.c
new file mode 100644
index 000000000..48224b6ed
--- /dev/null
+++ b/arch/arm/mach-mvebu/system-controller.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * System controller support for Armada 370, 375 and XP platforms.
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Lior Amsalem <alior@marvell.com>
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * The Armada 370, 375 and Armada XP SoCs have a range of
+ * miscellaneous registers, that do not belong to a particular device,
+ * but rather provide system-level features. This basic
+ * system-controller driver provides a device tree binding for those
+ * registers, and implements utility functions offering various
+ * features related to those registers.
+ *
+ * For now, the feature set is limited to restarting the platform by a
+ * soft-reset, but it might be extended in the future.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+#include <linux/reboot.h>
+#include "common.h"
+#include "mvebu-soc-id.h"
+#include "pmsu.h"
+
+#define ARMADA_375_CRYPT0_ENG_TARGET 41
+#define ARMADA_375_CRYPT0_ENG_ATTR    1
+
+static void __iomem *system_controller_base;
+static phys_addr_t system_controller_phys_base;
+
+struct mvebu_system_controller {
+	u32 rstoutn_mask_offset;
+	u32 system_soft_reset_offset;
+
+	u32 rstoutn_mask_reset_out_en;
+	u32 system_soft_reset;
+
+	u32 resume_boot_addr;
+
+	u32 dev_id;
+	u32 rev_id;
+};
+static struct mvebu_system_controller *mvebu_sc;
+
+static const struct mvebu_system_controller armada_370_xp_system_controller = {
+	.rstoutn_mask_offset = 0x60,
+	.system_soft_reset_offset = 0x64,
+	.rstoutn_mask_reset_out_en = 0x1,
+	.system_soft_reset = 0x1,
+	.dev_id = 0x38,
+	.rev_id = 0x3c,
+};
+
+static const struct mvebu_system_controller armada_375_system_controller = {
+	.rstoutn_mask_offset = 0x54,
+	.system_soft_reset_offset = 0x58,
+	.rstoutn_mask_reset_out_en = 0x1,
+	.system_soft_reset = 0x1,
+	.resume_boot_addr = 0xd4,
+	.dev_id = 0x38,
+	.rev_id = 0x3c,
+};
+
+static const struct mvebu_system_controller orion_system_controller = {
+	.rstoutn_mask_offset = 0x108,
+	.system_soft_reset_offset = 0x10c,
+	.rstoutn_mask_reset_out_en = 0x4,
+	.system_soft_reset = 0x1,
+};
+
+static const struct of_device_id of_system_controller_table[] = {
+	{
+		.compatible = "marvell,orion-system-controller",
+		.data = (void *) &orion_system_controller,
+	}, {
+		.compatible = "marvell,armada-370-xp-system-controller",
+		.data = (void *) &armada_370_xp_system_controller,
+	}, {
+		.compatible = "marvell,armada-375-system-controller",
+		.data = (void *) &armada_375_system_controller,
+	},
+	{ /* end of list */ },
+};
+
+void mvebu_restart(enum reboot_mode mode, const char *cmd)
+{
+	if (!system_controller_base) {
+		pr_err("Cannot restart, system-controller not available: check the device tree\n");
+	} else {
+		/*
+		 * Enable soft reset to assert RSTOUTn.
+		 */
+		writel(mvebu_sc->rstoutn_mask_reset_out_en,
+			system_controller_base +
+			mvebu_sc->rstoutn_mask_offset);
+		/*
+		 * Assert soft reset.
+		 */
+		writel(mvebu_sc->system_soft_reset,
+			system_controller_base +
+			mvebu_sc->system_soft_reset_offset);
+	}
+
+	while (1)
+		;
+}
+
+int mvebu_system_controller_get_soc_id(u32 *dev, u32 *rev)
+{
+	if (of_machine_is_compatible("marvell,armada380") &&
+		system_controller_base) {
+		*dev = readl(system_controller_base + mvebu_sc->dev_id) >> 16;
+		*rev = (readl(system_controller_base + mvebu_sc->rev_id) >> 8)
+			& 0xF;
+		return 0;
+	} else
+		return -ENODEV;
+}
+
+#if defined(CONFIG_SMP) && defined(CONFIG_MACH_MVEBU_V7)
+static void mvebu_armada375_smp_wa_init(void)
+{
+	u32 dev, rev;
+	phys_addr_t resume_addr_reg;
+
+	if (mvebu_get_soc_id(&dev, &rev) != 0)
+		return;
+
+	if (rev != ARMADA_375_Z1_REV)
+		return;
+
+	resume_addr_reg = system_controller_phys_base +
+		mvebu_sc->resume_boot_addr;
+	mvebu_setup_boot_addr_wa(ARMADA_375_CRYPT0_ENG_TARGET,
+				 ARMADA_375_CRYPT0_ENG_ATTR,
+				 resume_addr_reg);
+}
+
+void mvebu_system_controller_set_cpu_boot_addr(void *boot_addr)
+{
+	BUG_ON(system_controller_base == NULL);
+	BUG_ON(mvebu_sc->resume_boot_addr == 0);
+
+	if (of_machine_is_compatible("marvell,armada375"))
+		mvebu_armada375_smp_wa_init();
+
+	writel(__pa_symbol(boot_addr), system_controller_base +
+	       mvebu_sc->resume_boot_addr);
+}
+#endif
+
+static int __init mvebu_system_controller_init(void)
+{
+	const struct of_device_id *match;
+	struct device_node *np;
+
+	np = of_find_matching_node_and_match(NULL, of_system_controller_table,
+					     &match);
+	if (np) {
+		struct resource res;
+		system_controller_base = of_iomap(np, 0);
+		of_address_to_resource(np, 0, &res);
+		system_controller_phys_base = res.start;
+		mvebu_sc = (struct mvebu_system_controller *)match->data;
+		of_node_put(np);
+	}
+
+	return 0;
+}
+
+early_initcall(mvebu_system_controller_init);