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, 141 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/hsti.c b/drivers/crypto/ccp/hsti.c
new file mode 100644
index 000000000..df09e0322
--- /dev/null
+++ b/drivers/crypto/ccp/hsti.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Secure Processor device driver, security attributes
+ *
+ * Copyright (C) 2023-2024 Advanced Micro Devices, Inc.
+ *
+ * Author: Mario Limonciello <mario.limonciello@amd.com>
+ */
+
+#include <linux/device.h>
+
+#include "psp-dev.h"
+#include "hsti.h"
+
+#define PSP_CAPABILITY_PSP_SECURITY_OFFSET	8
+
+struct hsti_request {
+	struct psp_req_buffer_hdr header;
+	u32 hsti;
+} __packed;
+
+#define security_attribute_show(name)						\
+static ssize_t name##_show(struct device *d, struct device_attribute *attr,	\
+			   char *buf)						\
+{										\
+	struct sp_device *sp = dev_get_drvdata(d);				\
+	struct psp_device *psp = sp->psp_data;					\
+	return sysfs_emit(buf, "%d\n", psp->capability.name);		\
+}
+
+security_attribute_show(fused_part)
+static DEVICE_ATTR_RO(fused_part);
+security_attribute_show(boot_integrity)
+static DEVICE_ATTR_RO(boot_integrity);
+security_attribute_show(debug_lock_on)
+static DEVICE_ATTR_RO(debug_lock_on);
+security_attribute_show(tsme_status)
+static DEVICE_ATTR_RO(tsme_status);
+security_attribute_show(anti_rollback_status)
+static DEVICE_ATTR_RO(anti_rollback_status);
+security_attribute_show(rpmc_production_enabled)
+static DEVICE_ATTR_RO(rpmc_production_enabled);
+security_attribute_show(rpmc_spirom_available)
+static DEVICE_ATTR_RO(rpmc_spirom_available);
+security_attribute_show(hsp_tpm_available)
+static DEVICE_ATTR_RO(hsp_tpm_available);
+security_attribute_show(rom_armor_enforced)
+static DEVICE_ATTR_RO(rom_armor_enforced);
+
+static struct attribute *psp_security_attrs[] = {
+	&dev_attr_fused_part.attr,
+	&dev_attr_boot_integrity.attr,
+	&dev_attr_debug_lock_on.attr,
+	&dev_attr_tsme_status.attr,
+	&dev_attr_anti_rollback_status.attr,
+	&dev_attr_rpmc_production_enabled.attr,
+	&dev_attr_rpmc_spirom_available.attr,
+	&dev_attr_hsp_tpm_available.attr,
+	&dev_attr_rom_armor_enforced.attr,
+	NULL
+};
+
+static umode_t psp_security_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct sp_device *sp = dev_get_drvdata(dev);
+	struct psp_device *psp = sp->psp_data;
+
+	if (psp && psp->capability.security_reporting)
+		return 0444;
+
+	return 0;
+}
+
+struct attribute_group psp_security_attr_group = {
+	.attrs = psp_security_attrs,
+	.is_visible = psp_security_is_visible,
+};
+
+static int psp_populate_hsti(struct psp_device *psp)
+{
+	struct hsti_request *req;
+	int ret;
+
+	/* Are the security attributes already reported? */
+	if (psp->capability.security_reporting)
+		return 0;
+
+	/* Allocate command-response buffer */
+	req = kzalloc_obj(*req);
+	if (!req)
+		return -ENOMEM;
+
+	req->header.payload_size = sizeof(*req);
+
+	ret = psp_send_platform_access_msg(PSP_CMD_HSTI_QUERY, (struct psp_request *)req);
+	if (ret)
+		goto out;
+
+	if (req->header.status != 0) {
+		dev_dbg(psp->dev, "failed to populate HSTI state: %d\n", req->header.status);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	psp->capability.security_reporting = 1;
+	psp->capability.raw |= req->hsti << PSP_CAPABILITY_PSP_SECURITY_OFFSET;
+
+out:
+	kfree(req);
+
+	return ret;
+}
+
+int psp_init_hsti(struct psp_device *psp)
+{
+	int ret;
+
+	if (PSP_FEATURE(psp, HSTI)) {
+		ret = psp_populate_hsti(psp);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * At this stage, if security information hasn't been populated by
+	 * either the PSP or by the driver through the platform command,
+	 * then there is nothing more to do.
+	 */
+	if (!psp->capability.security_reporting)
+		return 0;
+
+	if (psp->capability.tsme_status) {
+		if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
+			dev_notice(psp->dev, "psp: Both TSME and SME are active, SME is unnecessary when TSME is active.\n");
+		else
+			dev_notice(psp->dev, "psp: TSME enabled\n");
+	}
+
+	return 0;
+}