Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 361 insertions, 0 deletions

diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c
new file mode 100644
index 000000000..4ae0cfcd1
--- /dev/null
+++ b/fs/pstore/blk.c
@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implements pstore backend driver that write to block (or non-block) storage
+ * devices, using the pstore/zone API.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/string.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pstore_blk.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/init_syscalls.h>
+#include <linux/mount.h>
+
+static long kmsg_size = CONFIG_PSTORE_BLK_KMSG_SIZE;
+module_param(kmsg_size, long, 0400);
+MODULE_PARM_DESC(kmsg_size, "kmsg dump record size in kbytes");
+
+static int max_reason = CONFIG_PSTORE_BLK_MAX_REASON;
+module_param(max_reason, int, 0400);
+MODULE_PARM_DESC(max_reason,
+		 "maximum reason for kmsg dump (default 2: Oops and Panic)");
+
+#if IS_ENABLED(CONFIG_PSTORE_PMSG)
+static long pmsg_size = CONFIG_PSTORE_BLK_PMSG_SIZE;
+#else
+static long pmsg_size = -1;
+#endif
+module_param(pmsg_size, long, 0400);
+MODULE_PARM_DESC(pmsg_size, "pmsg size in kbytes");
+
+#if IS_ENABLED(CONFIG_PSTORE_CONSOLE)
+static long console_size = CONFIG_PSTORE_BLK_CONSOLE_SIZE;
+#else
+static long console_size = -1;
+#endif
+module_param(console_size, long, 0400);
+MODULE_PARM_DESC(console_size, "console size in kbytes");
+
+#if IS_ENABLED(CONFIG_PSTORE_FTRACE)
+static long ftrace_size = CONFIG_PSTORE_BLK_FTRACE_SIZE;
+#else
+static long ftrace_size = -1;
+#endif
+module_param(ftrace_size, long, 0400);
+MODULE_PARM_DESC(ftrace_size, "ftrace size in kbytes");
+
+static bool best_effort;
+module_param(best_effort, bool, 0400);
+MODULE_PARM_DESC(best_effort, "use best effort to write (i.e. do not require storage driver pstore support, default: off)");
+
+/*
+ * blkdev - the block device to use for pstore storage
+ * See Documentation/admin-guide/pstore-blk.rst for details.
+ */
+static char blkdev[80] = CONFIG_PSTORE_BLK_BLKDEV;
+module_param_string(blkdev, blkdev, 80, 0400);
+MODULE_PARM_DESC(blkdev, "block device for pstore storage");
+
+/*
+ * All globals must only be accessed under the pstore_blk_lock
+ * during the register/unregister functions.
+ */
+static DEFINE_MUTEX(pstore_blk_lock);
+static struct file *psblk_file;
+static struct pstore_device_info *pstore_device_info;
+
+#define check_size(name, alignsize) ({				\
+	long _##name_ = (name);					\
+	_##name_ = _##name_ <= 0 ? 0 : (_##name_ * 1024);	\
+	if (_##name_ & ((alignsize) - 1)) {			\
+		pr_info(#name " must align to %d\n",		\
+				(alignsize));			\
+		_##name_ = ALIGN(name, (alignsize));		\
+	}							\
+	_##name_;						\
+})
+
+#define verify_size(name, alignsize, enabled) {			\
+	long _##name_;						\
+	if (enabled)						\
+		_##name_ = check_size(name, alignsize);		\
+	else							\
+		_##name_ = 0;					\
+	/* Synchronize module parameters with resuls. */	\
+	name = _##name_ / 1024;					\
+	dev->zone.name = _##name_;				\
+}
+
+static int __register_pstore_device(struct pstore_device_info *dev)
+{
+	int ret;
+
+	lockdep_assert_held(&pstore_blk_lock);
+
+	if (!dev) {
+		pr_err("NULL device info\n");
+		return -EINVAL;
+	}
+	if (!dev->zone.total_size) {
+		pr_err("zero sized device\n");
+		return -EINVAL;
+	}
+	if (!dev->zone.read) {
+		pr_err("no read handler for device\n");
+		return -EINVAL;
+	}
+	if (!dev->zone.write) {
+		pr_err("no write handler for device\n");
+		return -EINVAL;
+	}
+
+	/* someone already registered before */
+	if (pstore_device_info)
+		return -EBUSY;
+
+	/* zero means not limit on which backends to attempt to store. */
+	if (!dev->flags)
+		dev->flags = UINT_MAX;
+
+	/* Copy in module parameters. */
+	verify_size(kmsg_size, 4096, dev->flags & PSTORE_FLAGS_DMESG);
+	verify_size(pmsg_size, 4096, dev->flags & PSTORE_FLAGS_PMSG);
+	verify_size(console_size, 4096, dev->flags & PSTORE_FLAGS_CONSOLE);
+	verify_size(ftrace_size, 4096, dev->flags & PSTORE_FLAGS_FTRACE);
+	dev->zone.max_reason = max_reason;
+
+	/* Initialize required zone ownership details. */
+	dev->zone.name = KBUILD_MODNAME;
+	dev->zone.owner = THIS_MODULE;
+
+	ret = register_pstore_zone(&dev->zone);
+	if (ret == 0)
+		pstore_device_info = dev;
+
+	return ret;
+}
+/**
+ * register_pstore_device() - register non-block device to pstore/blk
+ *
+ * @dev: non-block device information
+ *
+ * Return:
+ * * 0		- OK
+ * * Others	- something error.
+ */
+int register_pstore_device(struct pstore_device_info *dev)
+{
+	int ret;
+
+	mutex_lock(&pstore_blk_lock);
+	ret = __register_pstore_device(dev);
+	mutex_unlock(&pstore_blk_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(register_pstore_device);
+
+static void __unregister_pstore_device(struct pstore_device_info *dev)
+{
+	lockdep_assert_held(&pstore_blk_lock);
+	if (pstore_device_info && pstore_device_info == dev) {
+		unregister_pstore_zone(&dev->zone);
+		pstore_device_info = NULL;
+	}
+}
+
+/**
+ * unregister_pstore_device() - unregister non-block device from pstore/blk
+ *
+ * @dev: non-block device information
+ */
+void unregister_pstore_device(struct pstore_device_info *dev)
+{
+	mutex_lock(&pstore_blk_lock);
+	__unregister_pstore_device(dev);
+	mutex_unlock(&pstore_blk_lock);
+}
+EXPORT_SYMBOL_GPL(unregister_pstore_device);
+
+static ssize_t psblk_generic_blk_read(char *buf, size_t bytes, loff_t pos)
+{
+	return kernel_read(psblk_file, buf, bytes, &pos);
+}
+
+static ssize_t psblk_generic_blk_write(const char *buf, size_t bytes,
+		loff_t pos)
+{
+	/* Console/Ftrace backend may handle buffer until flush dirty zones */
+	if (in_interrupt() || irqs_disabled())
+		return -EBUSY;
+	return kernel_write(psblk_file, buf, bytes, &pos);
+}
+
+/*
+ * This takes its configuration only from the module parameters now.
+ */
+static int __register_pstore_blk(struct pstore_device_info *dev,
+				 const char *devpath)
+{
+	int ret = -ENODEV;
+
+	lockdep_assert_held(&pstore_blk_lock);
+
+	psblk_file = filp_open(devpath, O_RDWR | O_DSYNC | O_NOATIME | O_EXCL, 0);
+	if (IS_ERR(psblk_file)) {
+		ret = PTR_ERR(psblk_file);
+		pr_err("failed to open '%s': %d!\n", devpath, ret);
+		goto err;
+	}
+
+	if (!S_ISBLK(file_inode(psblk_file)->i_mode)) {
+		pr_err("'%s' is not block device!\n", devpath);
+		goto err_fput;
+	}
+
+	dev->zone.total_size =
+		bdev_nr_bytes(I_BDEV(psblk_file->f_mapping->host));
+
+	ret = __register_pstore_device(dev);
+	if (ret)
+		goto err_fput;
+
+	return 0;
+
+err_fput:
+	fput(psblk_file);
+err:
+	psblk_file = NULL;
+
+	return ret;
+}
+
+/* get information of pstore/blk */
+int pstore_blk_get_config(struct pstore_blk_config *info)
+{
+	strncpy(info->device, blkdev, 80);
+	info->max_reason = max_reason;
+	info->kmsg_size = check_size(kmsg_size, 4096);
+	info->pmsg_size = check_size(pmsg_size, 4096);
+	info->ftrace_size = check_size(ftrace_size, 4096);
+	info->console_size = check_size(console_size, 4096);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pstore_blk_get_config);
+
+
+#ifndef MODULE
+static const char devname[] = "/dev/pstore-blk";
+static __init const char *early_boot_devpath(const char *initial_devname)
+{
+	/*
+	 * During early boot the real root file system hasn't been
+	 * mounted yet, and no device nodes are present yet. Use the
+	 * same scheme to find the device that we use for mounting
+	 * the root file system.
+	 */
+	dev_t dev = name_to_dev_t(initial_devname);
+
+	if (!dev) {
+		pr_err("failed to resolve '%s'!\n", initial_devname);
+		return initial_devname;
+	}
+
+	init_unlink(devname);
+	init_mknod(devname, S_IFBLK | 0600, new_encode_dev(dev));
+
+	return devname;
+}
+#else
+static inline const char *early_boot_devpath(const char *initial_devname)
+{
+	return initial_devname;
+}
+#endif
+
+static int __init __best_effort_init(void)
+{
+	struct pstore_device_info *best_effort_dev;
+	int ret;
+
+	/* No best-effort mode requested. */
+	if (!best_effort)
+		return 0;
+
+	/* Reject an empty blkdev. */
+	if (!blkdev[0]) {
+		pr_err("blkdev empty with best_effort=Y\n");
+		return -EINVAL;
+	}
+
+	best_effort_dev = kzalloc(sizeof(*best_effort_dev), GFP_KERNEL);
+	if (!best_effort_dev)
+		return -ENOMEM;
+
+	best_effort_dev->zone.read = psblk_generic_blk_read;
+	best_effort_dev->zone.write = psblk_generic_blk_write;
+
+	ret = __register_pstore_blk(best_effort_dev,
+				    early_boot_devpath(blkdev));
+	if (ret)
+		kfree(best_effort_dev);
+	else
+		pr_info("attached %s (%lu) (no dedicated panic_write!)\n",
+			blkdev, best_effort_dev->zone.total_size);
+
+	return ret;
+}
+
+static void __exit __best_effort_exit(void)
+{
+	/*
+	 * Currently, the only user of psblk_file is best_effort, so
+	 * we can assume that pstore_device_info is associated with it.
+	 * Once there are "real" blk devices, there will need to be a
+	 * dedicated pstore_blk_info, etc.
+	 */
+	if (psblk_file) {
+		struct pstore_device_info *dev = pstore_device_info;
+
+		__unregister_pstore_device(dev);
+		kfree(dev);
+		fput(psblk_file);
+		psblk_file = NULL;
+	}
+}
+
+static int __init pstore_blk_init(void)
+{
+	int ret;
+
+	mutex_lock(&pstore_blk_lock);
+	ret = __best_effort_init();
+	mutex_unlock(&pstore_blk_lock);
+
+	return ret;
+}
+late_initcall(pstore_blk_init);
+
+static void __exit pstore_blk_exit(void)
+{
+	mutex_lock(&pstore_blk_lock);
+	__best_effort_exit();
+	/* If we've been asked to unload, unregister any remaining device. */
+	__unregister_pstore_device(pstore_device_info);
+	mutex_unlock(&pstore_blk_lock);
+}
+module_exit(pstore_blk_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("WeiXiong Liao <liaoweixiong@allwinnertech.com>");
+MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
+MODULE_DESCRIPTION("pstore backend for block devices");