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![Geert Uytterhoeven](/assets/img/avatar_default.png)
On 32-bit:
fs/pstore/blk.c: In function ‘__best_effort_init’:
include/linux/kern_levels.h:5:18: warning: format ‘%zu’ expects argument of type ‘size_t’, but argument 3 has type ‘long unsigned int’ [-Wformat=]
5 | #define KERN_SOH "\001" /* ASCII Start Of Header */
| ^~~~~~
include/linux/kern_levels.h:14:19: note: in expansion of macro ‘KERN_SOH’
14 | #define KERN_INFO KERN_SOH "6" /* informational */
| ^~~~~~~~
include/linux/printk.h:373:9: note: in expansion of macro ‘KERN_INFO’
373 | printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
| ^~~~~~~~~
fs/pstore/blk.c:314:3: note: in expansion of macro ‘pr_info’
314 | pr_info("attached %s (%zu) (no dedicated panic_write!)\n",
| ^~~~~~~
Cc: stable@vger.kernel.org
Fixes: 7bb9557b48
("pstore/blk: Use the normal block device I/O path")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210629103700.1935012-1-geert@linux-m68k.org
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
361 lines
9.1 KiB
C
361 lines
9.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Implements pstore backend driver that write to block (or non-block) storage
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* devices, using the pstore/zone API.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/blkdev.h>
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#include <linux/string.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/pstore_blk.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/init_syscalls.h>
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#include <linux/mount.h>
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static long kmsg_size = CONFIG_PSTORE_BLK_KMSG_SIZE;
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module_param(kmsg_size, long, 0400);
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MODULE_PARM_DESC(kmsg_size, "kmsg dump record size in kbytes");
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static int max_reason = CONFIG_PSTORE_BLK_MAX_REASON;
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module_param(max_reason, int, 0400);
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MODULE_PARM_DESC(max_reason,
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"maximum reason for kmsg dump (default 2: Oops and Panic)");
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#if IS_ENABLED(CONFIG_PSTORE_PMSG)
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static long pmsg_size = CONFIG_PSTORE_BLK_PMSG_SIZE;
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#else
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static long pmsg_size = -1;
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#endif
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module_param(pmsg_size, long, 0400);
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MODULE_PARM_DESC(pmsg_size, "pmsg size in kbytes");
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#if IS_ENABLED(CONFIG_PSTORE_CONSOLE)
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static long console_size = CONFIG_PSTORE_BLK_CONSOLE_SIZE;
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#else
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static long console_size = -1;
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#endif
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module_param(console_size, long, 0400);
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MODULE_PARM_DESC(console_size, "console size in kbytes");
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#if IS_ENABLED(CONFIG_PSTORE_FTRACE)
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static long ftrace_size = CONFIG_PSTORE_BLK_FTRACE_SIZE;
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#else
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static long ftrace_size = -1;
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#endif
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module_param(ftrace_size, long, 0400);
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MODULE_PARM_DESC(ftrace_size, "ftrace size in kbytes");
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static bool best_effort;
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module_param(best_effort, bool, 0400);
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MODULE_PARM_DESC(best_effort, "use best effort to write (i.e. do not require storage driver pstore support, default: off)");
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/*
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* blkdev - the block device to use for pstore storage
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* See Documentation/admin-guide/pstore-blk.rst for details.
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*/
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static char blkdev[80] = CONFIG_PSTORE_BLK_BLKDEV;
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module_param_string(blkdev, blkdev, 80, 0400);
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MODULE_PARM_DESC(blkdev, "block device for pstore storage");
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/*
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* All globals must only be accessed under the pstore_blk_lock
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* during the register/unregister functions.
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*/
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static DEFINE_MUTEX(pstore_blk_lock);
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static struct file *psblk_file;
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static struct pstore_device_info *pstore_device_info;
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#define check_size(name, alignsize) ({ \
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long _##name_ = (name); \
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_##name_ = _##name_ <= 0 ? 0 : (_##name_ * 1024); \
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if (_##name_ & ((alignsize) - 1)) { \
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pr_info(#name " must align to %d\n", \
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(alignsize)); \
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_##name_ = ALIGN(name, (alignsize)); \
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} \
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_##name_; \
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})
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#define verify_size(name, alignsize, enabled) { \
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long _##name_; \
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if (enabled) \
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_##name_ = check_size(name, alignsize); \
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else \
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_##name_ = 0; \
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/* Synchronize module parameters with resuls. */ \
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name = _##name_ / 1024; \
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dev->zone.name = _##name_; \
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}
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static int __register_pstore_device(struct pstore_device_info *dev)
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{
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int ret;
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lockdep_assert_held(&pstore_blk_lock);
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if (!dev) {
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pr_err("NULL device info\n");
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return -EINVAL;
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}
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if (!dev->zone.total_size) {
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pr_err("zero sized device\n");
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return -EINVAL;
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}
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if (!dev->zone.read) {
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pr_err("no read handler for device\n");
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return -EINVAL;
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}
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if (!dev->zone.write) {
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pr_err("no write handler for device\n");
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return -EINVAL;
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}
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/* someone already registered before */
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if (pstore_device_info)
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return -EBUSY;
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/* zero means not limit on which backends to attempt to store. */
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if (!dev->flags)
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dev->flags = UINT_MAX;
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/* Copy in module parameters. */
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verify_size(kmsg_size, 4096, dev->flags & PSTORE_FLAGS_DMESG);
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verify_size(pmsg_size, 4096, dev->flags & PSTORE_FLAGS_PMSG);
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verify_size(console_size, 4096, dev->flags & PSTORE_FLAGS_CONSOLE);
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verify_size(ftrace_size, 4096, dev->flags & PSTORE_FLAGS_FTRACE);
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dev->zone.max_reason = max_reason;
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/* Initialize required zone ownership details. */
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dev->zone.name = KBUILD_MODNAME;
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dev->zone.owner = THIS_MODULE;
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ret = register_pstore_zone(&dev->zone);
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if (ret == 0)
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pstore_device_info = dev;
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return ret;
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}
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/**
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* register_pstore_device() - register non-block device to pstore/blk
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*
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* @dev: non-block device information
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*
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* Return:
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* * 0 - OK
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* * Others - something error.
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*/
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int register_pstore_device(struct pstore_device_info *dev)
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{
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int ret;
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mutex_lock(&pstore_blk_lock);
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ret = __register_pstore_device(dev);
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mutex_unlock(&pstore_blk_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(register_pstore_device);
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static void __unregister_pstore_device(struct pstore_device_info *dev)
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{
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lockdep_assert_held(&pstore_blk_lock);
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if (pstore_device_info && pstore_device_info == dev) {
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unregister_pstore_zone(&dev->zone);
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pstore_device_info = NULL;
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}
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}
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/**
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* unregister_pstore_device() - unregister non-block device from pstore/blk
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*
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* @dev: non-block device information
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*/
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void unregister_pstore_device(struct pstore_device_info *dev)
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{
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mutex_lock(&pstore_blk_lock);
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__unregister_pstore_device(dev);
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mutex_unlock(&pstore_blk_lock);
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}
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EXPORT_SYMBOL_GPL(unregister_pstore_device);
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static ssize_t psblk_generic_blk_read(char *buf, size_t bytes, loff_t pos)
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{
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return kernel_read(psblk_file, buf, bytes, &pos);
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}
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static ssize_t psblk_generic_blk_write(const char *buf, size_t bytes,
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loff_t pos)
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{
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/* Console/Ftrace backend may handle buffer until flush dirty zones */
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if (in_interrupt() || irqs_disabled())
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return -EBUSY;
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return kernel_write(psblk_file, buf, bytes, &pos);
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}
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/*
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* This takes its configuration only from the module parameters now.
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*/
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static int __register_pstore_blk(struct pstore_device_info *dev,
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const char *devpath)
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{
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int ret = -ENODEV;
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lockdep_assert_held(&pstore_blk_lock);
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psblk_file = filp_open(devpath, O_RDWR | O_DSYNC | O_NOATIME | O_EXCL, 0);
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if (IS_ERR(psblk_file)) {
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ret = PTR_ERR(psblk_file);
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pr_err("failed to open '%s': %d!\n", devpath, ret);
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goto err;
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}
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if (!S_ISBLK(file_inode(psblk_file)->i_mode)) {
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pr_err("'%s' is not block device!\n", devpath);
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goto err_fput;
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}
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dev->zone.total_size =
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bdev_nr_bytes(I_BDEV(psblk_file->f_mapping->host));
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ret = __register_pstore_device(dev);
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if (ret)
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goto err_fput;
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return 0;
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err_fput:
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fput(psblk_file);
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err:
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psblk_file = NULL;
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return ret;
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}
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/* get information of pstore/blk */
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int pstore_blk_get_config(struct pstore_blk_config *info)
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{
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strncpy(info->device, blkdev, 80);
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info->max_reason = max_reason;
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info->kmsg_size = check_size(kmsg_size, 4096);
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info->pmsg_size = check_size(pmsg_size, 4096);
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info->ftrace_size = check_size(ftrace_size, 4096);
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info->console_size = check_size(console_size, 4096);
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return 0;
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}
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EXPORT_SYMBOL_GPL(pstore_blk_get_config);
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#ifndef MODULE
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static const char devname[] = "/dev/pstore-blk";
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static __init const char *early_boot_devpath(const char *initial_devname)
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{
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/*
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* During early boot the real root file system hasn't been
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* mounted yet, and no device nodes are present yet. Use the
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* same scheme to find the device that we use for mounting
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* the root file system.
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*/
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dev_t dev = name_to_dev_t(initial_devname);
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if (!dev) {
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pr_err("failed to resolve '%s'!\n", initial_devname);
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return initial_devname;
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}
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init_unlink(devname);
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init_mknod(devname, S_IFBLK | 0600, new_encode_dev(dev));
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return devname;
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}
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#else
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static inline const char *early_boot_devpath(const char *initial_devname)
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{
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return initial_devname;
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}
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#endif
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static int __init __best_effort_init(void)
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{
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struct pstore_device_info *best_effort_dev;
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int ret;
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/* No best-effort mode requested. */
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if (!best_effort)
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return 0;
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/* Reject an empty blkdev. */
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if (!blkdev[0]) {
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pr_err("blkdev empty with best_effort=Y\n");
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return -EINVAL;
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}
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best_effort_dev = kzalloc(sizeof(*best_effort_dev), GFP_KERNEL);
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if (!best_effort_dev)
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return -ENOMEM;
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best_effort_dev->zone.read = psblk_generic_blk_read;
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best_effort_dev->zone.write = psblk_generic_blk_write;
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ret = __register_pstore_blk(best_effort_dev,
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early_boot_devpath(blkdev));
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if (ret)
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kfree(best_effort_dev);
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else
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pr_info("attached %s (%lu) (no dedicated panic_write!)\n",
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blkdev, best_effort_dev->zone.total_size);
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return ret;
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}
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static void __exit __best_effort_exit(void)
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{
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/*
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* Currently, the only user of psblk_file is best_effort, so
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* we can assume that pstore_device_info is associated with it.
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* Once there are "real" blk devices, there will need to be a
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* dedicated pstore_blk_info, etc.
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*/
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if (psblk_file) {
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struct pstore_device_info *dev = pstore_device_info;
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__unregister_pstore_device(dev);
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kfree(dev);
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fput(psblk_file);
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psblk_file = NULL;
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}
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}
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static int __init pstore_blk_init(void)
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{
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int ret;
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mutex_lock(&pstore_blk_lock);
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ret = __best_effort_init();
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mutex_unlock(&pstore_blk_lock);
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return ret;
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}
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late_initcall(pstore_blk_init);
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static void __exit pstore_blk_exit(void)
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{
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mutex_lock(&pstore_blk_lock);
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__best_effort_exit();
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/* If we've been asked to unload, unregister any remaining device. */
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__unregister_pstore_device(pstore_device_info);
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mutex_unlock(&pstore_blk_lock);
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}
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module_exit(pstore_blk_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("WeiXiong Liao <liaoweixiong@allwinnertech.com>");
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MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
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MODULE_DESCRIPTION("pstore backend for block devices");
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