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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /fs/pstore/pmsg.c | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/pstore/pmsg.c')
-rw-r--r-- | fs/pstore/pmsg.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/fs/pstore/pmsg.c b/fs/pstore/pmsg.c new file mode 100644 index 000000000..d8542ec2f --- /dev/null +++ b/fs/pstore/pmsg.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2014 Google, Inc. + */ + +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/fs.h> +#include <linux/uaccess.h> +#include "internal.h" + +static DEFINE_MUTEX(pmsg_lock); + +static ssize_t write_pmsg(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct pstore_record record; + int ret; + + if (!count) + return 0; + + pstore_record_init(&record, psinfo); + record.type = PSTORE_TYPE_PMSG; + record.size = count; + + /* check outside lock, page in any data. write_user also checks */ + if (!access_ok(buf, count)) + return -EFAULT; + + mutex_lock(&pmsg_lock); + ret = psinfo->write_user(&record, buf); + mutex_unlock(&pmsg_lock); + return ret ? ret : count; +} + +static const struct file_operations pmsg_fops = { + .owner = THIS_MODULE, + .llseek = noop_llseek, + .write = write_pmsg, +}; + +static struct class *pmsg_class; +static int pmsg_major; +#define PMSG_NAME "pmsg" +#undef pr_fmt +#define pr_fmt(fmt) PMSG_NAME ": " fmt + +static char *pmsg_devnode(struct device *dev, umode_t *mode) +{ + if (mode) + *mode = 0220; + return NULL; +} + +void pstore_register_pmsg(void) +{ + struct device *pmsg_device; + + pmsg_major = register_chrdev(0, PMSG_NAME, &pmsg_fops); + if (pmsg_major < 0) { + pr_err("register_chrdev failed\n"); + goto err; + } + + pmsg_class = class_create(THIS_MODULE, PMSG_NAME); + if (IS_ERR(pmsg_class)) { + pr_err("device class file already in use\n"); + goto err_class; + } + pmsg_class->devnode = pmsg_devnode; + + pmsg_device = device_create(pmsg_class, NULL, MKDEV(pmsg_major, 0), + NULL, "%s%d", PMSG_NAME, 0); + if (IS_ERR(pmsg_device)) { + pr_err("failed to create device\n"); + goto err_device; + } + return; + +err_device: + class_destroy(pmsg_class); +err_class: + unregister_chrdev(pmsg_major, PMSG_NAME); +err: + return; +} + +void pstore_unregister_pmsg(void) +{ + device_destroy(pmsg_class, MKDEV(pmsg_major, 0)); + class_destroy(pmsg_class); + unregister_chrdev(pmsg_major, PMSG_NAME); +} |