1 // SPDX-License-Identifier: GPL-2.0-only
15 #include <linux/poll.h>
28  * This avoids deadlocks on printk locks without having to break locks. Also
42 	if (mce->kflags & MCE_HANDLED_CEC)  in dev_mce_log()
47 	entry = mcelog->next;  in dev_mce_log()
53 	if (entry >= mcelog->len) {  in dev_mce_log()
54 		set_bit(MCE_OVERFLOW, (unsigned long *)&mcelog->flags);  in dev_mce_log()
58 	mcelog->next = entry + 1;  in dev_mce_log()
60 	memcpy(mcelog->entry + entry, mce, sizeof(struct mce));  in dev_mce_log()
61 	mcelog->entry[entry].finished = 1;  in dev_mce_log()
62 	mcelog->entry[entry].kflags = 0;  in dev_mce_log()
71 		mce->kflags |= MCE_HANDLED_MCELOG;  in dev_mce_log()
132 	    (mce_chrdev_open_count && (file->f_flags & O_EXCL))) {  in mce_chrdev_open()
135 		return -EBUSY;  in mce_chrdev_open()
138 	if (file->f_flags & O_EXCL)  in mce_chrdev_open()
151 	mce_chrdev_open_count--;  in mce_chrdev_release()
169 		return -EINVAL;  in __mce_read_apei()
172 	/* Error or no more MCE record */  in __mce_read_apei()
177 		 * "no record" instead of "no device."  in __mce_read_apei()
179 		if (rc == -ENODEV)  in __mce_read_apei()
183 	rc = -EFAULT;  in __mce_read_apei()
189 	 * /sbin/mcelog, but we have no interface to support that now,  in __mce_read_apei()
218 	err = -EINVAL;  in mce_chrdev_read()
219 	if (*off != 0 || usize < mcelog->len * sizeof(struct mce))  in mce_chrdev_read()
222 	next = mcelog->next;  in mce_chrdev_read()
226 		struct mce *m = &mcelog->entry[i];  in mce_chrdev_read()
232 	memset(mcelog->entry, 0, next * sizeof(struct mce));  in mce_chrdev_read()
233 	mcelog->next = 0;  in mce_chrdev_read()
236 		err = -EFAULT;  in mce_chrdev_read()
241 	return err ? err : buf - ubuf;  in mce_chrdev_read()
247 	if (READ_ONCE(mcelog->next))  in mce_chrdev_poll()
260 		return -EPERM;  in mce_chrdev_ioctl()
266 		return put_user(mcelog->len, p);  in mce_chrdev_ioctl()
271 			flags = mcelog->flags;  in mce_chrdev_ioctl()
272 		} while (cmpxchg(&mcelog->flags, flags, 0) != flags);  in mce_chrdev_ioctl()
277 		return -ENOTTY;  in mce_chrdev_ioctl()
299 		return -EPERM;  in mce_chrdev_write()
305 		return -EIO;  in mce_chrdev_write()
310 		return -EFAULT;  in mce_chrdev_write()
313 		return -EINVAL;  in mce_chrdev_write()
331 	.poll			= mce_chrdev_poll,
350 		return -ENOMEM;  in dev_mcelog_init_device()
352 	memcpy(mcelog->signature, MCE_LOG_SIGNATURE, sizeof(mcelog->signature));  in dev_mcelog_init_device()
353 	mcelog->len = mce_log_len;  in dev_mcelog_init_device()
354 	mcelog->recordlen = sizeof(struct mce);  in dev_mcelog_init_device()
359 		if (err == -EBUSY)  in dev_mcelog_init_device()
361 			pr_info("Unable to init device /dev/mcelog, already registered");  in dev_mcelog_init_device()
363 			pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);  in dev_mcelog_init_device()