Commit fd2d7a4a authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'pstore-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux 

Pull pstore updates from Kees Cook:

 - Don't use semaphores in always-atomic-context code (Jann Horn)

 - Add "ECC:" prefix to ECC messages (Vincent Whitchurch)

* tag 'pstore-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: Don't use semaphores in always-atomic-context code
  pstore: Add prefix to ECC messages
parents b7a801f3 8126b1c7

drivers/firmware/efi/efi-pstore.c

+1 −1
Original line number Diff line number Diff line
@@ -266,7 +266,7 @@ static int efi_pstore_write(struct pstore_record *record) 
		efi_name[i] = name[i];



	ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,

			      preemptible(), record->size, record->psi->buf);

			      false, record->size, record->psi->buf);



	if (record->reason == KMSG_DUMP_OOPS && try_module_get(THIS_MODULE))

		if (!schedule_work(&efivar_work))

fs/pstore/platform.c

+18 −20
Original line number Diff line number Diff line
@@ -143,21 +143,22 @@ static void pstore_timer_kick(void) 
	mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));

}



static bool pstore_cannot_block_path(enum kmsg_dump_reason reason)

{

	/*

 * Should pstore_dump() wait for a concurrent pstore_dump()? If

 * not, the current pstore_dump() will report a failure to dump

 * and return.

	 * In case of NMI path, pstore shouldn't be blocked

	 * regardless of reason.

	 */

static bool pstore_cannot_wait(enum kmsg_dump_reason reason)

{

	/* In NMI path, pstore shouldn't block regardless of reason. */

	if (in_nmi())

		return true;



	switch (reason) {

	/* In panic case, other cpus are stopped by smp_send_stop(). */

	case KMSG_DUMP_PANIC:

	/* Emergency restart shouldn't be blocked. */

	/*

	 * Emergency restart shouldn't be blocked by spinning on

	 * pstore_info::buf_lock.

	 */

	case KMSG_DUMP_EMERG:

		return true;

	default:
@@ -389,21 +390,19 @@ static void pstore_dump(struct kmsg_dumper *dumper, 
	unsigned long	total = 0;

	const char	*why;

	unsigned int	part = 1;

	unsigned long	flags = 0;

	int		ret;



	why = kmsg_dump_reason_str(reason);



	if (down_trylock(&psinfo->buf_lock)) {

		/* Failed to acquire lock: give up if we cannot wait. */

		if (pstore_cannot_wait(reason)) {

			pr_err("dump skipped in %s path: may corrupt error record\n",

	if (pstore_cannot_block_path(reason)) {

		if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) {

			pr_err("dump skipped in %s path because of concurrent dump\n",

					in_nmi() ? "NMI" : why);

			return;

		}

		if (down_interruptible(&psinfo->buf_lock)) {

			pr_err("could not grab semaphore?!\n");

			return;

		}

	} else {

		spin_lock_irqsave(&psinfo->buf_lock, flags);

	}



	kmsg_dump_rewind(&iter);
@@ -467,8 +466,7 @@ static void pstore_dump(struct kmsg_dumper *dumper, 
		total += record.size;

		part++;

	}



	up(&psinfo->buf_lock);

	spin_unlock_irqrestore(&psinfo->buf_lock, flags);

}



static struct kmsg_dumper pstore_dumper = {
@@ -594,7 +592,7 @@ int pstore_register(struct pstore_info *psi) 
		psi->write_user = pstore_write_user_compat;

	psinfo = psi;

	mutex_init(&psinfo->read_mutex);

	sema_init(&psinfo->buf_lock, 1);

	spin_lock_init(&psinfo->buf_lock);



	if (psi->flags & PSTORE_FLAGS_DMESG)

		allocate_buf_for_compression();

fs/pstore/ram_core.c

+2 −2
Original line number Diff line number Diff line
@@ -263,10 +263,10 @@ ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz, 


	if (prz->corrected_bytes || prz->bad_blocks)

		ret = snprintf(str, len, ""

			"\n%d Corrected bytes, %d unrecoverable blocks\n",

			"\nECC: %d Corrected bytes, %d unrecoverable blocks\n",

			prz->corrected_bytes, prz->bad_blocks);

	else

		ret = snprintf(str, len, "\nNo errors detected\n");

		ret = snprintf(str, len, "\nECC: No errors detected\n");



	return ret;

}

include/linux/pstore.h

+3 −3
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ 
#include <linux/errno.h>

#include <linux/kmsg_dump.h>

#include <linux/mutex.h>

#include <linux/semaphore.h>

#include <linux/spinlock.h>

#include <linux/time.h>

#include <linux/types.h>
@@ -87,7 +87,7 @@ struct pstore_record { 
 * @owner:	module which is responsible for this backend driver

 * @name:	name of the backend driver

 *

 * @buf_lock:	semaphore to serialize access to @buf

 * @buf_lock:	spinlock to serialize access to @buf

 * @buf:	preallocated crash dump buffer

 * @bufsize:	size of @buf available for crash dump bytes (must match

 *		smallest number of bytes available for writing to a
@@ -178,7 +178,7 @@ struct pstore_info { 
	struct module	*owner;

	const char	*name;



	struct semaphore buf_lock;

	spinlock_t	buf_lock;

	char		*buf;

	size_t		bufsize;