summaryrefslogtreecommitdiff
path: root/include/linux/pstore.h
diff options
context:
space:
mode:
authorKees Cook <keescook@chromium.org>2018-12-01 01:36:58 +0300
committerKees Cook <keescook@chromium.org>2018-12-04 04:11:02 +0300
commitea84b580b95521644429cc6748b6c2bf27c8b0f3 (patch)
tree85cffd2d9d61cd2ee0fe379384f9f2fe12292598 /include/linux/pstore.h
parent69596433bc28a4642bdc84676f44cfa3b16d0588 (diff)
downloadlinux-ea84b580b95521644429cc6748b6c2bf27c8b0f3.tar.xz
pstore: Convert buf_lock to semaphore
Instead of running with interrupts disabled, use a semaphore. This should make it easier for backends that may need to sleep (e.g. EFI) when performing a write: |BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 |in_atomic(): 1, irqs_disabled(): 1, pid: 2236, name: sig-xstate-bum |Preemption disabled at: |[<ffffffff99d60512>] pstore_dump+0x72/0x330 |CPU: 26 PID: 2236 Comm: sig-xstate-bum Tainted: G D 4.20.0-rc3 #45 |Call Trace: | dump_stack+0x4f/0x6a | ___might_sleep.cold.91+0xd3/0xe4 | __might_sleep+0x50/0x90 | wait_for_completion+0x32/0x130 | virt_efi_query_variable_info+0x14e/0x160 | efi_query_variable_store+0x51/0x1a0 | efivar_entry_set_safe+0xa3/0x1b0 | efi_pstore_write+0x109/0x140 | pstore_dump+0x11c/0x330 | kmsg_dump+0xa4/0xd0 | oops_exit+0x22/0x30 ... Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Fixes: 21b3ddd39fee ("efi: Don't use spinlocks for efi vars") Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'include/linux/pstore.h')
-rw-r--r--include/linux/pstore.h7
1 files changed, 3 insertions, 4 deletions
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index a9ec285d85d1..b146181e8709 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -26,7 +26,7 @@
#include <linux/errno.h>
#include <linux/kmsg_dump.h>
#include <linux/mutex.h>
-#include <linux/spinlock.h>
+#include <linux/semaphore.h>
#include <linux/time.h>
#include <linux/types.h>
@@ -99,7 +99,7 @@ struct pstore_record {
* @owner: module which is responsible for this backend driver
* @name: name of the backend driver
*
- * @buf_lock: spinlock to serialize access to @buf
+ * @buf_lock: semaphore 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
@@ -184,7 +184,7 @@ struct pstore_info {
struct module *owner;
char *name;
- spinlock_t buf_lock;
+ struct semaphore buf_lock;
char *buf;
size_t bufsize;
@@ -210,7 +210,6 @@ struct pstore_info {
extern int pstore_register(struct pstore_info *);
extern void pstore_unregister(struct pstore_info *);
-extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);
struct pstore_ftrace_record {
unsigned long ip;