diff options
| author | Kees Cook | 2018-11-30 14:36:58 -0800 |
|---|---|---|
| committer | Kees Cook | 2018-12-03 17:11:02 -0800 |
| commit | ea84b580b95521644429cc6748b6c2bf27c8b0f3 (patch) | |
| tree | 85cffd2d9d61cd2ee0fe379384f9f2fe12292598 /include/linux/pstore.h | |
| parent | 69596433bc28a4642bdc84676f44cfa3b16d0588 (diff) | |
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.h | 7 |
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; |