diff options
| -rw-r--r-- | fs/pstore/platform.c | 35 | ||||
| -rw-r--r-- | include/linux/pstore.h | 8 |
2 files changed, 37 insertions, 6 deletions
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 57bbf9078ac8..45d18d115bce 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -72,6 +72,27 @@ static char *reason_str[] = { "Oops", "Panic", "Kexec", "Restart", "Halt", "Poweroff", "Emergency" }; +bool pstore_cannot_block_path(enum kmsg_dump_reason reason) +{ + /* + * In case of NMI path, pstore shouldn't be blocked + * 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 by spin lock. */ + case KMSG_DUMP_EMERG: + return true; + default: + return false; + } +} +EXPORT_SYMBOL_GPL(pstore_cannot_block_path); + /* * callback from kmsg_dump. (s2,l2) has the most recently * written bytes, older bytes are in (s1,l1). Save as much @@ -97,10 +118,12 @@ static void pstore_dump(struct kmsg_dumper *dumper, else why = "Unknown"; - if (in_nmi()) { - is_locked = spin_trylock(&psinfo->buf_lock); - if (!is_locked) - pr_err("pstore dump routine blocked in NMI, may corrupt error record\n"); + if (pstore_cannot_block_path(reason)) { + is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags); + if (!is_locked) { + pr_err("pstore dump routine blocked in %s path, may corrupt error record\n" + , in_nmi() ? "NMI" : why); + } } else spin_lock_irqsave(&psinfo->buf_lock, flags); oopscount++; @@ -131,9 +154,9 @@ static void pstore_dump(struct kmsg_dumper *dumper, total += l1_cpy + l2_cpy; part++; } - if (in_nmi()) { + if (pstore_cannot_block_path(reason)) { if (is_locked) - spin_unlock(&psinfo->buf_lock); + spin_unlock_irqrestore(&psinfo->buf_lock, flags); } else spin_unlock_irqrestore(&psinfo->buf_lock, flags); } diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 2ca8cde5459d..9b169690013d 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -22,6 +22,8 @@ #ifndef _LINUX_PSTORE_H #define _LINUX_PSTORE_H +#include <linux/kmsg_dump.h> + /* types */ enum pstore_type_id { PSTORE_TYPE_DMESG = 0, @@ -50,6 +52,7 @@ struct pstore_info { #ifdef CONFIG_PSTORE extern int pstore_register(struct pstore_info *); +extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason); extern int pstore_write(enum pstore_type_id type, char *buf, size_t size); #else static inline int @@ -57,6 +60,11 @@ pstore_register(struct pstore_info *psi) { return -ENODEV; } +static inline bool +pstore_cannot_block_path(enum kmsg_dump_reason reason) +{ + return false; +} static inline int pstore_write(enum pstore_type_id type, char *buf, size_t size) { |