diff options
-rw-r--r-- | arch/ia64/Kconfig | 1 | ||||
-rw-r--r-- | drivers/firmware/efivars.c | 11 | ||||
-rw-r--r-- | fs/pstore/platform.c | 35 | ||||
-rw-r--r-- | include/linux/pstore.h | 6 | ||||
-rw-r--r-- | init/Kconfig | 7 | ||||
-rw-r--r-- | kernel/sysctl.c | 9 |
6 files changed, 60 insertions, 9 deletions
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 3279646120e3..5fb10644d9ed 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -40,6 +40,7 @@ config IA64 select ARCH_THREAD_INFO_ALLOCATOR select ARCH_CLOCKSOURCE_DATA select GENERIC_TIME_VSYSCALL_OLD + select SYSCTL_ARCH_UNALIGN_NO_WARN select HAVE_MOD_ARCH_SPECIFIC select MODULES_USE_ELF_RELA default y diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index f5596db0cf58..245231126c97 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1210,7 +1210,16 @@ static int efi_pstore_write(enum pstore_type_id type, u64 storage_space, remaining_space, max_variable_size; efi_status_t status = EFI_NOT_FOUND; - spin_lock(&efivars->lock); + if (pstore_cannot_block_path(reason)) { + /* + * If the lock is taken by another cpu in non-blocking path, + * this driver returns without entering firmware to avoid + * hanging up. + */ + if (!spin_trylock(&efivars->lock)) + return -EBUSY; + } else + spin_lock(&efivars->lock); /* * Check if there is a space enough to log. diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 5ea2e77ff023..86d1038b5a12 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -96,6 +96,27 @@ static const char *get_reason_str(enum kmsg_dump_reason reason) } } +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 @@ -114,10 +135,12 @@ static void pstore_dump(struct kmsg_dumper *dumper, why = get_reason_str(reason); - 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++; @@ -143,9 +166,9 @@ static void pstore_dump(struct kmsg_dumper *dumper, total += hsize + len; 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 1788909d9a99..75d01760c911 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -68,12 +68,18 @@ struct pstore_info { #ifdef CONFIG_PSTORE extern int pstore_register(struct pstore_info *); +extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason); #else static inline int pstore_register(struct pstore_info *psi) { return -ENODEV; } +static inline bool +pstore_cannot_block_path(enum kmsg_dump_reason reason) +{ + return false; +} #endif #endif /*_LINUX_PSTORE_H*/ diff --git a/init/Kconfig b/init/Kconfig index 01180da49add..cab5a6c0506d 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1240,6 +1240,13 @@ config SYSCTL_ARCH_UNALIGN_ALLOW the unaligned access emulation. see arch/parisc/kernel/unaligned.c for reference +config SYSCTL_ARCH_UNALIGN_NO_WARN + bool + help + Enable support for /proc/sys/kernel/ignore-unaligned-usertrap + Allows arch to define/use @no_unaligned_warning to possibly warn + about unaligned access emulation going on under the hood. + config KALLSYMS bool "Load all symbols for debugging/ksymoops" if EXPERT default y diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 878b4c41cfb7..9f7a6c51376f 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -164,10 +164,13 @@ extern int unaligned_enabled; #endif #ifdef CONFIG_IA64 -extern int no_unaligned_warning; extern int unaligned_dump_stack; #endif +#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN +extern int no_unaligned_warning; +#endif + #ifdef CONFIG_PROC_SYSCTL static int proc_do_cad_pid(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); @@ -916,7 +919,7 @@ static struct ctl_table kern_table[] = { .proc_handler = proc_doulongvec_minmax, }, #endif -#ifdef CONFIG_IA64 +#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN { .procname = "ignore-unaligned-usertrap", .data = &no_unaligned_warning, @@ -924,6 +927,8 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, +#endif +#ifdef CONFIG_IA64 { .procname = "unaligned-dump-stack", .data = &unaligned_dump_stack, |