diff options
Diffstat (limited to '')
| -rw-r--r-- | kernel/printk.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index 2531017795f6..a23315dc4498 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -210,7 +210,7 @@ __setup("log_buf_len=", log_buf_len_setup); #ifdef CONFIG_BOOT_PRINTK_DELAY -static unsigned int boot_delay; /* msecs delay after each printk during bootup */ +static int boot_delay; /* msecs delay after each printk during bootup */ static unsigned long long loops_per_msec; /* based on boot_delay */ static int __init boot_delay_setup(char *str) @@ -261,6 +261,12 @@ static inline void boot_delay_msec(void) } #endif +#ifdef CONFIG_SECURITY_DMESG_RESTRICT +int dmesg_restrict = 1; +#else +int dmesg_restrict; +#endif + int do_syslog(int type, char __user *buf, int len, bool from_file) { unsigned i, j, limit, count; @@ -268,7 +274,20 @@ int do_syslog(int type, char __user *buf, int len, bool from_file) char c; int error = 0; - error = security_syslog(type, from_file); + /* + * If this is from /proc/kmsg we only do the capabilities checks + * at open time. + */ + if (type == SYSLOG_ACTION_OPEN || !from_file) { + if (dmesg_restrict && !capable(CAP_SYS_ADMIN)) + return -EPERM; + if ((type != SYSLOG_ACTION_READ_ALL && + type != SYSLOG_ACTION_SIZE_BUFFER) && + !capable(CAP_SYS_ADMIN)) + return -EPERM; + } + + error = security_syslog(type); if (error) return error; @@ -647,6 +666,7 @@ static inline int can_use_console(unsigned int cpu) * released but interrupts still disabled. */ static int acquire_console_semaphore_for_printk(unsigned int cpu) + __releases(&logbuf_lock) { int retval = 0; @@ -1062,13 +1082,15 @@ void printk_tick(void) int printk_needs_cpu(int cpu) { + if (unlikely(cpu_is_offline(cpu))) + printk_tick(); return per_cpu(printk_pending, cpu); } void wake_up_klogd(void) { if (waitqueue_active(&log_wait)) - __raw_get_cpu_var(printk_pending) = 1; + this_cpu_write(printk_pending, 1); } /** @@ -1511,7 +1533,7 @@ int kmsg_dump_unregister(struct kmsg_dumper *dumper) } EXPORT_SYMBOL_GPL(kmsg_dump_unregister); -static const char const *kmsg_reasons[] = { +static const char * const kmsg_reasons[] = { [KMSG_DUMP_OOPS] = "oops", [KMSG_DUMP_PANIC] = "panic", [KMSG_DUMP_KEXEC] = "kexec", |