diff options
| -rw-r--r-- | include/linux/kdb.h | 1 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_io.c | 9 | ||||
| -rw-r--r-- | kernel/printk/printk.c | 3 |
3 files changed, 5 insertions, 8 deletions
diff --git a/include/linux/kdb.h b/include/linux/kdb.h index eb706188dc23..68bd88223417 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -161,6 +161,7 @@ enum kdb_msgsrc { }; extern int kdb_trap_printk; +extern int kdb_printf_cpu; extern __printf(2, 0) int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list args); extern __printf(1, 2) int kdb_printf(const char *, ...); diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c index daa76154fb1b..e74be38245ad 100644 --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -30,6 +30,7 @@ char kdb_prompt_str[CMD_BUFLEN]; int kdb_trap_printk; +int kdb_printf_cpu = -1; static int kgdb_transition_check(char *buffer) { @@ -554,24 +555,19 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) int linecount; int colcount; int logging, saved_loglevel = 0; - int saved_trap_printk; int retlen = 0; int fnd, len; int this_cpu, old_cpu; - static int kdb_printf_cpu = -1; char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; char *moreprompt = "more> "; struct console *c = console_drivers; unsigned long uninitialized_var(flags); - local_irq_save(flags); - saved_trap_printk = kdb_trap_printk; - kdb_trap_printk = 0; - /* Serialize kdb_printf if multiple cpus try to write at once. * But if any cpu goes recursive in kdb, just print the output, * even if it is interleaved with any other text. */ + local_irq_save(flags); this_cpu = smp_processor_id(); for (;;) { old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu); @@ -849,7 +845,6 @@ kdb_print_out: console_loglevel = saved_loglevel; /* kdb_printf_cpu locked the code above. */ smp_store_release(&kdb_printf_cpu, old_cpu); - kdb_trap_printk = saved_trap_printk; local_irq_restore(flags); return retlen; } diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 577f2288d19f..a3ce35e0fa1e 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1926,7 +1926,8 @@ int vprintk_default(const char *fmt, va_list args) int r; #ifdef CONFIG_KGDB_KDB - if (unlikely(kdb_trap_printk)) { + /* Allow to pass printk() to kdb but avoid a recursion. */ + if (unlikely(kdb_trap_printk && kdb_printf_cpu < 0)) { r = vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args); return r; } |