Since the panic_on_oops is disabled, when getting a BUG hit in the code, the system continues and does not panic. However, a short time later, a hard lockup is hit and the system does panic. Even though the system panicked at hard lockup, the panic string is still the first BUG hit. For example: Without the patch: crash> sys|grep PANIC PANIC: "BUG: unable to handle kernel paging request at ffffab835d7f9d50" With the patch: crash> sys|grep PANIC PANIC: "Kernel panic - not syncing: Hard LOCKUP" Let's search for the panic string based on the severity of the panic event, and also refactore the get_panicmsg() a little bit to improve readability. Reported-by: John Pittman <jpittman(a)redhat.com&gt; Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com&gt; --- task.c | 109 +++++++++++++++++++++++---------------------------------- 1 file changed, 44 insertions(+), 65 deletions(-) diff --git a/task.c b/task.c index 4018a543b715..6809c27c4b91 100644 --- a/task.c +++ b/task.c @@ -6301,6 +6301,31 @@ get_active_task(int cpu) return NO_TASK; } +/* + * Arrange the panic strings based on the severity of the panic + * events. + */ +static const char* panic_msg[] = { + "SysRq : Crash", + "SysRq : Trigger a crash", + "SysRq : Netdump", + "Kernel panic: ", + "Kernel panic - ", + "Kernel BUG at", + "kernel BUG at", + "Unable to handle kernel paging request", + "Unable to handle kernel NULL pointer dereference", + "BUG: unable to handle kernel ", + "general protection fault: ", + "double fault: ", + "divide error: ", + "stack segment: ", + "[Hardware Error]: ", + "Bad mode in ", + "Oops: ", +}; + +#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0])) /* * Read the panic string. @@ -6308,7 +6333,7 @@ get_active_task(int cpu) char * get_panicmsg(char *buf) { - int msg_found; + int msg_found, i; BZERO(buf, BUFSIZE); msg_found = FALSE; @@ -6332,76 +6357,30 @@ get_panicmsg(char *buf) * active-task flag appropriately. The message may or * may not be used as the panic message. */ - rewind(pc->tmpfile); - while (fgets(buf, BUFSIZE, pc->tmpfile)) { - if (strstr(buf, "SysRq : Crash") || - strstr(buf, "SysRq : Trigger a crash")) { - pc->flags |= SYSRQ; - break; - } - } - rewind(pc->tmpfile); - while (!msg_found && fgets(buf, BUFSIZE, pc->tmpfile)) { - if (strstr(buf, "general protection fault: ") || - strstr(buf, "double fault: ") || - strstr(buf, "divide error: ") || - strstr(buf, "stack segment: ")) { - msg_found = TRUE; - break; - } - } - rewind(pc->tmpfile); - while (!msg_found && fgets(buf, BUFSIZE, pc->tmpfile)) { - if (strstr(buf, "SysRq : Netdump") || - strstr(buf, "SysRq : Crash") || - strstr(buf, "SysRq : Trigger a crash")) { - pc->flags |= SYSRQ; - msg_found = TRUE; - break; + for (i = 0; i < ARRAY_SIZE(panic_msg); i++) { + rewind(pc->tmpfile); + while (fgets(buf, BUFSIZE, pc->tmpfile)) { + if (strstr(buf, panic_msg[i])) { + msg_found = TRUE; + if(strstr(buf, "SysRq :")) + pc->flags |= SYSRQ; + goto FOUND; + } } - } - rewind(pc->tmpfile); - while (!msg_found && fgets(buf, BUFSIZE, pc->tmpfile)) { - if (strstr(buf, "Oops: ") || - strstr(buf, "Kernel BUG at") || - strstr(buf, "kernel BUG at") || - strstr(buf, "Unable to handle kernel paging request") || - strstr(buf, "Unable to handle kernel NULL pointer dereference") || - strstr(buf, "BUG: unable to handle kernel ")) - msg_found = TRUE; + } + rewind(pc->tmpfile); while (!msg_found && fgets(buf, BUFSIZE, pc->tmpfile)) { - if (strstr(buf, "sysrq") && - symbol_exists("sysrq_pressed")) { - get_symbol_data("sysrq_pressed", sizeof(int), - &msg_found); - break; - } + if (strstr(buf, "sysrq") && + symbol_exists("sysrq_pressed")) { + get_symbol_data("sysrq_pressed", sizeof(int), + &msg_found); + break; + } } - rewind(pc->tmpfile); - while (!msg_found && fgets(buf, BUFSIZE, pc->tmpfile)) { - if (strstr(buf, "Kernel panic: ") || - strstr(buf, "Kernel panic - ")) { - msg_found = TRUE; - break; - } - } - rewind(pc->tmpfile); - while (!msg_found && fgets(buf, BUFSIZE, pc->tmpfile)) { - if (strstr(buf, "[Hardware Error]: ")) { - msg_found = TRUE; - break; - } - } - rewind(pc->tmpfile); - while (!msg_found && fgets(buf, BUFSIZE, pc->tmpfile)) { - if (strstr(buf, "Bad mode in ")) { - msg_found = TRUE; - break; - } - } +FOUND: close_tmpfile(); if (!msg_found) -- 2.41.0