Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2c3b20e91fe3a083c5d9bc79437c485866ea251c Commit: 2c3b20e91fe3a083c5d9bc79437c485866ea251c Parent: 67e2be02328b9a61a9c799fbdd4ec94d7da0c323 Author: Arjan van de Ven <[EMAIL PROTECTED]> AuthorDate: Thu Dec 20 15:01:17 2007 +0100 Committer: Ingo Molnar <[EMAIL PROTECTED]> CommitDate: Thu Dec 20 15:01:17 2007 +0100
debug: add end-of-oops marker Right now it's nearly impossible for parsers that collect kernel crashes from logs or emails (such as www.kerneloops.org) to detect the end-of-oops condition. In addition, it's not currently possible to detect whether or not 2 oopses that look alike are actually the same oops reported twice, or are truly two unique oopses. This patch adds an end-of-oops marker, and makes the end marker include a very simple 64-bit random ID to be able to detect duplicate reports. Normally, this ID is calculated as a late_initcall() (in the hope that at that time there is enough entropy to get a unique enough ID); however for early oopses the oops_exit() function needs to generate the ID on the fly. We do this all at the _end_ of an oops printout, so this does not impact our ability to get the most important portions of a crash out to the console first. [ Sidenote: the already existing oopses-since-bootup counter we print during crashes serves as the differentiator between multiple oopses that trigger during the same bootup. ] Tested on 32-bit and 64-bit x86. Artificially injected very early crashes as well, as expected they result in this constant ID after multiple bootups: ---[ end trace ca143223eefdc828 ]--- ---[ end trace ca143223eefdc828 ]--- because the random pools are still all zero. But it all still works fine and causes no additional problems (which is the main goal of instrumentation code). Signed-off-by: Arjan van de Ven <[EMAIL PROTECTED]> Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]> --- kernel/panic.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/kernel/panic.c b/kernel/panic.c index 6f6e03e..da4d6ba 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -19,6 +19,7 @@ #include <linux/nmi.h> #include <linux/kexec.h> #include <linux/debug_locks.h> +#include <linux/random.h> int panic_on_oops; int tainted; @@ -266,12 +267,29 @@ void oops_enter(void) } /* + * 64-bit random ID for oopses: + */ +static u64 oops_id; + +static int init_oops_id(void) +{ + if (!oops_id) + get_random_bytes(&oops_id, sizeof(oops_id)); + + return 0; +} +late_initcall(init_oops_id); + +/* * Called when the architecture exits its oops handler, after printing * everything. */ void oops_exit(void) { do_oops_enter_exit(); + init_oops_id(); + printk(KERN_WARNING "---[ end trace %016llx ]---\n", + (unsigned long long)oops_id); } #ifdef CONFIG_CC_STACKPROTECTOR - To unsubscribe from this list: send the line "unsubscribe git-commits-head" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html