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authorStephen Boyd <swboyd@chromium.org>2021-07-08 04:09:17 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-08 21:48:22 +0300
commit22f4e66df79d0a730fcd6c17f3403b5ab8c72ced (patch)
tree149957884ca6184a0da29e8fc17e876af053db3d /lib/dump_stack.c
parent83cc6fa0049d7c5333a53f4d959a9457340284ea (diff)
downloadlinux-22f4e66df79d0a730fcd6c17f3403b5ab8c72ced.tar.xz
dump_stack: add vmlinux build ID to stack traces
Add the running kernel's build ID[1] to the stacktrace information header. This makes it simpler for developers to locate the vmlinux with full debuginfo for a particular kernel stacktrace. Combined with scripts/decode_stracktrace.sh, a developer can download the correct vmlinux from a debuginfod[2] server and find the exact file and line number for the functions plus offsets in a stacktrace. This is especially useful for pstore crash debugging where the kernel crashes are recorded in the pstore logs and the recovery kernel is different or the debuginfo doesn't exist on the device due to space concerns (the data can be large and a security concern). The stacktrace can be analyzed after the crash by using the build ID to find the matching vmlinux and understand where in the function something went wrong. Example stacktrace from lkdtm: WARNING: CPU: 4 PID: 3255 at drivers/misc/lkdtm/bugs.c:83 lkdtm_WARNING+0x28/0x30 [lkdtm] Modules linked in: lkdtm rfcomm algif_hash algif_skcipher af_alg xt_cgroup uinput xt_MASQUERADE CPU: 4 PID: 3255 Comm: bash Not tainted 5.11 #3 aa23f7a1231c229de205662d5a9e0d4c580f19a1 Hardware name: Google Lazor (rev3+) with KB Backlight (DT) pstate: 00400009 (nzcv daif +PAN -UAO -TCO BTYPE=--) pc : lkdtm_WARNING+0x28/0x30 [lkdtm] The hex string aa23f7a1231c229de205662d5a9e0d4c580f19a1 is the build ID, following the kernel version number. Put it all behind a config option, STACKTRACE_BUILD_ID, so that kernel developers can remove this information if they decide it is too much. Link: https://lkml.kernel.org/r/20210511003845.2429846-5-swboyd@chromium.org Link: https://fedoraproject.org/wiki/Releases/FeatureBuildId [1] Link: https://sourceware.org/elfutils/Debuginfod.html [2] Signed-off-by: Stephen Boyd <swboyd@chromium.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Evan Green <evgreen@chromium.org> Cc: Hsin-Yi Wang <hsinyi@chromium.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sasha Levin <sashal@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/dump_stack.c')
-rw-r--r--lib/dump_stack.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 27f16872320d..cd3387bb34e5 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -5,6 +5,7 @@
*/
#include <linux/kernel.h>
+#include <linux/buildid.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
@@ -36,6 +37,14 @@ void __init dump_stack_set_arch_desc(const char *fmt, ...)
va_end(args);
}
+#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+#define BUILD_ID_FMT " %20phN"
+#define BUILD_ID_VAL vmlinux_build_id
+#else
+#define BUILD_ID_FMT "%s"
+#define BUILD_ID_VAL ""
+#endif
+
/**
* dump_stack_print_info - print generic debug info for dump_stack()
* @log_lvl: log level
@@ -45,13 +54,13 @@ void __init dump_stack_set_arch_desc(const char *fmt, ...)
*/
void dump_stack_print_info(const char *log_lvl)
{
- printk("%sCPU: %d PID: %d Comm: %.20s %s%s %s %.*s\n",
+ printk("%sCPU: %d PID: %d Comm: %.20s %s%s %s %.*s" BUILD_ID_FMT "\n",
log_lvl, raw_smp_processor_id(), current->pid, current->comm,
kexec_crash_loaded() ? "Kdump: loaded " : "",
print_tainted(),
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ init_utsname()->version, BUILD_ID_VAL);
if (dump_stack_arch_desc_str[0] != '\0')
printk("%sHardware name: %s\n",