Taint kernel after WARN_ON(condition)
The kernel is sent to tainted within the warn_on_slowpath() function, and
whenever a warning occurs the new taint flag 'W' is set. This is useful to
know if a warning occurred before a BUG by preserving the warning as a flag
in the taint state.
This does not work on architectures where WARN_ON has its own definition.
These archs are:
1. s390
2. superh
3. avr32
4. parisc
The maintainers of these architectures have been added in the Cc: list
in this email to alert them to the situation.
The documentation in oops-tracing.txt has been updated to include the
new flag.
Signed-off-by: Nur Hussein <nurhussein@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt
index 7f60dfe..b152e81 100644
--- a/Documentation/oops-tracing.txt
+++ b/Documentation/oops-tracing.txt
@@ -253,6 +253,10 @@
8: 'D' if the kernel has died recently, i.e. there was an OOPS or BUG.
+ 9: 'A' if the ACPI table has been overridden.
+
+ 10: 'W' if a warning has previously been issued by the kernel.
+
The primary reason for the 'Tainted: ' string is to tell kernel
debuggers if this is a clean kernel or if anything unusual has
occurred. Tainting is permanent: even if an offending module is
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index cd6d02c..28caa53 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -255,6 +255,7 @@
#define TAINT_USER (1<<6)
#define TAINT_DIE (1<<7)
#define TAINT_OVERRIDDEN_ACPI_TABLE (1<<8)
+#define TAINT_WARN (1<<9)
extern void dump_stack(void) __cold;
diff --git a/kernel/panic.c b/kernel/panic.c
index 24af9f8..425567f 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -153,6 +153,8 @@
* 'M' - System experienced a machine check exception.
* 'B' - System has hit bad_page.
* 'U' - Userspace-defined naughtiness.
+ * 'A' - ACPI table overridden.
+ * 'W' - Taint on warning.
*
* The string is overwritten by the next call to print_taint().
*/
@@ -161,7 +163,7 @@
{
static char buf[20];
if (tainted) {
- snprintf(buf, sizeof(buf), "Tainted: %c%c%c%c%c%c%c%c%c",
+ snprintf(buf, sizeof(buf), "Tainted: %c%c%c%c%c%c%c%c%c%c",
tainted & TAINT_PROPRIETARY_MODULE ? 'P' : 'G',
tainted & TAINT_FORCED_MODULE ? 'F' : ' ',
tainted & TAINT_UNSAFE_SMP ? 'S' : ' ',
@@ -170,7 +172,8 @@
tainted & TAINT_BAD_PAGE ? 'B' : ' ',
tainted & TAINT_USER ? 'U' : ' ',
tainted & TAINT_DIE ? 'D' : ' ',
- tainted & TAINT_OVERRIDDEN_ACPI_TABLE ? 'A' : ' ');
+ tainted & TAINT_OVERRIDDEN_ACPI_TABLE ? 'A' : ' ',
+ tainted & TAINT_WARN ? 'W' : ' ');
}
else
snprintf(buf, sizeof(buf), "Not tainted");
@@ -312,6 +315,7 @@
print_modules();
dump_stack();
print_oops_end_marker();
+ add_taint(TAINT_WARN);
}
EXPORT_SYMBOL(warn_on_slowpath);
#endif