The quilt patch titled
Subject: kernel/panic: add verbose logging of kernel taints in backtraces
has been removed from the -mm tree. Its filename was
kernel-panic-add-verbose-logging-of-kernel-taints-in-backtraces.patch
This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Jani Nikula <jani.nikula@xxxxxxxxx>
Subject: kernel/panic: add verbose logging of kernel taints in backtraces
Date: Fri, 31 May 2024 12:04:57 +0300
With nearly 20 taint flags and respective characters, it's getting a bit
difficult to remember what each taint flag character means. Add verbose
logging of the set taints in the format:
Tainted: [P]=PROPRIETARY_MODULE, [W]=WARN
in dump_stack_print_info() when there are taints.
Note that the "negative flag" G is not included.
Link: https://lkml.kernel.org/r/7321e306166cb2ca2807ab8639e665baa2462e9c.1717146197.git.jani.nikula@xxxxxxxxx
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/panic.h | 8 ++++---
kernel/panic.c | 45 ++++++++++++++++++++++++++++++----------
lib/dump_stack.c | 3 ++
3 files changed, 42 insertions(+), 14 deletions(-)
--- a/include/linux/panic.h~kernel-panic-add-verbose-logging-of-kernel-taints-in-backtraces
+++ a/include/linux/panic.h
@@ -77,9 +77,10 @@ static inline void set_arch_panic_timeou
#define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1)
struct taint_flag {
- char c_true; /* character printed when tainted */
- char c_false; /* character printed when not tainted */
- bool module; /* also show as a per-module taint flag */
+ char c_true; /* character printed when tainted */
+ char c_false; /* character printed when not tainted */
+ bool module; /* also show as a per-module taint flag */
+ const char *desc; /* verbose description of the set taint flag */
};
extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];
@@ -90,6 +91,7 @@ enum lockdep_ok {
};
extern const char *print_tainted(void);
+extern const char *print_tainted_verbose(void);
extern void add_taint(unsigned flag, enum lockdep_ok);
extern int test_taint(unsigned flag);
extern unsigned long get_taint(void);
--- a/kernel/panic.c~kernel-panic-add-verbose-logging-of-kernel-taints-in-backtraces
+++ a/kernel/panic.c
@@ -475,6 +475,7 @@ EXPORT_SYMBOL(panic);
[ TAINT_##taint ] = { \
.c_true = _c_true, .c_false = _c_false, \
.module = _module, \
+ .desc = #taint, \
}
/*
@@ -505,8 +506,9 @@ const struct taint_flag taint_flags[TAIN
#undef TAINT_FLAG
-static void print_tainted_seq(struct seq_buf *s)
+static void print_tainted_seq(struct seq_buf *s, bool verbose)
{
+ const char *sep = "";
int i;
if (!tainted_mask) {
@@ -520,10 +522,32 @@ static void print_tainted_seq(struct seq
bool is_set = test_bit(i, &tainted_mask);
char c = is_set ? t->c_true : t->c_false;
- seq_buf_putc(s, c);
+ if (verbose) {
+ if (is_set) {
+ seq_buf_printf(s, "%s[%c]=%s", sep, c, t->desc);
+ sep = ", ";
+ }
+ } else {
+ seq_buf_putc(s, c);
+ }
}
}
+static const char *_print_tainted(bool verbose)
+{
+ /* FIXME: what should the size be? */
+ static char buf[sizeof(taint_flags)];
+ struct seq_buf s;
+
+ BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT);
+
+ seq_buf_init(&s, buf, sizeof(buf));
+
+ print_tainted_seq(&s, verbose);
+
+ return seq_buf_str(&s);
+}
+
/**
* print_tainted - return a string to represent the kernel taint state.
*
@@ -534,16 +558,15 @@ static void print_tainted_seq(struct seq
*/
const char *print_tainted(void)
{
- static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
- struct seq_buf s;
-
- BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT);
-
- seq_buf_init(&s, buf, sizeof(buf));
-
- print_tainted_seq(&s);
+ return _print_tainted(false);
+}
- return seq_buf_str(&s);
+/**
+ * print_tainted_verbose - A more verbose version of print_tainted()
+ */
+const char *print_tainted_verbose(void)
+{
+ return _print_tainted(true);
}
int test_taint(unsigned flag)
--- a/lib/dump_stack.c~kernel-panic-add-verbose-logging-of-kernel-taints-in-backtraces
+++ a/lib/dump_stack.c
@@ -62,6 +62,9 @@ void dump_stack_print_info(const char *l
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version, BUILD_ID_VAL);
+ if (get_taint())
+ printk("%s%s\n", log_lvl, print_tainted_verbose());
+
if (dump_stack_arch_desc_str[0] != '\0')
printk("%sHardware name: %s\n",
log_lvl, dump_stack_arch_desc_str);
_
Patches currently in -mm which might be from jani.nikula@xxxxxxxxx are
