Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
printk: Add a short description string to kmsg_dump()
kmsg_dump doesn't forward the panic reason string to the kmsg_dumper
callback.
This patch adds a new struct kmsg_dump_detail, that will hold the
reason and description, and pass it to the dump() callback.
To avoid updating all kmsg_dump() call, it adds a kmsg_dump_desc()
function and a macro for backward compatibility.
I've written this for drm_panic, but it can be useful for other
kmsg_dumper.
It allows to see the panic reason, like "sysrq triggered crash"
or "VFS: Unable to mount root fs on xxxx" on the drm panic screen.
v2:
* Use a struct kmsg_dump_detail to hold the reason and description
pointer, for more flexibility if we want to add other parameters.
(Kees Cook)
* Fix powerpc/nvram_64 build, as I didn't update the forward
declaration of oops_to_nvram()
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Kees Cook <kees@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240702122639.248110-1-jfalempe@redhat.com
+45
-24
+4
-4
arch/powerpc/kernel/nvram_64.c
+4
-4
arch/powerpc/kernel/nvram_64.c
···
73
73
};
74
74
75
75
static void oops_to_nvram(struct kmsg_dumper *dumper,
76
-
enum kmsg_dump_reason reason);
76
+
struct kmsg_dump_detail *detail);
77
77
78
78
static struct kmsg_dumper nvram_kmsg_dumper = {
79
79
.dump = oops_to_nvram
···
643
643
* partition. If that's too much, go back and capture uncompressed text.
644
644
*/
645
645
static void oops_to_nvram(struct kmsg_dumper *dumper,
646
-
enum kmsg_dump_reason reason)
646
+
struct kmsg_dump_detail *detail)
647
647
{
648
648
struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
649
649
static unsigned int oops_count = 0;
···
655
655
unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
656
656
int rc = -1;
657
657
658
-
switch (reason) {
658
+
switch (detail->reason) {
659
659
case KMSG_DUMP_SHUTDOWN:
660
660
/* These are almost always orderly shutdowns. */
661
661
return;
···
671
671
break;
672
672
default:
673
673
pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
674
-
__func__, (int) reason);
674
+
__func__, (int) detail->reason);
675
675
return;
676
676
}
677
677
+2
-2
arch/powerpc/platforms/powernv/opal-kmsg.c
+2
-2
arch/powerpc/platforms/powernv/opal-kmsg.c
···
20
20
* message, it just ensures that OPAL completely flushes the console buffer.
21
21
*/
22
22
static void kmsg_dump_opal_console_flush(struct kmsg_dumper *dumper,
23
-
enum kmsg_dump_reason reason)
23
+
struct kmsg_dump_detail *detail)
24
24
{
25
25
/*
26
26
* Outside of a panic context the pollers will continue to run,
27
27
* so we don't need to do any special flushing.
28
28
*/
29
-
if (reason != KMSG_DUMP_PANIC)
29
+
if (detail->reason != KMSG_DUMP_PANIC)
30
30
return;
31
31
32
32
opal_flush_console(0);
+1
-1
arch/um/kernel/kmsg_dump.c
+1
-1
arch/um/kernel/kmsg_dump.c
+2
-2
drivers/gpu/drm/drm_panic.c
+2
-2
drivers/gpu/drm/drm_panic.c
···
655
655
return container_of(kd, struct drm_plane, kmsg_panic);
656
656
}
657
657
658
-
static void drm_panic(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason)
658
+
static void drm_panic(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail)
659
659
{
660
660
struct drm_plane *plane = to_drm_plane(dumper);
661
661
662
-
if (reason == KMSG_DUMP_PANIC)
662
+
if (detail->reason == KMSG_DUMP_PANIC)
663
663
draw_panic_plane(plane);
664
664
}
665
665
+2
-2
drivers/hv/hv_common.c
+2
-2
drivers/hv/hv_common.c
···
207
207
* buffer and call into Hyper-V to transfer the data.
208
208
*/
209
209
static void hv_kmsg_dump(struct kmsg_dumper *dumper,
210
-
enum kmsg_dump_reason reason)
210
+
struct kmsg_dump_detail *detail)
211
211
{
212
212
struct kmsg_dump_iter iter;
213
213
size_t bytes_written;
214
214
215
215
/* We are only interested in panics. */
216
-
if (reason != KMSG_DUMP_PANIC || !sysctl_record_panic_msg)
216
+
if (detail->reason != KMSG_DUMP_PANIC || !sysctl_record_panic_msg)
217
217
return;
218
218
219
219
/*
+1
-1
drivers/mtd/mtdoops.c
+1
-1
drivers/mtd/mtdoops.c
+5
-5
fs/pstore/platform.c
+5
-5
fs/pstore/platform.c
···
275
275
* end of the buffer.
276
276
*/
277
277
static void pstore_dump(struct kmsg_dumper *dumper,
278
-
enum kmsg_dump_reason reason)
278
+
struct kmsg_dump_detail *detail)
279
279
{
280
280
struct kmsg_dump_iter iter;
281
281
unsigned long total = 0;
···
285
285
int saved_ret = 0;
286
286
int ret;
287
287
288
-
why = kmsg_dump_reason_str(reason);
288
+
why = kmsg_dump_reason_str(detail->reason);
289
289
290
-
if (pstore_cannot_block_path(reason)) {
290
+
if (pstore_cannot_block_path(detail->reason)) {
291
291
if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) {
292
292
pr_err("dump skipped in %s path because of concurrent dump\n",
293
293
in_nmi() ? "NMI" : why);
···
311
311
pstore_record_init(&record, psinfo);
312
312
record.type = PSTORE_TYPE_DMESG;
313
313
record.count = oopscount;
314
-
record.reason = reason;
314
+
record.reason = detail->reason;
315
315
record.part = part;
316
316
record.buf = psinfo->buf;
317
317
···
352
352
}
353
353
354
354
ret = psinfo->write(&record);
355
-
if (ret == 0 && reason == KMSG_DUMP_OOPS) {
355
+
if (ret == 0 && detail->reason == KMSG_DUMP_OOPS) {
356
356
pstore_new_entry = 1;
357
357
pstore_timer_kick();
358
358
} else {
+19
-3
include/linux/kmsg_dump.h
+19
-3
include/linux/kmsg_dump.h
···
40
40
};
41
41
42
42
/**
43
+
* struct kmsg_dump_detail - kernel crash detail
44
+
* @reason: reason for the crash, see kmsg_dump_reason.
45
+
* @description: optional short string, to provide additional information.
46
+
*/
47
+
48
+
struct kmsg_dump_detail {
49
+
enum kmsg_dump_reason reason;
50
+
const char *description;
51
+
};
52
+
53
+
/**
43
54
* struct kmsg_dumper - kernel crash message dumper structure
44
55
* @list: Entry in the dumper list (private)
45
56
* @dump: Call into dumping code which will retrieve the data with
···
60
49
*/
61
50
struct kmsg_dumper {
62
51
struct list_head list;
63
-
void (*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason);
52
+
void (*dump)(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail);
64
53
enum kmsg_dump_reason max_reason;
65
54
bool registered;
66
55
};
67
56
68
57
#ifdef CONFIG_PRINTK
69
-
void kmsg_dump(enum kmsg_dump_reason reason);
58
+
void kmsg_dump_desc(enum kmsg_dump_reason reason, const char *desc);
70
59
71
60
bool kmsg_dump_get_line(struct kmsg_dump_iter *iter, bool syslog,
72
61
char *line, size_t size, size_t *len);
···
82
71
83
72
const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason);
84
73
#else
85
-
static inline void kmsg_dump(enum kmsg_dump_reason reason)
74
+
static inline void kmsg_dump_desc(enum kmsg_dump_reason reason, const char *desc)
86
75
{
87
76
}
88
77
···
117
106
return "Disabled";
118
107
}
119
108
#endif
109
+
110
+
static inline void kmsg_dump(enum kmsg_dump_reason reason)
111
+
{
112
+
kmsg_dump_desc(reason, NULL);
113
+
}
120
114
121
115
#endif /* _LINUX_KMSG_DUMP_H */
+1
-1
kernel/panic.c
+1
-1
kernel/panic.c
+8
-3
kernel/printk/printk.c
+8
-3
kernel/printk/printk.c
···
4126
4126
EXPORT_SYMBOL_GPL(kmsg_dump_reason_str);
4127
4127
4128
4128
/**
4129
-
* kmsg_dump - dump kernel log to kernel message dumpers.
4129
+
* kmsg_dump_desc - dump kernel log to kernel message dumpers.
4130
4130
* @reason: the reason (oops, panic etc) for dumping
4131
+
* @desc: a short string to describe what caused the panic or oops. Can be NULL
4132
+
* if no additional description is available.
4131
4133
*
4132
4134
* Call each of the registered dumper's dump() callback, which can
4133
4135
* retrieve the kmsg records with kmsg_dump_get_line() or
4134
4136
* kmsg_dump_get_buffer().
4135
4137
*/
4136
-
void kmsg_dump(enum kmsg_dump_reason reason)
4138
+
void kmsg_dump_desc(enum kmsg_dump_reason reason, const char *desc)
4137
4139
{
4138
4140
struct kmsg_dumper *dumper;
4141
+
struct kmsg_dump_detail detail = {
4142
+
.reason = reason,
4143
+
.description = desc};
4139
4144
4140
4145
rcu_read_lock();
4141
4146
list_for_each_entry_rcu(dumper, &dump_list, list) {
···
4158
4153
continue;
4159
4154
4160
4155
/* invoke dumper which will iterate over records */
4161
-
dumper->dump(dumper, reason);
4156
+
dumper->dump(dumper, &detail);
4162
4157
}
4163
4158
rcu_read_unlock();
4164
4159
}