mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-02 07:04:24 +00:00
![Pekka Enberg](/assets/img/avatar_default.png)
As suggested by Vegard Nossum, use KERN_WARNING for error reporting to make sure kmemcheck reports end up in syslog. Suggested-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261990935.4641.7.camel@penberg-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
227 lines
5.2 KiB
C
227 lines
5.2 KiB
C
#include <linux/interrupt.h>
|
|
#include <linux/kdebug.h>
|
|
#include <linux/kmemcheck.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/stacktrace.h>
|
|
#include <linux/string.h>
|
|
|
|
#include "error.h"
|
|
#include "shadow.h"
|
|
|
|
enum kmemcheck_error_type {
|
|
KMEMCHECK_ERROR_INVALID_ACCESS,
|
|
KMEMCHECK_ERROR_BUG,
|
|
};
|
|
|
|
#define SHADOW_COPY_SIZE (1 << CONFIG_KMEMCHECK_SHADOW_COPY_SHIFT)
|
|
|
|
struct kmemcheck_error {
|
|
enum kmemcheck_error_type type;
|
|
|
|
union {
|
|
/* KMEMCHECK_ERROR_INVALID_ACCESS */
|
|
struct {
|
|
/* Kind of access that caused the error */
|
|
enum kmemcheck_shadow state;
|
|
/* Address and size of the erroneous read */
|
|
unsigned long address;
|
|
unsigned int size;
|
|
};
|
|
};
|
|
|
|
struct pt_regs regs;
|
|
struct stack_trace trace;
|
|
unsigned long trace_entries[32];
|
|
|
|
/* We compress it to a char. */
|
|
unsigned char shadow_copy[SHADOW_COPY_SIZE];
|
|
unsigned char memory_copy[SHADOW_COPY_SIZE];
|
|
};
|
|
|
|
/*
|
|
* Create a ring queue of errors to output. We can't call printk() directly
|
|
* from the kmemcheck traps, since this may call the console drivers and
|
|
* result in a recursive fault.
|
|
*/
|
|
static struct kmemcheck_error error_fifo[CONFIG_KMEMCHECK_QUEUE_SIZE];
|
|
static unsigned int error_count;
|
|
static unsigned int error_rd;
|
|
static unsigned int error_wr;
|
|
static unsigned int error_missed_count;
|
|
|
|
static struct kmemcheck_error *error_next_wr(void)
|
|
{
|
|
struct kmemcheck_error *e;
|
|
|
|
if (error_count == ARRAY_SIZE(error_fifo)) {
|
|
++error_missed_count;
|
|
return NULL;
|
|
}
|
|
|
|
e = &error_fifo[error_wr];
|
|
if (++error_wr == ARRAY_SIZE(error_fifo))
|
|
error_wr = 0;
|
|
++error_count;
|
|
return e;
|
|
}
|
|
|
|
static struct kmemcheck_error *error_next_rd(void)
|
|
{
|
|
struct kmemcheck_error *e;
|
|
|
|
if (error_count == 0)
|
|
return NULL;
|
|
|
|
e = &error_fifo[error_rd];
|
|
if (++error_rd == ARRAY_SIZE(error_fifo))
|
|
error_rd = 0;
|
|
--error_count;
|
|
return e;
|
|
}
|
|
|
|
void kmemcheck_error_recall(void)
|
|
{
|
|
static const char *desc[] = {
|
|
[KMEMCHECK_SHADOW_UNALLOCATED] = "unallocated",
|
|
[KMEMCHECK_SHADOW_UNINITIALIZED] = "uninitialized",
|
|
[KMEMCHECK_SHADOW_INITIALIZED] = "initialized",
|
|
[KMEMCHECK_SHADOW_FREED] = "freed",
|
|
};
|
|
|
|
static const char short_desc[] = {
|
|
[KMEMCHECK_SHADOW_UNALLOCATED] = 'a',
|
|
[KMEMCHECK_SHADOW_UNINITIALIZED] = 'u',
|
|
[KMEMCHECK_SHADOW_INITIALIZED] = 'i',
|
|
[KMEMCHECK_SHADOW_FREED] = 'f',
|
|
};
|
|
|
|
struct kmemcheck_error *e;
|
|
unsigned int i;
|
|
|
|
e = error_next_rd();
|
|
if (!e)
|
|
return;
|
|
|
|
switch (e->type) {
|
|
case KMEMCHECK_ERROR_INVALID_ACCESS:
|
|
printk(KERN_WARNING "WARNING: kmemcheck: Caught %d-bit read from %s memory (%p)\n",
|
|
8 * e->size, e->state < ARRAY_SIZE(desc) ?
|
|
desc[e->state] : "(invalid shadow state)",
|
|
(void *) e->address);
|
|
|
|
printk(KERN_WARNING);
|
|
for (i = 0; i < SHADOW_COPY_SIZE; ++i)
|
|
printk(KERN_CONT "%02x", e->memory_copy[i]);
|
|
printk(KERN_CONT "\n");
|
|
|
|
printk(KERN_WARNING);
|
|
for (i = 0; i < SHADOW_COPY_SIZE; ++i) {
|
|
if (e->shadow_copy[i] < ARRAY_SIZE(short_desc))
|
|
printk(KERN_CONT " %c", short_desc[e->shadow_copy[i]]);
|
|
else
|
|
printk(KERN_CONT " ?");
|
|
}
|
|
printk(KERN_CONT "\n");
|
|
printk(KERN_WARNING "%*c\n", 2 + 2
|
|
* (int) (e->address & (SHADOW_COPY_SIZE - 1)), '^');
|
|
break;
|
|
case KMEMCHECK_ERROR_BUG:
|
|
printk(KERN_EMERG "ERROR: kmemcheck: Fatal error\n");
|
|
break;
|
|
}
|
|
|
|
__show_regs(&e->regs, 1);
|
|
print_stack_trace(&e->trace, 0);
|
|
}
|
|
|
|
static void do_wakeup(unsigned long data)
|
|
{
|
|
while (error_count > 0)
|
|
kmemcheck_error_recall();
|
|
|
|
if (error_missed_count > 0) {
|
|
printk(KERN_WARNING "kmemcheck: Lost %d error reports because "
|
|
"the queue was too small\n", error_missed_count);
|
|
error_missed_count = 0;
|
|
}
|
|
}
|
|
|
|
static DECLARE_TASKLET(kmemcheck_tasklet, &do_wakeup, 0);
|
|
|
|
/*
|
|
* Save the context of an error report.
|
|
*/
|
|
void kmemcheck_error_save(enum kmemcheck_shadow state,
|
|
unsigned long address, unsigned int size, struct pt_regs *regs)
|
|
{
|
|
static unsigned long prev_ip;
|
|
|
|
struct kmemcheck_error *e;
|
|
void *shadow_copy;
|
|
void *memory_copy;
|
|
|
|
/* Don't report several adjacent errors from the same EIP. */
|
|
if (regs->ip == prev_ip)
|
|
return;
|
|
prev_ip = regs->ip;
|
|
|
|
e = error_next_wr();
|
|
if (!e)
|
|
return;
|
|
|
|
e->type = KMEMCHECK_ERROR_INVALID_ACCESS;
|
|
|
|
e->state = state;
|
|
e->address = address;
|
|
e->size = size;
|
|
|
|
/* Save regs */
|
|
memcpy(&e->regs, regs, sizeof(*regs));
|
|
|
|
/* Save stack trace */
|
|
e->trace.nr_entries = 0;
|
|
e->trace.entries = e->trace_entries;
|
|
e->trace.max_entries = ARRAY_SIZE(e->trace_entries);
|
|
e->trace.skip = 0;
|
|
save_stack_trace_bp(&e->trace, regs->bp);
|
|
|
|
/* Round address down to nearest 16 bytes */
|
|
shadow_copy = kmemcheck_shadow_lookup(address
|
|
& ~(SHADOW_COPY_SIZE - 1));
|
|
BUG_ON(!shadow_copy);
|
|
|
|
memcpy(e->shadow_copy, shadow_copy, SHADOW_COPY_SIZE);
|
|
|
|
kmemcheck_show_addr(address);
|
|
memory_copy = (void *) (address & ~(SHADOW_COPY_SIZE - 1));
|
|
memcpy(e->memory_copy, memory_copy, SHADOW_COPY_SIZE);
|
|
kmemcheck_hide_addr(address);
|
|
|
|
tasklet_hi_schedule_first(&kmemcheck_tasklet);
|
|
}
|
|
|
|
/*
|
|
* Save the context of a kmemcheck bug.
|
|
*/
|
|
void kmemcheck_error_save_bug(struct pt_regs *regs)
|
|
{
|
|
struct kmemcheck_error *e;
|
|
|
|
e = error_next_wr();
|
|
if (!e)
|
|
return;
|
|
|
|
e->type = KMEMCHECK_ERROR_BUG;
|
|
|
|
memcpy(&e->regs, regs, sizeof(*regs));
|
|
|
|
e->trace.nr_entries = 0;
|
|
e->trace.entries = e->trace_entries;
|
|
e->trace.max_entries = ARRAY_SIZE(e->trace_entries);
|
|
e->trace.skip = 1;
|
|
save_stack_trace(&e->trace);
|
|
|
|
tasklet_hi_schedule_first(&kmemcheck_tasklet);
|
|
}
|