Commit a5cf4b08 authored by Jim Keniston's avatar Jim Keniston Committed by Benjamin Herrenschmidt

powerpc/pseries/nvram: Capture oops/panic reports in ibm, oops-log partition

Create the lnx,oops-log NVRAM partition, and capture the end of the printk
buffer in it when there's an oops or panic.  If we can't create the
lnx,oops-log partition, capture the oops/panic report in ibm,rtas-log.
Signed-off-by: default avatarJim Keniston <jkenisto@us.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 0f4ac132
......@@ -16,6 +16,8 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/kmsg_dump.h>
#include <asm/uaccess.h>
#include <asm/nvram.h>
#include <asm/rtas.h>
......@@ -39,7 +41,7 @@ struct nvram_os_partition {
const char *name;
int req_size; /* desired size, in bytes */
int min_size; /* minimum acceptable size (0 means req_size) */
long size; /* size of data portion of partition */
long size; /* size of data portion (excluding err_log_info) */
long index; /* offset of data portion of partition */
};
......@@ -50,11 +52,35 @@ static struct nvram_os_partition rtas_log_partition = {
.index = -1
};
static struct nvram_os_partition oops_log_partition = {
.name = "lnx,oops-log",
.req_size = 4000,
.min_size = 2000,
.index = -1
};
static const char *pseries_nvram_os_partitions[] = {
"ibm,rtas-log",
"lnx,oops-log",
NULL
};
static void oops_to_nvram(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason,
const char *old_msgs, unsigned long old_len,
const char *new_msgs, unsigned long new_len);
static struct kmsg_dumper nvram_kmsg_dumper = {
.dump = oops_to_nvram
};
/* See clobbering_unread_rtas_event() */
#define NVRAM_RTAS_READ_TIMEOUT 5 /* seconds */
static unsigned long last_unread_rtas_event; /* timestamp */
/* We preallocate oops_buf during init to avoid kmalloc during oops/panic. */
static char *oops_buf;
static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
{
unsigned int i;
......@@ -214,8 +240,11 @@ int nvram_write_os_partition(struct nvram_os_partition *part, char * buff,
int nvram_write_error_log(char * buff, int length,
unsigned int err_type, unsigned int error_log_cnt)
{
return nvram_write_os_partition(&rtas_log_partition, buff, length,
int rc = nvram_write_os_partition(&rtas_log_partition, buff, length,
err_type, error_log_cnt);
if (!rc)
last_unread_rtas_event = get_seconds();
return rc;
}
/* nvram_read_error_log
......@@ -274,6 +303,7 @@ int nvram_clear_error_log(void)
printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
return rc;
}
last_unread_rtas_event = 0;
return 0;
}
......@@ -342,9 +372,35 @@ static int __init pseries_nvram_init_os_partition(struct nvram_os_partition
return 0;
}
static void __init nvram_init_oops_partition(int rtas_partition_exists)
{
int rc;
rc = pseries_nvram_init_os_partition(&oops_log_partition);
if (rc != 0) {
if (!rtas_partition_exists)
return;
pr_notice("nvram: Using %s partition to log both"
" RTAS errors and oops/panic reports\n",
rtas_log_partition.name);
memcpy(&oops_log_partition, &rtas_log_partition,
sizeof(rtas_log_partition));
}
oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
rc = kmsg_dump_register(&nvram_kmsg_dumper);
if (rc != 0) {
pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
kfree(oops_buf);
return;
}
}
static int __init pseries_nvram_init_log_partitions(void)
{
(void) pseries_nvram_init_os_partition(&rtas_log_partition);
int rc;
rc = pseries_nvram_init_os_partition(&rtas_log_partition);
nvram_init_oops_partition(rc == 0);
return 0;
}
machine_arch_initcall(pseries, pseries_nvram_init_log_partitions);
......@@ -378,3 +434,59 @@ int __init pSeries_nvram_init(void)
return 0;
}
/*
* Try to capture the last capture_len bytes of the printk buffer. Return
* the amount actually captured.
*/
static size_t capture_last_msgs(const char *old_msgs, size_t old_len,
const char *new_msgs, size_t new_len,
char *captured, size_t capture_len)
{
if (new_len >= capture_len) {
memcpy(captured, new_msgs + (new_len - capture_len),
capture_len);
return capture_len;
} else {
/* Grab the end of old_msgs. */
size_t old_tail_len = min(old_len, capture_len - new_len);
memcpy(captured, old_msgs + (old_len - old_tail_len),
old_tail_len);
memcpy(captured + old_tail_len, new_msgs, new_len);
return old_tail_len + new_len;
}
}
/*
* Are we using the ibm,rtas-log for oops/panic reports? And if so,
* would logging this oops/panic overwrite an RTAS event that rtas_errd
* hasn't had a chance to read and process? Return 1 if so, else 0.
*
* We assume that if rtas_errd hasn't read the RTAS event in
* NVRAM_RTAS_READ_TIMEOUT seconds, it's probably not going to.
*/
static int clobbering_unread_rtas_event(void)
{
return (oops_log_partition.index == rtas_log_partition.index
&& last_unread_rtas_event
&& get_seconds() - last_unread_rtas_event <=
NVRAM_RTAS_READ_TIMEOUT);
}
/* our kmsg_dump callback */
static void oops_to_nvram(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason,
const char *old_msgs, unsigned long old_len,
const char *new_msgs, unsigned long new_len)
{
static unsigned int oops_count = 0;
size_t text_len;
if (clobbering_unread_rtas_event())
return;
text_len = capture_last_msgs(old_msgs, old_len, new_msgs, new_len,
oops_buf, oops_log_partition.size);
(void) nvram_write_os_partition(&oops_log_partition, oops_buf,
(int) text_len, ERR_TYPE_KERNEL_PANIC, ++oops_count);
}
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment