From: Pan Xinhui <[email protected]>
When we merge two contiguous partitions whose signatures are marked
NVRAM_SIG_FREE, We need update prev's length and checksum, then write it
to nvram, not cur's. So lets fix this mistake now.
Also use memset instead of strncpy to set the partition's name. It's
more readable if we want to fill up with duplicate chars .
Signed-off-by: Pan Xinhui <[email protected]>
---
arch/powerpc/kernel/nvram_64.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
index 21a278b7..40e80ca 100644
--- a/arch/powerpc/kernel/nvram_64.c
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -969,7 +969,7 @@ int __init nvram_remove_partition(const char *name, int sig,
/* Make partition a free partition */
part->header.signature = NVRAM_SIG_FREE;
- strncpy(part->header.name, "wwwwwwwwwwww", 12);
+ memset(part->header.name, 'w', 12);
part->header.checksum = nvram_checksum(&part->header);
rc = nvram_write_header(part);
if (rc <= 0) {
@@ -987,8 +987,8 @@ int __init nvram_remove_partition(const char *name, int sig,
}
if (prev) {
prev->header.length += part->header.length;
- prev->header.checksum = nvram_checksum(&part->header);
- rc = nvram_write_header(part);
+ prev->header.checksum = nvram_checksum(&prev->header);
+ rc = nvram_write_header(prev);
if (rc <= 0) {
printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
return rc;
--
2.5.0
Hi, all
I do some tests *without* my fix patch. after reboot, I saw logs below.
[ 0.271236] WARNING: nvram partition checksum was 58, should be 24!
[ 0.271239] Terminating nvram partition scan
If I do tests *with* my fix patch, logs are:
[ 0.291419] --------NVRAM Partitions---------
[ 0.291422] indx sig chks len name
[ 0.291425] 0 51 15 512 ibm,CPU0log
[ 0.291428] 8192 51 94 128 ibm,CPU1log
[ 0.291431] 10240 70 fc 256 common
[ 0.291434] 14336 a0 b5 131 ibm,rtas-log
[ 0.291437] 16432 a0 4f 251 lnx,oops-log
[ 0.291440] 20448 7f 26 2818 wwwwwwwwwwww
HOW TO REPRODUCE this warning?:
root@ubuntu:/home/pp/host# ./a.out 0 xinhui 4096
root@ubuntu:/home/pp/host# ./a.out 0 xinhui2 4096
root@ubuntu:/home/pp/host# ./a.out 0 xinhui3 4096
root@ubuntu:/home/pp/host# ./a.out 1 xinhui2
root@ubuntu:/home/pp/host# ./a.out 1 xinhui3
root@ubuntu:/home/pp/host# ./a.out 1 xinhui
then logs from dmesg are:
[ 844.205337] XINHUI: dev_nvram_ioctl, [xinhui],[0]
[ 844.205449] --------NVRAM Partitions---------
[ 844.205482] indx sig chks len name
[ 844.205510] 0 51 15 512 ibm,CPU0log
[ 844.205541] 8192 51 94 128 ibm,CPU1log
[ 844.205573] 10240 70 fc 256 common
[ 844.205604] 14336 a0 b5 131 ibm,rtas-log
[ 844.205636] 16432 a0 4f 251 lnx,oops-log
[ 844.205667] 20448 7f 5e 2818 free space
[ 851.636438] XINHUI: dev_nvram_ioctl, [xinhui],[4096]
[ 851.636534] --------NVRAM Partitions---------
[ 851.636573] indx sig chks len name
[ 851.636614] 0 51 15 512 ibm,CPU0log
[ 851.636651] 8192 51 94 128 ibm,CPU1log
[ 851.636688] 10240 70 fc 256 common
[ 851.636725] 14336 a0 b5 131 ibm,rtas-log
[ 851.636762] 16432 a0 4f 251 lnx,oops-log
[ 851.636798] 20448 ef 89 257 xinhui
[ 851.636836] 24560 7f 5c 2561 free space
[ 855.354409] XINHUI: dev_nvram_ioctl, [xinhui2],[4096]
[ 855.354600] --------NVRAM Partitions---------
[ 855.354639] indx sig chks len name
[ 855.354671] 0 51 15 512 ibm,CPU0log
[ 855.354708] 8192 51 94 128 ibm,CPU1log
[ 855.355499] 10240 70 fc 256 common
[ 855.356186] 14336 a0 b5 131 ibm,rtas-log
[ 855.356816] 16432 a0 4f 251 lnx,oops-log
[ 855.357429] 20448 ef 89 257 xinhui
[ 855.357966] 24560 ef bb 257 xinhui2
[ 855.358466] 28672 7f 5a 2304 free space
[ 857.866574] XINHUI: dev_nvram_ioctl, [xinhui3],[4096]
[ 857.867449] --------NVRAM Partitions---------
[ 857.868250] indx sig chks len name
[ 857.869082] 0 51 15 512 ibm,CPU0log
[ 857.869901] 8192 51 94 128 ibm,CPU1log
[ 857.870727] 10240 70 fc 256 common
[ 857.871569] 14336 a0 b5 131 ibm,rtas-log
[ 857.872392] 16432 a0 4f 251 lnx,oops-log
[ 857.873202] 20448 ef 89 257 xinhui
[ 857.874019] 24560 ef bb 257 xinhui2
[ 857.874811] 28672 ef bc 257 xinhui3
[ 857.875568] 32784 7f 58 2047 free space
[ 1015.661796] XINHUI: dev_nvram_ioctl, [xinhui2],[16383]
[ 1015.662670] --------NVRAM Partitions---------
[ 1015.663457] indx sig chks len name
[ 1015.664150] 0 51 15 512 ibm,CPU0log
[ 1015.664788] 8192 51 94 128 ibm,CPU1log
[ 1015.665396] 10240 70 fc 256 common
[ 1015.665948] 14336 a0 b5 131 ibm,rtas-log
[ 1015.666470] 16432 a0 4f 251 lnx,oops-log
[ 1015.666977] 20448 ef 89 257 xinhui
[ 1015.667455] 24560 7f 1b 257 wwwwwwwwwwww
[ 1015.667914] 28672 ef bc 257 xinhui3
[ 1015.668359] 32784 7f 58 2047 free space
[ 1017.452055] XINHUI: dev_nvram_ioctl, [xinhui3],[16383]
[ 1017.452902] --------NVRAM Partitions---------
[ 1017.453731] indx sig chks len name
[ 1017.454531] 0 51 15 512 ibm,CPU0log
[ 1017.455341] 8192 51 94 128 ibm,CPU1log
[ 1017.456121] 10240 70 fc 256 common
[ 1017.456916] 14336 a0 b5 131 ibm,rtas-log
[ 1017.457705] 16432 a0 4f 251 lnx,oops-log
[ 1017.458473] 20448 ef 89 257 xinhui
[ 1017.459256] 24560 7f 58 2561 wwwwwwwwwwww
[ 1020.871652] XINHUI: dev_nvram_ioctl, [xinhui],[16383]
[ 1020.872141] --------NVRAM Partitions---------
[ 1020.872584] indx sig chks len name
[ 1020.873021] 0 51 15 512 ibm,CPU0log
[ 1020.873475] 8192 51 94 128 ibm,CPU1log
[ 1020.873907] 10240 70 fc 256 common
[ 1020.874339] 14336 a0 b5 131 ibm,rtas-log
[ 1020.874777] 16432 a0 4f 251 lnx,oops-log
[ 1020.875205] 20448 7f 24 2818 wwwwwwwwwwww
the we reboot system, we would see warning logs, it means nvram partition is corrupted!
WHY IT CORRUPTED?:
when we combine two continuous partitions, current codes do wrong merge!
see my fix patch codes below:
@@ -1017,8 +1017,8 @@ int nvram_remove_partition(const char *name, int sig,
}
if (prev) {
prev->header.length += part->header.length;
- prev->header.checksum = nvram_checksum(&part->header);
[XINHUI]: we update prev->header.length, then we need re-calculate it's checksum, not part's!
- rc = nvram_write_header(part);
[XINHUI]: we update prev->header, so we need write prev's header to nvram. not part's!
+ prev->header.checksum = nvram_checksum(&prev->header);
+ rc = nvram_write_header(prev);
[XINHUI]: this is the correct code.
if (rc <= 0) {
printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
return rc;
these two partitions looks like
before merge:
------ ----------- --------- -------
other| | prev | | part | | other...
------ ---------- --------- -------
after merge:
------ ---------------------- -------
other| | prev(updated) | | other...
------ ---------------------- -------
NOW let me share the *debug* patch and the user-space codes, they are :
>From 5f7e0fe90b7671f8bbb142d9df1f5d4013819c48 Mon Sep 17 00:00:00 2001
From: Pan Xinhui <[email protected]>
Date: Fri, 11 Dec 2015 12:36:57 +0800
Subject: [PATCH] debug nvram
Signed-off-by: Pan Xinhui <[email protected]>
---
arch/powerpc/kernel/nvram_64.c | 53 ++++++++++++++++++++++++++++++++----------
1 file changed, 41 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
index a8939f5..4d91654 100644
--- a/arch/powerpc/kernel/nvram_64.c
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -36,6 +36,13 @@
#include <asm/machdep.h>
#undef DEBUG_NVRAM
+#define DEBUG_NVRAM
+struct x{
+ char name[12];
+ unsigned int size;
+};
+#define IOC_NVRAM_CREATE _IOWR('p', 0x44, struct x)
+#define IOC_NVRAM_REMOVE _IOWR('p', 0x45, struct x)
#define NVRAM_HEADER_LEN sizeof(struct nvram_header)
#define NVRAM_BLOCK_LEN NVRAM_HEADER_LEN
@@ -843,9 +850,12 @@ out:
}
+static void nvram_print_partitions(char * label);
+
static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
+ int remove = 0;
switch(cmd) {
#ifdef CONFIG_PPC_PMAC
case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
@@ -867,6 +877,25 @@ static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
return 0;
}
#endif /* CONFIG_PPC_PMAC */
+ case IOC_NVRAM_REMOVE:
+ remove = 1;
+ case IOC_NVRAM_CREATE: {
+ struct x h;
+ if (copy_from_user(&h, (void __user*)arg, sizeof(h)) != 0) {
+ printk("XINHUI: %s fails\n", __func__);
+ return 0;
+ }
+ printk("XINHUI: %s, [%s],[%d]\n", __func__, h.name, h.size);
+ if (remove == 0)
+ nvram_create_partition(h.name, 0xef, h.size, 0x100);
+ else
+ nvram_remove_partition(h.name, 0xef, NULL);
+ }
+
+#ifdef DEBUG_NVRAM
+ nvram_print_partitions("NVRAM Partitions");
+#endif
+ return 0;
default:
return -EINVAL;
}
@@ -878,6 +907,7 @@ const struct file_operations nvram_fops = {
.read = dev_nvram_read,
.write = dev_nvram_write,
.unlocked_ioctl = dev_nvram_ioctl,
+ .compat_ioctl = dev_nvram_ioctl,
};
static struct miscdevice nvram_dev = {
@@ -888,7 +918,7 @@ static struct miscdevice nvram_dev = {
#ifdef DEBUG_NVRAM
-static void __init nvram_print_partitions(char * label)
+static void nvram_print_partitions(char * label)
{
struct nvram_partition * tmp_part;
@@ -904,7 +934,7 @@ static void __init nvram_print_partitions(char * label)
#endif
-static int __init nvram_write_header(struct nvram_partition * part)
+static int nvram_write_header(struct nvram_partition * part)
{
loff_t tmp_index;
int rc;
@@ -920,7 +950,7 @@ static int __init nvram_write_header(struct nvram_partition * part)
}
-static unsigned char __init nvram_checksum(struct nvram_header *p)
+static unsigned char nvram_checksum(struct nvram_header *p)
{
unsigned int c_sum, c_sum2;
unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
@@ -965,7 +995,7 @@ static int nvram_can_remove_partition(struct nvram_partition *part,
* leave these alone.
*/
-int __init nvram_remove_partition(const char *name, int sig,
+int nvram_remove_partition(const char *name, int sig,
const char *exceptions[])
{
struct nvram_partition *part, *prev, *tmp;
@@ -1023,7 +1053,7 @@ int __init nvram_remove_partition(const char *name, int sig,
* you need to query for the actual size yourself after the
* call using nvram_partition_get_size().
*/
-loff_t __init nvram_create_partition(const char *name, int sig,
+loff_t nvram_create_partition(const char *name, int sig,
int req_size, int min_size)
{
struct nvram_partition *part;
--
2.5.0
*user-space* codes:
#include <stdio.h>
#include <fcntl.h>
#include <sys/types.h>
#include <linux/ioctl.h>
struct x{
char name[12];
unsigned int size;
};
#define IOC_NVRAM_CREATE _IOWR('p', 0x44, struct x)
#define IOC_NVRAM_REMOVE _IOWR('p', 0x45, struct x)
void main(int argc, char *argv[])
{
int fd;
unsigned int cmd;
struct x h;
fd = open("/dev/nvram", O_RDWR);
if (fd < 0) {
printf("fails open\n");
return;
}
cmd = atoi(argv[1]);
if (cmd == 0)
cmd = IOC_NVRAM_CREATE;
else
cmd = IOC_NVRAM_REMOVE;
strncpy(h.name, argv[2], 12);
if (cmd == IOC_NVRAM_CREATE)
h.size = atoi(argv[3]);
printf("%s, %d\n", h.name, h.size);
if (ioctl(fd, cmd, &h) < 0) {
printf("fails ioctl\n");
return;
}
close(fd);
return;
}
any comments are welcome :)
thanks
xinhui
On 2015年12月10日 15:30, xinhui wrote:
> From: Pan Xinhui <[email protected]>
>
> When we merge two contiguous partitions whose signatures are marked
> NVRAM_SIG_FREE, We need update prev's length and checksum, then write it
> to nvram, not cur's. So lets fix this mistake now.
>
> Also use memset instead of strncpy to set the partition's name. It's
> more readable if we want to fill up with duplicate chars .
>
> Signed-off-by: Pan Xinhui <[email protected]>
> ---
> arch/powerpc/kernel/nvram_64.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
> index 21a278b7..40e80ca 100644
> --- a/arch/powerpc/kernel/nvram_64.c
> +++ b/arch/powerpc/kernel/nvram_64.c
> @@ -969,7 +969,7 @@ int __init nvram_remove_partition(const char *name, int sig,
>
> /* Make partition a free partition */
> part->header.signature = NVRAM_SIG_FREE;
> - strncpy(part->header.name, "wwwwwwwwwwww", 12);
> + memset(part->header.name, 'w', 12);
> part->header.checksum = nvram_checksum(&part->header);
> rc = nvram_write_header(part);
> if (rc <= 0) {
> @@ -987,8 +987,8 @@ int __init nvram_remove_partition(const char *name, int sig,
> }
> if (prev) {
> prev->header.length += part->header.length;
> - prev->header.checksum = nvram_checksum(&part->header);
> - rc = nvram_write_header(part);
> + prev->header.checksum = nvram_checksum(&prev->header);
> + rc = nvram_write_header(prev);
> if (rc <= 0) {
> printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
> return rc;
>