Re: [PATCH v2 7/8] powerpc/pseries: Read of-config partition viapstore

From: Aruna Balakrishnaiah
Date: Thu Apr 25 2013 - 01:10:33 EST

On Thursday 25 April 2013 02:13 AM, Kees Cook wrote:

Hi Kees,

On Tue, Apr 23, 2013 at 11:20 PM, Aruna Balakrishnaiah
<aruna@xxxxxxxxxxxxxxxxxx> wrote:
This patch set exploits the pstore subsystem to read details of
of-config partition in NVRAM to a separate file in /dev/pstore.
For instance, of-config partition details will be stored in a
file named [of-nvram-5].

Signed-off-by: Aruna Balakrishnaiah <aruna@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Jim Keniston <jkenisto@xxxxxxxxxx>
---
arch/powerpc/platforms/pseries/nvram.c | 55 +++++++++++++++++++++++++++-----
fs/pstore/inode.c | 3 ++
include/linux/pstore.h | 1 +
3 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index b118382..de448af 100644
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -132,9 +132,16 @@ static size_t oops_data_sz;
static struct z_stream_s stream;

#ifdef CONFIG_PSTORE
+static struct nvram_os_partition of_config_partition = {
+ .name = "of-config",
+ .index = -1,
+ .os_partition = false
+};
+
static enum pstore_type_id nvram_type_ids[] = {
PSTORE_TYPE_DMESG,
PSTORE_TYPE_RTAS,
+ PSTORE_TYPE_OF,
-1
};
static int read_type;
@@ -332,10 +339,15 @@ int nvram_read_partition(struct nvram_os_partition *part, char *buff,

tmp_index = part->index;

- rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
- if (rc <= 0) {
- pr_err("%s: Failed nvram_read (%d)\n", __FUNCTION__, rc);
- return rc;
+ if (part->os_partition) {
+ rc = ppc_md.nvram_read((char *)&info,
+ sizeof(struct err_log_info),
+ &tmp_index);
+ if (rc <= 0) {
+ pr_err("%s: Failed nvram_read (%d)\n", __FUNCTION__,
+ rc);
+ return rc;
+ }
}

rc = ppc_md.nvram_read(buff, length, &tmp_index);
@@ -344,8 +356,10 @@ int nvram_read_partition(struct nvram_os_partition *part, char *buff,
return rc;
}

- *error_log_cnt = info.seq_num;
- *err_type = info.error_type;
+ if (part->os_partition) {
+ *error_log_cnt = info.seq_num;
+ *err_type = info.error_type;
+ }

return 0;
}
@@ -516,7 +530,7 @@ static int nvram_pstore_write(enum pstore_type_id type,
}

/*
- * Reads the oops/panic report and ibm,rtas-log partition.
+ * Reads the oops/panic report, rtas and of-config partition.
* Returns the length of the data we read from each partition.
* Returns 0 if we've been called before.
*/
@@ -525,9 +539,11 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
struct pstore_info *psi)
{
struct oops_log_info *oops_hdr;
- unsigned int err_type, id_no;
+ unsigned int err_type, id_no, size = 0;
struct nvram_os_partition *part = NULL;
char *buff = NULL;
+ int sig = 0;
+ loff_t p;

read_type++;

@@ -542,10 +558,29 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
time->tv_sec = last_rtas_event;
time->tv_nsec = 0;
break;
+ case PSTORE_TYPE_OF:
+ sig = NVRAM_SIG_OF;
+ part = &of_config_partition;
+ *type = PSTORE_TYPE_OF;
+ *id = PSTORE_TYPE_OF;
+ time->tv_sec = 0;
+ time->tv_nsec = 0;
+ break;
default:
return 0;
}

+ if (!part->os_partition) {
+ p = nvram_find_partition(part->name, sig, &size);
+ if (p <= 0) {
+ pr_err("nvram: Failed to find partition %s, "
+ "err %d\n", part->name, (int)p);
+ return 0;
+ }
+ part->index = p;
+ part->size = size;
+ }
+
buff = kmalloc(part->size, GFP_KERNEL);

if (!buff)
@@ -557,7 +592,9 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
}

*count = 0;
- *id = id_no;
+
+ if (part->os_partition)
+ *id = id_no;

if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
oops_hdr = (struct oops_log_info *)buff;
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index ec24f9c..8d4fb65 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -327,6 +327,9 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
case PSTORE_TYPE_PPC_RTAS:
sprintf(name, "rtas-%s-%lld", psname, id);
break;
+ case PSTORE_TYPE_PPC_OF:
+ sprintf(name, "of-%s-%lld", psname, id);
+ break;
case PSTORE_TYPE_UNKNOWN:
sprintf(name, "unknown-%s-%lld", psname, id);
break;
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index d7a8fe9..615dc18 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -37,6 +37,7 @@ enum pstore_type_id {
PSTORE_TYPE_FTRACE = 3,
/* PPC64 partition types */
PSTORE_TYPE_PPC_RTAS = 4,
+ PSTORE_TYPE_PPC_OF = 5,
PSTORE_TYPE_UNKNOWN = 255
};


Should this be named just "PSTORE_TYPE_OF" instead of "...PPC_OF"?

I renamed it from PSTORE_TYPE_OF to PSTORE_TYPE_PPC_OF as per Michael's
suggestion. But I have made a mistake of not changing the new name in nvram.c
file.

Will wait for other review comments and repost the patch.


-Kees

--
Kees Cook
Chrome OS Security
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