[PATCH 1/3] fix one type of return value in pstore
[PATCH 2/3] fix pstore filesystem mount/remount issue
[PATCH 3/3] fix potential logic issue in pstore read interface
These patches fix some potential errors for pstore when erst as
the underlying interface. And fix a pstore filesystem mount/remount
issue.
the return type of function _read_ in pstore is size_t,
but in the callback function of _read_, the logic doesn't
consider it too much, which means if negative value (assuming
error here) is returned, it will be converted to positive because
of type casting. ssize_t is enough for this function.
Signed-off-by: Chen Gong <[email protected]>
---
drivers/acpi/apei/erst.c | 4 ++--
fs/pstore/platform.c | 4 ++--
include/linux/pstore.h | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index d6cb0ff..d5a89d0 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -929,7 +929,7 @@ static int erst_check_table(struct acpi_table_erst *erst_tab)
return 0;
}
-static size_t erst_reader(u64 *id, enum pstore_type_id *type,
+static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
struct timespec *time);
static u64 erst_writer(enum pstore_type_id type, size_t size);
@@ -957,7 +957,7 @@ struct cper_pstore_record {
char data[];
} __packed;
-static size_t erst_reader(u64 *id, enum pstore_type_id *type,
+static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
struct timespec *time)
{
int rc;
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index f835a25..912403c 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -152,7 +152,7 @@ EXPORT_SYMBOL_GPL(pstore_register);
void pstore_get_records(void)
{
struct pstore_info *psi = psinfo;
- size_t size;
+ ssize_t size;
u64 id;
enum pstore_type_id type;
struct timespec time;
@@ -163,7 +163,7 @@ void pstore_get_records(void)
mutex_lock(&psinfo->buf_mutex);
while ((size = psi->read(&id, &type, &time)) > 0) {
- if (pstore_mkfile(type, psi->name, id, psi->buf, size,
+ if (pstore_mkfile(type, psi->name, id, psi->buf, (size_t)size,
time, psi->erase))
failed++;
}
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 4197773..14ce2f5 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -35,7 +35,7 @@ struct pstore_info {
struct mutex buf_mutex; /* serialize access to 'buf' */
char *buf;
size_t bufsize;
- size_t (*read)(u64 *id, enum pstore_type_id *type,
+ ssize_t (*read)(u64 *id, enum pstore_type_id *type,
struct timespec *time);
u64 (*write)(enum pstore_type_id type, size_t size);
int (*erase)(u64 id);
--
1.7.5.185.g0b9dee
Currently after mount/remount operation on pstore filesystem,
the content on pstore will be lost. It is because current ERST
implementation doesn't support multi-user usage, which moves
internal pointer to the end after accessing it. Adding
multi-user support for pstore usage.
Signed-off-by: Chen Gong <[email protected]>
---
drivers/acpi/apei/erst.c | 48 +++++++++++++++++++++++++++++++++------------
fs/pstore/platform.c | 8 ++++++-
include/linux/pstore.h | 2 +
3 files changed, 44 insertions(+), 14 deletions(-)
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index d5a89d0..ddb68c4 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -929,6 +929,8 @@ static int erst_check_table(struct acpi_table_erst *erst_tab)
return 0;
}
+static int erst_open_pstore(struct pstore_info *psi);
+static int erst_close_pstore(struct pstore_info *psi);
static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
struct timespec *time);
static u64 erst_writer(enum pstore_type_id type, size_t size);
@@ -936,6 +938,8 @@ static u64 erst_writer(enum pstore_type_id type, size_t size);
static struct pstore_info erst_info = {
.owner = THIS_MODULE,
.name = "erst",
+ .open = erst_open_pstore,
+ .close = erst_close_pstore,
.read = erst_reader,
.write = erst_writer,
.erase = erst_clear
@@ -957,12 +961,32 @@ struct cper_pstore_record {
char data[];
} __packed;
+static int reader_pos;
+
+static int erst_open_pstore(struct pstore_info *psi)
+{
+ int rc;
+
+ if (erst_disable)
+ return -ENODEV;
+
+ rc = erst_get_record_id_begin(&reader_pos);
+
+ return rc;
+}
+
+static int erst_close_pstore(struct pstore_info *psi)
+{
+ erst_get_record_id_end();
+
+ return 0;
+}
+
static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
struct timespec *time)
{
int rc;
- ssize_t len;
- unsigned long flags;
+ ssize_t len = 0;
u64 record_id;
struct cper_pstore_record *rcd = (struct cper_pstore_record *)
(erst_info.buf - sizeof(*rcd));
@@ -970,24 +994,21 @@ static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
if (erst_disable)
return -ENODEV;
- raw_spin_lock_irqsave(&erst_lock, flags);
skip:
- rc = __erst_get_next_record_id(&record_id);
- if (rc) {
- raw_spin_unlock_irqrestore(&erst_lock, flags);
- return rc;
- }
+ rc = erst_get_record_id_next(&reader_pos, &record_id);
+ if (rc)
+ goto out;
+
/* no more record */
if (record_id == APEI_ERST_INVALID_RECORD_ID) {
- raw_spin_unlock_irqrestore(&erst_lock, flags);
- return 0;
+ rc = -1;
+ goto out;
}
- len = __erst_read(record_id, &rcd->hdr, sizeof(*rcd) +
+ len = erst_read(record_id, &rcd->hdr, sizeof(*rcd) +
erst_erange.size);
if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
goto skip;
- raw_spin_unlock_irqrestore(&erst_lock, flags);
*id = record_id;
if (uuid_le_cmp(rcd->sec_hdr.section_type,
@@ -1005,7 +1026,8 @@ skip:
time->tv_sec = 0;
time->tv_nsec = 0;
- return len - sizeof(*rcd);
+out:
+ return (rc < 0) ? rc : (len - sizeof(*rcd));
}
static u64 erst_writer(enum pstore_type_id type, size_t size)
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 912403c..f2c3ff2 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -156,17 +156,23 @@ void pstore_get_records(void)
u64 id;
enum pstore_type_id type;
struct timespec time;
- int failed = 0;
+ int failed = 0, rc;
if (!psi)
return;
mutex_lock(&psinfo->buf_mutex);
+ rc = psi->open(psi);
+ if (rc)
+ goto out;
+
while ((size = psi->read(&id, &type, &time)) > 0) {
if (pstore_mkfile(type, psi->name, id, psi->buf, (size_t)size,
time, psi->erase))
failed++;
}
+ psi->close(psi);
+out:
mutex_unlock(&psinfo->buf_mutex);
if (failed)
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 14ce2f5..2455ef2 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -35,6 +35,8 @@ struct pstore_info {
struct mutex buf_mutex; /* serialize access to 'buf' */
char *buf;
size_t bufsize;
+ int (*open)(struct pstore_info *psi);
+ int (*close)(struct pstore_info *psi);
ssize_t (*read)(u64 *id, enum pstore_type_id *type,
struct timespec *time);
u64 (*write)(enum pstore_type_id type, size_t size);
--
1.7.5.185.g0b9dee
1) in the calling of erst_read, the parameter of buffer size
maybe overflows and cause crash
2) the return value of erst_read should be checked more strictly
Signed-off-by: Chen Gong <[email protected]>
---
drivers/acpi/apei/erst.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index ddb68c4..e6cef8e 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -1006,7 +1006,14 @@ skip:
}
len = erst_read(record_id, &rcd->hdr, sizeof(*rcd) +
- erst_erange.size);
+ erst_info.bufsize);
+ /* The record may be cleared by others, try read next record */
+ if (len == -ENOENT)
+ goto skip;
+ else if (len < 0) {
+ rc = -1;
+ goto out;
+ }
if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
goto skip;
--
1.7.5.185.g0b9dee