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authorSeiji Aguchi2012-11-26 16:07:44 -0800
committerTony Luck2012-11-26 16:07:44 -0800
commit755d4fe46529018ae45bc7c86df682de45ace764 (patch)
tree470788ad3e9fa704ef41fa62ac9e770193010853 /drivers/firmware
parenta9efd39cd547223597cfe7c53acec44c099b9264 (diff)
efi_pstore: Add a sequence counter to a variable name
[Issue] Currently, a variable name, which identifies each entry, consists of type, id and ctime. But if multiple events happens in a short time, a second/third event may fail to log because efi_pstore can't distinguish each event with current variable name. [Solution] A reasonable way to identify all events precisely is introducing a sequence counter to the variable name. The sequence counter has already supported in a pstore layer with "oopscount". So, this patch adds it to a variable name. Also, it is passed to read/erase callbacks of platform drivers in accordance with the modification of the variable name. <before applying this patch> a variable name of first event: dump-type0-1-12345678 a variable name of second event: dump-type0-1-12345678 type:0 id:1 ctime:12345678 If multiple events happen in a short time, efi_pstore can't distinguish them because variable names are same among them. <after applying this patch> it can be distinguishable by adding a sequence counter as follows. a variable name of first event: dump-type0-1-1-12345678 a variable name of Second event: dump-type0-1-2-12345678 type:0 id:1 sequence counter: 1(first event), 2(second event) ctime:12345678 In case of a write callback executed in pstore_console_write(), "0" is added to an argument of the write callback because it just logs all kernel messages and doesn't need to care about multiple events. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Mike Waychison <mikew@google.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efivars.c23
1 files changed, 14 insertions, 9 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 3803621c0d45..7ad3aae6e085 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -658,13 +658,14 @@ static int efi_pstore_close(struct pstore_info *psi)
}
static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
- struct timespec *timespec,
+ int *count, struct timespec *timespec,
char **buf, struct pstore_info *psi)
{
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
struct efivars *efivars = psi->data;
char name[DUMP_NAME_LEN];
int i;
+ int cnt;
unsigned int part, size;
unsigned long time;
@@ -674,8 +675,10 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
for (i = 0; i < DUMP_NAME_LEN; i++) {
name[i] = efivars->walk_entry->var.VariableName[i];
}
- if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {
+ if (sscanf(name, "dump-type%u-%u-%d-%lu",
+ type, &part, &cnt, &time) == 4) {
*id = part;
+ *count = cnt;
timespec->tv_sec = time;
timespec->tv_nsec = 0;
get_var_data_locked(efivars, &efivars->walk_entry->var);
@@ -698,7 +701,8 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
static int efi_pstore_write(enum pstore_type_id type,
enum kmsg_dump_reason reason, u64 *id,
- unsigned int part, size_t size, struct pstore_info *psi)
+ unsigned int part, int count, size_t size,
+ struct pstore_info *psi)
{
char name[DUMP_NAME_LEN];
efi_char16_t efi_name[DUMP_NAME_LEN];
@@ -725,7 +729,7 @@ static int efi_pstore_write(enum pstore_type_id type,
return -ENOSPC;
}
- sprintf(name, "dump-type%u-%u-%lu", type, part,
+ sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
get_seconds());
for (i = 0; i < DUMP_NAME_LEN; i++)
@@ -746,7 +750,7 @@ static int efi_pstore_write(enum pstore_type_id type,
return ret;
};
-static int efi_pstore_erase(enum pstore_type_id type, u64 id,
+static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
struct timespec time, struct pstore_info *psi)
{
char name[DUMP_NAME_LEN];
@@ -756,7 +760,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id,
struct efivar_entry *entry, *found = NULL;
int i;
- sprintf(name, "dump-type%u-%u-%lu", type, (unsigned int)id,
+ sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
time.tv_sec);
spin_lock(&efivars->lock);
@@ -807,7 +811,7 @@ static int efi_pstore_close(struct pstore_info *psi)
return 0;
}
-static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
+static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, int *count,
struct timespec *timespec,
char **buf, struct pstore_info *psi)
{
@@ -816,12 +820,13 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
static int efi_pstore_write(enum pstore_type_id type,
enum kmsg_dump_reason reason, u64 *id,
- unsigned int part, size_t size, struct pstore_info *psi)
+ unsigned int part, int count, size_t size,
+ struct pstore_info *psi)
{
return 0;
}
-static int efi_pstore_erase(enum pstore_type_id type, u64 id,
+static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
struct timespec time, struct pstore_info *psi)
{
return 0;