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efi_pstore: Remove a logic erasing entries from a write callback to hold multiple logs 

[Issue]

Currently, efi_pstore driver simply overwrites existing panic messages in NVRAM.
So, in the following scenario, we will lose 1st panic messages.

1. kernel panics.
2. efi_pstore is kicked and writes panic messages to NVRAM.
3. system reboots.
4. kernel panics again before a user checks the 1st panic messages in NVRAM.

[Solution]

A reasonable solution to fix the issue is just holding multiple logs without erasing
existing entries.
This patch removes a logic erasing existing entries in a write callback
because the logic is not needed in the write callback to support holding multiple logs.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Seiji Aguchi 2012-11-14 20:26:46 +00:00 committed by Tony Luck
parent dd230fecab
commit 96480d9c8f
1 changed files with 2 additions and 37 deletions
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39
drivers/firmware/efivars.c
View File

@ -701,18 +701,13 @@ static int efi_pstore_write(enum pstore_type_id type,
unsigned int part, size_t size, struct pstore_info *psi)
{
char name[DUMP_NAME_LEN];
char stub_name[DUMP_NAME_LEN];
efi_char16_t efi_name[DUMP_NAME_LEN];
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
struct efivars *efivars = psi->data;
struct efivar_entry *entry, *found = NULL;
int i, ret = 0;
u64 storage_space, remaining_space, max_variable_size;
efi_status_t status = EFI_NOT_FOUND;
sprintf(stub_name, "dump-type%u-%u-", type, part);
sprintf(name, "%s%lu", stub_name, get_seconds());
spin_lock(&efivars->lock);
/*
@ -730,35 +725,8 @@ static int efi_pstore_write(enum pstore_type_id type,
return -ENOSPC;
}
for (i = 0; i < DUMP_NAME_LEN; i++)
efi_name[i] = stub_name[i];
/*
* Clean up any entries with the same name
*/
list_for_each_entry(entry, &efivars->list, list) {
get_var_data_locked(efivars, &entry->var);
if (efi_guidcmp(entry->var.VendorGuid, vendor))
continue;
if (utf16_strncmp(entry->var.VariableName, efi_name,
utf16_strlen(efi_name)))
continue;
/* Needs to be a prefix */
if (entry->var.VariableName[utf16_strlen(efi_name)] == 0)
continue;
/* found */
found = entry;
efivars->ops->set_variable(entry->var.VariableName,
&entry->var.VendorGuid,
PSTORE_EFI_ATTRIBUTES,
0, NULL);
}
if (found)
list_del(&found->list);
sprintf(name, "dump-type%u-%u-%lu", type, part,
get_seconds());
for (i = 0; i < DUMP_NAME_LEN; i++)
efi_name[i] = name[i];
@ -768,9 +736,6 @@ static int efi_pstore_write(enum pstore_type_id type,
spin_unlock(&efivars->lock);
if (found)
efivar_unregister(found);
if (size)
ret = efivar_create_sysfs_entry(efivars,
utf16_strsize(efi_name,