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-rw-r--r--arch/powerpc/kernel/nvram_64.c2
-rw-r--r--drivers/acpi/apei/erst.c1
-rw-r--r--drivers/firmware/efi/efi-pstore.c4
-rw-r--r--fs/pstore/platform.c44
-rw-r--r--fs/pstore/ram.c1
-rw-r--r--include/linux/pstore.h7
6 files changed, 27 insertions, 32 deletions
diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
index 22e9d281324d..e7d4ce6964ae 100644
--- a/arch/powerpc/kernel/nvram_64.c
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -563,8 +563,6 @@ static int nvram_pstore_init(void)
nvram_pstore_info.buf = oops_data;
nvram_pstore_info.bufsize = oops_data_sz;
- spin_lock_init(&nvram_pstore_info.buf_lock);
-
rc = pstore_register(&nvram_pstore_info);
if (rc && (rc != -EPERM))
/* Print error only when pstore.backend == nvram */
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index a5e1d963208e..9953e50667ec 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -1176,7 +1176,6 @@ static int __init erst_init(void)
"Error Record Serialization Table (ERST) support is initialized.\n");
buf = kmalloc(erst_erange.size, GFP_KERNEL);
- spin_lock_init(&erst_info.buf_lock);
if (buf) {
erst_info.buf = buf + sizeof(struct cper_pstore_record);
erst_info.bufsize = erst_erange.size -
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index cfe87b465819..0f7d97917197 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -259,8 +259,7 @@ static int efi_pstore_write(struct pstore_record *record)
efi_name[i] = name[i];
ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
- !pstore_cannot_block_path(record->reason),
- record->size, record->psi->buf);
+ preemptible(), record->size, record->psi->buf);
if (record->reason == KMSG_DUMP_OOPS)
efivar_run_worker();
@@ -369,7 +368,6 @@ static __init int efivars_pstore_init(void)
return -ENOMEM;
efi_pstore_info.bufsize = 1024;
- spin_lock_init(&efi_pstore_info.buf_lock);
if (pstore_register(&efi_pstore_info)) {
kfree(efi_pstore_info.buf);
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 2387cb74f729..2d1066ed3c28 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -161,26 +161,27 @@ static const char *get_reason_str(enum kmsg_dump_reason reason)
}
}
-bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
+/*
+ * Should pstore_dump() wait for a concurrent pstore_dump()? If
+ * not, the current pstore_dump() will report a failure to dump
+ * and return.
+ */
+static bool pstore_cannot_wait(enum kmsg_dump_reason reason)
{
- /*
- * In case of NMI path, pstore shouldn't be blocked
- * regardless of reason.
- */
+ /* In NMI path, pstore shouldn't block regardless of reason. */
if (in_nmi())
return true;
switch (reason) {
/* In panic case, other cpus are stopped by smp_send_stop(). */
case KMSG_DUMP_PANIC:
- /* Emergency restart shouldn't be blocked by spin lock. */
+ /* Emergency restart shouldn't be blocked. */
case KMSG_DUMP_EMERG:
return true;
default:
return false;
}
}
-EXPORT_SYMBOL_GPL(pstore_cannot_block_path);
#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
static int zbufsize_deflate(size_t size)
@@ -400,23 +401,23 @@ static void pstore_dump(struct kmsg_dumper *dumper,
unsigned long total = 0;
const char *why;
unsigned int part = 1;
- unsigned long flags = 0;
- int is_locked;
int ret;
why = get_reason_str(reason);
- if (pstore_cannot_block_path(reason)) {
- is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
- if (!is_locked) {
- pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
- , in_nmi() ? "NMI" : why);
+ if (down_trylock(&psinfo->buf_lock)) {
+ /* Failed to acquire lock: give up if we cannot wait. */
+ if (pstore_cannot_wait(reason)) {
+ pr_err("dump skipped in %s path: may corrupt error record\n",
+ in_nmi() ? "NMI" : why);
+ return;
+ }
+ if (down_interruptible(&psinfo->buf_lock)) {
+ pr_err("could not grab semaphore?!\n");
return;
}
- } else {
- spin_lock_irqsave(&psinfo->buf_lock, flags);
- is_locked = 1;
}
+
oopscount++;
while (total < kmsg_bytes) {
char *dst;
@@ -433,7 +434,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
record.part = part;
record.buf = psinfo->buf;
- if (big_oops_buf && is_locked) {
+ if (big_oops_buf) {
dst = big_oops_buf;
dst_size = big_oops_buf_sz;
} else {
@@ -451,7 +452,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
dst_size, &dump_size))
break;
- if (big_oops_buf && is_locked) {
+ if (big_oops_buf) {
zipped_len = pstore_compress(dst, psinfo->buf,
header_size + dump_size,
psinfo->bufsize);
@@ -474,8 +475,8 @@ static void pstore_dump(struct kmsg_dumper *dumper,
total += record.size;
part++;
}
- if (is_locked)
- spin_unlock_irqrestore(&psinfo->buf_lock, flags);
+
+ up(&psinfo->buf_lock);
}
static struct kmsg_dumper pstore_dumper = {
@@ -594,6 +595,7 @@ int pstore_register(struct pstore_info *psi)
psi->write_user = pstore_write_user_compat;
psinfo = psi;
mutex_init(&psinfo->read_mutex);
+ sema_init(&psinfo->buf_lock, 1);
spin_unlock(&pstore_lock);
if (owner && !try_module_get(owner)) {
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 202eaa82bcc6..e6d9560ea455 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -815,7 +815,6 @@ static int ramoops_probe(struct platform_device *pdev)
err = -ENOMEM;
goto fail_clear;
}
- spin_lock_init(&cxt->pstore.buf_lock);
cxt->pstore.flags = PSTORE_FLAGS_DMESG;
if (cxt->console_size)
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index a9ec285d85d1..b146181e8709 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -26,7 +26,7 @@
#include <linux/errno.h>
#include <linux/kmsg_dump.h>
#include <linux/mutex.h>
-#include <linux/spinlock.h>
+#include <linux/semaphore.h>
#include <linux/time.h>
#include <linux/types.h>
@@ -99,7 +99,7 @@ struct pstore_record {
* @owner: module which is responsible for this backend driver
* @name: name of the backend driver
*
- * @buf_lock: spinlock to serialize access to @buf
+ * @buf_lock: semaphore to serialize access to @buf
* @buf: preallocated crash dump buffer
* @bufsize: size of @buf available for crash dump bytes (must match
* smallest number of bytes available for writing to a
@@ -184,7 +184,7 @@ struct pstore_info {
struct module *owner;
char *name;
- spinlock_t buf_lock;
+ struct semaphore buf_lock;
char *buf;
size_t bufsize;
@@ -210,7 +210,6 @@ struct pstore_info {
extern int pstore_register(struct pstore_info *);
extern void pstore_unregister(struct pstore_info *);
-extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);
struct pstore_ftrace_record {
unsigned long ip;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-13 15:43:55 +0000