[PATCH] pstore: ramoops: support pmsg size larger than kmalloc limitation

[Yuxiao Zhang]

Current pmsg implementation is using kmalloc for pmsg record buffer,
which has max size limits based on page size. Currently even we
allocate enough space with pmsg-size, pmsg will still fail if the
file size is larger than what kmalloc allowed.

Since we don't need physical contiguous memory for pmsg buffer
, we can use kvmalloc to avoid such limitation.

Signed-off-by: Yuxiao Zhang <yuxiaozhang@xxxxxxxxxx>
---
 fs/pstore/inode.c    | 2 +-
 fs/pstore/platform.c | 9 +++++----
 fs/pstore/ram.c      | 5 +++--
 fs/pstore/ram_core.c | 3 ++-
 4 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index ffbadb8b3032..df7fb2ad4599 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -54,7 +54,7 @@ static void free_pstore_private(struct
pstore_private *private)
  if (!private)
  return;
  if (private->record) {
- kfree(private->record->buf);
+ kvfree(private->record->buf);
  kfree(private->record->priv);
  kfree(private->record);
  }
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index cbc0b468c1ab..f51e9460ac9d 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -32,6 +32,7 @@
 #include <linux/uaccess.h>
 #include <linux/jiffies.h>
 #include <linux/workqueue.h>
+#include <linux/mm.h>

 #include "internal.h"

@@ -549,7 +550,7 @@ static int pstore_write_user_compat(struct
pstore_record *record,
  if (record->buf)
  return -EINVAL;

- record->buf = memdup_user(buf, record->size);
+ record->buf = vmemdup_user(buf, record->size);
  if (IS_ERR(record->buf)) {
  ret = PTR_ERR(record->buf);
  goto out;
@@ -557,7 +558,7 @@ static int pstore_write_user_compat(struct
pstore_record *record,

  ret = record->psi->write(record);

- kfree(record->buf);
+ kvfree(record->buf);
 out:
  record->buf = NULL;

@@ -730,7 +731,7 @@ static void decompress_record(struct pstore_record *record)
  return;

  /* Swap out compressed contents with decompressed contents. */
- kfree(record->buf);
+ kvfree(record->buf);
  record->buf = unzipped;
  record->size = unzipped_len;
  record->compressed = false;
@@ -783,7 +784,7 @@ void pstore_get_backend_records(struct pstore_info *psi,
  rc = pstore_mkfile(root, record);
  if (rc) {
  /* pstore_mkfile() did not take record, so free it. */
- kfree(record->buf);
+ kvfree(record->buf);
  kfree(record->priv);
  kfree(record);
  if (rc != -EEXIST || !quiet)
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index ade66dbe5f39..296465b14fa9 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -20,6 +20,7 @@
 #include <linux/compiler.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/mm.h>

 #include "internal.h"
 #include "ram_internal.h"
@@ -268,7 +269,7 @@ static ssize_t ramoops_pstore_read(struct
pstore_record *record)
  /* ECC correction notice */
  record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);

- record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
+ record->buf = kvmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
  if (record->buf == NULL) {
  size = -ENOMEM;
  goto out;
@@ -282,7 +283,7 @@ static ssize_t ramoops_pstore_read(struct
pstore_record *record)

 out:
  if (free_prz) {
- kfree(prz->old_log);
+ kvfree(prz->old_log);
  kfree(prz);
  }

diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 966191d3a5ba..3453d493ec27 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -17,6 +17,7 @@
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <linux/vmalloc.h>
+#include <linux/mm.h>
 #include <asm/page.h>

 #include "ram_internal.h"
@@ -385,7 +386,7 @@ void *persistent_ram_old(struct persistent_ram_zone *prz)

 void persistent_ram_free_old(struct persistent_ram_zone *prz)
 {
- kfree(prz->old_log);
+ kvfree(prz->old_log);
  prz->old_log = NULL;
  prz->old_log_size = 0;
 }
--

-------------------------------------------
Thanks in advance.
-Yuxiao