pstore/pmsg: drop bounce buffer
Removing a bounce buffer copy operation in the pmsg driver path is
always better. We also gain in overall performance by not requesting
a vmalloc on every write as this can cause precious RT tasks, such
as user facing media operation, to stall while memory is being
reclaimed. Added a write_buf_user to the pstore functions, a backup
platform write_buf_user that uses the small buffer that is part of
the instance, and implemented a ramoops write_buf_user that only
supports PSTORE_TYPE_PMSG.
Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index 4660aaa..c668c86 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -17,11 +17,12 @@
#ifndef __LINUX_PSTORE_RAM_H__
#define __LINUX_PSTORE_RAM_H__
+#include <linux/compiler.h>
#include <linux/device.h>
+#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/types.h>
-#include <linux/init.h>
struct persistent_ram_buffer;
struct rs_control;
@@ -59,7 +60,9 @@
void persistent_ram_zap(struct persistent_ram_zone *prz);
int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
- unsigned int count);
+ unsigned int count);
+int persistent_ram_write_user(struct persistent_ram_zone *prz,
+ const void __user *s, unsigned int count);
void persistent_ram_save_old(struct persistent_ram_zone *prz);
size_t persistent_ram_old_size(struct persistent_ram_zone *prz);