[PATCH] kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup()

From: Chen Gang
Date: Sun Nov 03 2013 - 09:24:46 EST


do_blk_trace_setup() will fully initialize 'buts.name', so can remove
the related memcpy(). And also use BLKTRACE_BDEV_SIZE and ARRAY_SIZE
instead of hard code number '32'.


Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx>
---
include/linux/blktrace_api.h | 2 +-
kernel/trace/blktrace.c | 3 +--
2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index a12f6ed..afc1343 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -89,7 +89,7 @@ static inline int blk_trace_init_sysfs(struct device *dev)
#ifdef CONFIG_COMPAT

struct compat_blk_user_trace_setup {
- char name[32];
+ char name[BLKTRACE_BDEV_SIZE];
u16 act_mask;
u32 buf_size;
u32 buf_nr;
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 7f727b3..f785aef 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -579,13 +579,12 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name,
.end_lba = cbuts.end_lba,
.pid = cbuts.pid,
};
- memcpy(&buts.name, &cbuts.name, 32);

ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
if (ret)
return ret;

- if (copy_to_user(arg, &buts.name, 32)) {
+ if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) {
blk_trace_remove(q);
return -EFAULT;
}
--
1.7.7.6
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