2010-12-13 14:05:36

by Anton Arapov

Subject: [PATCH] lib: fix vscnprintf() if @size is == 0

vscnprintf() should return 0 if @size is == 0. Update the comment for it,
as @size is unsigned.

This change based on the code of commit b903c0b8899b46829a9b80ba55b61079b35940ec
moves the real fix into vscnprinf() from scnprintf() and makes scnprintf() call
vscnprintf(), thus avoid code duplication.

Signed-off-by: Anton Arapov <[email protected]>
---
lib/vsprintf.c | 16 ++++++++--------
1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c150d3d..85e6b27 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1451,7 +1451,7 @@ EXPORT_SYMBOL(vsnprintf);
* @args: Arguments for the format string
*
* The return value is the number of characters which have been written into
- * the @buf not including the trailing '\0'. If @size is <= 0 the function
+ * the @buf not including the trailing '\0'. If @size is == 0 the function
* returns 0.
*
* Call this function if you are already dealing with a va_list.
@@ -1465,7 +1465,11 @@ int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)

i = vsnprintf(buf, size, fmt, args);

- return (i >= size) ? (size - 1) : i;
+ if (likely(i < size))
+ return i;
+ if (size != 0)
+ return size - 1;
+ return 0;
}
EXPORT_SYMBOL(vscnprintf);

@@ -1513,14 +1517,10 @@ int scnprintf(char *buf, size_t size, const char *fmt, ...)
int i;

va_start(args, fmt);
- i = vsnprintf(buf, size, fmt, args);
+ i = vscnprintf(buf, size, fmt, args);
va_end(args);

- if (likely(i < size))
- return i;
- if (size != 0)
- return size - 1;
- return 0;
+ return i;
}
EXPORT_SYMBOL(scnprintf);

--
1.7.1

2010-12-13 14:25:49

by Changli Gao

Subject: Re: [PATCH] lib: fix vscnprintf() if @size is == 0

On Mon, Dec 13, 2010 at 10:05 PM, Anton Arapov <[email protected]> wrote:
> vscnprintf() should return 0 if @size is == 0. Update the comment for it,
> as @size is unsigned.
>
> This change based on the code of commit b903c0b8899b46829a9b80ba55b61079b35940ec
> moves the real fix into vscnprinf() from scnprintf() and makes scnprintf() call
> vscnprintf(), thus avoid code duplication.
>
> Signed-off-by: Anton Arapov <[email protected]>

Acked-by: Changli Gao <[email protected]>

--
Regards,
Changli Gao([email protected])