Re: 2.6.17-mm2

Andrew Morton
2006-06-28T10:48:07Z

On Wed, 28 Jun 2006 03:42:15 -0700
Andrew Morton <akpm@osdl.org> wrote:

> his is caused by the vsprintf() changes. Right now, if you do
>
> snprintf(buf, 4, "1111111111111");
>
> the memory at `buf' gets [31 31 31 31 00], which is not good.
>
> This'll plug it, but I didn't check very hard whether it still has any
> off-by-ones, or if breaks the intent of Jeremy's patch. I think it's OK..

That diff was against an older kernel and doesn't apply. This is against
mainline:

--- a/lib/vsprintf.c~vsnprintf-fix
+++ a/lib/vsprintf.c
@@ -259,7 +259,9 @@ int vsnprintf(char *buf, size_t size, co
int len;
unsigned long long num;
int i, base;
- char *str, *end, c;
+ char *str; /* Where we're writing to */
+ char *end; /* The last byte we can write to */
+ char c;
const char *s;

int flags; /* flags to number() */
@@ -283,12 +285,12 @@ int vsnprintf(char *buf, size_t size, co
}

str = buf;
- end = buf + size;
+ end = buf + size - 1;

/* Make sure end is always >= buf */
- if (end < buf) {
+ if (end < buf - 1) {
end = ((void *)-1);
- size = end - buf;
+ size = end - buf + 1;
}

for (; *fmt ; ++fmt) {
@@ -494,7 +496,6 @@ int vsnprintf(char *buf, size_t size, co
/* the trailing null byte doesn't count towards the total */
return str-buf;
}
-
EXPORT_SYMBOL(vsnprintf);

/**
_