| Message ID | 1314826019-22330-2-git-send-email-msalter@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/09/11 07:26, Mark Salter wrote: > The existing __strnlen_user macro simply resolved to strnlen. However, the > count returned by strnlen_user should include the NULL byte. This patch > fixes the __strnlen_user macro to include the NULL byte in the count. > > Signed-off-by: Mark Salter<msalter@redhat.com> > --- > include/asm-generic/uaccess.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h > index ac68c99..1d0fdf8 100644 > --- a/include/asm-generic/uaccess.h > +++ b/include/asm-generic/uaccess.h > @@ -289,7 +289,7 @@ strncpy_from_user(char *dst, const char __user *src, long count) > * Return 0 on exception, a value greater than N if too long > */ > #ifndef __strnlen_user > -#define __strnlen_user strnlen > +#define __strnlen_user(s, n) (strnlen((s), (n)) + 1) > #endif I don't think this is correct because if you hit maxlen you will add one to it. e.g. __strnlen_user("abcd\0", 3) would return 4 instead of 3. It should probably be something like this: #define __strnlen_user(s, n) ({ \ size_t k = strnlen(s, n); \ k< n ? k + 1 : n; }) I wonder if this change will break anything since it has been incorrect (according to the comment in uaccess.h at least) for a while. Why does __strnlen_user have different semantics to strnlen anway? ~Ryan
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index ac68c99..1d0fdf8 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -289,7 +289,7 @@ strncpy_from_user(char *dst, const char __user *src, long count) * Return 0 on exception, a value greater than N if too long */ #ifndef __strnlen_user -#define __strnlen_user strnlen +#define __strnlen_user(s, n) (strnlen((s), (n)) + 1) #endif static inline long strnlen_user(const char __user *src, long n)
The existing __strnlen_user macro simply resolved to strnlen. However, the count returned by strnlen_user should include the NULL byte. This patch fixes the __strnlen_user macro to include the NULL byte in the count. Signed-off-by: Mark Salter <msalter@redhat.com> --- include/asm-generic/uaccess.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)