Messages in this thread Patch in this message | | | From | Marcin Slusarz <> | Subject | [PATCH 1/6] ERR_PTR: if errno value is known at compile time, make sure it's valid | Date | Sun, 18 May 2008 23:56:53 +0200 |
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ERR_PTR is easy to call with wrong argument (positive errno), and this error lead to catastrophic event - oops or kernel panic (dereference of invalid pointer).
As most of error handling code paths are rarely tested, this kind of bug can be hidden for years.
(Currently there are > 1400 calls of ERR_PTR with constant argument.)
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> --- include/linux/err.h | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/include/linux/err.h b/include/linux/err.h index ec87f31..7b5daa6 100644 --- a/include/linux/err.h +++ b/include/linux/err.h @@ -19,11 +19,13 @@ #define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO) -static inline void *ERR_PTR(long error) +static inline void *__ERR_PTR(long error) { return (void *) error; } +#define ERR_PTR(error) (BUILD_BUG_ON(__builtin_constant_p(error) && !IS_ERR_VALUE(error)), __ERR_PTR(error)) + static inline long PTR_ERR(const void *ptr) { return (long) ptr; -- 1.5.4.5
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