From: Jani Nikula on
Add __must_check to error pointer handlers to have the compiler warn
about mistakes like:

if (err)

Signed-off-by: Jani Nikula <ext-jani.1.nikula(a)>
include/linux/err.h | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/err.h b/include/linux/err.h
index 1b12642..448afc1 100644
--- a/include/linux/err.h
+++ b/include/linux/err.h
@@ -19,22 +19,22 @@

#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)

-static inline void *ERR_PTR(long error)
+static inline void * __must_check ERR_PTR(long error)
return (void *) error;

-static inline long PTR_ERR(const void *ptr)
+static inline long __must_check PTR_ERR(const void *ptr)
return (long) ptr;

-static inline long IS_ERR(const void *ptr)
+static inline long __must_check IS_ERR(const void *ptr)
return IS_ERR_VALUE((unsigned long)ptr);

-static inline long IS_ERR_OR_NULL(const void *ptr)
+static inline long __must_check IS_ERR_OR_NULL(const void *ptr)
return !ptr || IS_ERR_VALUE((unsigned long)ptr);
@@ -46,7 +46,7 @@ static inline long IS_ERR_OR_NULL(const void *ptr)
* Explicitly cast an error-valued pointer to another pointer type in such a
* way as to make it clear that's what's going on.
-static inline void *ERR_CAST(const void *ptr)
+static inline void * __must_check ERR_CAST(const void *ptr)
/* cast away the const */
return (void *) ptr;

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)
More majordomo info at
Please read the FAQ at