diff options
Diffstat (limited to 'include/linux/kernel.h')
| -rw-r--r-- | include/linux/kernel.h | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 7c4e8f1f72d8..941dc0a5a877 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -666,7 +666,7 @@ do { \ * your code. (Extra memory is used for special buffers that are * allocated when trace_printk() is used.) * - * A little optization trick is done here. If there's only one + * A little optimization trick is done here. If there's only one * argument, there's no need to scan the string for printf formats. * The trace_puts() will suffice. But how can we take advantage of * using trace_puts() when trace_printk() has only one argument? @@ -966,6 +966,22 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } "pointer type mismatch in container_of()"); \ ((type *)(__mptr - offsetof(type, member))); }) +/** + * container_of_safe - cast a member of a structure out to the containing structure + * @ptr: the pointer to the member. + * @type: the type of the container struct this is embedded in. + * @member: the name of the member within the struct. + * + * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. + */ +#define container_of_safe(ptr, type, member) ({ \ + void *__mptr = (void *)(ptr); \ + BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ + !__same_type(*(ptr), void), \ + "pointer type mismatch in container_of()"); \ + IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \ + ((type *)(__mptr - offsetof(type, member))); }) + /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ #ifdef CONFIG_FTRACE_MCOUNT_RECORD # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD |