linux-hardened/include/linux/kmemcheck.h
Vegard Nossum fc7d0c9f21 kmemcheck: introduce bitfield API
Add the bitfield API which can be used to annotate bitfields in structs
and get rid of false positive reports.

According to Al Viro, the syntax we were using (putting #ifdef inside
macro arguments) was not valid C. He also suggested using begin/end
markers instead, which is what we do now.

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2009-06-15 15:49:23 +02:00

153 lines
4 KiB
C

#ifndef LINUX_KMEMCHECK_H
#define LINUX_KMEMCHECK_H
#include <linux/mm_types.h>
#include <linux/types.h>
#ifdef CONFIG_KMEMCHECK
extern int kmemcheck_enabled;
/* The slab-related functions. */
void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node);
void kmemcheck_free_shadow(struct page *page, int order);
void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
size_t size);
void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size);
void kmemcheck_pagealloc_alloc(struct page *p, unsigned int order,
gfp_t gfpflags);
void kmemcheck_show_pages(struct page *p, unsigned int n);
void kmemcheck_hide_pages(struct page *p, unsigned int n);
bool kmemcheck_page_is_tracked(struct page *p);
void kmemcheck_mark_unallocated(void *address, unsigned int n);
void kmemcheck_mark_uninitialized(void *address, unsigned int n);
void kmemcheck_mark_initialized(void *address, unsigned int n);
void kmemcheck_mark_freed(void *address, unsigned int n);
void kmemcheck_mark_unallocated_pages(struct page *p, unsigned int n);
void kmemcheck_mark_uninitialized_pages(struct page *p, unsigned int n);
void kmemcheck_mark_initialized_pages(struct page *p, unsigned int n);
int kmemcheck_show_addr(unsigned long address);
int kmemcheck_hide_addr(unsigned long address);
#else
#define kmemcheck_enabled 0
static inline void
kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
{
}
static inline void
kmemcheck_free_shadow(struct page *page, int order)
{
}
static inline void
kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
size_t size)
{
}
static inline void kmemcheck_slab_free(struct kmem_cache *s, void *object,
size_t size)
{
}
static inline void kmemcheck_pagealloc_alloc(struct page *p,
unsigned int order, gfp_t gfpflags)
{
}
static inline bool kmemcheck_page_is_tracked(struct page *p)
{
return false;
}
static inline void kmemcheck_mark_unallocated(void *address, unsigned int n)
{
}
static inline void kmemcheck_mark_uninitialized(void *address, unsigned int n)
{
}
static inline void kmemcheck_mark_initialized(void *address, unsigned int n)
{
}
static inline void kmemcheck_mark_freed(void *address, unsigned int n)
{
}
static inline void kmemcheck_mark_unallocated_pages(struct page *p,
unsigned int n)
{
}
static inline void kmemcheck_mark_uninitialized_pages(struct page *p,
unsigned int n)
{
}
static inline void kmemcheck_mark_initialized_pages(struct page *p,
unsigned int n)
{
}
#endif /* CONFIG_KMEMCHECK */
/*
* Bitfield annotations
*
* How to use: If you have a struct using bitfields, for example
*
* struct a {
* int x:8, y:8;
* };
*
* then this should be rewritten as
*
* struct a {
* kmemcheck_bitfield_begin(flags);
* int x:8, y:8;
* kmemcheck_bitfield_end(flags);
* };
*
* Now the "flags_begin" and "flags_end" members may be used to refer to the
* beginning and end, respectively, of the bitfield (and things like
* &x.flags_begin is allowed). As soon as the struct is allocated, the bit-
* fields should be annotated:
*
* struct a *a = kmalloc(sizeof(struct a), GFP_KERNEL);
* kmemcheck_annotate_bitfield(a, flags);
*
* Note: We provide the same definitions for both kmemcheck and non-
* kmemcheck kernels. This makes it harder to introduce accidental errors. It
* is also allowed to pass NULL pointers to kmemcheck_annotate_bitfield().
*/
#define kmemcheck_bitfield_begin(name) \
int name##_begin[0];
#define kmemcheck_bitfield_end(name) \
int name##_end[0];
#define kmemcheck_annotate_bitfield(ptr, name) \
do if (ptr) { \
int _n = (long) &((ptr)->name##_end) \
- (long) &((ptr)->name##_begin); \
BUILD_BUG_ON(_n < 0); \
\
kmemcheck_mark_initialized(&((ptr)->name##_begin), _n); \
} while (0)
#define kmemcheck_annotate_variable(var) \
do { \
kmemcheck_mark_initialized(&(var), sizeof(var)); \
} while (0) \
#endif /* LINUX_KMEMCHECK_H */