kcsan: Add Kernel Concurrency Sanitizer infrastructure

Kernel Concurrency Sanitizer (KCSAN) is a dynamic data-race detector for
kernel space. KCSAN is a sampling watchpoint-based data-race detector.
See the included Documentation/dev-tools/kcsan.rst for more details.

This patch adds basic infrastructure, but does not yet enable KCSAN for
any architecture.

Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
Marco Elver 2019-11-14 19:02:54 +01:00 committed by Paul E. McKenney
parent 31f4f5b495
commit dfd402a4c4
24 changed files with 2006 additions and 9 deletions

View file

@ -178,6 +178,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
#endif
#include <uapi/linux/types.h>
#include <linux/kcsan-checks.h>
#define __READ_ONCE_SIZE \
({ \
@ -193,12 +194,6 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
} \
})
static __always_inline
void __read_once_size(const volatile void *p, void *res, int size)
{
__READ_ONCE_SIZE;
}
#ifdef CONFIG_KASAN
/*
* We can't declare function 'inline' because __no_sanitize_address confilcts
@ -207,18 +202,44 @@ void __read_once_size(const volatile void *p, void *res, int size)
* '__maybe_unused' allows us to avoid defined-but-not-used warnings.
*/
# define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused
# define __no_sanitize_or_inline __no_kasan_or_inline
#else
# define __no_kasan_or_inline __always_inline
#endif
static __no_kasan_or_inline
#ifdef __SANITIZE_THREAD__
/*
* Rely on __SANITIZE_THREAD__ instead of CONFIG_KCSAN, to avoid not inlining in
* compilation units where instrumentation is disabled.
*/
# define __no_kcsan_or_inline __no_sanitize_thread notrace __maybe_unused
# define __no_sanitize_or_inline __no_kcsan_or_inline
#else
# define __no_kcsan_or_inline __always_inline
#endif
#ifndef __no_sanitize_or_inline
#define __no_sanitize_or_inline __always_inline
#endif
static __no_kcsan_or_inline
void __read_once_size(const volatile void *p, void *res, int size)
{
kcsan_check_atomic_read(p, size);
__READ_ONCE_SIZE;
}
static __no_sanitize_or_inline
void __read_once_size_nocheck(const volatile void *p, void *res, int size)
{
__READ_ONCE_SIZE;
}
static __always_inline void __write_once_size(volatile void *p, void *res, int size)
static __no_kcsan_or_inline
void __write_once_size(volatile void *p, void *res, int size)
{
kcsan_check_atomic_write(p, size);
switch (size) {
case 1: *(volatile __u8 *)p = *(__u8 *)res; break;
case 2: *(volatile __u16 *)p = *(__u16 *)res; break;