mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
78c32f4cb1
Comparing pointers with reference count checking is tricky to avoid a SEGV. Add a convenience macro to simplify and use. Signed-off-by: Ian Rogers <irogers@google.com> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: German Gomez <german.gomez@arm.com> Cc: James Clark <james.clark@arm.com> Cc: Nick Terrell <terrelln@fb.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Changbin Du <changbin.du@huawei.com> Cc: liuwenyu <liuwenyu7@huawei.com> Cc: Yang Jihong <yangjihong1@huawei.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Cc: Yanteng Si <siyanteng@loongson.cn> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20231024222353.3024098-5-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
113 lines
3.4 KiB
C
113 lines
3.4 KiB
C
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
|
|
#ifndef __LIBPERF_INTERNAL_RC_CHECK_H
|
|
#define __LIBPERF_INTERNAL_RC_CHECK_H
|
|
|
|
#include <stdlib.h>
|
|
#include <linux/zalloc.h>
|
|
|
|
/*
|
|
* Enable reference count checking implicitly with leak checking, which is
|
|
* integrated into address sanitizer.
|
|
*/
|
|
#if defined(__SANITIZE_ADDRESS__) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
|
|
#define REFCNT_CHECKING 1
|
|
#elif defined(__has_feature)
|
|
#if __has_feature(address_sanitizer) || __has_feature(leak_sanitizer)
|
|
#define REFCNT_CHECKING 1
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
* Shared reference count checking macros.
|
|
*
|
|
* Reference count checking is an approach to sanitizing the use of reference
|
|
* counted structs. It leverages address and leak sanitizers to make sure gets
|
|
* are paired with a put. Reference count checking adds a malloc-ed layer of
|
|
* indirection on a get, and frees it on a put. A missed put will be reported as
|
|
* a memory leak. A double put will be reported as a double free. Accessing
|
|
* after a put will cause a use-after-free and/or a segfault.
|
|
*/
|
|
|
|
#ifndef REFCNT_CHECKING
|
|
/* Replaces "struct foo" so that the pointer may be interposed. */
|
|
#define DECLARE_RC_STRUCT(struct_name) \
|
|
struct struct_name
|
|
|
|
/* Declare a reference counted struct variable. */
|
|
#define RC_STRUCT(struct_name) struct struct_name
|
|
|
|
/*
|
|
* Interpose the indirection. Result will hold the indirection and object is the
|
|
* reference counted struct.
|
|
*/
|
|
#define ADD_RC_CHK(result, object) (result = object, object)
|
|
|
|
/* Strip the indirection layer. */
|
|
#define RC_CHK_ACCESS(object) object
|
|
|
|
/* Frees the object and the indirection layer. */
|
|
#define RC_CHK_FREE(object) free(object)
|
|
|
|
/* A get operation adding the indirection layer. */
|
|
#define RC_CHK_GET(result, object) ADD_RC_CHK(result, object)
|
|
|
|
/* A put operation removing the indirection layer. */
|
|
#define RC_CHK_PUT(object) {}
|
|
|
|
/* Pointer equality when the indirection may or may not be there. */
|
|
#define RC_CHK_EQUAL(object1, object2) (object1 == object2)
|
|
|
|
#else
|
|
|
|
/* Replaces "struct foo" so that the pointer may be interposed. */
|
|
#define DECLARE_RC_STRUCT(struct_name) \
|
|
struct original_##struct_name; \
|
|
struct struct_name { \
|
|
struct original_##struct_name *orig; \
|
|
}; \
|
|
struct original_##struct_name
|
|
|
|
/* Declare a reference counted struct variable. */
|
|
#define RC_STRUCT(struct_name) struct original_##struct_name
|
|
|
|
/*
|
|
* Interpose the indirection. Result will hold the indirection and object is the
|
|
* reference counted struct.
|
|
*/
|
|
#define ADD_RC_CHK(result, object) \
|
|
( \
|
|
object ? (result = malloc(sizeof(*result)), \
|
|
result ? (result->orig = object, result) \
|
|
: (result = NULL, NULL)) \
|
|
: (result = NULL, NULL) \
|
|
)
|
|
|
|
/* Strip the indirection layer. */
|
|
#define RC_CHK_ACCESS(object) object->orig
|
|
|
|
/* Frees the object and the indirection layer. */
|
|
#define RC_CHK_FREE(object) \
|
|
do { \
|
|
zfree(&object->orig); \
|
|
free(object); \
|
|
} while(0)
|
|
|
|
/* A get operation adding the indirection layer. */
|
|
#define RC_CHK_GET(result, object) ADD_RC_CHK(result, (object ? object->orig : NULL))
|
|
|
|
/* A put operation removing the indirection layer. */
|
|
#define RC_CHK_PUT(object) \
|
|
do { \
|
|
if (object) { \
|
|
object->orig = NULL; \
|
|
free(object); \
|
|
} \
|
|
} while(0)
|
|
|
|
/* Pointer equality when the indirection may or may not be there. */
|
|
#define RC_CHK_EQUAL(object1, object2) (object1 == object2 || \
|
|
(object1 && object2 && object1->orig == object2->orig))
|
|
|
|
#endif
|
|
|
|
#endif /* __LIBPERF_INTERNAL_RC_CHECK_H */
|