From: David Gow <[email protected]>
Currently, KUnit's string streams are themselves "KUnit resources".
This is redundant since the stream itself is already allocated with
kunit_kzalloc() and will thus be freed automatically at the end of the
test.
string-stream is only used internally within KUnit, and isn't using the
extra features that resources provide like reference counting, being
able to locate them dynamically as "test-local variables", etc.
Indeed, the resource's refcount is never incremented when the
pointer is returned. The fact that it's always manually destroyed is
more evidence that the reference counting is unused.
Signed-off-by: David Gow <[email protected]>
Signed-off-by: Daniel Latypov <[email protected]>
---
v1 -> v2: no changes
---
lib/kunit/string-stream.c | 90 +++++++--------------------------------
lib/kunit/string-stream.h | 2 +-
lib/kunit/test.c | 2 +-
3 files changed, 18 insertions(+), 76 deletions(-)
diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
index 141789ca8949..a2496abef152 100644
--- a/lib/kunit/string-stream.c
+++ b/lib/kunit/string-stream.c
@@ -12,64 +12,31 @@
#include "string-stream.h"
-struct string_stream_fragment_alloc_context {
- struct kunit *test;
- int len;
- gfp_t gfp;
-};
-static int string_stream_fragment_init(struct kunit_resource *res,
- void *context)
+static struct string_stream_fragment *alloc_string_stream_fragment(
+ struct kunit *test, int len, gfp_t gfp)
{
- struct string_stream_fragment_alloc_context *ctx = context;
struct string_stream_fragment *frag;
- frag = kunit_kzalloc(ctx->test, sizeof(*frag), ctx->gfp);
+ frag = kunit_kzalloc(test, sizeof(*frag), gfp);
if (!frag)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
- frag->test = ctx->test;
- frag->fragment = kunit_kmalloc(ctx->test, ctx->len, ctx->gfp);
+ frag->test = test;
+ frag->fragment = kunit_kmalloc(test, len, gfp);
if (!frag->fragment)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
- res->data = frag;
-
- return 0;
+ return frag;
}
-static void string_stream_fragment_free(struct kunit_resource *res)
+static void string_stream_fragment_destroy(struct string_stream_fragment *frag)
{
- struct string_stream_fragment *frag = res->data;
-
list_del(&frag->node);
kunit_kfree(frag->test, frag->fragment);
kunit_kfree(frag->test, frag);
}
-static struct string_stream_fragment *alloc_string_stream_fragment(
- struct kunit *test, int len, gfp_t gfp)
-{
- struct string_stream_fragment_alloc_context context = {
- .test = test,
- .len = len,
- .gfp = gfp
- };
-
- return kunit_alloc_resource(test,
- string_stream_fragment_init,
- string_stream_fragment_free,
- gfp,
- &context);
-}
-
-static int string_stream_fragment_destroy(struct string_stream_fragment *frag)
-{
- return kunit_destroy_resource(frag->test,
- kunit_resource_instance_match,
- frag);
-}
-
int string_stream_vadd(struct string_stream *stream,
const char *fmt,
va_list args)
@@ -169,48 +136,23 @@ struct string_stream_alloc_context {
gfp_t gfp;
};
-static int string_stream_init(struct kunit_resource *res, void *context)
+struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp)
{
struct string_stream *stream;
- struct string_stream_alloc_context *ctx = context;
- stream = kunit_kzalloc(ctx->test, sizeof(*stream), ctx->gfp);
+ stream = kunit_kzalloc(test, sizeof(*stream), gfp);
if (!stream)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
- res->data = stream;
- stream->gfp = ctx->gfp;
- stream->test = ctx->test;
+ stream->gfp = gfp;
+ stream->test = test;
INIT_LIST_HEAD(&stream->fragments);
spin_lock_init(&stream->lock);
- return 0;
+ return stream;
}
-static void string_stream_free(struct kunit_resource *res)
+void string_stream_destroy(struct string_stream *stream)
{
- struct string_stream *stream = res->data;
-
string_stream_clear(stream);
}
-
-struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp)
-{
- struct string_stream_alloc_context context = {
- .test = test,
- .gfp = gfp
- };
-
- return kunit_alloc_resource(test,
- string_stream_init,
- string_stream_free,
- gfp,
- &context);
-}
-
-int string_stream_destroy(struct string_stream *stream)
-{
- return kunit_destroy_resource(stream->test,
- kunit_resource_instance_match,
- stream);
-}
diff --git a/lib/kunit/string-stream.h b/lib/kunit/string-stream.h
index 43f9508a55b4..494dee0f24bd 100644
--- a/lib/kunit/string-stream.h
+++ b/lib/kunit/string-stream.h
@@ -46,6 +46,6 @@ int string_stream_append(struct string_stream *stream,
bool string_stream_is_empty(struct string_stream *stream);
-int string_stream_destroy(struct string_stream *stream);
+void string_stream_destroy(struct string_stream *stream);
#endif /* _KUNIT_STRING_STREAM_H */
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index b73d5bb5c473..0fb2771ca03e 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -267,7 +267,7 @@ static void kunit_fail(struct kunit *test, const struct kunit_loc *loc,
kunit_print_string_stream(test, stream);
- WARN_ON(string_stream_destroy(stream));
+ string_stream_destroy(stream);
}
static void __noreturn kunit_abort(struct kunit *test)
base-commit: 94681e289bf5d10c9db9db143d1a22d8717205c5
--
2.37.1.359.gd136c6c3e2-goog
kunit_kfree() exists to clean up allocations from kunit_kmalloc() and
friends early instead of waiting for this to happen automatically at the
end of the test.
But it can be used on *anything* registered with the kunit resource API.
E.g. the last 2 statements are equivalent:
struct kunit_resource *res = something();
kfree(res->data);
kunit_put_resource(res);
The problem is that there could be multiple resources that point to the
same `data`.
E.g. you can have a named resource acting as a pseudo-global variable in
a test. If you point it to data allocated with kunit_kmalloc(), then
calling `kunit_kfree(ptr)` has the chance to delete either the named
resource or to kfree `ptr`.
Which one it does depends on the order the resources are registered as
kunit_kfree() will delete resources in LIFO order.
So this patch restricts kunit_kfree() to only working on resources
created by kunit_kmalloc(). Calling it is therefore guaranteed to free
the memory, not do anything else.
Note: kunit_resource_instance_match() wasn't used outside of KUnit, so
it should be safe to remove from the public interface. It's also
generally dangerous, as shown above, and shouldn't be used.
Signed-off-by: Daniel Latypov <[email protected]>
Reviewed-by: David Gow <[email protected]>
---
v1 -> v2: no changes
---
include/kunit/resource.h | 16 ----------------
lib/kunit/kunit-test.c | 7 +++++++
lib/kunit/test.c | 10 ++++++++--
3 files changed, 15 insertions(+), 18 deletions(-)
diff --git a/include/kunit/resource.h b/include/kunit/resource.h
index 09c2b34d1c61..cf6fb8f2ac1b 100644
--- a/include/kunit/resource.h
+++ b/include/kunit/resource.h
@@ -300,22 +300,6 @@ typedef bool (*kunit_resource_match_t)(struct kunit *test,
struct kunit_resource *res,
void *match_data);
-/**
- * kunit_resource_instance_match() - Match a resource with the same instance.
- * @test: Test case to which the resource belongs.
- * @res: The resource.
- * @match_data: The resource pointer to match against.
- *
- * An instance of kunit_resource_match_t that matches a resource whose
- * allocation matches @match_data.
- */
-static inline bool kunit_resource_instance_match(struct kunit *test,
- struct kunit_resource *res,
- void *match_data)
-{
- return res->data == match_data;
-}
-
/**
* kunit_resource_name_match() - Match a resource with the same name.
* @test: Test case to which the resource belongs.
diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
index 13d0bd8b07a9..4df0335d0d06 100644
--- a/lib/kunit/kunit-test.c
+++ b/lib/kunit/kunit-test.c
@@ -161,6 +161,13 @@ static void kunit_resource_test_alloc_resource(struct kunit *test)
kunit_put_resource(res);
}
+static inline bool kunit_resource_instance_match(struct kunit *test,
+ struct kunit_resource *res,
+ void *match_data)
+{
+ return res->data == match_data;
+}
+
/*
* Note: tests below use kunit_alloc_and_get_resource(), so as a consequence
* they have a reference to the associated resource that they must release
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 0fb2771ca03e..82019a78462e 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -689,12 +689,18 @@ void *kunit_kmalloc_array(struct kunit *test, size_t n, size_t size, gfp_t gfp)
}
EXPORT_SYMBOL_GPL(kunit_kmalloc_array);
+static inline bool kunit_kfree_match(struct kunit *test,
+ struct kunit_resource *res, void *match_data)
+{
+ /* Only match resources allocated with kunit_kmalloc() and friends. */
+ return res->free == kunit_kmalloc_array_free && res->data == match_data;
+}
+
void kunit_kfree(struct kunit *test, const void *ptr)
{
struct kunit_resource *res;
- res = kunit_find_resource(test, kunit_resource_instance_match,
- (void *)ptr);
+ res = kunit_find_resource(test, kunit_kfree_match, (void *)ptr);
/*
* Removing the resource from the list of resources drops the
--
2.37.1.359.gd136c6c3e2-goog
On Fri, Jul 22, 2022 at 1:15 PM 'Daniel Latypov' via KUnit Development
<[email protected]> wrote:
>
> From: David Gow <[email protected]>
>
> Currently, KUnit's string streams are themselves "KUnit resources".
> This is redundant since the stream itself is already allocated with
> kunit_kzalloc() and will thus be freed automatically at the end of the
> test.
>
> string-stream is only used internally within KUnit, and isn't using the
> extra features that resources provide like reference counting, being
> able to locate them dynamically as "test-local variables", etc.
>
> Indeed, the resource's refcount is never incremented when the
> pointer is returned. The fact that it's always manually destroyed is
> more evidence that the reference counting is unused.
>
> Signed-off-by: David Gow <[email protected]>
> Signed-off-by: Daniel Latypov <[email protected]>
Reviewed-by: Brendan Higgins <[email protected]>
On Fri, Jul 22, 2022 at 1:15 PM Daniel Latypov <[email protected]> wrote:
>
> kunit_kfree() exists to clean up allocations from kunit_kmalloc() and
> friends early instead of waiting for this to happen automatically at the
> end of the test.
>
> But it can be used on *anything* registered with the kunit resource API.
>
> E.g. the last 2 statements are equivalent:
> struct kunit_resource *res = something();
> kfree(res->data);
> kunit_put_resource(res);
>
> The problem is that there could be multiple resources that point to the
> same `data`.
>
> E.g. you can have a named resource acting as a pseudo-global variable in
> a test. If you point it to data allocated with kunit_kmalloc(), then
> calling `kunit_kfree(ptr)` has the chance to delete either the named
> resource or to kfree `ptr`.
> Which one it does depends on the order the resources are registered as
> kunit_kfree() will delete resources in LIFO order.
>
> So this patch restricts kunit_kfree() to only working on resources
> created by kunit_kmalloc(). Calling it is therefore guaranteed to free
> the memory, not do anything else.
>
> Note: kunit_resource_instance_match() wasn't used outside of KUnit, so
> it should be safe to remove from the public interface. It's also
> generally dangerous, as shown above, and shouldn't be used.
>
> Signed-off-by: Daniel Latypov <[email protected]>
> Reviewed-by: David Gow <[email protected]>
Reviewed-by: Brendan Higgins <[email protected]>