From patchwork Sat Mar 25 04:31:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gow X-Patchwork-Id: 13187571 X-Patchwork-Delegate: brendanhiggins@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EAB6C6FD1F for ; Sat, 25 Mar 2023 04:31:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232098AbjCYEbj (ORCPT ); Sat, 25 Mar 2023 00:31:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231976AbjCYEb0 (ORCPT ); Sat, 25 Mar 2023 00:31:26 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A29F21A976 for ; Fri, 24 Mar 2023 21:31:20 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id p12-20020a25420c000000b00b6eb3c67574so3632520yba.11 for ; Fri, 24 Mar 2023 21:31:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1679718680; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=qvsBLzafDFRdEeFlhtCKfSPH7Z58gGOcQ/NMYd5XVas=; b=Dkx+4oPW0lddcPp4uMCQo6pmYmmbn0VU/J6ph6FIZMvJHQ04WSJmMD7xcIcZLJ6PdN mzLHDd4+oVvLMi1Zcdmmen6ZKzyf+g1GWgtWOeOuWYuo4GIJOr/0XBgAc273lDPvOxyn x/DczHXGxTwgZwYMHRELVpV4Toxy+2KxrL1CRJni3/TMk9xGSF+B6Ixg0Qh2jk842ljw rlDf4yUosLnhwdKudLfaiffDtlBTk7P4a9n3NnW6nlLUy3fEX7Q/qxKKYau9bO29v/Ww aJhM3eN9NL0dDmMVQAe0W1p9zzom/gVxfE5CItxvv4NN8JpOss79ZwU5ox4G1jGQ9ykB S25A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679718680; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=qvsBLzafDFRdEeFlhtCKfSPH7Z58gGOcQ/NMYd5XVas=; b=zHFdnk+WtFlEC5d3+zv66h3UVAOthJUi/f3XTBLKSKQWvevJthqIm7nnyh4W3jMvb3 KB63iFLABT5t1TLbwm5EGkMwHZYpYDkYcaxnu+4ibwNKZtOzgJmBdkijUHmclNu4b87z foZn3gj8eWo8VzPF6kjKnQco3zCVdm++6oFDwvC57StfFfjS22+Z2quaFLmrJKTn05KU F8jHQn8wf/OP68X1wWx8fNbU/R9C7ljn2uoa3agpcXP1r3wvDC408Rom+GJC6UeFgKsc HWo9YXY/d2eZb+T1EC6qO2PfB4rwpUJcnJaUFlA3Xo6rXGq/L6pg3wzuppNErf1yUwPw p+Nw== X-Gm-Message-State: AAQBX9dE8uieamv96sOW51cAdFnr8bwhIMs2/PvV1LGla3kn9x/LLjY8 nFlLjman91RBbWRFI6o9BoY3Zq2QwsVv/A== X-Google-Smtp-Source: AKy350aAmbbgvFfbZgCOgJD0jK2dcqvaJW7t4SFAmuugOJrv8Crpejpj64U5SmpXoebmhM46ApGf7S32uVGC0Q== X-Received: from slicestar.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:20a1]) (user=davidgow job=sendgmr) by 2002:a81:ac64:0:b0:544:b9b2:5c32 with SMTP id z36-20020a81ac64000000b00544b9b25c32mr2114854ywj.7.1679718679808; Fri, 24 Mar 2023 21:31:19 -0700 (PDT) Date: Sat, 25 Mar 2023 12:31:03 +0800 In-Reply-To: <20230325043104.3761770-1-davidgow@google.com> Mime-Version: 1.0 References: <20230325043104.3761770-1-davidgow@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230325043104.3761770-2-davidgow@google.com> Subject: [RFC PATCH 1/2] kunit: resource: Add kunit_defer() functionality From: David Gow To: Greg Kroah-Hartman , Matti Vaittinen , Maxime Ripard , Brendan Higgins , Stephen Boyd , Shuah Khan Cc: David Gow , "Rafael J . Wysocki" , Andy Shevchenko , Heikki Krogerus , Jonathan Cameron , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Many uses of the KUnit resource system are intended to simply defer calling a function until the test exits (be it due to success or failure). The existing kunit_alloc_resource() function is often used for this, but was awkward to use (requiring passing NULL init functions, etc), and returned a resource without incrementing its reference count, which -- while okay for this use-case -- could cause problems in others. Instead, introduce a simple kunit_defer() API: a simple function (returning nothing, accepting a single void* argument) can be scheduled to be called when the test exits. Deferred functions are called in the opposite order to that which they were registered. This is implemented as a resource under the hood, so the ordering between resource cleanup and deferred functions is maintained. Signed-off-by: David Gow --- include/kunit/resource.h | 87 +++++++++++++++++++++++++++++++ lib/kunit/resource.c | 110 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 197 insertions(+) diff --git a/include/kunit/resource.h b/include/kunit/resource.h index cf6fb8f2ac1b..6c4728ca9237 100644 --- a/include/kunit/resource.h +++ b/include/kunit/resource.h @@ -387,4 +387,91 @@ static inline int kunit_destroy_named_resource(struct kunit *test, */ void kunit_remove_resource(struct kunit *test, struct kunit_resource *res); +typedef void (*kunit_defer_function_t)(void *ctx); + +/** + * kunit_defer() - Defer a function call until the test ends. + * @test: Test case to associate the deferred function with. + * @func: The function to run on test exit + * @ctx: Data passed into @func + * @internal_gfp: gfp to use for internal allocations, if unsure, use GFP_KERNEL + * + * Defer the execution of a function until the test exits, either normally or + * due to a failure. @ctx is passed as additional context. All functions + * registered with kunit_defer() will execute in the opposite order to that + * they were registered in. + * + * This is useful for cleaning up allocated memory and resources. + * + * RETURNS: + * An opaque "cancellation token", or NULL on error. Pass this token to + * kunit_defer_cancel() in order to cancel the deferred execution of func(). + */ +void *kunit_defer(struct kunit *test, kunit_defer_function_t func, + void *ctx, gfp_t internal_gfp); + +/** + * kunit_defer_cancel_token() - Cancel a deferred function call. + * @test: Test case the deferred function is associated with. + * @cancel_token: The cancellation token returned by kunit_defer() + * + * Prevent a function deferred using kunit_defer() from executing when the + * test ends. + * + * Prefer using this to kunit_defer_cancel() where possible. + */ +void kunit_defer_cancel_token(struct kunit *test, void *cancel_token); + +/** + * kunit_defer_trigger_token() - Run a deferred function call immediately. + * @test: Test case the deferred function is associated with. + * @cancel_token: The cancellation token returned by kunit_defer() + * + * Execute a deferred function call immediately, instead of waiting for the + * test to end. + * + * Prefer using this to kunit_defer_trigger() where possible. + */ +void kunit_defer_trigger_token(struct kunit *test, void *cancel_token); + +/** + * kunit_defer_cancel() - Cancel a matching deferred function call. + * @test: Test case the deferred function is associated with. + * @func: The deferred function to cancel. + * @ctx: The context passed to the deferred function to trigger. + * + * Prevent a function deferred via kunit_defer() from executing at shutdown. + * Unlike kunit_defer_cancel_token(), this takes the (func, ctx) pair instead of + * the cancellation token. If that function/context pair was deferred multiple + * times, only the most recent one will be cancelled. + * + * Prefer using kunit_defer_cancel_token() to this where possible. + */ +void kunit_defer_cancel(struct kunit *test, + kunit_defer_function_t func, + void *ctx); + +/** + * kunit_defer_trigger() - Run a matching deferred function call immediately. + * @test: Test case the deferred function is associated with. + * @func: The deferred function to trigger. + * @ctx: The context passed to the deferred function to trigger. + * + * Execute a function deferred via kunit_defer() immediately, rather than when + * the test ends. + * Unlike kunit_defer_trigger_token(), this takes the (func, ctx) pair instead of + * the cancellation token. If that function/context pair was deferred multiple + * times, it will only be executed once here. The most recent deferral will + * no longer execute when the test ends. + * + * kunit_defer_trigger(test, func, ctx); + * is equivalent to + * func(ctx); + * kunit_defer_cancel(test, func, ctx); + * + * Prefer using kunit_defer_trigger_token() to this where possible. + */ +void kunit_defer_trigger(struct kunit *test, + kunit_defer_function_t func, + void *ctx); #endif /* _KUNIT_RESOURCE_H */ diff --git a/lib/kunit/resource.c b/lib/kunit/resource.c index c414df922f34..0d0c48054d45 100644 --- a/lib/kunit/resource.c +++ b/lib/kunit/resource.c @@ -77,3 +77,113 @@ int kunit_destroy_resource(struct kunit *test, kunit_resource_match_t match, return 0; } EXPORT_SYMBOL_GPL(kunit_destroy_resource); + +struct kunit_defer_ctx { + kunit_defer_function_t func; + void *ctx; +}; + +static void __kunit_defer_free(struct kunit_resource *res) +{ + struct kunit_defer_ctx *defer_ctx = (struct kunit_defer_ctx *)res->data; + + defer_ctx->func(defer_ctx->ctx); + + kfree(res->data); +} + +void *kunit_defer(struct kunit *test, kunit_defer_function_t func, + void *ctx, gfp_t internal_gfp) +{ + struct kunit_resource *res; + struct kunit_defer_ctx *defer_ctx; + + KUNIT_ASSERT_NOT_NULL_MSG(test, func, "Tried to defer a NULL function!"); + + res = kzalloc(sizeof(*res), internal_gfp); + if (!res) + return NULL; + + defer_ctx = kzalloc(sizeof(*defer_ctx), internal_gfp); + if (!defer_ctx) + goto free_res; + + defer_ctx->func = func; + defer_ctx->ctx = ctx; + + res->should_kfree = true; + __kunit_add_resource(test, NULL, __kunit_defer_free, res, defer_ctx); + + return (void *)res; + +free_res: + kfree(res); + return NULL; +} + +void kunit_defer_cancel_token(struct kunit *test, void *cancel_token) +{ + struct kunit_resource *res = (struct kunit_resource *)cancel_token; + + /* Remove the free function so we don't run the deferred function. */ + res->free = NULL; + + kunit_remove_resource(test, res); +} + +void kunit_defer_trigger_token(struct kunit *test, void *cancel_token) +{ + struct kunit_resource *res = (struct kunit_resource *)cancel_token; + + /* Removing the resource should trigger the res->free function. */ + kunit_remove_resource(test, res); +} + +static bool __kunit_defer_match(struct kunit *test, + struct kunit_resource *res, void *match_data) +{ + struct kunit_defer_ctx *match_ctx = (struct kunit_defer_ctx *)match_data; + struct kunit_defer_ctx *res_ctx = (struct kunit_defer_ctx *)res->data; + + /* Make sure this is a free function. */ + if (res->free != __kunit_defer_free) + return false; + + /* Both the function and context data should match. */ + return (match_ctx->func == res_ctx->func) && (match_ctx->ctx == res_ctx->ctx); +} + +void kunit_defer_cancel(struct kunit *test, + kunit_defer_function_t func, + void *ctx) +{ + struct kunit_defer_ctx defer_ctx; + struct kunit_resource *res; + + defer_ctx.func = func; + defer_ctx.ctx = ctx; + + res = kunit_find_resource(test, __kunit_defer_match, &defer_ctx); + if (res) { + kunit_defer_cancel_token(test, res); + kunit_put_resource(res); + } +} + +void kunit_defer_trigger(struct kunit *test, + kunit_defer_function_t func, + void *ctx) +{ + struct kunit_defer_ctx defer_ctx; + struct kunit_resource *res; + + defer_ctx.func = func; + defer_ctx.ctx = ctx; + + res = kunit_find_resource(test, __kunit_defer_match, &defer_ctx); + if (res) { + kunit_defer_trigger_token(test, res); + /* We have to put() this here, else free won't be called. */ + kunit_put_resource(res); + } +}