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Peter Anvin" , x86@kernel.org, Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Mathieu Desnoyers , David Hildenbrand , Jonathan Corbet , Matthew Wilcox , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-doc@vger.kernel.org, Jinchao Wang Subject: [RFC PATCH 12/13] mm/kwatch: add KUnit tests for the watch expression parser Date: Wed, 15 Jul 2026 02:33:39 +0800 Message-ID: <20260714183339.13044-1-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260714182243.10687-1-wangjinchao600@gmail.com> References: <20260714182243.10687-1-wangjinchao600@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Cover base anchors (stack, argN, absolute address), positive and negative offsets, dereference chains, and rejection of malformed expressions (missing offsets, bad argument index, junk offsets). Signed-off-by: Jinchao Wang --- mm/kwatch/.kunitconfig | 9 +++ mm/kwatch/Kconfig | 10 +++ mm/kwatch/Makefile | 1 + mm/kwatch/deref_test.c | 137 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 157 insertions(+) create mode 100644 mm/kwatch/.kunitconfig create mode 100644 mm/kwatch/deref_test.c diff --git a/mm/kwatch/.kunitconfig b/mm/kwatch/.kunitconfig new file mode 100644 index 000000000000..7e977ddf0da1 --- /dev/null +++ b/mm/kwatch/.kunitconfig @@ -0,0 +1,9 @@ +CONFIG_KUNIT=y +CONFIG_KWATCH=y +CONFIG_KWATCH_KUNIT_TEST=y +CONFIG_PERF_EVENTS=y +CONFIG_HAVE_HW_BREAKPOINT=y +CONFIG_HAVE_REINSTALL_HW_BREAKPOINT=y +CONFIG_KPROBES=y +CONFIG_KRETPROBES=y +CONFIG_PRINTK=y diff --git a/mm/kwatch/Kconfig b/mm/kwatch/Kconfig index b1c37a829dd5..74083040a1a3 100644 --- a/mm/kwatch/Kconfig +++ b/mm/kwatch/Kconfig @@ -15,3 +15,13 @@ config KWATCH exact instruction causing the illegal access. If unsure, say N. + +config KWATCH_KUNIT_TEST + bool "KUnit tests for KWatch" if !KUNIT_ALL_TESTS + depends on KWATCH && KUNIT + default KUNIT_ALL_TESTS + help + Enable KUnit tests for the KWatch kernel module. + This suite tests the core parsing logic, the pointer-chasing + finite state machine, and edge cases involving complex watchpoint + expressions. If unsure, say N. diff --git a/mm/kwatch/Makefile b/mm/kwatch/Makefile index 02d7917602f1..1d223d73b461 100644 --- a/mm/kwatch/Makefile +++ b/mm/kwatch/Makefile @@ -1,3 +1,4 @@ obj-$(CONFIG_KWATCH) += kwatch.o kwatch-y := core.o deref.o task_ctx.o hwbp.o probe.o anchor.o +kwatch-$(CONFIG_KWATCH_KUNIT_TEST) += deref_test.o diff --git a/mm/kwatch/deref_test.c b/mm/kwatch/deref_test.c new file mode 100644 index 000000000000..094b7afeb235 --- /dev/null +++ b/mm/kwatch/deref_test.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "kwatch.h" +#include + +static void kwatch_test_parse_deref_chain(struct kunit *test) +{ + struct kwatch_config cfg; + int ret; + + // Test 1: stack + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "stack"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_STACK); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 1); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], 0); + + // Test 2: arg1 + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg1"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_ARG1); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 1); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], 0); + + // Test 3: arg6+8 + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg6+8"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_ARG6); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 1); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], 8); + + // Test 4: arg2-16 + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg2-16"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_ARG2); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 1); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], -16); + + // Test 5: arg3->8 + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg3->8"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_ARG3); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 2); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], 0); + KUNIT_EXPECT_EQ(test, cfg.offsets[1], 8); + + // Test 6: arg4+8->16 + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg4+8->16"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_ARG4); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 2); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], 8); + KUNIT_EXPECT_EQ(test, cfg.offsets[1], 16); + + // Test 7: arg5-8->-16 + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg5-8->-16"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_ARG5); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 2); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], -8); + KUNIT_EXPECT_EQ(test, cfg.offsets[1], -16); + + // Test 8: stack->0->8 + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "stack->0->8"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_STACK); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 3); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], 0); + KUNIT_EXPECT_EQ(test, cfg.offsets[1], 0); + KUNIT_EXPECT_EQ(test, cfg.offsets[2], 8); + + // Test 9: arg1->+8 + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg1->+8"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_ARG1); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 2); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], 0); + KUNIT_EXPECT_EQ(test, cfg.offsets[1], 8); + + // Test 9.1: arg1-> (implicit 0 should fail) + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg1->"); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + // Test 9.2: stack->->8 (implicit 0 should fail) + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "stack->->8"); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + // Test 10: Invalid base + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "invalid_base"); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + // Test 11: Invalid offset + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg1+abc"); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + // Test 12: Invalid arg + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "arg7"); + KUNIT_EXPECT_EQ(test, ret, -EINVAL); + + // Test 13: Absolute address + memset(&cfg, 0, sizeof(cfg)); + ret = kwatch_deref_parse(&cfg, "0xffffffff81000000+8"); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, cfg.base, KWATCH_BASE_ABS_ADDR); + KUNIT_EXPECT_EQ(test, cfg.sym_addr, 0xffffffff81000000UL); + KUNIT_EXPECT_EQ(test, cfg.offset_count, 1); + KUNIT_EXPECT_EQ(test, cfg.offsets[0], 8); +} + +static struct kunit_case kwatch_deref_test_cases[] = { + KUNIT_CASE(kwatch_test_parse_deref_chain), + {} +}; + +static struct kunit_suite kwatch_deref_test_suite = { + .name = "kwatch_deref", + .test_cases = kwatch_deref_test_cases, +}; + +kunit_test_suite(kwatch_deref_test_suite); + +MODULE_DESCRIPTION("KUnit tests for the KWatch watch expression parser"); +MODULE_LICENSE("GPL"); -- 2.53.0