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Message-ID: <202503030848.30D0E54E7@keescook> References: <20250303050921.3033083-1-jeffxu@google.com> <20250303050921.3033083-8-jeffxu@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250303050921.3033083-8-jeffxu@google.com> X-Rspam-User: X-Stat-Signature: orz8xdh9z9u1kgxxboajhfgp974r5ktc X-Rspamd-Queue-Id: CB3AB1C0015 X-Rspamd-Server: rspam07 X-HE-Tag: 1741021278-940379 X-HE-Meta: U2FsdGVkX198jhmxR+dtav7J2hyx6zO6++siYySkjugx8a0iY3L9dCCbyDB0mEmxOJ9+AEreqcadrirRZIuSTyz0qyG/AsxjUIoYgh2PBluMzFld5sD/03CvYo/e5KGge+8wrgH7dPWE3H2c7+2Ralg8FXZ/aC5q8gb/RDqvEZ9hBJJxVnM4/pb/4YImnXrXH2DFkkow/ZIrNpC/jNqb0ZBcum8YkbynSiCB7/7NfzaMid0hRQ3vW601xB8LGZ4Vj3XwerZWArf4jkb4avwBU73xoIfnYER/brQGri/0L2L8wSfLPrOvUQDPODImcWCQ6hhvJfAMcwDOfnWRG04+cFVKQVi3P/IgEIBSksLlPLJGq0V7MPqRV328ktvcKTt+jdfY40g9qQkkV5GCQMIlFX/dNvFaPvEtj4Hz9bJiaQhqB9I9XYlvqcziCp9MXA/8H7JsgQmDMHRC20z8Lyg2iH4A0I0ycdTvjBqZrZYbvZ0Q7M4bao8P/GM2fpGOj9eK+N1hdxOeiK2kj77jF+z6TTNHwaFcv05zNmdfLvBpe9FTC5X0tFTPHBhhRQ/mXkOhskx8Dqdli/OxeayDAWqwW85ZXyONfQFFSRMxL381jA33hHFMD/1zMsLpbSLmxiqBcfxGC4cYmW4nGnvWPwt9Jwe9JtqvMQ233Crp3kgtjdwlC9UNf1fMgkPGALLLxlFn+j/IF1wmUBPnoD37is48H60WeLlljEhR7+Lc9EsPfoEQIxJML+Ykog4oyMhxnYq4/iWOCF4MN0/aUqD36NnsUVQ8P/Nd8w6o3gJxqrQGTfbnmDunrC/LeXfEpo+zbYBO+Zbr6FVmjWwThXQney2E8fN4GFW2cnXBEa3XHgJ+c2dGXJmmzNzu7Zrsa/6P4dHFc3pI6MV+/j1jSFLAUZ88tBNGgg74gxvJK6E7LV277QutWGElTnszoehU95elVkO2YxYzefVxSgCFulNZbeP D8Cqd7ZK 8h0Uw0EpfxoBSCf9UgV7o8T8FreLSQO1F77AeqOGVaEmUZDUo74+2U+cPl8gAxdUEXkpAYO/aW5lRcFxaOaXYUgyEEA1UOkDeuYx22UlCRBCF3lzCWqelDjfvc+lQH1lWNUOZXYeZUll16MYMKjMGnhTH4v3k6Z1j5n0d7PVmk+PNq9AKUvU3Y4GpbKrFHC5nllQ0hAX0xXKYM+qpejlgsuBP6lDOyHLGPU/Bfc3xdaBNLEh7jhjQ0477sf9373Atu2MBgHenmjGURrrlg40Iumcm8EWkyN1WfWZ21kruGKNLWDGM9ZsBgV7gz/r/xY1DGujf94MXhatLQenyeqDYz/L7Up+9pWkpo3Cy X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Mar 03, 2025 at 05:09:21AM +0000, jeffxu@chromium.org wrote: > From: Jeff Xu > > Add sysmap_is_sealed.c to test system mappings are sealed. > > Note: CONFIG_MSEAL_SYSTEM_MAPPINGS must be set, as indicated in > config file. > > Signed-off-by: Jeff Xu > --- > .../mseal_system_mappings/.gitignore | 2 + > .../selftests/mseal_system_mappings/Makefile | 6 + > .../selftests/mseal_system_mappings/config | 1 + > .../mseal_system_mappings/sysmap_is_sealed.c | 113 ++++++++++++++++++ > 4 files changed, 122 insertions(+) > create mode 100644 tools/testing/selftests/mseal_system_mappings/.gitignore > create mode 100644 tools/testing/selftests/mseal_system_mappings/Makefile > create mode 100644 tools/testing/selftests/mseal_system_mappings/config > create mode 100644 tools/testing/selftests/mseal_system_mappings/sysmap_is_sealed.c > > diff --git a/tools/testing/selftests/mseal_system_mappings/.gitignore b/tools/testing/selftests/mseal_system_mappings/.gitignore > new file mode 100644 > index 000000000000..319c497a595e > --- /dev/null > +++ b/tools/testing/selftests/mseal_system_mappings/.gitignore > @@ -0,0 +1,2 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +sysmap_is_sealed > diff --git a/tools/testing/selftests/mseal_system_mappings/Makefile b/tools/testing/selftests/mseal_system_mappings/Makefile > new file mode 100644 > index 000000000000..2b4504e2f52f > --- /dev/null > +++ b/tools/testing/selftests/mseal_system_mappings/Makefile > @@ -0,0 +1,6 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +CFLAGS += -std=c99 -pthread -Wall $(KHDR_INCLUDES) > + > +TEST_GEN_PROGS := sysmap_is_sealed > + > +include ../lib.mk > diff --git a/tools/testing/selftests/mseal_system_mappings/config b/tools/testing/selftests/mseal_system_mappings/config > new file mode 100644 > index 000000000000..675cb9f37b86 > --- /dev/null > +++ b/tools/testing/selftests/mseal_system_mappings/config > @@ -0,0 +1 @@ > +CONFIG_MSEAL_SYSTEM_MAPPINGS=y > diff --git a/tools/testing/selftests/mseal_system_mappings/sysmap_is_sealed.c b/tools/testing/selftests/mseal_system_mappings/sysmap_is_sealed.c > new file mode 100644 > index 000000000000..c1e93794a58b > --- /dev/null > +++ b/tools/testing/selftests/mseal_system_mappings/sysmap_is_sealed.c > @@ -0,0 +1,113 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * test system mappings are sealed when > + * KCONFIG_MSEAL_SYSTEM_MAPPINGS=y > + */ > + > +#define _GNU_SOURCE > +#include > +#include > +#include > +#include > +#include > + > +#include "../kselftest.h" > +#include "../kselftest_harness.h" > + > +#define VDSO_NAME "[vdso]" > +#define VVAR_NAME "[vvar]" > +#define VVAR_VCLOCK_NAME "[vvar_vclock]" > +#define UPROBES_NAME "[uprobes]" > +#define SIGPAGE_NAME "[sigpage]" > +#define VECTORS_NAME "[vectors]" These are only ever used once, and it feels like having them spelled out right in the variant definitions would be more readable, but I'm not sure I feel strongly enough about it to say it should be changed. They're available via "variant->name" as well, which makes it unlikely the macros will be used anywhere in the future? Maybe you have plans for them. :) > +#define VMFLAGS "VmFlags:" This one gets a strlen() on it, so it feels better to have a macro. > +#define MSEAL_FLAGS "sl" > +#define MAX_LINE_LEN 512 > + > +bool has_mapping(char *name, FILE *maps) > +{ > + char line[MAX_LINE_LEN]; > + > + while (fgets(line, sizeof(line), maps)) { > + if (strstr(line, name)) > + return true; > + } > + > + return false; > +} > + > +bool mapping_is_sealed(char *name, FILE *maps) > +{ > + char line[MAX_LINE_LEN]; > + > + while (fgets(line, sizeof(line), maps)) { > + if (!strncmp(line, VMFLAGS, strlen(VMFLAGS))) { > + if (strstr(line, MSEAL_FLAGS)) > + return true; > + > + return false; > + } > + } > + > + return false; > +} > + > +FIXTURE(basic) { > + FILE *maps; > +}; > + > +FIXTURE_SETUP(basic) > +{ > + self->maps = fopen("/proc/self/smaps", "r"); > + if (!self->maps) > + SKIP(return, "Could not open /proc/self/smap, errno=%d", > + errno); Good SKIP usage, though I wonder if not having /proc should be a full blown failure? > +}; > + > +FIXTURE_TEARDOWN(basic) > +{ > + if (self->maps) > + fclose(self->maps); > +}; > + > +FIXTURE_VARIANT(basic) > +{ > + char *name; > +}; > + > +FIXTURE_VARIANT_ADD(basic, vdso) { > + .name = VDSO_NAME, > +}; > + > +FIXTURE_VARIANT_ADD(basic, vvar) { > + .name = VVAR_NAME, > +}; > + > +FIXTURE_VARIANT_ADD(basic, vvar_vclock) { > + .name = VVAR_VCLOCK_NAME, > +}; > + > +FIXTURE_VARIANT_ADD(basic, sigpage) { > + .name = SIGPAGE_NAME, > +}; > + > +FIXTURE_VARIANT_ADD(basic, vectors) { > + .name = VECTORS_NAME, > +}; > + > +FIXTURE_VARIANT_ADD(basic, uprobes) { > + .name = UPROBES_NAME, > +}; I love seeing variants used in the test harness. :) > + > +TEST_F(basic, is_sealed) > +{ > + if (!has_mapping(variant->name, self->maps)) { > + SKIP(return, "could not found the mapping, %s", typo nit: "find" instead of "found" > + variant->name); > + } > + > + EXPECT_TRUE(mapping_is_sealed(variant->name, self->maps)); > +}; This is a good "positive" test, but I'd like to see a negative test added as well. (This adds robustness against something going "all wrong" or "all right", like imagine that someone adds a VmFlags string named "slow", suddenly this test will always pass due to matching "sl". With a negative test added, it will fail when it finds "sl" when it's not expected.) For example, also check "[stack]" and "[heap]" and expect them NOT to be sealed. You could update the variant as: FIXTURE_VARIANT(basic) { char *name; bool sealed; }; FIXTURE_VARIANT_ADD(basic, vdso) { .name = "[vdso]", .sealed = true, }; FIXTURE_VARIANT_ADD(basic, stack) { .name = "[stack]", .sealed = false, }; And then update the is_sealed test to: EXPECT_EQ(variant->sealed, mapping_is_sealed(variant->name, self->maps)); -- Kees Cook