Re: [PATCH v8 7/7] selftest: test system mappings are sealed.

[Lorenzo Stoakes]

On Mon, Mar 03, 2025 at 12:08:49PM +0000, Lorenzo Stoakes wrote:
>
> On Mon, Mar 03, 2025 at 05:09:21AM +0000, jeffxu@xxxxxxxxxxxx wrote:
> > From: Jeff Xu <jeffxu@xxxxxxxxxxxx>
> >
> > 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 <jeffxu@xxxxxxxxxxxx>
>
> We do need to add this to the general selftests Makefile, but this code is
> fine, so have a:
>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
>
> Congratulations! :) and thanks for addressing the issues that were raised,
> appreciate your efforts on this.
>
> Maybe you could send a fix patch? As it's such a small fix.
>
> Cheers, Lorenzo
>
>
> > ---
> >  .../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 ++++++++++++++++++
>
> Can you add this to tools/testing/selftests/Makefile? I _think_ adding:
>
> TARGETS += mm
>
> Should do it. Thanks!

Obviously I meant to say:

	TARGETS += mseal_system_mappings

Doh! :)

>
> >  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 <stdio.h>
> > +#include <errno.h>
> > +#include <unistd.h>
> > +#include <string.h>
> > +#include <stdbool.h>
> > +
> > +#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]"
> > +
> > +#define VMFLAGS "VmFlags:"
> > +#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);
> > +};
> > +
> > +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,
> > +};
> > +
> > +TEST_F(basic, is_sealed)
> > +{
> > +	if (!has_mapping(variant->name, self->maps)) {
> > +		SKIP(return, "could not found the mapping, %s",
> > +			variant->name);
> > +	}
> > +
> > +	EXPECT_TRUE(mapping_is_sealed(variant->name, self->maps));
> > +};
> > +
> > +TEST_HARNESS_MAIN
> > --
> > 2.48.1.711.g2feabab25a-goog
> >