[PATCH v2] selftests/seccomp: Get page size from sysconf

[PATCH v2] selftests/seccomp: Get page size from sysconf

[Bamvor Jian Zhang]

The commit fd88d16c58c2 ("selftests/seccomp: Be more precise with
syscall arguments.") use PAGE_SIZE directly which lead to build
failure on arm64.

Replace it with generic interface(sysconf(_SC_PAGESIZE)) to fix this
failure.

Build and test successful on x86_64 and arm64.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
Add assertion for page_size.

 tools/testing/selftests/seccomp/seccomp_bpf.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index e38cc54..882fe83 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -492,6 +492,9 @@ TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
 	pid_t parent = getppid();
 	int fd;
 	void *map1, *map2;
+	int page_size = sysconf(_SC_PAGESIZE);
+
+	ASSERT_LT(0, page_size);
 
 	ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 	ASSERT_EQ(0, ret);
@@ -504,16 +507,16 @@ TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
 
 	EXPECT_EQ(parent, syscall(__NR_getppid));
 	map1 = (void *)syscall(sysno,
-		NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE, fd, PAGE_SIZE);
+		NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
 	EXPECT_NE(MAP_FAILED, map1);
 	/* mmap2() should never return. */
 	map2 = (void *)syscall(sysno,
-		 NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
+		 NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
 	EXPECT_EQ(MAP_FAILED, map2);
 
 	/* The test failed, so clean up the resources. */
-	munmap(map1, PAGE_SIZE);
-	munmap(map2, PAGE_SIZE);
+	munmap(map1, page_size);
+	munmap(map2, page_size);
 	close(fd);
 }
 
-- 
2.1.4

Re: [PATCH v2] selftests/seccomp: Get page size from sysconf

[Kees Cook]

On Thu, Nov 12, 2015 at 7:17 PM, Bamvor Jian Zhang
<bamvor.zhangjian-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> The commit fd88d16c58c2 ("selftests/seccomp: Be more precise with
> syscall arguments.") use PAGE_SIZE directly which lead to build
> failure on arm64.
>
> Replace it with generic interface(sysconf(_SC_PAGESIZE)) to fix this
> failure.
>
> Build and test successful on x86_64 and arm64.
>
> Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

Acked-by: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>

Shuah, can you please pull this for kselftest? It fixes arm64 after
Robert's changes.

Thanks!

-Kees

> ---
> Add assertion for page_size.
>
>  tools/testing/selftests/seccomp/seccomp_bpf.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
> index e38cc54..882fe83 100644
> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
> @@ -492,6 +492,9 @@ TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
>         pid_t parent = getppid();
>         int fd;
>         void *map1, *map2;
> +       int page_size = sysconf(_SC_PAGESIZE);
> +
> +       ASSERT_LT(0, page_size);
>
>         ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
>         ASSERT_EQ(0, ret);
> @@ -504,16 +507,16 @@ TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
>
>         EXPECT_EQ(parent, syscall(__NR_getppid));
>         map1 = (void *)syscall(sysno,
> -               NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE, fd, PAGE_SIZE);
> +               NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
>         EXPECT_NE(MAP_FAILED, map1);
>         /* mmap2() should never return. */
>         map2 = (void *)syscall(sysno,
> -                NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
> +                NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
>         EXPECT_EQ(MAP_FAILED, map2);
>
>         /* The test failed, so clean up the resources. */
> -       munmap(map1, PAGE_SIZE);
> -       munmap(map2, PAGE_SIZE);
> +       munmap(map1, page_size);
> +       munmap(map2, page_size);
>         close(fd);
>  }
>
> --
> 2.1.4
>



-- 
Kees Cook
Chrome OS Security

Re: [PATCH v2] selftests/seccomp: Get page size from sysconf

[Michael Ellerman]

On Fri, 2015-11-13 at 14:41 -0800, Kees Cook wrote:

> On Thu, Nov 12, 2015 at 7:17 PM, Bamvor Jian Zhang
> <bamvor.zhangjian-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:

> > The commit fd88d16c58c2 ("selftests/seccomp: Be more precise with
> > syscall arguments.") use PAGE_SIZE directly which lead to build
> > failure on arm64.
> > 
> > Replace it with generic interface(sysconf(_SC_PAGESIZE)) to fix this
> > failure.
> > 
> > Build and test successful on x86_64 and arm64.
> > 
> > Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> 
> Acked-by: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> 
> Shuah, can you please pull this for kselftest? It fixes arm64 after
> Robert's changes.

Also works on powerpc with 64k pages.

Tested-by: Michael Ellerman <mpe-Gsx/Oe8HsFggBc27wqDAHg@public.gmane.org>

cheers

Re: [PATCH v2] selftests/seccomp: Get page size from sysconf

[Shuah Khan]

On 11/13/2015 03:41 PM, Kees Cook wrote:
> On Thu, Nov 12, 2015 at 7:17 PM, Bamvor Jian Zhang
> <bamvor.zhangjian-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
>> The commit fd88d16c58c2 ("selftests/seccomp: Be more precise with
>> syscall arguments.") use PAGE_SIZE directly which lead to build
>> failure on arm64.
>>
>> Replace it with generic interface(sysconf(_SC_PAGESIZE)) to fix this
>> failure.
>>
>> Build and test successful on x86_64 and arm64.
>>
>> Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> 
> Acked-by: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> 
> Shuah, can you please pull this for kselftest? It fixes arm64 after
> Robert's changes.
> 

Thanks for finding and fixing this. Applied to linux-kselftest fixes
for 4.4-rc2 with Kees's Ack.

thanks,
-- Shuah

-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org | (970) 217-8978