Re: [RFC PATCH 11/12] selftests/seccomp: Make seccomp tests work on big endian
From: Kees Cook <hidden>
Date: 2015-07-15 15:16:13
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On Wed, Jul 15, 2015 at 12:37 AM, Michael Ellerman [off-list ref] wrote:
quoted hunk ↗ jump to hunk
The seccomp_bpf test uses BPF_LD|BPF_W|BPF_ABS to load 32-bit values from seccomp_data->args. On big endian machines this will load the high word of the argument, which is not what the test wants. Borrow a hack from samples/seccomp/bpf-helper.h which changes the offset on big endian to account for this. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- tools/testing/selftests/seccomp/seccomp_bpf.c | 6 ++++++ 1 file changed, 6 insertions(+)diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index b2374c131340..51adb9afb511 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c@@ -82,7 +82,13 @@ struct seccomp_data { }; #endif +#if __BYTE_ORDER == __LITTLE_ENDIAN #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) +#elif __BYTE_ORDER == __BIG_ENDIAN +#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32)) +#else +#error "wut?" +#endif
Ah-ha! Yes, thanks. Could you change the #error to something that describes the particular (impossible) failure condition? "wut? Unknown __BYTE_ORDER?!". Not a huge deal, but I always like verbose errors. :) Especially for "impossible" situations. :) -Kees
#define SIBLING_EXIT_UNKILLED 0xbadbeef #define SIBLING_EXIT_FAILURE 0xbadface -- 2.1.0
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