| Message ID | 20170807081636.65099-1-tmricht@linux.vnet.ibm.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 08/07/2017 10:16 AM, Thomas Richter wrote: > Commit 18f3d6be6be1 ("selftests/bpf: Add test cases to test narrower ctx field loads") > introduced new eBPF test cases. One of them (test_pkt_md_access.c) > fails on s390x. The BPF verifier error message is: > > [root@s8360046 bpf]# ./test_progs > test_pkt_access:PASS:ipv4 349 nsec > test_pkt_access:PASS:ipv6 212 nsec > [....] > libbpf: load bpf program failed: Permission denied > libbpf: -- BEGIN DUMP LOG --- > libbpf: > 0: (71) r2 = *(u8 *)(r1 +0) > invalid bpf_context access off=0 size=1 > > libbpf: -- END LOG -- > libbpf: failed to load program 'test1' > libbpf: failed to load object './test_pkt_md_access.o' > Summary: 29 PASSED, 1 FAILED > [root@s8360046 bpf]# > > This is caused by a byte endianness issue. S390x is a big endian > architecture. Pointer access to the lowest byte or halfword of a > four byte value need to add an offset. > On little endian architectures this offset is not needed. > > Fix this and use the same approach as the originator used for other files > (for example test_verifier.c) in his original commit. > > With this fix the test program test_progs succeeds on s390x: > [root@s8360046 bpf]# ./test_progs > test_pkt_access:PASS:ipv4 236 nsec > test_pkt_access:PASS:ipv6 217 nsec > test_xdp:PASS:ipv4 3624 nsec > test_xdp:PASS:ipv6 1722 nsec > test_l4lb:PASS:ipv4 926 nsec > test_l4lb:PASS:ipv6 1322 nsec > test_tcp_estats:PASS: 0 nsec > test_bpf_obj_id:PASS:get-fd-by-notexist-prog-id 0 nsec > test_bpf_obj_id:PASS:get-fd-by-notexist-map-id 0 nsec > test_bpf_obj_id:PASS:get-prog-info(fd) 0 nsec > test_bpf_obj_id:PASS:get-map-info(fd) 0 nsec > test_bpf_obj_id:PASS:get-prog-info(fd) 0 nsec > test_bpf_obj_id:PASS:get-map-info(fd) 0 nsec > test_bpf_obj_id:PASS:get-prog-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:get-prog-info(next_id->fd) 0 nsec > test_bpf_obj_id:PASS:get-prog-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:get-prog-info(next_id->fd) 0 nsec > test_bpf_obj_id:PASS:check total prog id found by get_next_id 0 nsec > test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:check get-map-info(next_id->fd) 0 nsec > test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec > test_bpf_obj_id:PASS:check get-map-info(next_id->fd) 0 nsec > test_bpf_obj_id:PASS:check total map id found by get_next_id 0 nsec > test_pkt_md_access:PASS: 277 nsec > Summary: 30 PASSED, 0 FAILED > [root@s8360046 bpf]# Fixes: 18f3d6be6be1 ("selftests/bpf: Add test cases to test narrower ctx field loads") > Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com> > Acked-by: Daniel Borkmann <daniel@iogearbox.net> (Patch is for -net tree.) Thanks Thomas!
From: Thomas Richter <tmricht@linux.vnet.ibm.com> Date: Mon, 7 Aug 2017 10:16:36 +0200 > Commit 18f3d6be6be1 ("selftests/bpf: Add test cases to test narrower ctx field loads") > introduced new eBPF test cases. One of them (test_pkt_md_access.c) > fails on s390x. The BPF verifier error message is: > > [root@s8360046 bpf]# ./test_progs > test_pkt_access:PASS:ipv4 349 nsec > test_pkt_access:PASS:ipv6 212 nsec > [....] > libbpf: load bpf program failed: Permission denied > libbpf: -- BEGIN DUMP LOG --- > libbpf: > 0: (71) r2 = *(u8 *)(r1 +0) > invalid bpf_context access off=0 size=1 > > libbpf: -- END LOG -- > libbpf: failed to load program 'test1' > libbpf: failed to load object './test_pkt_md_access.o' > Summary: 29 PASSED, 1 FAILED > [root@s8360046 bpf]# > > This is caused by a byte endianness issue. S390x is a big endian > architecture. Pointer access to the lowest byte or halfword of a > four byte value need to add an offset. > On little endian architectures this offset is not needed. > > Fix this and use the same approach as the originator used for other files > (for example test_verifier.c) in his original commit. > > With this fix the test program test_progs succeeds on s390x: ... > Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com> > Acked-by: Daniel Borkmann <daniel@iogearbox.net> Applied, thanks.
diff --git a/tools/testing/selftests/bpf/test_pkt_md_access.c b/tools/testing/selftests/bpf/test_pkt_md_access.c index 71729d4..7956302 100644 --- a/tools/testing/selftests/bpf/test_pkt_md_access.c +++ b/tools/testing/selftests/bpf/test_pkt_md_access.c @@ -12,12 +12,23 @@ int _version SEC("version") = 1; +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ #define TEST_FIELD(TYPE, FIELD, MASK) \ { \ TYPE tmp = *(volatile TYPE *)&skb->FIELD; \ if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK)) \ return TC_ACT_SHOT; \ } +#else +#define TEST_FIELD_OFFSET(a, b) ((sizeof(a) - sizeof(b)) / sizeof(b)) +#define TEST_FIELD(TYPE, FIELD, MASK) \ + { \ + TYPE tmp = *((volatile TYPE *)&skb->FIELD + \ + TEST_FIELD_OFFSET(skb->FIELD, TYPE)); \ + if (tmp != ((*(volatile __u32 *)&skb->FIELD) & MASK)) \ + return TC_ACT_SHOT; \ + } +#endif SEC("test1") int process(struct __sk_buff *skb)
Commit 18f3d6be6be1 ("selftests/bpf: Add test cases to test narrower ctx field loads") introduced new eBPF test cases. One of them (test_pkt_md_access.c) fails on s390x. The BPF verifier error message is: [root@s8360046 bpf]# ./test_progs test_pkt_access:PASS:ipv4 349 nsec test_pkt_access:PASS:ipv6 212 nsec [....] libbpf: load bpf program failed: Permission denied libbpf: -- BEGIN DUMP LOG --- libbpf: 0: (71) r2 = *(u8 *)(r1 +0) invalid bpf_context access off=0 size=1 libbpf: -- END LOG -- libbpf: failed to load program 'test1' libbpf: failed to load object './test_pkt_md_access.o' Summary: 29 PASSED, 1 FAILED [root@s8360046 bpf]# This is caused by a byte endianness issue. S390x is a big endian architecture. Pointer access to the lowest byte or halfword of a four byte value need to add an offset. On little endian architectures this offset is not needed. Fix this and use the same approach as the originator used for other files (for example test_verifier.c) in his original commit. With this fix the test program test_progs succeeds on s390x: [root@s8360046 bpf]# ./test_progs test_pkt_access:PASS:ipv4 236 nsec test_pkt_access:PASS:ipv6 217 nsec test_xdp:PASS:ipv4 3624 nsec test_xdp:PASS:ipv6 1722 nsec test_l4lb:PASS:ipv4 926 nsec test_l4lb:PASS:ipv6 1322 nsec test_tcp_estats:PASS: 0 nsec test_bpf_obj_id:PASS:get-fd-by-notexist-prog-id 0 nsec test_bpf_obj_id:PASS:get-fd-by-notexist-map-id 0 nsec test_bpf_obj_id:PASS:get-prog-info(fd) 0 nsec test_bpf_obj_id:PASS:get-map-info(fd) 0 nsec test_bpf_obj_id:PASS:get-prog-info(fd) 0 nsec test_bpf_obj_id:PASS:get-map-info(fd) 0 nsec test_bpf_obj_id:PASS:get-prog-fd(next_id) 0 nsec test_bpf_obj_id:PASS:get-prog-info(next_id->fd) 0 nsec test_bpf_obj_id:PASS:get-prog-fd(next_id) 0 nsec test_bpf_obj_id:PASS:get-prog-info(next_id->fd) 0 nsec test_bpf_obj_id:PASS:check total prog id found by get_next_id 0 nsec test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec test_bpf_obj_id:PASS:check get-map-info(next_id->fd) 0 nsec test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec test_bpf_obj_id:PASS:check get-map-info(next_id->fd) 0 nsec test_bpf_obj_id:PASS:check total map id found by get_next_id 0 nsec test_pkt_md_access:PASS: 277 nsec Summary: 30 PASSED, 0 FAILED [root@s8360046 bpf]# Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> --- tools/testing/selftests/bpf/test_pkt_md_access.c | 11 +++++++++++ 1 file changed, 11 insertions(+)