kernel/linux.git/tools/testing/selftests/bpf, branch v5.9.12

selftests/bpf: Fix error return code in run_getsockopt_test()

2020-11-24T12:39:02+00:00

[ Upstream commit 2acc3c1bc8e98bc66b1badec42e9ea205b4fcdaa ] Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: 65b4414a05eb ("selftests/bpf: add sockopt test that exercises BPF_F_ALLOW_MULTI") Reported-by: Hulk Robot Signed-off-by: Wang Hai Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20201116101633.64627-1-wanghai38@huawei.com Signed-off-by: Sasha Levin

bpf: Zero-fill re-used per-cpu map element

2020-11-18T18:22:18+00:00

[ Upstream commit d3bec0138bfbe58606fc1d6f57a4cdc1a20218db ] Zero-fill element values for all other cpus than current, just as when not using prealloc. This is the only way the bpf program can ensure known initial values for all cpus ('onallcpus' cannot be set when coming from the bpf program). The scenario is: bpf program inserts some elements in a per-cpu map, then deletes some (or userspace does). When later adding new elements using bpf_map_update_elem(), the bpf program can only set the value of the new elements for the current cpu. When prealloc is enabled, previously deleted elements are re-used. Without the fix, values for other cpus remain whatever they were when the re-used entry was previously freed. A selftest is added to validate correct operation in above scenario as well as in case of LRU per-cpu map element re-use. Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements") Signed-off-by: David Verbeiren Signed-off-by: Alexei Starovoitov Acked-by: Matthieu Baerts Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201104112332.15191-1-david.verbeiren@tessares.net Signed-off-by: Sasha Levin

kbuild: explicitly specify the build id style

2020-11-18T18:22:07+00:00

[ Upstream commit a968433723310f35898b4a2f635a7991aeef66b1 ] ld's --build-id defaults to "sha1" style, while lld defaults to "fast". The build IDs are very different between the two, which may confuse programs that reference them. Signed-off-by: Bill Wendling Acked-by: David S. Miller Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

selftests/bpf: Define string const as global for test_sysctl_prog.c

2020-11-05T10:51:21+00:00

[ Upstream commit 6e057fc15a2da4ee03eb1fa6889cf687e690106e ] When tweaking llvm optimizations, I found that selftest build failed with the following error: libbpf: elf: skipping unrecognized data section(6) .rodata.str1.1 libbpf: prog 'sysctl_tcp_mem': bad map relo against '.L__const.is_tcp_mem.tcp_mem_name' in section '.rodata.str1.1' Error: failed to open BPF object file: Relocation failed make: *** [/work/net-next/tools/testing/selftests/bpf/test_sysctl_prog.skel.h] Error 255 make: *** Deleting file `/work/net-next/tools/testing/selftests/bpf/test_sysctl_prog.skel.h' The local string constant "tcp_mem_name" is put into '.rodata.str1.1' section which libbpf cannot handle. Using untweaked upstream llvm, "tcp_mem_name" is completely inlined after loop unrolling. Commit 7fb5eefd7639 ("selftests/bpf: Fix test_sysctl_loop{1, 2} failure due to clang change") solved a similar problem by defining the string const as a global. Let us do the same here for test_sysctl_prog.c so it can weather future potential llvm changes. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200910202718.956042-1-yhs@fb.com Signed-off-by: Sasha Levin

selftests/bpf: Fix test_sysctl_loop{1, 2} failure due to clang change

2020-10-29T09:12:17+00:00

[ Upstream commit 7fb5eefd76394cfefb380724a87ca40b47d44405 ] Andrii reported that with latest clang, when building selftests, we have error likes: error: progs/test_sysctl_loop1.c:23:16: in function sysctl_tcp_mem i32 (%struct.bpf_sysctl*): Looks like the BPF stack limit of 512 bytes is exceeded. Please move large on stack variables into BPF per-cpu array map. The error is triggered by the following LLVM patch: https://reviews.llvm.org/D87134 For example, the following code is from test_sysctl_loop1.c: static __always_inline int is_tcp_mem(struct bpf_sysctl *ctx) { volatile char tcp_mem_name[] = "net/ipv4/tcp_mem/very_very_very_very_long_pointless_string"; ... } Without the above LLVM patch, the compiler did optimization to load the string (59 bytes long) with 7 64bit loads, 1 8bit load and 1 16bit load, occupying 64 byte stack size. With the above LLVM patch, the compiler only uses 8bit loads, but subregister is 32bit. So stack requirements become 4 * 59 = 236 bytes. Together with other stuff on the stack, total stack size exceeds 512 bytes, hence compiler complains and quits. To fix the issue, removing "volatile" key word or changing "volatile" to "const"/"static const" does not work, the string is put in .rodata.str1.1 section, which libbpf did not process it and errors out with libbpf: elf: skipping unrecognized data section(6) .rodata.str1.1 libbpf: prog 'sysctl_tcp_mem': bad map relo against '.L__const.is_tcp_mem.tcp_mem_name' in section '.rodata.str1.1' Defining the string const as global variable can fix the issue as it puts the string constant in '.rodata' section which is recognized by libbpf. In the future, when libbpf can process '.rodata.str*.*' properly, the global definition can be changed back to local definition. Defining tcp_mem_name as a global, however, triggered a verifier failure. ./test_progs -n 7/21 libbpf: load bpf program failed: Permission denied libbpf: -- BEGIN DUMP LOG --- libbpf: invalid stack off=0 size=1 verification time 6975 usec stack depth 160+64 processed 889 insns (limit 1000000) max_states_per_insn 4 total_states 14 peak_states 14 mark_read 10 libbpf: -- END LOG -- libbpf: failed to load program 'sysctl_tcp_mem' libbpf: failed to load object 'test_sysctl_loop2.o' test_bpf_verif_scale:FAIL:114 #7/21 test_sysctl_loop2.o:FAIL This actually exposed a bpf program bug. In test_sysctl_loop{1,2}, we have code like const char tcp_mem_name[] = "<...long string...>"; ... char name[64]; ... for (i = 0; i < sizeof(tcp_mem_name); ++i) if (name[i] != tcp_mem_name[i]) return 0; In the above code, if sizeof(tcp_mem_name) > 64, name[i] access may be out of bound. The sizeof(tcp_mem_name) is 59 for test_sysctl_loop1.c and 79 for test_sysctl_loop2.c. Without promotion-to-global change, old compiler generates code where the overflowed stack access is actually filled with valid value, so hiding the bpf program bug. With promotion-to-global change, the code is different, more specifically, the previous loading constants to stack is gone, and "name" occupies stack[-64:0] and overflow access triggers a verifier error. To fix the issue, adjust "name" buffer size properly. Reported-by: Andrii Nakryiko Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200909171542.3673449-1-yhs@fb.com Signed-off-by: Sasha Levin

selftests/bpf: Fix endianness issues in sk_lookup/ctx_narrow_access

2020-10-29T09:11:31+00:00

[ Upstream commit 6458bde368cee77e798d05cccd2316db4d748c41 ] This test makes a lot of narrow load checks while assuming little endian architecture, and therefore fails on s390. Fix by introducing LSB and LSW macros and using them to perform narrow loads. Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point") Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200929201814.44360-1-iii@linux.ibm.com Signed-off-by: Sasha Levin

selftests: Remove fmod_ret from test_overhead

2020-10-29T09:11:30+00:00

[ Upstream commit b000def2e052fc8ddea31a18019f6ebe044defb3 ] The test_overhead prog_test included an fmod_ret program that attached to __set_task_comm() in the kernel. However, this function was never listed as allowed for return modification, so this only worked because of the verifier skipping tests when a trampoline already existed for the attach point. Now that the verifier checks have been fixed, remove fmod_ret from the test so it works again. Fixes: 4eaf0b5c5e04 ("selftest/bpf: Fmod_ret prog and implement test_overhead as part of bench") Acked-by: Andrii Nakryiko Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

selftests/bpf: Fix endianness issue in test_sockopt_sk

2020-10-29T09:11:23+00:00

[ Upstream commit fec47bbc10b243690f5d0ee484a0bbdee273e71b ] getsetsockopt() calls getsockopt() with optlen == 1, but then checks the resulting int. It is ok on little endian, but not on big endian. Fix by checking char instead. Fixes: 8a027dc0d8f5 ("selftests/bpf: add sockopt test that exercises sk helpers") Signed-off-by: Ilya Leoshkevich Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200915113928.3768496-1-iii@linux.ibm.com Signed-off-by: Sasha Levin

selftests/bpf: Fix endianness issue in sk_assign

2020-10-29T09:11:23+00:00

[ Upstream commit b6ed6cf4a3acdeab9aed8e0a524850761ec9b152 ] server_map's value size is 8, but the test tries to put an int there. This sort of works on x86 (unless followed by non-0), but hard fails on s390. Fix by using __s64 instead of int. Fixes: 2d7824ffd25c ("selftests: bpf: Add test for sk_assign") Signed-off-by: Ilya Leoshkevich Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200915113815.3768217-1-iii@linux.ibm.com Signed-off-by: Sasha Levin

selftests/bpf: Fix test_vmlinux test to use bpf_probe_read_user()

2020-10-29T09:11:13+00:00

[ Upstream commit 02f47faa25db134f6043fb6b12a68b5d4c980bb6 ] The test is reading UAPI kernel structure from user-space. So it doesn't need CO-RE relocations and has to use bpf_probe_read_user(). Fixes: acbd06206bbb ("selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200818213356.2629020-6-andriin@fb.com Signed-off-by: Sasha Levin