kernel/linux.git/tools/testing/selftests/bpf, branch v6.6.47

bpf: Replace bpf_lpm_trie_key 0-length array with flexible array

2024-08-19T04:04:27+00:00

[ Upstream commit 896880ff30866f386ebed14ab81ce1ad3710cfc4 ] Replace deprecated 0-length array in struct bpf_lpm_trie_key with flexible array. Found with GCC 13: ../kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=] 207 | *(__be16 *)&key->data[i]); | ^~~~~~~~~~~~~ ../include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16' 102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) | ^ ../include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu' 97 | #define be16_to_cpu __be16_to_cpu | ^~~~~~~~~~~~~ ../kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu' 206 | u16 diff = be16_to_cpu(*(__be16 *)&node->data[i] ^ | ^~~~~~~~~~~ In file included from ../include/linux/bpf.h:7: ../include/uapi/linux/bpf.h:82:17: note: while referencing 'data' 82 | __u8 data[0]; /* Arbitrary size */ | ^~~~ And found at run-time under CONFIG_FORTIFY_SOURCE: UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49 index 0 is out of range for type '__u8 [*]' Changing struct bpf_lpm_trie_key is difficult since has been used by userspace. For example, in Cilium: struct egress_gw_policy_key { struct bpf_lpm_trie_key lpm_key; __u32 saddr; __u32 daddr; }; While direct references to the "data" member haven't been found, there are static initializers what include the final member. For example, the "{}" here: struct egress_gw_policy_key in_key = { .lpm_key = { 32 + 24, {} }, .saddr = CLIENT_IP, .daddr = EXTERNAL_SVC_IP & 0Xffffff, }; To avoid the build time and run time warnings seen with a 0-sized trailing array for struct bpf_lpm_trie_key, introduce a new struct that correctly uses a flexible array for the trailing bytes, struct bpf_lpm_trie_key_u8. As part of this, include the "header" portion (which is just the "prefixlen" member), so it can be used by anything building a bpf_lpr_trie_key that has trailing members that aren't a u8 flexible array (like the self-test[1]), which is named struct bpf_lpm_trie_key_hdr. Unfortunately, C++ refuses to parse the __struct_group() helper, so it is not possible to define struct bpf_lpm_trie_key_hdr directly in struct bpf_lpm_trie_key_u8, so we must open-code the union directly. Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out, and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment to the UAPI header directing folks to the two new options. Reported-by: Mark Rutland Signed-off-by: Kees Cook Signed-off-by: Daniel Borkmann Acked-by: Gustavo A. R. Silva Closes: https://paste.debian.net/hidden/ca500597/ Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1] Link: https://lore.kernel.org/bpf/20240222155612.it.533-kees@kernel.org Stable-dep-of: 59f2f841179a ("bpf: Avoid kfree_rcu() under lock in bpf_lpm_trie.") Signed-off-by: Sasha Levin

selftests/bpf: Fix send_signal test with nested CONFIG_PARAVIRT

2024-08-14T11:58:42+00:00

[ Upstream commit 7015843afcaf68c132784c89528dfddc0005e483 ] Alexei reported that send_signal test may fail with nested CONFIG_PARAVIRT configs. In this particular case, the base VM is AMD with 166 cpus, and I run selftests with regular qemu on top of that and indeed send_signal test failed. I also tried with an Intel box with 80 cpus and there is no issue. The main qemu command line includes: -enable-kvm -smp 16 -cpu host The failure log looks like: $ ./test_progs -t send_signal [ 48.501588] watchdog: BUG: soft lockup - CPU#9 stuck for 26s! [test_progs:2225] [ 48.503622] Modules linked in: bpf_testmod(O) [ 48.503622] CPU: 9 PID: 2225 Comm: test_progs Tainted: G O 6.9.0-08561-g2c1713a8f1c9-dirty #69 [ 48.507629] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 [ 48.511635] RIP: 0010:handle_softirqs+0x71/0x290 [ 48.511635] Code: [...] 10 0a 00 00 00 31 c0 65 66 89 05 d5 f4 fa 7e fb bb ff ff ff ff <49> c7 c2 cb [ 48.518527] RSP: 0018:ffffc90000310fa0 EFLAGS: 00000246 [ 48.519579] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 00000000000006e0 [ 48.522526] RDX: 0000000000000006 RSI: ffff88810791ae80 RDI: 0000000000000000 [ 48.523587] RBP: ffffc90000fabc88 R08: 00000005a0af4f7f R09: 0000000000000000 [ 48.525525] R10: 0000000561d2f29c R11: 0000000000006534 R12: 0000000000000280 [ 48.528525] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 48.528525] FS: 00007f2f2885cd00(0000) GS:ffff888237c40000(0000) knlGS:0000000000000000 [ 48.531600] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 48.535520] CR2: 00007f2f287059f0 CR3: 0000000106a28002 CR4: 00000000003706f0 [ 48.537538] Call Trace: [ 48.537538] [ 48.537538] ? watchdog_timer_fn+0x1cd/0x250 [ 48.539590] ? lockup_detector_update_enable+0x50/0x50 [ 48.539590] ? __hrtimer_run_queues+0xff/0x280 [ 48.542520] ? hrtimer_interrupt+0x103/0x230 [ 48.544524] ? __sysvec_apic_timer_interrupt+0x4f/0x140 [ 48.545522] ? sysvec_apic_timer_interrupt+0x3a/0x90 [ 48.547612] ? asm_sysvec_apic_timer_interrupt+0x1a/0x20 [ 48.547612] ? handle_softirqs+0x71/0x290 [ 48.547612] irq_exit_rcu+0x63/0x80 [ 48.551585] sysvec_apic_timer_interrupt+0x75/0x90 [ 48.552521] [ 48.553529] [ 48.553529] asm_sysvec_apic_timer_interrupt+0x1a/0x20 [ 48.555609] RIP: 0010:finish_task_switch.isra.0+0x90/0x260 [ 48.556526] Code: [...] 9f 58 0a 00 00 48 85 db 0f 85 89 01 00 00 4c 89 ff e8 53 d9 bd 00 fb 66 90 <4d> 85 ed 74 [ 48.562524] RSP: 0018:ffffc90000fabd38 EFLAGS: 00000282 [ 48.563589] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff83385620 [ 48.563589] RDX: ffff888237c73ae4 RSI: 0000000000000000 RDI: ffff888237c6fd00 [ 48.568521] RBP: ffffc90000fabd68 R08: 0000000000000000 R09: 0000000000000000 [ 48.569528] R10: 0000000000000001 R11: 0000000000000000 R12: ffff8881009d0000 [ 48.573525] R13: ffff8881024e5400 R14: ffff88810791ae80 R15: ffff888237c6fd00 [ 48.575614] ? finish_task_switch.isra.0+0x8d/0x260 [ 48.576523] __schedule+0x364/0xac0 [ 48.577535] schedule+0x2e/0x110 [ 48.578555] pipe_read+0x301/0x400 [ 48.579589] ? destroy_sched_domains_rcu+0x30/0x30 [ 48.579589] vfs_read+0x2b3/0x2f0 [ 48.579589] ksys_read+0x8b/0xc0 [ 48.583590] do_syscall_64+0x3d/0xc0 [ 48.583590] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [ 48.586525] RIP: 0033:0x7f2f28703fa1 [ 48.587592] Code: [...] 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 80 3d c5 23 14 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 [ 48.593534] RSP: 002b:00007ffd90f8cf88 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 48.595589] RAX: ffffffffffffffda RBX: 00007ffd90f8d5e8 RCX: 00007f2f28703fa1 [ 48.595589] RDX: 0000000000000001 RSI: 00007ffd90f8cfb0 RDI: 0000000000000006 [ 48.599592] RBP: 00007ffd90f8d2f0 R08: 0000000000000064 R09: 0000000000000000 [ 48.602527] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 48.603589] R13: 00007ffd90f8d608 R14: 00007f2f288d8000 R15: 0000000000f6bdb0 [ 48.605527] In the test, two processes are communicating through pipe. Further debugging with strace found that the above splat is triggered as read() syscall could not receive the data even if the corresponding write() syscall in another process successfully wrote data into the pipe. The failed subtest is "send_signal_perf". The corresponding perf event has sample_period 1 and config PERF_COUNT_SW_CPU_CLOCK. sample_period 1 means every overflow event will trigger a call to the BPF program. So I suspect this may overwhelm the system. So I increased the sample_period to 100,000 and the test passed. The sample_period 10,000 still has the test failed. In other parts of selftest, e.g., [1], sample_freq is used instead. So I decided to use sample_freq = 1,000 since the test can pass as well. [1] https://lore.kernel.org/bpf/20240604070700.3032142-1-song@kernel.org/ Reported-by: Alexei Starovoitov Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20240605201203.2603846-1-yonghong.song@linux.dev Signed-off-by: Sasha Levin

libbpf: Fix no-args func prototype BTF dumping syntax

2024-08-03T06:54:36+00:00

[ Upstream commit 189f1a976e426011e6a5588f1d3ceedf71fe2965 ] For all these years libbpf's BTF dumper has been emitting not strictly valid syntax for function prototypes that have no input arguments. Instead of `int (*blah)()` we should emit `int (*blah)(void)`. This is not normally a problem, but it manifests when we get kfuncs in vmlinux.h that have no input arguments. Due to compiler internal specifics, we get no BTF information for such kfuncs, if they are not declared with proper `(void)`. The fix is trivial. We also need to adjust a few ancient tests that happily assumed `()` is correct. Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Reported-by: Tejun Heo Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20240712224442.282823-1-andrii@kernel.org Signed-off-by: Sasha Levin

selftests/bpf: fexit_sleep: Fix stack allocation for arm64

2024-08-03T06:54:36+00:00

[ Upstream commit e1ef78dce9b7b0fa7f9d88bb3554441d74d33b34 ] On ARM64 the stack pointer should be aligned at a 16 byte boundary or the SPAlignmentFault can occur. The fexit_sleep selftest allocates the stack for the child process as a character array, this is not guaranteed to be aligned at 16 bytes. Because of the SPAlignmentFault, the child process is killed before it can do the nanosleep call and hence fentry_cnt remains as 0. This causes the main thread to hang on the following line: while (READ_ONCE(fexit_skel->bss->fentry_cnt) != 2); Fix this by allocating the stack using mmap() as described in the example in the man page of clone(). Remove the fexit_sleep test from the DENYLIST of arm64. Fixes: eddbe8e65214 ("selftest/bpf: Add a test to check trampoline freeing logic.") Signed-off-by: Puranjay Mohan Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20240715173327.8657-1-puranjay@kernel.org Signed-off-by: Sasha Levin

selftests/bpf: Close obj in error path in xdp_adjust_tail

2024-08-03T06:53:43+00:00

[ Upstream commit 52b49ec1b2c78deb258596c3b231201445ef5380 ] If bpf_object__load() fails in test_xdp_adjust_frags_tail_grow(), "obj" opened before this should be closed. So use "goto out" to close it instead of using "return" here. Fixes: 110221081aac ("bpf: selftests: update xdp_adjust_tail selftest to include xdp frags") Signed-off-by: Geliang Tang Link: https://lore.kernel.org/r/f282a1ed2d0e3fb38cceefec8e81cabb69cab260.1720615848.git.tanggeliang@kylinos.cn Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

selftests/bpf: Null checks for links in bpf_tcp_ca

2024-08-03T06:53:42+00:00

[ Upstream commit eef0532e900c20a6760da829e82dac3ee18688c5 ] Run bpf_tcp_ca selftests (./test_progs -t bpf_tcp_ca) on a Loongarch platform, some "Segmentation fault" errors occur: ''' test_dctcp:PASS:bpf_dctcp__open_and_load 0 nsec test_dctcp:FAIL:bpf_map__attach_struct_ops unexpected error: -524 #29/1 bpf_tcp_ca/dctcp:FAIL test_cubic:PASS:bpf_cubic__open_and_load 0 nsec test_cubic:FAIL:bpf_map__attach_struct_ops unexpected error: -524 #29/2 bpf_tcp_ca/cubic:FAIL test_dctcp_fallback:PASS:dctcp_skel 0 nsec test_dctcp_fallback:PASS:bpf_dctcp__load 0 nsec test_dctcp_fallback:FAIL:dctcp link unexpected error: -524 #29/4 bpf_tcp_ca/dctcp_fallback:FAIL test_write_sk_pacing:PASS:open_and_load 0 nsec test_write_sk_pacing:FAIL:attach_struct_ops unexpected error: -524 #29/6 bpf_tcp_ca/write_sk_pacing:FAIL test_update_ca:PASS:open 0 nsec test_update_ca:FAIL:attach_struct_ops unexpected error: -524 settcpca:FAIL:setsockopt unexpected setsockopt: \ actual -1 == expected -1 (network_helpers.c:99: errno: No such file or directory) \ Failed to call post_socket_cb start_test:FAIL:start_server_str unexpected start_server_str: \ actual -1 == expected -1 test_update_ca:FAIL:ca1_ca1_cnt unexpected ca1_ca1_cnt: \ actual 0 <= expected 0 #29/9 bpf_tcp_ca/update_ca:FAIL #29 bpf_tcp_ca:FAIL Caught signal #11! Stack trace: ./test_progs(crash_handler+0x28)[0x5555567ed91c] linux-vdso.so.1(__vdso_rt_sigreturn+0x0)[0x7ffffee408b0] ./test_progs(bpf_link__update_map+0x80)[0x555556824a78] ./test_progs(+0x94d68)[0x5555564c4d68] ./test_progs(test_bpf_tcp_ca+0xe8)[0x5555564c6a88] ./test_progs(+0x3bde54)[0x5555567ede54] ./test_progs(main+0x61c)[0x5555567efd54] /usr/lib64/libc.so.6(+0x22208)[0x7ffff2aaa208] /usr/lib64/libc.so.6(__libc_start_main+0xac)[0x7ffff2aaa30c] ./test_progs(_start+0x48)[0x55555646bca8] Segmentation fault ''' This is because BPF trampoline is not implemented on Loongarch yet, "link" returned by bpf_map__attach_struct_ops() is NULL. test_progs crashs when this NULL link passes to bpf_link__update_map(). This patch adds NULL checks for all links in bpf_tcp_ca to fix these errors. If "link" is NULL, goto the newly added label "out" to destroy the skel. v2: - use "goto out" instead of "return" as Eduard suggested. Fixes: 06da9f3bd641 ("selftests/bpf: Test switching TCP Congestion Control algorithms.") Signed-off-by: Geliang Tang Reviewed-by: Alan Maguire Link: https://lore.kernel.org/r/b4c841492bd4ed97964e4e61e92827ce51bf1dc9.1720615848.git.tanggeliang@kylinos.cn Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

selftests/bpf: Close fd in error path in drop_on_reuseport

2024-08-03T06:53:42+00:00

[ Upstream commit adae187ebedcd95d02f045bc37dfecfd5b29434b ] In the error path when update_lookup_map() fails in drop_on_reuseport in prog_tests/sk_lookup.c, "server1", the fd of server 1, should be closed. This patch fixes this by using "goto close_srv1" lable instead of "detach" to close "server1" in this case. Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point") Acked-by: Eduard Zingerman Signed-off-by: Geliang Tang Link: https://lore.kernel.org/r/86aed33b4b0ea3f04497c757845cff7e8e621a2d.1720515893.git.tanggeliang@kylinos.cn Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

selftests/bpf: Check length of recv in test_sockmap

2024-08-03T06:53:38+00:00

[ Upstream commit de1b5ea789dc28066cc8dc634b6825bd6148f38b ] The value of recv in msg_loop may be negative, like EWOULDBLOCK, so it's necessary to check if it is positive before accumulating it to bytes_recvd. Fixes: 16962b2404ac ("bpf: sockmap, add selftests") Signed-off-by: Geliang Tang Signed-off-by: Daniel Borkmann Tested-by: Jakub Sitnicki Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/5172563f7c7b2a2e953cef02e89fc34664a7b190.1716446893.git.tanggeliang@kylinos.cn Signed-off-by: Sasha Levin

selftests/bpf: Fix prog numbers in test_sockmap

2024-08-03T06:53:36+00:00

[ Upstream commit 6c8d7598dfed759bf1d9d0322b4c2b42eb7252d8 ] bpf_prog5 and bpf_prog7 are removed from progs/test_sockmap_kern.h in commit d79a32129b21 ("bpf: Selftests, remove prints from sockmap tests"), now there are only 9 progs in it, not 11: SEC("sk_skb1") int bpf_prog1(struct __sk_buff *skb) SEC("sk_skb2") int bpf_prog2(struct __sk_buff *skb) SEC("sk_skb3") int bpf_prog3(struct __sk_buff *skb) SEC("sockops") int bpf_sockmap(struct bpf_sock_ops *skops) SEC("sk_msg1") int bpf_prog4(struct sk_msg_md *msg) SEC("sk_msg2") int bpf_prog6(struct sk_msg_md *msg) SEC("sk_msg3") int bpf_prog8(struct sk_msg_md *msg) SEC("sk_msg4") int bpf_prog9(struct sk_msg_md *msg) SEC("sk_msg5") int bpf_prog10(struct sk_msg_md *msg) This patch updates the array sizes of prog_fd[], prog_attach_type[] and prog_type[] from 11 to 9 accordingly. Fixes: d79a32129b21 ("bpf: Selftests, remove prints from sockmap tests") Signed-off-by: Geliang Tang Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/9c10d9f974f07fcb354a43a8eca67acb2fafc587.1715926605.git.tanggeliang@kylinos.cn Signed-off-by: Sasha Levin

selftests/bpf: Extend tcx tests to cover late tcx_entry release

2024-07-25T07:50:56+00:00

[ Upstream commit 5f1d18de79180deac2822c93e431bbe547f7d3ce ] Add a test case which replaces an active ingress qdisc while keeping the miniq in-tact during the transition period to the new clsact qdisc. # ./vmtest.sh -- ./test_progs -t tc_link [...] ./test_progs -t tc_link [ 3.412871] bpf_testmod: loading out-of-tree module taints kernel. [ 3.413343] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #332 tc_links_after:OK #333 tc_links_append:OK #334 tc_links_basic:OK #335 tc_links_before:OK #336 tc_links_chain_classic:OK #337 tc_links_chain_mixed:OK #338 tc_links_dev_chain0:OK #339 tc_links_dev_cleanup:OK #340 tc_links_dev_mixed:OK #341 tc_links_ingress:OK #342 tc_links_invalid:OK #343 tc_links_prepend:OK #344 tc_links_replace:OK #345 tc_links_revision:OK Summary: 14/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann Cc: Martin KaFai Lau Link: https://lore.kernel.org/r/20240708133130.11609-2-daniel@iogearbox.net Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin