kernel/git/stable/linux.git/tools/bpf, branch linux-4.20.y

bpftool: fix percpu maps updating

2019-03-13T21:04:10+00:00

[ Upstream commit b0ca5ecb8e2279d706261f525f1bd0ba9e3fe800 ] When updating a percpu map, bpftool currently copies the provided value only into the first per CPU copy of the specified value, all others instances are left zeroed. This change explicitly copies the user-provided bytes to all the per CPU instances, keeping the sub-command syntax unchanged. v2 -> v3: - drop unused argument, as per Quentin's suggestion v1 -> v2: - rename the helper as per Quentin's suggestion Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool") Signed-off-by: Paolo Abeni Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

bpftool: Fix prog dump by tag

2019-03-13T21:04:10+00:00

[ Upstream commit 752bcf80f5549c9901b2e8bc77b2138de55b1026 ] Lance reported an issue with bpftool not being able to dump program if there are more programs loaded and you want to dump any but the first program, like: # bpftool prog 28: kprobe name trace_req_start tag 1dfc28ba8b3dd597 gpl loaded_at 2019-01-18T17:02:40+1100 uid 0 xlated 112B jited 109B memlock 4096B map_ids 13 29: kprobe name trace_req_compl tag 5b6a5ecc6030a683 gpl loaded_at 2019-01-18T17:02:40+1100 uid 0 xlated 928B jited 575B memlock 4096B map_ids 13,14 # bpftool prog dum jited tag 1dfc28ba8b3dd597 0: push %rbp 1: mov %rsp,%rbp ... # bpftool prog dum jited tag 5b6a5ecc6030a683 Error: can't get prog info (29): Bad address The problem is in the prog_fd_by_tag function not cleaning the struct bpf_prog_info before another request, so the previous program length is still in there and kernel assumes it needs to dump the program, which fails because there's no user pointer set. Moving the struct bpf_prog_info declaration into the loop, so it gets cleaned before each query. Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool") Reported-by: Lance Digby Signed-off-by: Jiri Olsa Reviewed-by: Quentin Monnet Acked-by: Jakub Kicinski Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

tools: bpftool: fix -Wmissing declaration warnings

2019-02-12T19:02:19+00:00

[ Upstream commit c101189bc9680675a2686bafe908015a07a0da51 ] Help compiler check arguments for several utility functions used to print items to the console by adding the "printf" attribute when declaring those functions. Also, declare as "static" two functions that are only used in prog.c. All of them discovered by compiling bpftool with -Wmissing-format-attribute -Wmissing-declarations. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

bpftool: Improve handling of ENOENT on map dumps

2019-02-12T19:02:06+00:00

[ Upstream commit bf598a8f0f771302d4ecb0ef0003c54732221597 ] bpftool output is not user friendly when dumping a map with only a few populated entries: $ bpftool map 1: devmap name tx_devmap flags 0x0 key 4B value 4B max_entries 64 memlock 4096B 2: array name tx_idxmap flags 0x0 key 4B value 4B max_entries 64 memlock 4096B $ bpftool map dump id 1 key: 00 00 00 00 value: No such file or directory key: 01 00 00 00 value: No such file or directory key: 02 00 00 00 value: No such file or directory key: 03 00 00 00 value: 03 00 00 00 Handle ENOENT by keeping the line format sane and dumping "" for the value $ bpftool map dump id 1 key: 00 00 00 00 value: key: 01 00 00 00 value: key: 02 00 00 00 value: key: 03 00 00 00 value: 03 00 00 00 ... Signed-off-by: David Ahern Acked-by: Jakub Kicinski Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

tools: bpftool: fix a bitfield pretty print issue

2018-11-29T00:40:02+00:00

Commit b12d6ec09730 ("bpf: btf: add btf print functionality") added btf pretty print functionality to bpftool. There is a problem though in printing a bitfield whose type has modifiers. For example, for a type like typedef int ___int; struct tmp_t { int a:3; ___int b:3; }; Suppose we have a map struct bpf_map_def SEC("maps") tmpmap = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(__u32), .value_size = sizeof(struct tmp_t), .max_entries = 1, }; and the hash table is populated with one element with key 0 and value (.a = 1 and .b = 2). In BTF, the struct member "b" will have a type "typedef" which points to an int type. The current implementation does not pass the bit offset during transition from typedef to int type, hence incorrectly print the value as $ bpftool m d id 79 [{ "key": 0, "value": { "a": 0x1, "b": 0x1 } } ] This patch fixed the issue by carrying bit_offset along the type chain during bit_field print. The correct result can be printed as $ bpftool m d id 76 [{ "key": 0, "value": { "a": 0x1, "b": 0x2 } } ] The kernel pretty print is implemented correctly and does not have this issue. Fixes: b12d6ec09730 ("bpf: btf: add btf print functionality") Signed-off-by: Yonghong Song Acked-by: Song Liu Signed-off-by: Alexei Starovoitov

tools: bpftool: fix potential NULL pointer dereference in do_load

2018-11-21T23:45:51+00:00

This patch fixes a possible null pointer dereference in do_load, detected by the semantic patch deref_null.cocci, with the following warning: ./tools/bpf/bpftool/prog.c:1021:23-25: ERROR: map_replace is NULL but dereferenced. The following code has potential null pointer references: 881 map_replace = reallocarray(map_replace, old_map_fds + 1, 882 sizeof(*map_replace)); 883 if (!map_replace) { 884 p_err("mem alloc failed"); 885 goto err_free_reuse_maps; 886 } ... 1019 err_free_reuse_maps: 1020 for (i = 0; i < old_map_fds; i++) 1021 close(map_replace[i].fd); 1022 free(map_replace); Fixes: 3ff5a4dc5d89 ("tools: bpftool: allow reuse of maps with bpftool prog load") Co-developed-by: Wen Yang Signed-off-by: Wen Yang Signed-off-by: Jakub Kicinski Signed-off-by: Daniel Borkmann

tools: bpftool: update references to other man pages in documentation

2018-11-09T07:20:52+00:00

Update references to other bpftool man pages at the bottom of each manual page. Also reference the "bpf(2)" and "bpf-helpers(7)" man pages. References are sorted by number of man section, then by "prog-and-map-go-first", the other pages in alphabetical order. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann

tools: bpftool: pass an argument to silence open_obj_pinned()

2018-11-09T07:20:52+00:00

Function open_obj_pinned() prints error messages when it fails to open a link in the BPF virtual file system. However, in some occasions it is not desirable to print an error, for example when we parse all links under the bpffs root, and the error is due to some paths actually being symbolic links. Example output: # ls -l /sys/fs/bpf/ lrwxrwxrwx 1 root root 0 Oct 18 19:00 ip -> /sys/fs/bpf/tc/ drwx------ 3 root root 0 Oct 18 19:00 tc lrwxrwxrwx 1 root root 0 Oct 18 19:00 xdp -> /sys/fs/bpf/tc/ # bpftool --bpffs prog show Error: bpf obj get (/sys/fs/bpf): Permission denied Error: bpf obj get (/sys/fs/bpf): Permission denied # strace -e bpf bpftool --bpffs prog show bpf(BPF_OBJ_GET, {pathname="/sys/fs/bpf/ip", bpf_fd=0}, 72) = -1 EACCES (Permission denied) Error: bpf obj get (/sys/fs/bpf): Permission denied bpf(BPF_OBJ_GET, {pathname="/sys/fs/bpf/xdp", bpf_fd=0}, 72) = -1 EACCES (Permission denied) Error: bpf obj get (/sys/fs/bpf): Permission denied ... To fix it, pass a bool as a second argument to the function, and prevent it from printing an error when the argument is set to true. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann

tools: bpftool: fix plain output and doc for --bpffs option

2018-11-09T07:20:52+00:00

Edit the documentation of the -f|--bpffs option to make it explicit that it dumps paths of pinned programs when bpftool is used to list the programs only, so that users do not believe they will see the name of the newly pinned program with "bpftool prog pin" or "bpftool prog load". Also fix the plain output: do not add a blank line after each program block, in order to remain consistent with what bpftool does when the option is not passed. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann

tools: bpftool: prevent infinite loop in get_fdinfo()

2018-11-09T07:20:52+00:00

Function getline() returns -1 on failure to read a line, thus creating an infinite loop in get_fdinfo() if the key is not found. Fix it by calling the function only as long as we get a strictly positive return value. Found by copying the code for a key which is not always present... Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool") Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann