From 752bcf80f5549c9901b2e8bc77b2138de55b1026 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Fri, 18 Jan 2019 13:58:17 +0100 Subject: bpftool: Fix prog dump by tag 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 --- tools/bpf/bpftool/prog.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'tools/bpf/bpftool') diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 2d1bb7d6ff51..b54ed82b9589 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -78,13 +78,14 @@ static void print_boot_time(__u64 nsecs, char *buf, unsigned int size) static int prog_fd_by_tag(unsigned char *tag) { - struct bpf_prog_info info = {}; - __u32 len = sizeof(info); unsigned int id = 0; int err; int fd; while (true) { + struct bpf_prog_info info = {}; + __u32 len = sizeof(info); + err = bpf_prog_get_next_id(id, &id); if (err) { p_err("%s", strerror(errno)); -- cgit v1.2.3 From b0ca5ecb8e2279d706261f525f1bd0ba9e3fe800 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Mon, 21 Jan 2019 12:36:12 +0100 Subject: bpftool: fix percpu maps updating 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 --- tools/bpf/bpftool/map.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'tools/bpf/bpftool') diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index 2037e3dc864b..29a3468c6cf6 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -347,6 +347,20 @@ static char **parse_bytes(char **argv, const char *name, unsigned char *val, return argv + i; } +/* on per cpu maps we must copy the provided value on all value instances */ +static void fill_per_cpu_value(struct bpf_map_info *info, void *value) +{ + unsigned int i, n, step; + + if (!map_is_per_cpu(info->type)) + return; + + n = get_possible_cpus(); + step = round_up(info->value_size, 8); + for (i = 1; i < n; i++) + memcpy(value + i * step, value, info->value_size); +} + static int parse_elem(char **argv, struct bpf_map_info *info, void *key, void *value, __u32 key_size, __u32 value_size, __u32 *flags, __u32 **value_fd) @@ -426,6 +440,8 @@ static int parse_elem(char **argv, struct bpf_map_info *info, argv = parse_bytes(argv, "value", value, value_size); if (!argv) return -1; + + fill_per_cpu_value(info, value); } return parse_elem(argv, info, key, NULL, key_size, value_size, -- cgit v1.2.3 From 8c79b35693380d856dcbbc21629682a90f26ca62 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 28 Jan 2019 10:01:21 -0800 Subject: tools: bpftool: fix crash with un-owned prog arrays Prog arrays don't have 'owner_prog_type' and 'owner_jited' fields in their fdinfo when they are created. Those fields are set and reported when first program is checked for compatibility by bpf_prog_array_compatible(). This means that bpftool cannot expect the fields to always be there. Currently trying to show maps on a system with an un-owned prog array leads to a crash: $ bpftool map show 389: prog_array name tail_call_map flags 0x0 Error: key 'owner_prog_type' not found in fdinfo Error: key 'owner_jited' not found in fdinfo key 4B value 4B max_entries 4 memlock 4096B Segmentation fault (core dumped) We pass a NULL pointer to atoi(). Remove the assumption that fdinfo keys are always present. Add missing validations and remove the p_err() calls which may lead to broken JSON output as caller will not propagate the failure. Fixes: 99a44bef5870 ("tools: bpftool: add owner_prog_type and owner_jited to bpftool output") Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/common.c | 6 +----- tools/bpf/bpftool/map.c | 17 ++++++++--------- 2 files changed, 9 insertions(+), 14 deletions(-) (limited to 'tools/bpf/bpftool') diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index 897483457bf0..f7261fad45c1 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -297,10 +297,8 @@ char *get_fdinfo(int fd, const char *key) snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd); fdi = fopen(path, "r"); - if (!fdi) { - p_err("can't open fdinfo: %s", strerror(errno)); + if (!fdi) return NULL; - } while ((n = getline(&line, &line_n, fdi)) > 0) { char *value; @@ -313,7 +311,6 @@ char *get_fdinfo(int fd, const char *key) value = strchr(line, '\t'); if (!value || !value[1]) { - p_err("malformed fdinfo!?"); free(line); return NULL; } @@ -326,7 +323,6 @@ char *get_fdinfo(int fd, const char *key) return line; } - p_err("key '%s' not found in fdinfo", key); free(line); fclose(fdi); return NULL; diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index 29a3468c6cf6..1ef1ee2280a2 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -513,10 +513,9 @@ static int show_map_close_json(int fd, struct bpf_map_info *info) jsonw_uint_field(json_wtr, "owner_prog_type", prog_type); } - if (atoi(owner_jited)) - jsonw_bool_field(json_wtr, "owner_jited", true); - else - jsonw_bool_field(json_wtr, "owner_jited", false); + if (owner_jited) + jsonw_bool_field(json_wtr, "owner_jited", + !!atoi(owner_jited)); free(owner_prog_type); free(owner_jited); @@ -569,7 +568,8 @@ static int show_map_close_plain(int fd, struct bpf_map_info *info) char *owner_prog_type = get_fdinfo(fd, "owner_prog_type"); char *owner_jited = get_fdinfo(fd, "owner_jited"); - printf("\n\t"); + if (owner_prog_type || owner_jited) + printf("\n\t"); if (owner_prog_type) { unsigned int prog_type = atoi(owner_prog_type); @@ -579,10 +579,9 @@ static int show_map_close_plain(int fd, struct bpf_map_info *info) else printf("owner_prog_type %d ", prog_type); } - if (atoi(owner_jited)) - printf("owner jited"); - else - printf("owner not jited"); + if (owner_jited) + printf("owner%s jited", + atoi(owner_jited) ? "" : " not"); free(owner_prog_type); free(owner_jited); -- cgit v1.2.3