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authorTianyi Liu <i.pear@outlook.com>2022-09-28 11:09:32 +0300
committerAndrii Nakryiko <andrii@kernel.org>2022-10-01 01:40:46 +0300
commit3ca2fb497440a3c8294f9df0ce7b2c3c9a1c5875 (patch)
tree7ef24febc2a8323e03331e137d3b42c9ded065d8 /tools/bpf
parent51e05a8cf8eb34da7473823b7f236a77adfef0b4 (diff)
downloadlinux-3ca2fb497440a3c8294f9df0ce7b2c3c9a1c5875.tar.xz
bpftool: Fix error message of strerror
strerror() expects a positive errno, however variable err will never be positive when an error occurs. This causes bpftool to output too many "unknown error", even a simple "file not exist" error can not get an accurate message. This patch fixed all "strerror(err)" patterns in bpftool. Specially in btf.c#L823, hashmap__append() is an internal function of libbpf and will not change errno, so there's a little difference. Some libbpf_get_error() calls are kept for return values. Changes since v1: https://lore.kernel.org/bpf/SY4P282MB1084B61CD8671DFA395AA8579D539@SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM/ Check directly for NULL values instead of calling libbpf_get_error(). Signed-off-by: Tianyi Liu <i.pear@outlook.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/SY4P282MB1084AD9CD84A920F08DF83E29D549@SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM
Diffstat (limited to 'tools/bpf')
-rw-r--r--tools/bpf/bpftool/btf.c11
-rw-r--r--tools/bpf/bpftool/gen.c4
-rw-r--r--tools/bpf/bpftool/map_perf_ring.c7
3 files changed, 10 insertions, 12 deletions
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index 64411fe49a66..68a70ac03c80 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -635,10 +635,9 @@ static int do_dump(int argc, char **argv)
btf = btf__parse_split(*argv, base ?: base_btf);
err = libbpf_get_error(btf);
- if (err) {
- btf = NULL;
+ if (!btf) {
p_err("failed to load BTF from %s: %s",
- *argv, strerror(err));
+ *argv, strerror(errno));
goto done;
}
NEXT_ARG();
@@ -683,8 +682,8 @@ static int do_dump(int argc, char **argv)
btf = btf__load_from_kernel_by_id_split(btf_id, base_btf);
err = libbpf_get_error(btf);
- if (err) {
- p_err("get btf by id (%u): %s", btf_id, strerror(err));
+ if (!btf) {
+ p_err("get btf by id (%u): %s", btf_id, strerror(errno));
goto done;
}
}
@@ -820,7 +819,7 @@ build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
u32_as_hash_field(id));
if (err) {
p_err("failed to append entry to hashmap for BTF ID %u, object ID %u: %s",
- btf_id, id, strerror(errno));
+ btf_id, id, strerror(-err));
goto err_free;
}
}
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 7070dcffa822..cf8b4e525c88 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -1594,14 +1594,14 @@ static int do_object(int argc, char **argv)
err = bpf_linker__add_file(linker, file, NULL);
if (err) {
- p_err("failed to link '%s': %s (%d)", file, strerror(err), err);
+ p_err("failed to link '%s': %s (%d)", file, strerror(errno), errno);
goto out;
}
}
err = bpf_linker__finalize(linker);
if (err) {
- p_err("failed to finalize ELF file: %s (%d)", strerror(err), err);
+ p_err("failed to finalize ELF file: %s (%d)", strerror(errno), errno);
goto out;
}
diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c
index 1583281d1327..21d7d447e1f3 100644
--- a/tools/bpf/bpftool/map_perf_ring.c
+++ b/tools/bpf/bpftool/map_perf_ring.c
@@ -188,10 +188,9 @@ int do_event_pipe(int argc, char **argv)
opts.map_keys = &ctx.idx;
pb = perf_buffer__new_raw(map_fd, MMAP_PAGE_CNT, &perf_attr,
print_bpf_output, &ctx, &opts);
- err = libbpf_get_error(pb);
- if (err) {
+ if (!pb) {
p_err("failed to create perf buffer: %s (%d)",
- strerror(err), err);
+ strerror(errno), errno);
goto err_close_map;
}
@@ -206,7 +205,7 @@ int do_event_pipe(int argc, char **argv)
err = perf_buffer__poll(pb, 200);
if (err < 0 && err != -EINTR) {
p_err("perf buffer polling failed: %s (%d)",
- strerror(err), err);
+ strerror(errno), errno);
goto err_close_pb;
}
}