linux/tools/lib
Feng Yang 4dde20b1aa libbpf: Fix event name too long error
When the binary path is excessively long, the generated probe_name in libbpf
exceeds the kernel's MAX_EVENT_NAME_LEN limit (64 bytes).
This causes legacy uprobe event attachment to fail with error code -22.

The fix reorders the fields to place the unique ID before the name.
This ensures that even if truncation occurs via snprintf, the unique ID
remains intact, preserving event name uniqueness. Additionally, explicit
checks with MAX_EVENT_NAME_LEN are added to enforce length constraints.

Before Fix:
	./test_progs -t attach_probe/kprobe-long_name
	......
	libbpf: failed to add legacy kprobe event for 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0': -EINVAL
	libbpf: prog 'handle_kprobe': failed to create kprobe 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0' perf event: -EINVAL
	test_attach_kprobe_long_event_name:FAIL:attach_kprobe_long_event_name unexpected error: -22
	test_attach_probe:PASS:uprobe_ref_ctr_cleanup 0 nsec
	#13/11   attach_probe/kprobe-long_name:FAIL
	#13      attach_probe:FAIL

	./test_progs -t attach_probe/uprobe-long_name
	......
	libbpf: failed to add legacy uprobe event for /root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9: -EINVAL
	libbpf: prog 'handle_uprobe': failed to create uprobe '/root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9' perf event: -EINVAL
	test_attach_uprobe_long_event_name:FAIL:attach_uprobe_long_event_name unexpected error: -22
	#13/10   attach_probe/uprobe-long_name:FAIL
	#13      attach_probe:FAIL
After Fix:
	./test_progs -t attach_probe/uprobe-long_name
	#13/10   attach_probe/uprobe-long_name:OK
	#13      attach_probe:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

	./test_progs -t attach_probe/kprobe-long_name
	#13/11   attach_probe/kprobe-long_name:OK
	#13      attach_probe:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Fixes: 46ed5fc33d ("libbpf: Refactor and simplify legacy kprobe code")
Fixes: cc10623c68 ("libbpf: Add legacy uprobe attaching support")
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250417014848.59321-2-yangfeng59949@163.com
History 2025-04-22 17:13:37 -07:00
..
api libapi: Add missing header with NAME_MAX define to io_dir.h 2025-03-13 00:29:36 -07:00
bpf libbpf: Fix event name too long error 2025-04-22 17:13:37 -07:00
perf perf tools changes for v6.15 2025-03-31 08:52:33 -07:00
subcmd perf tools changes for v6.13 2024-11-26 14:54:00 -08:00
symbol tools: Drop nonsensical -O6 2024-09-11 13:08:36 -03:00
thermal tools: Remove redundant quiet setup 2025-02-18 16:27:43 -03:00
argv_split.c tools lib: Move argv_{split,free} from tools/perf/util/ 2019-07-01 22:50:40 -03:00
bitmap.c lib/interval_tree: add test case for interval_tree_iter_xxx() helpers 2025-03-17 12:17:00 -07:00
cmdline.c memblock test: fix implicit declaration of function 'memparse' 2024-08-06 08:21:25 +03:00
ctype.c tools perf: Move from sane_ctype.h obtained from git to the Linux's original 2019-06-25 21:02:47 -03:00
find_bit.c tools: sync find_bit() implementation 2022-09-21 12:21:44 -07:00
hweight.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
list_sort.c tools/lib/list_sort: remove unnecessary header includes 2024-11-05 17:12:33 -08:00
rbtree.c tools lib rbtree: pick some improvements from the kernel rbtree code 2024-05-08 08:41:27 -07:00
slab.c lib/rbtree: enable userland test suite for rbtree related data structure 2025-03-17 12:17:00 -07:00
str_error_r.c objtool, perf: Fix GCC 8 -Wrestrict error 2018-03-19 13:51:54 -03:00
string.c perf annotate: Add disasm_line__parse() to parse raw instruction for powerpc 2024-07-31 16:12:59 -03:00
vsprintf.c perf script: Pad DSO name for --call-trace 2019-05-28 18:37:44 -03:00
zalloc.c tools lib: Adopt zalloc()/zfree() from tools/perf 2019-07-09 10:13:26 -03:00