mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-06-02 04:02:30 -04:00
a633dab4b4
With gcc14, when building with RELEASE=1, I hit four below compilation
failure:
Error 1:
In file included from test_loader.c:6:
test_loader.c: In function ‘run_subtest’: test_progs.h:194:17:
error: ‘retval’ may be used uninitialized in this function
[-Werror=maybe-uninitialized]
194 | fprintf(stdout, ##format); \
| ^~~~~~~
test_loader.c:958:13: note: ‘retval’ was declared here
958 | int retval, err, i;
| ^~~~~~
The uninitialized var 'retval' actually could cause incorrect result.
Error 2:
In function ‘test_fd_array_cnt’:
prog_tests/fd_array.c:71:14: error: ‘btf_id’ may be used uninitialized in this
function [-Werror=maybe-uninitialized]
71 | fd = bpf_btf_get_fd_by_id(id);
| ^~~~~~~~~~~~~~~~~~~~~~~~
prog_tests/fd_array.c:302:15: note: ‘btf_id’ was declared here
302 | __u32 btf_id;
| ^~~~~~
Changing ASSERT_GE to ASSERT_EQ can fix the compilation error. Otherwise,
there is no functionality change.
Error 3:
prog_tests/tailcalls.c: In function ‘test_tailcall_hierarchy_count’:
prog_tests/tailcalls.c:1402:23: error: ‘fentry_data_fd’ may be used uninitialized
in this function [-Werror=maybe-uninitialized]
1402 | err = bpf_map_lookup_elem(fentry_data_fd, &i, &val);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The code is correct. The change intends to silence gcc errors.
Error 4: (this error only happens on arm64)
In file included from prog_tests/log_buf.c:4:
prog_tests/log_buf.c: In function ‘bpf_prog_load_log_buf’:
./test_progs.h:390:22: error: ‘log_buf’ may be used uninitialized [-Werror=maybe-uninitialized]
390 | int ___err = libbpf_get_error(___res); \
| ^~~~~~~~~~~~~~~~~~~~~~~~
prog_tests/log_buf.c:158:14: note: in expansion of macro ‘ASSERT_OK_PTR’
158 | if (!ASSERT_OK_PTR(log_buf, "log_buf_alloc"))
| ^~~~~~~~~~~~~
In file included from selftests/bpf/tools/include/bpf/bpf.h:32,
from ./test_progs.h:36:
selftests/bpf/tools/include/bpf/libbpf_legacy.h:113:17:
note: by argument 1 of type ‘const void *’ to ‘libbpf_get_error’ declared here
113 | LIBBPF_API long libbpf_get_error(const void *ptr);
| ^~~~~~~~~~~~~~~~
Adding a pragma to disable maybe-uninitialized fixed the issue.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250617044956.2686668-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.