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([39.156.73.10]) by newxmesmtplogicsvrsza29-0.qq.com (NewEsmtp) with SMTP id 2248902B; Thu, 05 Dec 2024 17:08:36 +0800 X-QQ-mid: xmsmtpt1733389716tmi4of4es Message-ID: X-QQ-XMAILINFO: N7h1OCCDntuj07DxHonYAwENPjq4EuWHyc2G6NkcfArv9/2UF+RGgDoV3nsHZ/ XMjZL7AasqNrreLIKj1RD82HY/ERt2WpVIPKjUa/CyREVCTllyw6KQCDk43sNm7q1ZsISOdg5xED q8ntMYxOQud6yF0Y+qDNcyTXKsGvr9GzXjgOXMIEf3uDBklyUSDMxcYzmyt38OJGqstIpOjxQ5RS c6nIux1GBe1tB8b1vt4ApBrbbeVnD468cr5AkSk/LcBoIBA6TEyfAmyXkv5u3cnh+nuMbv57EKjD O390n3MRgmDTgov7lhRxkWX+6eSHsItWqzt8ToNEzLjcCVYlmtsGVMx+EPBNC7geXD/je21vzvWn damafsKYkiSLWNLwNVG6fDDcc9Te7F0mdfQJ8lo2IsbRvo3wSb9VB38naRTY8sk1JrCMziz2woHX Up4eTcxXrS/G2UFiwh6Ch2IiT9HCvMrcehmM0zL8FqHECLh2MyHSxjD0TBedtjOfWmLfDcRpvJJs bNxXA/s2GZEfADSF0/QZJABICOt9uYa6oLOfqY7ZHgMXQZMakUowelsnujSlOyio/5o5nDsdEC1E W0QGnYu0GgG5CQMJCIeSZVRTeoJV21ExpnNAgVpp9+8V+hm+Lisgkamv7HGNY69l/uiITUQxllcH O7Y/LZks7jyE8bV97IUslvaBMyzYldP2xEvFQy/m0EVAHzQImSSAtoz/zWw83r28RwHwS1IFN5Q9 Nge8qc1gdaDvJ7pH8pNPLcldbKp2f2Y3IxAB96eQWz3TI/YtTEB5kOCOO+xmYRHRFpJE4X5KcYnp Rb4voynCs30iNbB+LI97MHop7wdkdGLkF4GunygRV99RWN7SJrw/N5c0WAxOiu8Cjy4OX8KSyrgB wg7L6N4jri6165SXKdl23zSWSWev1ce3KP5G6fHJLi/93kvaoyqMMiI+g4OpOdRZxv3KptRPgOrp PZAs/nWgrVJznDx8+J1p54n2HDZtP2 X-QQ-XMRINFO: NyFYKkN4Ny6FSmKK/uo/jdU= From: Rong Tao To: rongtao@cestc.cn, qmo@kernel.org, ast@kernel.org Cc: rtoax@foxmail.com, Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , bpf@vger.kernel.org (open list:BPF [TOOLING] (bpftool)), linux-kernel@vger.kernel.org (open list) Subject: [PATCH bpf-next] bpftool: Fix gen object segfault Date: Thu, 5 Dec 2024 17:08:34 +0800 X-OQ-MSGID: <20241205090835.248041-1-rtoax@foxmail.com> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Rong Tao If the input file and output file are the same, the input file is cleared due to opening, resulting in a NULL pointer access by libbpf. $ sudo ./bpftool gen object prog.o prog.o libbpf: failed to get ELF header for prog.o: invalid `Elf' handle Segmentation fault (gdb) bt #0 0x0000000000450285 in linker_append_elf_syms (linker=3D0x4feda0, ob= j=3D0x7fffffffe100) at linker.c:1296 #1 bpf_linker__add_file (linker=3D0x4feda0, filename=3D= , opts=3D) at linker.c:453 #2 0x000000000040c235 in do_object () #3 0x00000000004021d7 in main () (gdb) frame 0 #0 0x0000000000450285 in linker_append_elf_syms (linker=3D0x4feda0, ob= j=3D0x7fffffffe100) at linker.c:1296 1296 Elf64_Sym *sym =3D symtab->data->d_buf; Signed-off-by: Rong Tao --- tools/bpf/bpftool/gen.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index 5a4d3240689e..4cd135726758 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -1896,6 +1896,11 @@ static int do_object(int argc, char **argv) while (argc) { file =3D GET_ARG(); =20 + if (!strcmp(file, output_file)) { + p_err("Input/Output file couldn't be same."); + goto out; + } + err =3D bpf_linker__add_file(linker, file, NULL); if (err) { p_err("failed to link '%s': %s (%d)", file, strerror(errno), errno); --=20 2.47.1