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charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 78520140009 X-Stat-Signature: oiwh76ajy5ush76dauy573ummjfh9ak7 X-HE-Tag: 1679005396-367424 X-HE-Meta: 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 u8WiK+6b 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 16, 2023 at 10:03=E2=80=AFAM Jiri Olsa wrote= : > > Adding read_build_id function that parses out build id from > specified binary. > > It will replace extract_build_id and also be used in following > changes. > > Signed-off-by: Jiri Olsa > --- > tools/testing/selftests/bpf/trace_helpers.c | 86 +++++++++++++++++++++ > tools/testing/selftests/bpf/trace_helpers.h | 5 ++ > 2 files changed, 91 insertions(+) > > diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/= selftests/bpf/trace_helpers.c > index 934bf28fc888..72b38a41f574 100644 > --- a/tools/testing/selftests/bpf/trace_helpers.c > +++ b/tools/testing/selftests/bpf/trace_helpers.c > @@ -11,6 +11,9 @@ > #include > #include > #include "trace_helpers.h" > +#include > +#include > +#include > > #define TRACEFS_PIPE "/sys/kernel/tracing/trace_pipe" > #define DEBUGFS_PIPE "/sys/kernel/debug/tracing/trace_pipe" > @@ -234,3 +237,86 @@ ssize_t get_rel_offset(uintptr_t addr) > fclose(f); > return -EINVAL; > } > + > +static int > +parse_build_id_buf(const void *note_start, Elf32_Word note_size, > + char *build_id) nit: single line should we pass buffer size instead of assuming at least BPF_BUILD_ID_SIZE b= elow? > +{ > + Elf32_Word note_offs =3D 0, new_offs; > + > + while (note_offs + sizeof(Elf32_Nhdr) < note_size) { > + Elf32_Nhdr *nhdr =3D (Elf32_Nhdr *)(note_start + note_off= s); > + > + if (nhdr->n_type =3D=3D 3 && nhdr->n_namesz =3D=3D sizeof= ("GNU") && > + !strcmp((char *)(nhdr + 1), "GNU") && nhdr->n_descsz = > 0 && > + nhdr->n_descsz <=3D BPF_BUILD_ID_SIZE) { > + memcpy(build_id, note_start + note_offs + > + ALIGN(sizeof("GNU"), 4) + sizeof(Elf32_Nhd= r), nhdr->n_descsz); > + memset(build_id + nhdr->n_descsz, 0, BPF_BUILD_ID= _SIZE - nhdr->n_descsz); > + return (int) nhdr->n_descsz; > + } > + > + new_offs =3D note_offs + sizeof(Elf32_Nhdr) + > + ALIGN(nhdr->n_namesz, 4) + ALIGN(nhdr->n_descs= z, 4); > + if (new_offs >=3D note_size) > + break; while condition() above would handle this, so this check appears not necess= ary? so just assign note_offs directly? > + note_offs =3D new_offs; > + } > + > + return -EINVAL; nit: -ENOENT or -ESRCH? > +} > + > +/* Reads binary from *path* file and returns it in the *build_id* > + * which is expected to be at least BPF_BUILD_ID_SIZE bytes. > + * Returns size of build id on success. On error the error value > + * is returned. > + */ > +int read_build_id(const char *path, char *build_id) > +{ > + int fd, err =3D -EINVAL; > + Elf *elf =3D NULL; > + GElf_Ehdr ehdr; > + size_t max, i; > + > + fd =3D open(path, O_RDONLY | O_CLOEXEC); > + if (fd < 0) > + return -errno; > + > + (void)elf_version(EV_CURRENT); > + > + elf =3D elf_begin(fd, ELF_C_READ, NULL); ELF_C_READ_MMAP ? > + if (!elf) > + goto out; > + if (elf_kind(elf) !=3D ELF_K_ELF) > + goto out; > + if (gelf_getehdr(elf, &ehdr) =3D=3D NULL) nit: !gelf_getehdr() > + goto out; > + if (ehdr.e_ident[EI_CLASS] !=3D ELFCLASS64) > + goto out; does this have to be 64-bit specific?... you are using gelf stuff, you can be bitness-agnostic here > + > + for (i =3D 0; i < ehdr.e_phnum; i++) { > + GElf_Phdr mem, *phdr; > + char *data; > + > + phdr =3D gelf_getphdr(elf, i, &mem); > + if (!phdr) > + goto out; > + if (phdr->p_type !=3D PT_NOTE) > + continue; I don't know where ELF + build ID spec is (if at all), but it seems to always be in the ".note.gnu.build-id" section, so should we check the name here? > + data =3D elf_rawfile(elf, &max); > + if (!data) > + goto out; > + if (phdr->p_offset >=3D max || (phdr->p_offset + phdr->p_= memsz >=3D max)) `phdr->p_offset + phdr->p_memsz =3D=3D max` would be fine, no? > + goto out; > + err =3D parse_build_id_buf(data + phdr->p_offset, phdr->p= _memsz, build_id); > + if (err > 0) > + goto out; > + err =3D -EINVAL; > + } > + > +out: > + if (elf) > + elf_end(elf); > + close(fd); > + return err; > +} > diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/= selftests/bpf/trace_helpers.h > index 53efde0e2998..bc3b92057033 100644 > --- a/tools/testing/selftests/bpf/trace_helpers.h > +++ b/tools/testing/selftests/bpf/trace_helpers.h > @@ -4,6 +4,9 @@ > > #include > > +#define __ALIGN_MASK(x, mask) (((x)+(mask))&~(mask)) > +#define ALIGN(x, a) __ALIGN_MASK(x, (typeof(x))(a)-1) > + > struct ksym { > long addr; > char *name; > @@ -23,4 +26,6 @@ void read_trace_pipe(void); > ssize_t get_uprobe_offset(const void *addr); > ssize_t get_rel_offset(uintptr_t addr); > > +int read_build_id(const char *path, char *build_id); > + > #endif > -- > 2.39.2 >