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AJvYcCXsXadgRcBcZmouvm/i526m6U4iE2PUvM3PNkf33/REcXSzPfWcaAPuMqtBFfX+1mKqIa8LRtNoAuY4EYE=@vger.kernel.org X-Gm-Message-State: AOJu0YwpoKls7jVwKvYO9C+DR3hLc5bR5wDK8gF47Km/TJjP414noGkY 5E3qcy2Q7TdlxfbjIJ80WyVwvDPw7oCBgAUstYtTXcDnN5UDZBtvMTjt671Xl/Qq0BzkGVKPaVq j/bBM0A== X-Google-Smtp-Source: AGHT+IHW5zIoZNQ/PFJ4nieCzozKPWCoO+ogY5Jq02jaNhLsphiocOSJqBwzeG9L8zyDxjhIToN0yhyiQJB3 X-Received: from irogers.svl.corp.google.com ([2620:15c:2c5:11:8a11:10b5:af90:6031]) (user=irogers job=sendgmr) by 2002:a25:c306:0:b0:e63:c603:37d2 with SMTP id 3f1490d57ef6-e667b44294fmr573276.7.1742360879473; Tue, 18 Mar 2025 22:07:59 -0700 (PDT) Date: Tue, 18 Mar 2025 22:07:33 -0700 In-Reply-To: <20250319050741.269828-1-irogers@google.com> Message-Id: <20250319050741.269828-7-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250319050741.269828-1-irogers@google.com> X-Mailer: git-send-email 2.49.0.rc1.451.g8f38331e32-goog Subject: [PATCH v7 06/14] perf dso: Add support for reading the e_machine type for a dso From: Ian Rogers To: Ian Rogers , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Adrian Hunter , Kan Liang , John Garry , Will Deacon , James Clark , Mike Leach , Leo Yan , guoren , Paul Walmsley , Palmer Dabbelt , Albert Ou , Charlie Jenkins , Bibo Mao , Huacai Chen , Catalin Marinas , Jiri Slaby , "=?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?=" , Howard Chu , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "linux-csky@vger.kernel.org" , linux-riscv@lists.infradead.org, Arnd Bergmann Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" For ELF file dsos read the e_machine from the ELF header. For kernel types assume the e_machine matches the perf tool. In other cases return EM_NONE. When reading from the ELF header use DSO__SWAP that may need dso->needs_swap initializing. Factor out dso__swap_init to allow this. Signed-off-by: Ian Rogers --- tools/perf/util/dso.c | 89 ++++++++++++++++++++++++++++++++++++ tools/perf/util/dso.h | 3 ++ tools/perf/util/symbol-elf.c | 27 ----------- 3 files changed, 92 insertions(+), 27 deletions(-) diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index e0111049f6b0..8619b6eea62d 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -1194,6 +1194,68 @@ ssize_t dso__data_read_offset(struct dso *dso, struc= t machine *machine, return data_read_write_offset(dso, machine, offset, data, size, true); } =20 +uint16_t dso__e_machine(struct dso *dso, struct machine *machine) +{ + uint16_t e_machine =3D EM_NONE; + int fd; + + switch (dso__binary_type(dso)) { + case DSO_BINARY_TYPE__KALLSYMS: + case DSO_BINARY_TYPE__GUEST_KALLSYMS: + case DSO_BINARY_TYPE__VMLINUX: + case DSO_BINARY_TYPE__GUEST_VMLINUX: + case DSO_BINARY_TYPE__GUEST_KMODULE: + case DSO_BINARY_TYPE__GUEST_KMODULE_COMP: + case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE: + case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP: + case DSO_BINARY_TYPE__KCORE: + case DSO_BINARY_TYPE__GUEST_KCORE: + case DSO_BINARY_TYPE__BPF_PROG_INFO: + case DSO_BINARY_TYPE__BPF_IMAGE: + case DSO_BINARY_TYPE__OOL: + case DSO_BINARY_TYPE__JAVA_JIT: + return EM_HOST; + case DSO_BINARY_TYPE__DEBUGLINK: + case DSO_BINARY_TYPE__BUILD_ID_CACHE: + case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO: + case DSO_BINARY_TYPE__GNU_DEBUGDATA: + case DSO_BINARY_TYPE__SYSTEM_PATH_DSO: + case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO: + case DSO_BINARY_TYPE__FEDORA_DEBUGINFO: + case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO: + case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO: + case DSO_BINARY_TYPE__BUILDID_DEBUGINFO: + break; + case DSO_BINARY_TYPE__NOT_FOUND: + default: + return EM_NONE; + } + + mutex_lock(dso__data_open_lock()); + + /* + * dso__data(dso)->fd might be closed if other thread opened another + * file (dso) due to open file limit (RLIMIT_NOFILE). + */ + try_to_open_dso(dso, machine); + fd =3D dso__data(dso)->fd; + if (fd >=3D 0) { + _Static_assert(offsetof(Elf32_Ehdr, e_machine) =3D=3D 18, "Unexpected of= fset"); + _Static_assert(offsetof(Elf64_Ehdr, e_machine) =3D=3D 18, "Unexpected of= fset"); + if (dso__needs_swap(dso) =3D=3D DSO_SWAP__UNSET) { + unsigned char eidata; + + if (pread(fd, &eidata, sizeof(eidata), EI_DATA) =3D=3D sizeof(eidata)) + dso__swap_init(dso, eidata); + } + if (dso__needs_swap(dso) !=3D DSO_SWAP__UNSET && + pread(fd, &e_machine, sizeof(e_machine), 18) =3D=3D sizeof(e_machine= )) + e_machine =3D DSO__SWAP(dso, uint16_t, e_machine); + } + mutex_unlock(dso__data_open_lock()); + return e_machine; +} + /** * dso__data_read_addr - Read data from dso address * @dso: dso object @@ -1549,6 +1611,33 @@ void dso__put(struct dso *dso) RC_CHK_PUT(dso); } =20 +int dso__swap_init(struct dso *dso, unsigned char eidata) +{ + static unsigned int const endian =3D 1; + + dso__set_needs_swap(dso, DSO_SWAP__NO); + + switch (eidata) { + case ELFDATA2LSB: + /* We are big endian, DSO is little endian. */ + if (*(unsigned char const *)&endian !=3D 1) + dso__set_needs_swap(dso, DSO_SWAP__YES); + break; + + case ELFDATA2MSB: + /* We are little endian, DSO is big endian. */ + if (*(unsigned char const *)&endian !=3D 0) + dso__set_needs_swap(dso, DSO_SWAP__YES); + break; + + default: + pr_err("unrecognized DSO data encoding %d\n", eidata); + return -EINVAL; + } + + return 0; +} + void dso__set_build_id(struct dso *dso, struct build_id *bid) { RC_CHK_ACCESS(dso)->bid =3D *bid; diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h index 53e3b9b337e5..8c1e7cdbaefd 100644 --- a/tools/perf/util/dso.h +++ b/tools/perf/util/dso.h @@ -737,6 +737,8 @@ bool dso__sorted_by_name(const struct dso *dso); void dso__set_sorted_by_name(struct dso *dso); void dso__sort_by_name(struct dso *dso); =20 +int dso__swap_init(struct dso *dso, unsigned char eidata); + void dso__set_build_id(struct dso *dso, struct build_id *bid); bool dso__build_id_equal(const struct dso *dso, struct build_id *bid); void dso__read_running_kernel_build_id(struct dso *dso, @@ -826,6 +828,7 @@ int dso__data_file_size(struct dso *dso, struct machine= *machine); off_t dso__data_size(struct dso *dso, struct machine *machine); ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine, u64 offset, u8 *data, ssize_t size); +uint16_t dso__e_machine(struct dso *dso, struct machine *machine); ssize_t dso__data_read_addr(struct dso *dso, struct map *map, struct machine *machine, u64 addr, u8 *data, ssize_t size); diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 3fa92697c457..fbf6d0f73af9 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1174,33 +1174,6 @@ int filename__read_debuglink(const char *filename, c= har *debuglink, =20 #endif =20 -static int dso__swap_init(struct dso *dso, unsigned char eidata) -{ - static unsigned int const endian =3D 1; - - dso__set_needs_swap(dso, DSO_SWAP__NO); - - switch (eidata) { - case ELFDATA2LSB: - /* We are big endian, DSO is little endian. */ - if (*(unsigned char const *)&endian !=3D 1) - dso__set_needs_swap(dso, DSO_SWAP__YES); - break; - - case ELFDATA2MSB: - /* We are little endian, DSO is big endian. */ - if (*(unsigned char const *)&endian !=3D 0) - dso__set_needs_swap(dso, DSO_SWAP__YES); - break; - - default: - pr_err("unrecognized DSO data encoding %d\n", eidata); - return -EINVAL; - } - - return 0; -} - bool symsrc__possibly_runtime(struct symsrc *ss) { return ss->dynsym || ss->opdsec; --=20 2.49.0.rc1.451.g8f38331e32-goog