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AJvYcCU0kh+Y9W+Of4r2gDtuPewuL1CyBsVLNDF0eyq0C9XutTCEYL6vA2Yez0MCr4FBHbC4sD4VTgFqaazVrkD+l2bJ@lists.infradead.org X-Gm-Message-State: AOJu0Yw9Sbw2jF1VeIP/L2CVW+vEfbnGYAEb0Tjb7gmwZlXB5XvaaHFo /GXhSkeTCazhd3VIdaV4AkxnRS5yw8GvYbbsC1x4Y7u9xJmZ7Awnq8HDfInFglHq0cAl9edyn66 WY40DFw== X-Google-Smtp-Source: AGHT+IEReJ5DG45Y2N78xw+Wv9anGhMhyh78SY1Xp5hvlU3qYN+t3i78fMBSJgNA1+oBXk1aHtUloiroGn65 X-Received: from irogers.svl.corp.google.com ([2620:15c:2c5:11:1541:e490:aa80:5766]) (user=irogers job=sendgmr) by 2002:a05:690c:20b0:b0:6fd:2b79:fb13 with SMTP id 00721157ae682-6febf3b53d7mr4850647b3.6.1741393946311; Fri, 07 Mar 2025 16:32:26 -0800 (PST) Date: Fri, 7 Mar 2025 16:32:04 -0800 In-Reply-To: <20250308003209.234114-1-irogers@google.com> Message-Id: <20250308003209.234114-7-irogers@google.com> Mime-Version: 1.0 References: <20250308003209.234114-1-irogers@google.com> X-Mailer: git-send-email 2.49.0.rc0.332.g42c0ae87b1-goog Subject: [PATCH v5 06/11] 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?b?QmrDtnJuIFTDtnBlbA==?= " , 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250307_163227_731209_4DA02106 X-CRM114-Status: GOOD ( 18.76 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 | 88 ++++++++++++++++++++++++++++++++++++ tools/perf/util/dso.h | 3 ++ tools/perf/util/symbol-elf.c | 27 ----------- 3 files changed, 91 insertions(+), 27 deletions(-) diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index 5c6e85fdae0d..00fec1bc32bc 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -1170,6 +1170,67 @@ ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine, return data_read_write_offset(dso, machine, offset, data, size, true); } +uint16_t dso__e_machine(struct dso *dso, struct machine *machine) +{ + uint16_t e_machine = 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__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; + } + + pthread_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 = dso__data(dso)->fd; + if (fd >= 0) { + _Static_assert(offsetof(Elf32_Ehdr, e_machine) == 18, "Unexpected offset"); + _Static_assert(offsetof(Elf64_Ehdr, e_machine) == 18, "Unexpected offset"); + if (dso__needs_swap(dso) == DSO_SWAP__UNSET) { + unsigned char eidata; + + if (pread(fd, &eidata, sizeof(eidata), EI_DATA) == sizeof(eidata)) + dso__swap_init(dso, eidata); + } + if (dso__needs_swap(dso) != DSO_SWAP__UNSET && + pread(fd, &e_machine, sizeof(e_machine), 18) == sizeof(e_machine)) + e_machine = DSO__SWAP(dso, uint16_t, e_machine); + } + pthread_mutex_unlock(&dso__data_open_lock); + return e_machine; +} + /** * dso__data_read_addr - Read data from dso address * @dso: dso object @@ -1525,6 +1586,33 @@ void dso__put(struct dso *dso) RC_CHK_PUT(dso); } +int dso__swap_init(struct dso *dso, unsigned char eidata) +{ + static unsigned int const endian = 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 != 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 != 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 = *bid; diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h index 4aa8c3d36566..38d9e3eac501 100644 --- a/tools/perf/util/dso.h +++ b/tools/perf/util/dso.h @@ -730,6 +730,8 @@ 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); +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, @@ -818,6 +820,7 @@ 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 66fd1249660a..71df13a5722a 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1173,33 +1173,6 @@ int filename__read_debuglink(const char *filename, char *debuglink, #endif -static int dso__swap_init(struct dso *dso, unsigned char eidata) -{ - static unsigned int const endian = 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 != 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 != 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;