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-rw-r--r--elfinfo.cpp271
1 files changed, 271 insertions, 0 deletions
diff --git a/elfinfo.cpp b/elfinfo.cpp
new file mode 100644
index 0000000..a0138e2
--- /dev/null
+++ b/elfinfo.cpp
@@ -0,0 +1,271 @@
+#include <cctype>
+#include <cstdlib>
+#include <gelf.h>
+#include <err.h>
+#include <sysexits.h>
+#include <fcntl.h>
+#include <cstdio>
+#include <cstring>
+#include <vector>
+#include <algorithm>
+#include <getopt.h>
+#include <inttypes.h>
+#include <elf.h>
+
+#include "ld.h"
+
+using std::vector;
+
+enum class SectionType {
+ TEXT, DATA
+};
+
+const char *to_str(const SectionType &type) {
+ switch (type) {
+ case SectionType::TEXT:
+ return "text";
+ case SectionType::DATA:
+ return "data";
+ }
+}
+
+struct Section {
+ SectionType type;
+ const Elf64_Addr start;
+ const Elf64_Addr end;
+ const Elf64_Xword size;
+ Elf64_Addr used;
+
+ Section(SectionType type, Elf64_Addr start, Elf64_Xword size) : type(type), start(start), size(size),
+ end(start + size), used(0) {
+ }
+
+ bool contains(Elf64_Addr address, Elf64_Xword size) const {
+ return contains(address) && contains(address + size);
+ }
+
+ bool contains(Elf64_Addr address) const {
+ return start <= address && address < end;
+ }
+};
+
+vector<Section> sections;
+
+char *filename = nullptr;
+
+char *ld_filename = nullptr;
+
+char *program;
+
+__attribute__((noreturn))
+void usage(const char *reason = nullptr) {
+ if (reason) {
+ fprintf(stderr, "%s\n", reason);
+ }
+ fprintf(stderr, "usage: %s -f file [-l ld] [-t start:size] [-d start:size]\n", program);
+ fprintf(stderr, " -t/-d/-b: add text/data section\n");
+ fprintf(stderr, "At least one section or a ld file has to be specified\n");
+ exit(EX_USAGE);
+}
+
+void parse_start_size(char *input, Elf64_Addr &start, Elf64_Xword &size) {
+ char *str_size = strchr(input, ':');
+
+ if (!str_size) {
+ usage("bad section specification, missing ':'");
+ }
+
+ *str_size = '\0';
+ str_size++;
+
+ if (sscanf(input, "%" SCNi64, &start) != 1) {
+ usage("bad section specification, could not parse start number");
+ }
+
+ size_t str_size_len = strlen(str_size);
+
+ if (str_size_len < 1) {
+ usage("bad section specification");
+ }
+
+ char suffix = str_size[str_size_len - 1];
+ int modifier;
+
+ if (!isdigit(suffix)) {
+ switch (suffix) {
+ case 'k':
+ case 'K':
+ modifier = 1024;
+ break;
+ case 'm':
+ case 'M':
+ modifier = 1024 * 1024;
+ break;
+ default:
+ usage("bad size modifier, only 'k' and 'M' are allowed");
+ }
+ } else {
+ modifier = 1;
+ }
+
+ if (sscanf(str_size, "%" SCNi64, &size) != 1) {
+ usage("bad section specification, could not parse size number");
+ }
+ size = size * modifier;
+}
+
+bool debug = false;
+
+void parse_args(int argc, char **argv) {
+ int c;
+
+ while ((c = getopt(argc, argv, "Df:l:t:d:")) != -1) {
+ switch (c) {
+ case 'D':
+ debug = true;
+ break;
+ case 't':
+ case 'd': {
+ Elf64_Addr start;
+ Elf64_Xword size;
+ parse_start_size(optarg, start, size);
+ SectionType type = c == 't' ? SectionType::TEXT : SectionType::DATA;
+ sections.push_back(Section(type, start, size));
+ break;
+ }
+ case 'f':
+ filename = optarg;
+ break;
+ case 'l':
+ ld_filename = optarg;
+ break;
+ case '?':
+ if (optopt == 'c')
+ errx(EX_USAGE, "Option -%c requires an argument.\n", optopt);
+ else
+ errx(EX_USAGE, "Unknown option `-%c'.\n", optopt);
+ default:
+ abort();
+ }
+ }
+
+ if (!filename || (sections.empty() && !ld_filename)) {
+ usage();
+ }
+}
+
+void to_iso(Elf64_Addr i, char *buf) {
+ const char *suffix;
+ if (i > 1024 * 1024) {
+ i /= 1024 * 1024;
+ suffix = "M";
+ } else if (i > 1024) {
+ i /= 1024;
+ suffix = "k";
+ } else {
+ suffix = "";
+ }
+ sprintf(buf, "%" PRIu64 "%s", i, suffix);
+}
+
+int main(int argc, char **argv) {
+ program = argv[0];
+ parse_args(argc, argv);
+
+ if (ld_filename) {
+ ld_file file = ld_file_loader::load(ld_filename);
+ }
+
+ if (elf_version(EV_CURRENT) == EV_NONE)
+ errx(EX_SOFTWARE, "ELF library initialization failed: %s", elf_errmsg(-1));
+
+ int fd;
+ if ((fd = open(filename, O_RDONLY, 0)) < 0)
+ err(EX_NOINPUT, "open \"%s\" failed", argv[1]);
+
+ Elf *e;
+ if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL)
+ errx(EX_SOFTWARE, "elf_begin() failed: %s.", elf_errmsg(-1));
+ if (elf_kind(e) != ELF_K_ELF)
+ errx(EX_DATAERR, "%s is not an ELF object.", argv[1]);
+
+ size_t shstrndx;
+ if (elf_getshdrstrndx(e, &shstrndx) != 0)
+ errx(EX_SOFTWARE, "elf_getshdrstrndx() failed: %s.", elf_errmsg(-1));
+
+ size_t program_header_count;
+ if (elf_getphdrnum(e, &program_header_count) != 0)
+ errx(EX_DATAERR, "elf_getphdrnum() failed: %s.", elf_errmsg(-1));
+
+ size_t text_size = 0, data_size = 0, bss_size = 0;
+ for (int i = 0; i < program_header_count; i++) {
+ GElf_Phdr phdr;
+
+ if (gelf_getphdr(e, i, &phdr) != &phdr)
+ errx(EX_SOFTWARE, "getphdr() failed: %s.", elf_errmsg(-1));
+
+ if (phdr.p_type == PT_LOAD) {
+ SectionType expectedType;
+ size_t *size;
+
+ if (phdr.p_flags == (PF_X | PF_W | PF_R) || phdr.p_flags == (PF_X | PF_R)) {
+ if (debug) {
+ printf("Adding PH #%d as text\n", i);
+ }
+
+ expectedType = SectionType::TEXT;
+ size = &text_size;
+ } else if (phdr.p_flags == (PF_R | PF_W)) {
+ expectedType = SectionType::DATA;
+ if (phdr.p_filesz > 0) {
+ if (debug) {
+ printf("Adding PH #%d as data\n", i);
+ }
+ size = &data_size;
+ }
+ else {
+ if (debug) {
+ printf("Adding PH #%d as bss\n", i);
+ }
+ size = &bss_size;
+ }
+ } else {
+ warnx("Unknown flag combination: 0x%02x", phdr.p_flags);
+ warnx("Unknown flag combination: 0x%02x", PF_X | PF_R);
+ continue;
+ }
+
+ auto s = std::find_if(sections.begin(), sections.end(), [&](Section &section) {
+ return section.type == expectedType && section.contains(phdr.p_vaddr, phdr.p_memsz);
+ });
+
+ if (s == sections.end()) {
+ fprintf(stderr,
+ "Could not find a section for elf header #%d of type %s, at address 0x%08" PRIx64 " with size %" PRId64 "\n",
+ i, to_str(expectedType), phdr.p_vaddr, phdr.p_memsz);
+ }
+ else {
+ (*s).used += phdr.p_memsz;
+
+ *size += phdr.p_memsz;
+ }
+ } else {
+ // ignored
+ };
+ }
+
+ printf("Size by sections\n");
+ printf("Type Start End Size Used\n");
+ std::for_each(sections.begin(), sections.end(), [&](Section &s) {
+ char size[100];
+ to_iso(s.size, size);
+ int used_pct = (int) (double(s.used) / double(s.size) * 100.0);
+ printf("%4s %08" PRIx64 " %08" PRIx64 " %5s %8" PRId64 " %3d%%\n", to_str(s.type), s.start, s.end, size, s.used,
+ used_pct);
+ });
+
+ printf("\n");
+ printf("Size by type\n");
+ printf("text=%zu, data=%zu, bss=%zu\n", text_size, data_size, bss_size);
+ return EXIT_SUCCESS;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-04 04:38:56 +0000