diff options
| -rw-r--r-- | subx/020elf.cc | 58 |
1 files changed, 33 insertions, 25 deletions
diff --git a/subx/020elf.cc b/subx/020elf.cc index 8580d8a4..75f8558e 100644 --- a/subx/020elf.cc +++ b/subx/020elf.cc @@ -8,19 +8,19 @@ if (is_equal(argv[1], "run")) { load_elf(argv[2]); while (EIP < End_of_program) // weak final-gasp termination check run_one_instruction(); - raise << "executed past end of the world: " << EIP << " vs " << End_of_program << '\n' << end(); + info << "executed past end of the world: " << EIP << " vs " << End_of_program << '\n'; } :(code) void load_elf(const string& filename) { int fd = open(filename.c_str(), O_RDONLY); - if (fd < 0) die("%s: open", filename.c_str()); + if (fd < 0) raise << filename.c_str() << ": open" << perr() << '\n' << die(); off_t size = lseek(fd, 0, SEEK_END); lseek(fd, 0, SEEK_SET); uint8_t* elf_contents = static_cast<uint8_t*>(malloc(size)); - if (elf_contents == NULL) die("malloc(%d)", size); + if (elf_contents == NULL) raise << "malloc(" << size << ')' << perr() << '\n' << die(); ssize_t read_size = read(fd, elf_contents, size); - if (size != read_size) die("read → %d (!= %d)", size, read_size); + if (size != read_size) raise << "read → " << size << " (!= " << read_size << ')' << perr() << '\n' << die(); load_elf_contents(elf_contents, size); free(elf_contents); } @@ -29,25 +29,25 @@ void load_elf_contents(uint8_t* elf_contents, size_t size) { uint8_t magic[5] = {0}; memcpy(magic, elf_contents, 4); if (memcmp(magic, "\177ELF", 4) != 0) - die("Invalid ELF file starting with \"%s\"", magic); + raise << "Invalid ELF file; starts with \"" << magic << '"' << die(); if (elf_contents[4] != 1) - die("Only 32-bit ELF files (4-byte words; virtual addresses up to 4GB) supported.\n"); + raise << "Only 32-bit ELF files (4-byte words; virtual addresses up to 4GB) supported.\n" << die(); if (elf_contents[5] != 1) - die("Only little-endian ELF files supported.\n"); + raise << "Only little-endian ELF files supported.\n" << die(); // unused: remaining 10 bytes of e_ident uint32_t e_machine_type = u32_in(&elf_contents[16]); if (e_machine_type != 0x00030002) - die("ELF type/machine 0x%x isn't i386 executable", e_machine_type); + raise << "ELF type/machine 0x" << HEXWORD << e_machine_type << " isn't i386 executable\n" << die(); // unused: e_version. We only support version 1, and later versions will be backwards compatible. uint32_t e_entry = u32_in(&elf_contents[24]); uint32_t e_phoff = u32_in(&elf_contents[28]); // unused: e_shoff // unused: e_flags uint32_t e_ehsize = u16_in(&elf_contents[40]); - if (e_ehsize < 52) die("Invalid binary; ELF header too small\n"); + if (e_ehsize < 52) raise << "Invalid binary; ELF header too small\n" << die(); uint32_t e_phentsize = u16_in(&elf_contents[42]); uint32_t e_phnum = u16_in(&elf_contents[44]); - cerr << e_phnum << " entries in the program header, each " << e_phentsize << " bytes long\n"; + info << e_phnum << " entries in the program header, each " << e_phentsize << " bytes long\n"; // unused: e_shentsize // unused: e_shnum // unused: e_shstrndx @@ -63,25 +63,25 @@ void load_elf_contents(uint8_t* elf_contents, size_t size) { void load_program_header(uint8_t* elf_contents, size_t size, uint32_t offset, uint32_t e_ehsize) { uint32_t p_type = u32_in(&elf_contents[offset]); - cerr << "program header at offset " << offset << ": type " << p_type << '\n'; + info << "program header at offset " << offset << ": type " << p_type << '\n'; if (p_type != 1) { - cerr << "ignoring segment at offset " << offset << " of non PT_LOAD type " << p_type << " (see http://refspecs.linuxbase.org/elf/elf.pdf)\n"; + info << "ignoring segment at offset " << offset << " of non PT_LOAD type " << p_type << " (see http://refspecs.linuxbase.org/elf/elf.pdf)\n"; return; } uint32_t p_offset = u32_in(&elf_contents[offset + 4]); uint32_t p_vaddr = u32_in(&elf_contents[offset + 8]); - if (e_ehsize > p_vaddr) die("Invalid binary; program header overlaps ELF header\n"); + if (e_ehsize > p_vaddr) raise << "Invalid binary; program header overlaps ELF header\n" << die(); // unused: p_paddr uint32_t p_filesz = u32_in(&elf_contents[offset + 16]); uint32_t p_memsz = u32_in(&elf_contents[offset + 20]); if (p_filesz != p_memsz) - die("Can't handle segments where p_filesz != p_memsz (see http://refspecs.linuxbase.org/elf/elf.pdf)\n"); + raise << "Can't handle segments where p_filesz != p_memsz (see http://refspecs.linuxbase.org/elf/elf.pdf)\n" << die(); if (p_offset + p_filesz > size) - die("Invalid binary; segment at offset %d is too large: wants to end at %d but the file ends at %d\n", offset, p_offset+p_filesz, size); + raise << "Invalid binary; segment at offset " << offset << " is too large: wants to end at " << p_offset+p_filesz << " but the file ends at " << size << '\n' << die(); Mem.resize(p_vaddr + p_memsz); if (size > p_memsz) size = p_memsz; - cerr << "blitting file offsets (" << p_offset << ", " << (p_offset+p_filesz) << ") to addresses (" << p_vaddr << ", " << (p_vaddr+p_memsz) << ")\n"; + info << "blitting file offsets (" << p_offset << ", " << (p_offset+p_filesz) << ") to addresses (" << p_vaddr << ", " << (p_vaddr+p_memsz) << ")\n"; for (size_t i = 0; i < p_filesz; ++i) Mem.at(p_vaddr + i) = elf_contents[p_offset + i]; if (End_of_program < p_vaddr+p_memsz) @@ -96,16 +96,21 @@ inline uint16_t u16_in(uint8_t* p) { return p[0] | p[1] << 8; } -void die(const char* format, ...) { - va_list args; - va_start(args, format); - vfprintf(stderr, format, args); +:(before "End Types") +struct perr {}; +:(code) +ostream& operator<<(ostream& os, unused perr) { if (errno) - perror(""); - else - fprintf(stderr, "\n"); - va_end(args); - abort(); + os << ": " << std::strerror(errno); + return os; +} + +:(before "End Types") +struct die {}; +:(code) +ostream& operator<<(unused ostream& os, unused die) { + if (Trace_stream) Trace_stream->newline(); + exit(1); } :(before "End Includes") @@ -115,3 +120,6 @@ void die(const char* format, ...) { #include <unistd.h> #include <stdarg.h> #include <errno.h> + +#define info cerr +// #define info dbg |