From 94d89ede1c21e3bb53a95cb620963cf05b5b677d Mon Sep 17 00:00:00 2001 From: Rob Pike Date: Fri, 17 Jul 2009 17:32:34 -0700 Subject: [PATCH] take care of a few more magic numbers R=rsc DELTA=51 (41 added, 0 deleted, 10 changed) OCL=31815 CL=31818 --- src/cmd/6l/asm.c | 23 +++++++++++------- src/cmd/ld/elf64.h | 60 ++++++++++++++++++++++++++++++++++++---------- 2 files changed, 62 insertions(+), 21 deletions(-) diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c index 2fdae8b3c1..eb3a8921cd 100644 --- a/src/cmd/6l/asm.c +++ b/src/cmd/6l/asm.c @@ -126,8 +126,10 @@ asmb(void) uchar *op1; vlong vl, va, fo, w, symo; vlong symdatva = 0x99LL<<32; + int strtabindex; Elf64PHdr *ph; Elf64SHdr *sh; + char eident[EI_NIDENT]; if(debug['v']) Bprint(&bso, "%5.2f asmb\n", cputime()); @@ -501,6 +503,7 @@ asmb(void) w = STRTABSIZE; + strtabindex = nume64shdr; sh = newElf64SHdr(".shstrtab"); sh->type = SHT_STRTAB; sh->off = fo; @@ -531,15 +534,19 @@ asmb(void) sh->entsize = 24; // write out the main header */ - strnput("\177ELF", 4); /* e_ident */ - cput(2); /* class = 64 bit */ - cput(1); /* data = LSB */ - cput(1); /* version = CURRENT */ - strnput("", 9); + memset(eident, 0, sizeof eident); + eident[EI_MAG0] = '\177'; + eident[EI_MAG1] = 'E'; + eident[EI_MAG2] = 'L'; + eident[EI_MAG3] = 'F'; + eident[EI_CLASS] = ELFCLASS64; + eident[EI_DATA] = ELFDATA2LSB; + eident[EI_VERSION] = EV_CURRENT; + strnput(eident, EI_NIDENT); - wputl(2); /* type = EXEC */ + wputl(ET_EXEC); /* type = EXEC */ wputl(62); /* machine = AMD64 */ - lputl(1L); /* version = CURRENT */ + lputl(EV_CURRENT); /* version = CURRENT */ vputl(entryvalue()); /* entry vaddr */ vputl(64L); /* offset to first phdr */ vputl(64L+56*nume64phdr); /* offset to first shdr */ @@ -549,7 +556,7 @@ asmb(void) wputl(nume64phdr); /* # of Phdrs */ wputl(64); /* Shdr size */ wputl(nume64shdr); /* # of Shdrs */ - wputl(4); /* Shdr with strings */ + wputl(strtabindex); /* Shdr with strings */ elf64writephdrs(); elf64writeshdrs(); diff --git a/src/cmd/ld/elf64.h b/src/cmd/ld/elf64.h index 34348a1dbc..f7af0f07c9 100644 --- a/src/cmd/ld/elf64.h +++ b/src/cmd/ld/elf64.h @@ -49,9 +49,10 @@ typedef struct Elf64Hdr Elf64Hdr; typedef struct Elf64SHdr Elf64SHdr; typedef struct Elf64PHdr Elf64PHdr; +#define EI_NIDENT 16 struct Elf64Hdr { - uchar ident[16]; /* ELF identification */ + uchar ident[EI_NIDENT]; /* ELF identification */ Elf64_Half type; /* Object file type */ Elf64_Half machine; /* Machine type */ Elf64_Word version; /* Object file version */ @@ -67,16 +68,49 @@ struct Elf64Hdr Elf64_Half shstrndx; /* Section name string table index */ }; +/* E ident indexes */ +#define EI_MAG0 0 /* File identification */ +#define EI_MAG1 1 +#define EI_MAG2 2 +#define EI_MAG3 3 +#define EI_CLASS 4 /* File class */ +#define EI_DATA 5 /* Data encoding */ +#define EI_VERSION 6 /* File version */ +#define EI_OSABI 7 /* OS/ABI identification */ +#define EI_ABIVERSION 8 /* ABI version */ +#define EI_PAD 9 /*Start of padding bytes */ + +/* E types */ +#define ET_NONE 0 /* No file type */ +#define ET_REL 1 /* Relocatable object file */ +#define ET_EXEC 2 /* Executable file */ +#define ET_DYN 3 /* Shared object file */ +#define ET_CORE 4 /* Core file */ +#define ET_LOOS 0xFE00 /* Environment-specific use */ +#define ET_HIOS 0xFEFF +#define ET_LOPROC 0xFF00 /* Processor-specific use */ +#define ET_HIPROC 0xFFFF + +/* E classes */ +#define ELFCLASS32 1 /* 32-bit objects */ +#define ELFCLASS64 2 /* 64-bit objects */ + +/* E endians */ +#define ELFDATA2LSB 1 /* little-endian */ +#define ELFDATA2MSB 2 /* big-endian */ + +#define EV_CURRENT 1 /* current version of format */ + struct Elf64PHdr { - Elf64_Word type; /* Type of segment */ - Elf64_Word flags; /* Segment attributes */ - Elf64_Off off; /* Offset in file */ - Elf64_Addr vaddr; /* Virtual address in memory */ - Elf64_Addr paddr; /* Reserved */ - Elf64_Xword filesz; /* Size of segment in file */ - Elf64_Xword memsz; /* Size of segment in memory */ - Elf64_Xword align; /* Alignment of segment */ + Elf64_Word type; /* Type of segment */ + Elf64_Word flags; /* Segment attributes */ + Elf64_Off off; /* Offset in file */ + Elf64_Addr vaddr; /* Virtual address in memory */ + Elf64_Addr paddr; /* Reserved */ + Elf64_Xword filesz; /* Size of segment in file */ + Elf64_Xword memsz; /* Size of segment in memory */ + Elf64_Xword align; /* Alignment of segment */ }; /* P types */ @@ -116,18 +150,18 @@ struct Elf64SHdr #define SHT_HASH 5 /* Symbol hash table */ #define SHT_DYNAMIC 6 /* Dynamic linking tables */ #define SHT_NOTE 7 /* Note information */ -#define SHT_NOBITS 8 /* Uninitialized space; does not occupy any space in the file */ +#define SHT_NOBITS 8 /* Uninitialized space; does not occupy any space in the file */ #define SHT_REL 9 /* "Rel" type relocation entries */ #define SHT_SHLIB 10 /* Reserved */ -#define SHT_DYNSYM 11 /* A dynamic loader symbol table */ +#define SHT_DYNSYM 11 /* A dynamic loader symbol table */ #define SHT_LOOS 0x60000000 /* Environment-specific use */ -#define SHT_HIOS 0x6FFFFFFF +#define SHT_HIOS 0x6FFFFFFF #define SHT_LOPROC 0x70000000 /* Processor-specific use */ #define SHT_HIPROC 0x7FFFFFFF /* S flags */ #define SHF_WRITE 0x1 /* Writable data */ -#define SHF_ALLOC 0x2 /* Allocated in memory image of program */ +#define SHF_ALLOC 0x2 /* Allocated in memory image of program */ #define SHF_EXECINSTR 0x4 /* Executable instructions */ #define SHF_MASKOS 0x0F000000 /* Environment-specific use */ #define SHF_MASKPROC 0xF0000000 /* Processor-specific use */