cosmopolitan/libc/elf/elf.h
Justine Tunney 416fd86676 Make improvements
- Emulator can now test the αcτµαlly pδrταblε εxεcµταblε bootloader

- Whipped up a webserver named redbean. It services 150k requests per
  second on a single core. Bundling assets inside zip enables extremely
  fast serving for two reasons. The first is that zip central directory
  lookups go faster than stat() system calls. The second is that both
  zip and gzip content-encoding use DEFLATE, therefore, compressed
  responses can be served via the sendfile() system call which does an
  in-kernel copy directly from the zip executable structure. Also note
  that red bean zip executables can be deployed easily to all platforms,
  since these native executables work on Linux, Mac, BSD, and Windows.

- Address sanitizer now works very well
2020-09-14 00:02:34 -07:00

118 lines
4.7 KiB
C

#ifndef COSMOPOLITAN_LIBC_ELF_H_
#define COSMOPOLITAN_LIBC_ELF_H_
#ifndef __STRICT_ANSI__
#include "libc/bits/safemacros.h"
#include "libc/elf/def.h"
#include "libc/elf/struct/ehdr.h"
#include "libc/elf/struct/phdr.h"
#include "libc/elf/struct/shdr.h"
#include "libc/elf/struct/sym.h"
#include "libc/limits.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
/*───────────────────────────────────────────────────────────────────────────│─╗
│ cosmopolitan § executable & linkable format ─╬─│┼
╚────────────────────────────────────────────────────────────────────────────│*/
struct MappedFile;
Elf64_Ehdr *mapelfread(const char *, struct MappedFile *);
char *getelfstringtable(const Elf64_Ehdr *, size_t);
Elf64_Sym *getelfsymboltable(const Elf64_Ehdr *, size_t, Elf64_Xword *);
Elf64_Shdr *getelfsectionbyaddress(const Elf64_Ehdr *, size_t, void *);
bool iself64binary(const Elf64_Ehdr *, size_t);
forceinline void checkelfaddress(const Elf64_Ehdr *elf, size_t mapsize,
intptr_t addr, size_t addrsize) {
#if !(TRUSTWORTHY + ELF_TRUSTWORTHY + 0) || ELF_UNTRUSTWORTHY + 0
if (addr < (intptr_t)elf || addr + addrsize > (intptr_t)elf + mapsize) {
abort();
}
#endif
}
static inline bool iselfsymbolcontent(const Elf64_Sym *sym) {
return sym->st_size > 0 && (ELF64_ST_TYPE(sym->st_info) == STT_FUNC ||
ELF64_ST_TYPE(sym->st_info) == STT_OBJECT);
}
static inline Elf64_Phdr *getelfsegmentheaderaddress(const Elf64_Ehdr *elf,
size_t mapsize,
unsigned i) {
intptr_t addr =
((intptr_t)elf + (intptr_t)elf->e_phoff + (intptr_t)elf->e_phentsize * i);
checkelfaddress(elf, mapsize, addr, elf->e_phentsize);
return (Elf64_Phdr *)addr;
}
static inline Elf64_Shdr *getelfsectionheaderaddress(const Elf64_Ehdr *elf,
size_t mapsize,
Elf64_Half i) {
intptr_t addr =
((intptr_t)elf + (intptr_t)elf->e_shoff + (intptr_t)elf->e_shentsize * i);
checkelfaddress(elf, mapsize, addr, elf->e_shentsize);
return (Elf64_Shdr *)addr;
}
static inline void *getelfsectionaddress(const Elf64_Ehdr *elf, size_t mapsize,
const Elf64_Shdr *shdr) {
intptr_t addr, size;
addr = (intptr_t)elf + (intptr_t)shdr->sh_offset;
size = (intptr_t)shdr->sh_size;
checkelfaddress(elf, mapsize, addr, size);
return (void *)addr;
}
static inline char *getelfsectionnamestringtable(const Elf64_Ehdr *elf,
size_t mapsize) {
if (!elf->e_shoff || !elf->e_shentsize) return NULL;
return getelfsectionaddress(
elf, mapsize, getelfsectionheaderaddress(elf, mapsize, elf->e_shstrndx));
}
static inline void getelfvirtualaddressrange(const Elf64_Ehdr *elf,
size_t elfsize,
intptr_t *out_start,
intptr_t *out_end) {
unsigned i;
Elf64_Phdr *phdr;
intptr_t start, end, pstart, pend;
start = INTPTR_MAX;
end = 0;
for (i = 0; i < elf->e_phnum; ++i) {
phdr = getelfsegmentheaderaddress(elf, elfsize, i);
if (phdr->p_type != PT_LOAD) continue;
pstart = phdr->p_vaddr;
pend = phdr->p_vaddr + phdr->p_memsz;
if (pstart < start) start = pstart;
if (pend > end) end = pend;
}
if (out_start) *out_start = start;
if (out_end) *out_end = end;
}
static inline char *getelfstring(const Elf64_Ehdr *elf, size_t mapsize,
const char *strtab, Elf64_Word rva) {
intptr_t addr = (intptr_t)strtab + rva;
#if !(TRUSTWORTHY + ELF_TRUSTWORTHY + 0)
checkelfaddress(elf, mapsize, addr, 0);
checkelfaddress(elf, mapsize, addr,
strnlen((char *)addr, (intptr_t)elf + mapsize - addr) + 1);
#endif
return (char *)addr;
}
static inline const char *getelfsectionname(const Elf64_Ehdr *elf,
size_t mapsize, Elf64_Shdr *shdr) {
if (!elf || !shdr) return NULL;
return getelfstring(elf, mapsize, getelfsectionnamestringtable(elf, mapsize),
shdr->sh_name);
}
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* !ANSI */
#endif /* COSMOPOLITAN_LIBC_ELF_H_ */