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// See LICENSE for license details.
#include "file.h"
#include "pk.h"
#include "vm.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <elf.h>
#include <string.h>
void load_elf(const char* fn, elf_info* info)
{
file_t* file = file_open(fn, O_RDONLY, 0);
if (IS_ERR_VALUE(file))
goto fail;
Elf64_Ehdr eh64;
ssize_t ehdr_size = file_pread(file, &eh64, sizeof(eh64), 0);
if (ehdr_size < (ssize_t)sizeof(eh64) ||
!(eh64.e_ident[0] == '\177' && eh64.e_ident[1] == 'E' &&
eh64.e_ident[2] == 'L' && eh64.e_ident[3] == 'F'))
goto fail;
size_t bias = 0;
extern char _end;
if (eh64.e_type == ET_DYN)
bias = ROUNDUP((uintptr_t)&_end, RISCV_PGSIZE);
#define LOAD_ELF do { \
eh = (typeof(eh))&eh64; \
size_t phdr_size = eh->e_phnum*sizeof(*ph); \
if (info->phdr_top - phdr_size < info->stack_bottom) \
goto fail; \
info->phdr = info->phdr_top - phdr_size; \
ssize_t ret = file_pread(file, (void*)info->phdr, phdr_size, eh->e_phoff); \
if (ret < (ssize_t)phdr_size) goto fail; \
info->entry = bias + eh->e_entry; \
info->phnum = eh->e_phnum; \
info->phent = sizeof(*ph); \
ph = (typeof(ph))info->phdr; \
for(int i = 0; i < eh->e_phnum; i++, ph++) { \
if(ph->p_type == PT_LOAD && ph->p_memsz) { \
info->brk_min = MAX(info->brk_min, bias + ph->p_vaddr + ph->p_memsz); \
size_t vaddr = ROUNDDOWN(ph->p_vaddr, RISCV_PGSIZE), prepad = ph->p_vaddr - vaddr; \
size_t memsz = ph->p_memsz + prepad, filesz = ph->p_filesz + prepad; \
size_t offset = ph->p_offset - prepad; \
vaddr += bias; \
if (__do_mmap(vaddr, filesz, -1, MAP_FIXED|MAP_PRIVATE, file, offset) != vaddr) \
goto fail; \
size_t mapped = ROUNDUP(filesz, RISCV_PGSIZE); \
if (memsz > mapped) \
if (__do_mmap(vaddr + mapped, memsz - mapped, -1, MAP_FIXED|MAP_PRIVATE|MAP_ANONYMOUS, 0, 0) != vaddr + mapped) \
goto fail; \
} \
} \
} while(0)
info->elf64 = IS_ELF64(eh64);
if (info->elf64)
{
Elf64_Ehdr* eh;
Elf64_Phdr* ph;
LOAD_ELF;
}
else if (IS_ELF32(eh64))
{
Elf32_Ehdr* eh;
Elf32_Phdr* ph;
LOAD_ELF;
}
else
goto fail;
file_decref(file);
return;
fail:
panic("couldn't open ELF program: %s!", fn);
}
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