mirror of
https://github.com/CTCaer/hekate.git
synced 2024-11-01 08:21:45 +00:00
324 lines
6.6 KiB
C
324 lines
6.6 KiB
C
/*
|
|
* Copyright © 2018, M4xw
|
|
* Copyright © 2014, Owen Shepherd
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
|
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
|
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
|
|
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
|
|
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
|
|
* PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
#include <string.h>
|
|
|
|
#include "elfload.h"
|
|
|
|
el_status el_pread(el_ctx *ctx, void *def, size_t nb, size_t offset)
|
|
{
|
|
return ctx->pread(ctx, def, nb, offset) ? EL_OK : EL_EIO;
|
|
}
|
|
|
|
#define EL_PHOFF(ctx, num) (((ctx)->ehdr.e_phoff + (num) *(ctx)->ehdr.e_phentsize))
|
|
el_status el_findphdr(el_ctx *ctx, Elf_Phdr *phdr, uint32_t type, unsigned *i)
|
|
{
|
|
el_status rv = EL_OK;
|
|
for (; *i < ctx->ehdr.e_phnum; (*i)++)
|
|
{
|
|
if ((rv = el_pread(ctx, phdr, sizeof *phdr, EL_PHOFF(ctx, *i))))
|
|
return rv;
|
|
|
|
if (phdr->p_type == type)
|
|
{
|
|
return rv;
|
|
}
|
|
}
|
|
|
|
*i = -1;
|
|
return rv;
|
|
}
|
|
|
|
#define EL_SHOFF(ctx, num) (((ctx)->ehdr.e_shoff + (num) *(ctx)->ehdr.e_shentsize))
|
|
el_status el_findshdr(el_ctx *ctx, Elf_Shdr *shdr, uint32_t type, unsigned *i)
|
|
{
|
|
el_status rv = EL_OK;
|
|
|
|
for (; *i < ctx->ehdr.e_shnum; (*i)++)
|
|
{
|
|
if ((rv = el_pread(ctx, shdr, sizeof *shdr, EL_SHOFF(ctx, *i))))
|
|
|
|
return rv;
|
|
|
|
if (shdr->sh_type == type)
|
|
{
|
|
return rv;
|
|
}
|
|
}
|
|
|
|
*i = -1;
|
|
|
|
return rv;
|
|
}
|
|
|
|
el_status el_init(el_ctx *ctx)
|
|
{
|
|
el_status rv = EL_OK;
|
|
if ((rv = el_pread(ctx, &ctx->ehdr, sizeof ctx->ehdr, 0)))
|
|
return rv;
|
|
|
|
/* validate header */
|
|
|
|
if (!IS_ELF(ctx->ehdr))
|
|
return EL_NOTELF;
|
|
|
|
if (ctx->ehdr.e_ident[EI_CLASS] != ELFCLASS)
|
|
return EL_WRONGBITS;
|
|
|
|
if (ctx->ehdr.e_ident[EI_DATA] != ELFDATATHIS)
|
|
return EL_WRONGENDIAN;
|
|
|
|
if (ctx->ehdr.e_ident[EI_VERSION] != EV_CURRENT)
|
|
return EL_NOTELF;
|
|
|
|
if (ctx->ehdr.e_type != ET_EXEC && ctx->ehdr.e_type != ET_DYN)
|
|
return EL_NOTEXEC;
|
|
|
|
if (ctx->ehdr.e_machine != EM_THIS)
|
|
return EL_WRONGARCH;
|
|
|
|
if (ctx->ehdr.e_version != EV_CURRENT)
|
|
return EL_NOTELF;
|
|
|
|
/* load phdrs */
|
|
Elf_Phdr ph;
|
|
|
|
/* iterate through, calculate extents */
|
|
ctx->base_load_paddr = ctx->base_load_vaddr = 0;
|
|
ctx->align = 1;
|
|
ctx->memsz = 0;
|
|
|
|
unsigned i = 0;
|
|
for (;;)
|
|
{
|
|
if ((rv = el_findphdr(ctx, &ph, PT_LOAD, &i)))
|
|
return rv;
|
|
|
|
if (i == (unsigned)-1)
|
|
break;
|
|
|
|
Elf_Addr phend = ph.p_vaddr + ph.p_memsz;
|
|
if (phend > ctx->memsz)
|
|
ctx->memsz = phend;
|
|
|
|
if (ph.p_align > ctx->align)
|
|
ctx->align = ph.p_align;
|
|
|
|
i++;
|
|
}
|
|
|
|
// Program Header
|
|
if (ctx->ehdr.e_type == ET_DYN)
|
|
{
|
|
i = 0;
|
|
|
|
if ((rv = el_findphdr(ctx, &ph, PT_DYNAMIC, &i)))
|
|
return rv;
|
|
|
|
if (i == (unsigned)-1)
|
|
return EL_NODYN;
|
|
|
|
ctx->dynoff = ph.p_offset;
|
|
ctx->dynsize = ph.p_filesz;
|
|
}
|
|
else
|
|
{
|
|
ctx->dynoff = 0;
|
|
ctx->dynsize = 0;
|
|
}
|
|
|
|
// Section String Table
|
|
if (ctx->ehdr.e_type == ET_DYN)
|
|
{
|
|
i = ctx->ehdr.e_shstrndx - 1;
|
|
|
|
if ((rv = el_findshdr(ctx, &ctx->shstr, SHT_STRTAB, &i)))
|
|
return rv;
|
|
|
|
// Reset
|
|
i = 0;
|
|
|
|
if ((rv = el_findshdr(ctx, &ctx->symtab, SHT_SYMTAB, &i)))
|
|
return rv;
|
|
|
|
if (i == (unsigned)-1)
|
|
return EL_NODYN;
|
|
}
|
|
|
|
return rv;
|
|
}
|
|
|
|
/*
|
|
typedef void* (*el_alloc_cb)(
|
|
el_ctx *ctx,
|
|
Elf_Addr phys,
|
|
Elf_Addr virt,
|
|
Elf_Addr size);
|
|
*/
|
|
|
|
el_status el_load(el_ctx *ctx, el_alloc_cb alloc)
|
|
{
|
|
el_status rv = EL_OK;
|
|
|
|
/* address deltas */
|
|
Elf_Addr pdelta = ctx->base_load_paddr;
|
|
Elf_Addr vdelta = ctx->base_load_vaddr;
|
|
|
|
/* iterate paddrs */
|
|
Elf_Phdr ph;
|
|
unsigned i = 0;
|
|
for (;;)
|
|
{
|
|
if ((rv = el_findphdr(ctx, &ph, PT_LOAD, &i)))
|
|
return rv;
|
|
|
|
if (i == (unsigned)-1)
|
|
break;
|
|
|
|
Elf_Addr pload = ph.p_paddr + pdelta;
|
|
Elf_Addr vload = ph.p_vaddr + vdelta;
|
|
|
|
/* allocate mem */
|
|
char *dest = alloc(ctx, pload, vload, ph.p_memsz);
|
|
if (!dest)
|
|
return EL_ENOMEM;
|
|
|
|
EL_DEBUG("Loading seg fileoff %x, vaddr %x to %p\n",
|
|
ph.p_offset, ph.p_vaddr, dest);
|
|
|
|
/* read loaded portion */
|
|
if ((rv = el_pread(ctx, dest, ph.p_filesz, ph.p_offset)))
|
|
return rv;
|
|
|
|
/* zero mem-only portion */
|
|
memset(dest + ph.p_filesz, 0, ph.p_memsz - ph.p_filesz);
|
|
|
|
i++;
|
|
}
|
|
|
|
return rv;
|
|
}
|
|
|
|
el_status el_finddyn(el_ctx *ctx, Elf_Dyn *dyn, uint32_t tag)
|
|
{
|
|
el_status rv = EL_OK;
|
|
size_t ndyn = ctx->dynsize / sizeof(Elf_Dyn);
|
|
|
|
for (unsigned i = 0; i < ndyn; i++)
|
|
{
|
|
if ((rv = el_pread(ctx, dyn, sizeof *dyn, ctx->dynoff + i * sizeof *dyn)))
|
|
return rv;
|
|
|
|
if (dyn->d_tag == tag)
|
|
return EL_OK;
|
|
}
|
|
|
|
dyn->d_tag = DT_NULL;
|
|
return EL_OK;
|
|
}
|
|
|
|
el_status el_findrelocs(el_ctx *ctx, el_relocinfo *ri, uint32_t type)
|
|
{
|
|
el_status rv = EL_OK;
|
|
|
|
Elf_Dyn rel, relsz, relent;
|
|
|
|
if ((rv = el_finddyn(ctx, &rel, type)))
|
|
return rv;
|
|
|
|
if ((rv = el_finddyn(ctx, &relsz, type + 1)))
|
|
return rv;
|
|
|
|
if ((rv = el_finddyn(ctx, &relent, type + 2)))
|
|
return rv;
|
|
|
|
if (rel.d_tag == DT_NULL || relsz.d_tag == DT_NULL || relent.d_tag == DT_NULL)
|
|
{
|
|
ri->entrysize = 0;
|
|
ri->tablesize = 0;
|
|
ri->tableoff = 0;
|
|
}
|
|
else
|
|
{
|
|
ri->tableoff = rel.d_un.d_ptr;
|
|
ri->tablesize = relsz.d_un.d_val;
|
|
ri->entrysize = relent.d_un.d_val;
|
|
}
|
|
|
|
return rv;
|
|
}
|
|
|
|
extern el_status el_applyrel(el_ctx *ctx, Elf_Rel *rel);
|
|
extern el_status el_applyrela(el_ctx *ctx, Elf_RelA *rela);
|
|
|
|
el_status el_relocate(el_ctx *ctx)
|
|
{
|
|
el_status rv = EL_OK;
|
|
|
|
// not dynamic
|
|
if (ctx->ehdr.e_type != ET_DYN)
|
|
return EL_OK;
|
|
|
|
char *base = (char *)ctx->base_load_paddr;
|
|
|
|
el_relocinfo ri;
|
|
#ifdef EL_ARCH_USES_REL
|
|
if ((rv = el_findrelocs(ctx, &ri, DT_REL)))
|
|
return rv;
|
|
|
|
if (ri.entrysize != sizeof(Elf_Rel) && ri.tablesize)
|
|
{
|
|
EL_DEBUG("Relocation size %u doesn't match expected %u\n",
|
|
ri.entrysize, sizeof(Elf_Rel));
|
|
return EL_BADREL;
|
|
}
|
|
|
|
size_t relcnt = ri.tablesize / sizeof(Elf_Rel);
|
|
Elf_Rel *reltab = (Elf_Rel *)(base + ri.tableoff);
|
|
for (size_t i = 0; i < relcnt; i++)
|
|
{
|
|
if ((rv = el_applyrel(ctx, &reltab[i])))
|
|
return rv;
|
|
}
|
|
#endif
|
|
|
|
#ifdef EL_ARCH_USES_RELA
|
|
if ((rv = el_findrelocs(ctx, &ri, DT_RELA)))
|
|
return rv;
|
|
|
|
if (ri.entrysize != sizeof(Elf_RelA) && ri.tablesize)
|
|
{
|
|
EL_DEBUG("Relocation size %u doesn't match expected %u\n",
|
|
ri.entrysize, sizeof(Elf_RelA));
|
|
return EL_BADREL;
|
|
}
|
|
|
|
size_t relacnt = ri.tablesize / sizeof(Elf_RelA);
|
|
Elf_RelA *relatab = (Elf_RelA *)(base + ri.tableoff);
|
|
for (size_t i = 0; i < relacnt; i++)
|
|
{
|
|
if ((rv = el_applyrela(ctx, &relatab[i])))
|
|
return rv;
|
|
}
|
|
#endif
|
|
|
|
#if !defined(EL_ARCH_USES_REL) && !defined(EL_ARCH_USES_RELA)
|
|
#error No relocation type defined!
|
|
#endif
|
|
|
|
return rv;
|
|
}
|