static unsigned patch_internal(int call, unsigned len, void *insnbuf,
unsigned long ip)
{
u64 reloc;
struct vmi_relocation_info *const rel = (struct vmi_relocation_info *)&reloc;
reloc = call_vrom_long_func(vmi_rom, get_reloc, call);
switch(rel->type) {
case VMI_RELOCATION_CALL_REL:
BUG_ON(len < 5);
*(char *)insnbuf = MNEM_CALL;
patch_offset(insnbuf, ip, (unsigned long)rel->eip);
return 5;
case VMI_RELOCATION_JUMP_REL:
BUG_ON(len < 5);
*(char *)insnbuf = MNEM_JMP;
patch_offset(insnbuf, ip, (unsigned long)rel->eip);
return 5;
case VMI_RELOCATION_NOP:
/* obliterate the whole thing */
return 0;
case VMI_RELOCATION_NONE:
/* leave native code in place */
break;
default:
BUG();
}
return len;
}
void patch_cmd(int argc, char **argv) {
r_binfmt_s bin;
patch_options_parse(argc, argv);
r_binfmt_load(&bin, patch_options_filename, patch_options_arch);
if(patch_options_offset != R_BINFMT_BAD_ADDR) {
patch_offset(&bin,
patch_options_offset,
patch_options_bytes->bytes,
patch_options_bytes->len);
} else {
patch_address(&bin,
patch_options_address,
patch_options_bytes->bytes,
patch_options_bytes->len);
}
if(patch_options_output == NULL)
patch_options_output = patch_options_filename;
r_binfmt_write(&bin, patch_options_output);
printf("[+] Patched %" PRIu64 " bytes (result saved in %s)\n", patch_options_bytes->len, patch_options_output);
r_binfmt_free(&bin);
}
/*
* Apply patch if appropriate, return length of new instruction
* sequence. The callee does nop padding for us.
*/
static unsigned vmi_patch(u8 type, u16 clobbers, void *insns, unsigned len)
{
switch (type) {
case PARAVIRT_IRQ_DISABLE:
return patch_internal(VMI_CALL_DisableInterrupts, len, insns);
case PARAVIRT_IRQ_ENABLE:
return patch_internal(VMI_CALL_EnableInterrupts, len, insns);
case PARAVIRT_RESTORE_FLAGS:
return patch_internal(VMI_CALL_SetInterruptMask, len, insns);
case PARAVIRT_SAVE_FLAGS:
return patch_internal(VMI_CALL_GetInterruptMask, len, insns);
case PARAVIRT_SAVE_FLAGS_IRQ_DISABLE:
if (len >= 10) {
patch_internal(VMI_CALL_GetInterruptMask, len, insns);
patch_internal(VMI_CALL_DisableInterrupts, len-5, insns+5);
return 10;
} else {
/*
* You bastards didn't leave enough room to
* patch save_flags_irq_disable inline. Patch
* to a helper
*/
BUG_ON(len < 5);
*(char *)insns = MNEM_CALL;
patch_offset(insns, irq_save_disable_callout);
return 5;
}
case PARAVIRT_INTERRUPT_RETURN:
return patch_internal(VMI_CALL_IRET, len, insns);
case PARAVIRT_STI_SYSEXIT:
return patch_internal(VMI_CALL_SYSEXIT, len, insns);
default:
break;
}
return len;
}