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/* Pretty trivial, but in its own file to match the other architectures. */
#include "x86/jump-patch.h"
UNUSED
static void transform_dis_pcrel(struct transform_dis_ctx *ctx, uint64_t dpc,
struct arch_pcrel_info info) {
/* push %reg; mov $dpc, %reg; <orig but with reg instead>; pop %reg */
/* reg is rcx, or rax if the instruction might be using rcx. */
int rax = info.reg == 1;
void *code = *ctx->rewritten_ptr_ptr;
/* push */
op8(&code, rax ? 0x50 : 0x51);
/* mov */
#ifdef TARGET_x86_64
op8(&code, 0x48);
op8(&code, rax ? 0xb8 : 0xb9);
op64(&code, dpc);
#else
op8(&code, rax ? 0xb8 : 0xb9);
op32(&code, dpc);
#endif
ctx->write_newop_here = code;
code += ctx->base.op_size;
/* pop */
op8(&code, rax ? 0x58 : 0x59);
*ctx->rewritten_ptr_ptr = code;
ctx->base.newop[0] = rax ? 0 : 1;
ctx->base.modify = true;
}
static void transform_dis_branch(struct transform_dis_ctx *ctx, uint_tptr dpc,
int cc) {
if (dpc >= ctx->pc_patch_start && dpc < ctx->pc_patch_end) {
ctx->err = SUBSTITUTE_ERR_FUNC_BAD_INSN_AT_START;
return;
}
void *code = *ctx->rewritten_ptr_ptr;
ctx->write_newop_here = code;
code += ctx->base.op_size;
struct arch_dis_ctx arch;
uintptr_t source = (uintptr_t) code + 2;
int size = jump_patch_size(source, dpc, arch, true);
/* if not taken, jmp past the big jump - this is a bit suboptimal but not that bad */
op8(&code, 0xeb);
op8(&code, size);
make_jump_patch(&code, source, dpc, arch);
*ctx->rewritten_ptr_ptr = code;
ctx->base.newop[0] = 2;
ctx->base.modify = true;
if (!cc)
transform_dis_ret(ctx);
}
static void transform_dis_pre_dis(UNUSED struct transform_dis_ctx *ctx) {}
static void transform_dis_post_dis(UNUSED struct transform_dis_ctx *ctx) {}
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