- push_buf[0] = 0x68; /* pushq $... */
- store_unsigned_integer (&push_buf[1], 4, byte_order, ret_addr);
+
+ /* If pushing an address higher than or equal to 0x80000000,
+ avoid 'pushq', as that sign extends its 32-bit operand, which
+ would be incorrect. */
+ if (ret_addr <= 0x7fffffff)
+ {
+ push_buf[0] = 0x68; /* pushq $... */
+ store_unsigned_integer (&push_buf[1], 4, byte_order, ret_addr);
+ i = 5;
+ }
+ else
+ {
+ push_buf[i++] = 0x48; /* sub $0x8,%rsp */
+ push_buf[i++] = 0x83;
+ push_buf[i++] = 0xec;
+ push_buf[i++] = 0x08;
+
+ push_buf[i++] = 0xc7; /* movl $imm,(%rsp) */
+ push_buf[i++] = 0x04;
+ push_buf[i++] = 0x24;
+ store_unsigned_integer (&push_buf[i], 4, byte_order,
+ ret_addr & 0xffffffff);
+ i += 4;
+
+ push_buf[i++] = 0xc7; /* movl $imm,4(%rsp) */
+ push_buf[i++] = 0x44;
+ push_buf[i++] = 0x24;
+ push_buf[i++] = 0x04;
+ store_unsigned_integer (&push_buf[i], 4, byte_order,
+ ret_addr >> 32);
+ i += 4;
+ }
+ gdb_assert (i <= sizeof (push_buf));