Implement SIB addressing in JIT

dc8511 · May 13, 2018 · fb27d93 · fb27d93
1 parent 7a3a99a
commit fb27d93
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Showing 3 changed files with 27 additions and 2 deletions.
diff --git a/emu/gadgets-x86/memory.S b/emu/gadgets-x86/memory.S
@@ -21,6 +21,27 @@
 .endm
 .reg_gadgets addr
 
+.irp reg, REG_LIST
+    .irp times, 1,2,4
+        .gadget si_\reg\()_\times
+            .ifnc \reg,esp
+                leal (%_addr,%\reg,\times), %_addr
+            .else
+                leal (%_addr,%_esp,\times), %_addr
+            .endif
+            gret
+    .endr
+.endr
+.section .rodata
+.global si_gadgets
+si_gadgets:
+.irp reg, REG_LIST
+    .irp times, 1,2,4
+        .quad gadget_si_\reg\()_\times
+    .endr
+.endr
+.previous
+
 # memory stuff that can't go in a header file
 .irp type, read,write
     .global handle_\type\()_miss
@@ -47,5 +68,5 @@ segfault:
     movl $INT_GPF, %_tmp
     jmp jit_exit
 
-.rodata
+.section .rodata
 .gadget_array_list addr, REG_LIST
diff --git a/emu/gen.c b/emu/gen.c
@@ -33,6 +33,7 @@ extern gadget_t sub_gadgets[arg_cnt];
 extern gadget_t xor_gadgets[arg_cnt];
 
 extern gadget_t addr_gadgets[reg_cnt];
+extern gadget_t si_gadgets[reg_cnt * 3];
 
 #define GEN(thing) gen(state, (unsigned long) (thing))
 #define g(g) GEN(gadget_##g)
@@ -66,6 +67,8 @@ static inline void gen_op(struct gen_state *state, gadget_t *gadgets, enum arg a
     if (arg == arg_mem32 || arg == arg_addr) {
         GEN(addr_gadgets[modrm->base]);
         GEN(modrm->offset);
+        if (modrm->type == modrm_mem_si)
+            GEN(si_gadgets[modrm->index * 3 + modrm->shift]);
     }
     GEN(gadgets[arg]);
     if (arg == arg_imm)

diff --git a/ish-gdb.gdb b/ish-gdb.gdb
@@ -12,7 +12,8 @@ end
 
 define hook-stop
     python
-if gdb.selected_frame().find_sal().symtab.filename.endswith('.S'):
+symtab = gdb.selected_frame().find_sal().symtab
+if symtab is not None and symtab.filename.endswith('.S'):
     gdb.execute('set disassemble-next-line on')
 else:
     gdb.execute('set disassemble-next-line auto')