From: lace <>
Date: Sun, 25 Dec 2005 06:23:09 +0000 (+0000)
Subject: instruction_length(): Extended to support some new Microsoft binaries.
X-Git-Tag: bp_HEAD~9
X-Git-Url: https://git.jankratochvil.net/?p=captive.git;a=commitdiff_plain;h=94d79a630294939ea84ce7d9cabc6c114b8d02e4

instruction_length(): Extended to support some new Microsoft binaries.
instruction_length(): Improved error messages of unsupported opcodes.
---

diff --git a/src/libcaptive/ldr/loader.c b/src/libcaptive/ldr/loader.c
index 48fe811..51865ba 100644
--- a/src/libcaptive/ldr/loader.c
+++ b/src/libcaptive/ldr/loader.c
@@ -352,9 +352,23 @@ err_g_free_ModuleObject:
 	g_return_val_if_reached(FALSE);
 }
 
+static void instruction_fail(const guint8 *instr_base,gint offset_last,const gchar *location)
+{
+char instr_buf[4*3+1],*s;
+
+	g_return_if_fail(offset_last<=(gint)((sizeof(instr_buf)-1)/3));
+
+	s=instr_buf;
+	while (offset_last-->=0)
+		s+=sprintf(s," %02X",*instr_base++);
+	g_error("instruction_length(): Unhandled at %s:%s",location,instr_buf);
+	/* NOTREACHED */
+}
 
 static gsize instruction_length(const guint8 *instr)
 {
+#define INSTRUCTION_FAIL(offset_last) instruction_fail(instr,(offset_last),G_STRLOC)
+
 	if ((instr[0] & 0xF8)==0x50)	/* push %regular-register */
 		return 1;
 	if ((instr[0] & 0xF8)==0x58)	/* pop  %regular-register */
@@ -378,7 +392,7 @@ static gsize instruction_length(const guint8 *instr)
 					return 1+1+4+1;	/* 80 3D immediate-quad-indirect byte */
 				case 0x7C:	/* cmpb $byte,#immediate(%reg,1) */
 					return 1+1+1+1+1;	/* 80 7C address-mode immediate byte */
-				default: g_assert_not_reached();
+				default: INSTRUCTION_FAIL(1);
 				}
 		case 0x83:
 			switch (instr[1]) {
@@ -388,7 +402,7 @@ static gsize instruction_length(const guint8 *instr)
 					return 1+1+4+1;	/* 83 3D immediate-quad-indirect byte */
 				case 0x7C:	/* cmpl $byte,#immediate(%reg,1) */
 					return 1+1+1+1+1;	/* 80 7C address-mode immediate byte */
-				default: g_assert_not_reached();
+				default: INSTRUCTION_FAIL(1);
 				}
 		case 0x8A:	/* mov ??,?? */
 		case 0x8B:	/* mov Gb,Eb */
@@ -401,13 +415,17 @@ static gsize instruction_length(const guint8 *instr)
 				case 0x4C:	/* mov #offset(%reg,#mult),%reg */
 				case 0x54:	/* mov #offset(%reg,#mult),%reg */
 					return 1+1+1+1;	/* 8B 44 address-mode offset */
-				default: g_assert_not_reached();
+				case 0xC0:	/* mov %eax,%eax */
+					return 2;
+				case 0xFF:	/* mov %edi,%edi */
+					return 2;
+				default: INSTRUCTION_FAIL(1);
 				}
 		case 0x8D:	/* lea Gb,M */
 			switch (instr[1]) {
 				case 0x44:	/* mov #offset(%reg,%reg,#mult),%reg */
 					return 4;	/* 8B 44 address-mode offset */
-				default: g_assert_not_reached();
+				default: INSTRUCTION_FAIL(1);
 				}
 		case 0x8F:	/* lea Gb,M */
 			switch (instr[1]) {
@@ -415,9 +433,9 @@ static gsize instruction_length(const guint8 *instr)
 					switch (instr[2]) {
 						case 0x24:	/* popl (%esp,1) */
 							return 3;
-						default: g_assert_not_reached();
+						default: INSTRUCTION_FAIL(2);
 						}
-				default: g_assert_not_reached();
+				default: INSTRUCTION_FAIL(1);
 				}
 		case 0x9C:	/* pushf */
 			return 1;
@@ -439,11 +457,13 @@ static gsize instruction_length(const guint8 *instr)
 			return 1;
 		case 0xFF:	/* inc/dec Ev */
 			return 2;
-		default: g_assert_not_reached();
+		default: INSTRUCTION_FAIL(0);
 		}
 	g_assert_not_reached();	/* TODO:fill the table */
 	/* NOTREACHED */
 	return 0;
+
+#undef INSTRUCTION_FAIL
 }