cmpmrg_text: allow mixed align insns

diff --git a/tools/cmpmrg_text.c b/tools/cmpmrg_text.c
index 49284be..38acd6d 100644 (file)
--- a/tools/cmpmrg_text.c
+++ b/tools/cmpmrg_text.c
@@ -291,53 +291,61 @@ void parse_headers(FILE *f, unsigned int *base_out,
        *raw_symtab_out = symt_all;
 }
 
-static int handle_pad(uint8_t *d_obj, uint8_t *d_exe, int maxlen)
+static int try_align(uint8_t *d_obj, uint8_t *d_exe, int maxlen)
 {
-       static const uint8_t p7[7] = { 0x8d, 0xa4, 0x24, 0x00, 0x00, 0x00, 0x00 };
-       static const uint8_t p6[6] = { 0x8d, 0x9b, 0x00, 0x00, 0x00, 0x00 };
-       static const uint8_t p5[5] = { 0x05, 0x00, 0x00, 0x00, 0x00 }; // add eax, 0
-       static const uint8_t p4[4] = { 0x8d, 0x64, 0x24, 0x00 }; // lea
-       static const uint8_t p3[3] = { 0x8d, 0x49, 0x00 }; // lea ecx, [ecx]
-       static const uint8_t p2[2] = { 0x8b, 0xff }; // mov edi, edi
-       static const uint8_t p1[1] = { 0x90 }; // nop
+       static const uint8_t aligns[8][7] = {
+               { }, // [0] not used
+               { 0x90 }, // [1] nop
+               { 0x8b, 0xff }, // mov edi, edi
+               { 0x8d, 0x49, 0x00 }, // lea ecx, [ecx]
+               { 0x8d, 0x64, 0x24, 0x00 }, // lea
+               { 0x05, 0x00, 0x00, 0x00, 0x00 }, // add eax, 0
+               { 0x8d, 0x9b, 0x00, 0x00, 0x00, 0x00 },
+               { 0x8d, 0xa4, 0x24, 0x00, 0x00, 0x00, 0x00 },
+       };
+       int j = 0;
        int len;
        int i;
 
+       // check exe for common pad/align patterns
        for (i = 0; i < maxlen; i++)
                if (d_exe[i] != 0xcc)
                        break;
 
-       for (len = i; len > 0; )
+       while (j < 8) {
+               for (j = 1; j < 8; j++) {
+                       if (maxlen - i < j) {
+                               j = 8;
+                               break;
+                       }
+                       if (memcmp(&d_exe[i], aligns[j], j) == 0) {
+                               i += j;
+                               break;
+                       }
+               }
+       }
+       if (i == 0)
+               return 0;
+
+       // now check the obj
+       for (j = 0, len = i; len > 0; )
        {
                i = len;
                if (i > 7)
                        i = 7;
 
-               switch (i) {
-               #define CASE(x) \
-               case sizeof(p ## x): \
-                       if (memcmp(d_obj, p ## x, sizeof(p ## x))) \
-                               return 0; \
-                       memset(d_obj, 0xcc, sizeof(p ## x)); \
+               if (memcmp(d_obj, aligns[i], i) != 0)
                        break;
-               CASE(7)
-               CASE(6)
-               CASE(5)
-               CASE(4)
-               CASE(3)
-               CASE(2)
-               CASE(1)
-               default:
-                       printf("%s: unhandled len: %d\n", __func__, len);
-                       return 0;
-               #undef CASE
-               }
+
+               memcpy(d_obj, d_exe, i);
+               j += i;
 
                len -= i;
                d_obj += i;
+               d_exe += i;
        }
 
-       return 1;
+       return j;
 }
 
 struct equiv_opcode {
@@ -394,6 +402,9 @@ struct equiv_opcode {
        { 5, -1, 0, 0,
         { 0x00,0x04,0x24,0x00,0x90 }, { 0x00,0xc7,0xff,0x00,0xff },
         { 0x00,0x44,0x24,0x00,0x00 }, { 0x00,0xc7,0xff,0xff,0x00 }, },
+       { 8, -1, 0, 0,
+        { 0x00,0x04,0x24,0x00,0x00,0x00,0x00,0x90 }, { 0x00,0xc7,0xff,0x00,0x00,0x00,0x00,0xff },
+        { 0x00,0x44,0x24,0x00,0x00,0x00,0x00,0x00 }, { 0x00,0xc7,0xff,0xff,0x00,0x00,0x00,0x00 }, },
 
         // various align insns/fillups
        { 2, -1, 0, 0,
@@ -514,6 +525,7 @@ int main(int argc, char *argv[])
        long sztext_cmn;
        int do_cmp = 1;
        int retval = 1;
+       int bad = 0;
        int left;
        int arg;
        int ret;
@@ -581,16 +593,17 @@ int main(int argc, char *argv[])
        if (do_cmp)
        for (i = 0; i < sztext_cmn; i++)
        {
-               if (s_text_obj.data[i] == s_text_exe.data[i])
+               if (s_text_obj.data[i] == s_text_exe.data[i]) {
+                       bad = 0;
                        continue;
+               }
 
                left = sztext_cmn - i;
 
-               if (s_text_exe.data[i] == 0xcc || s_text_exe.data[i] == 0x90) {
-                       // padding
-                       if (handle_pad(s_text_obj.data + i,
-                           s_text_exe.data + i, left))
-                               continue;
+               ret = try_align(s_text_obj.data + i, s_text_exe.data + i, left);
+               if (ret > 0) {
+                       i += ret - 1;
+                       continue;
                }
 
                ret = check_equiv(s_text_obj.data + i, s_text_exe.data + i, left);
@@ -601,7 +614,10 @@ int main(int argc, char *argv[])
 
                printf("%x: %02x vs %02x\n", base + i,
                        s_text_obj.data[i], s_text_exe.data[i]);
-               goto out;
+               if (bad)
+                       goto out;
+
+               bad = 1;
        }
 
        // fill removed funcs with 'int3'