Changeset 51 for trunk/kLdr/kLdrModMachO.c

Timestamp:

Jul 9, 2013, 6:16:31 PM (12 years ago)

Author:

bird

Message:

mach_kernel doesn't have segments sorted by link address, but rather file offset, so counter that by sorting the segment array. Fixed RVA calc.

File:

• trunk/kLdr/kLdrModMachO.c (modified) (19 diffs)

trunk/kLdr/kLdrModMachO.c

@@ -103 +103 @@
 typedef struct KLDRMODMACHOSEG
 {
+    /** The orignal segment number (in case we had to resort it). */
+    KU32                    iOrgSegNo;
     /** The number of sections in the segment. */
     KU32                    cSections;
@@ -188 +190 @@
 static int  kldrModMachODoCreate(PKRDR pRdr, KLDRFOFF offImage, PKLDRMODMACHO *ppMod);
 static int  kldrModMachOPreParseLoadCommands(KU8 *pbLoadCommands, const mach_header_32_t *pHdr, PKRDR pRdr, KLDRFOFF offImage,
-                                             KU32 *pcSegments, KU32 *pcSections, KU32 *pcbStringPool, PKBOOL pfCanLoad);
+                                             KU32 *pcSegments, KU32 *pcSections, KU32 *pcbStringPool, PKBOOL pfCanLoad,
+                                             PKLDRADDR pLinkAddress);
 static int  kldrModMachOParseLoadCommands(PKLDRMODMACHO pModMachO, char *pbStringPool, KU32 cbStringPool);
 static int  kldrModMachOAdjustBaseAddress(PKLDRMODMACHO pModMachO, PKLDRADDR pBaseAddress);
@@ -292 +295 @@
     KBOOL fMakeGot;
     KBOOL fCanLoad = K_TRUE;
+    KLDRADDR LinkAddress;
     KU8 cbJmpStub;
     int rc;
@@ -352 +356 @@
     if (!rc)
         rc = kldrModMachOPreParseLoadCommands(pbLoadCommands, &s.Hdr32, pRdr, offImage,
-                                              &cSegments, &cSections, &cbStringPool, &fCanLoad);
+                                              &cSegments, &cSections, &cbStringPool, &fCanLoad, &LinkAddress);
     if (rc)
     {
@@ -456 +460 @@
         ||  s.Hdr32.magic == IMAGE_MACHO32_SIGNATURE_OE)
         pModMachO->Hdr.reserved = 0;
-    pModMachO->LinkAddress = 0;
+    pModMachO->LinkAddress = LinkAddress;
     pModMachO->cbImage = 0;
     pModMachO->fCanLoad = fCanLoad;
@@ -504 +508 @@
  * @param   pcbStringPool   Where to store the string pool size.
  * @param   pfCanLoad       Where to store the can-load-image indicator.
+ * @param   pLinkAddress    Where to store the image link address (i.e. the
+ *                          lowest segment address).
  */
 static int  kldrModMachOPreParseLoadCommands(KU8 *pbLoadCommands, const mach_header_32_t *pHdr, PKRDR pRdr, KLDRFOFF offImage,
-                                             KU32 *pcSegments, KU32 *pcSections, KU32 *pcbStringPool, PKBOOL pfCanLoad)
+                                             KU32 *pcSegments, KU32 *pcSections, KU32 *pcbStringPool, PKBOOL pfCanLoad,
+                                             PKLDRADDR pLinkAddress)
 {
     union
@@ -534 +541 @@
     *pcbStringPool = 0;
     *pfCanLoad = K_TRUE;
+    *pLinkAddress = ~(KLDRADDR)0;
 
     while (cLeft-- > 0)
@@ -696 +704 @@
 
 
-                    /* count segments and strings */
+                    /* count segments and strings, calculate image link address. */
                     switch (pHdr->filetype)
                     {
@@ -712 +720 @@
 
                             /* a new segment? */
-                            if (    !cSegments
+                            if (    cSections == 1
                                 ||  kHlpStrNComp(pSect->segname, (pSect - 1)->segname, sizeof(pSect->segname)))
                             {
@@ -729 +737 @@
                                 cSegments++;
                                 cbStringPool += kHlpStrNLen(&pSect->segname[0], sizeof(pSect->segname)) + 1;
+
+                                /* Link address lower? */
+                                if (*pLinkAddress > u.pSeg32->vmaddr)
+                                    *pLinkAddress = u.pSeg32->vmaddr;
                             }
                             break;
@@ -888 +900 @@
 
 
-                    /* count segments and strings */
+                    /* count segments and strings, calculate image link address. */
                     switch (pHdr->filetype)
                     {
@@ -904 +916 @@
 
                             /* a new segment? */
-                            if (    !cSegments
+                            if (    !cSections == 1
                                 ||  kHlpStrNComp(pSect->segname, (pSect - 1)->segname, sizeof(pSect->segname)))
                             {
@@ -921 +933 @@
                                 cSegments++;
                                 cbStringPool += kHlpStrNLen(&pSect->segname[0], sizeof(pSect->segname)) + 1;
+
+                                /* Link address lower? */
+                                if (*pLinkAddress > u.pSeg64->vmaddr)
+                                    *pLinkAddress = u.pSeg64->vmaddr;
                             }
                             break;
@@ -1100 +1116 @@
     PKLDRMODMACHOSECT pSectExtra = pModMachO->paSections;
     const KU32 cSegments = pModMachO->pMod->cSegments;
-    KU32 i;
+    KU32 i, c;
 
     while (cLeft-- > 0)
@@ -1119 +1135 @@
                 KU32 cSectionsLeft;
 
-                pModMachO->LinkAddress = u.pSeg32->vmaddr;
+                kHlpAssert(u.pSeg32->vmaddr >= pModMachO->LinkAddress);
 
                 /*
@@ -1254 +1270 @@
                 KU32 cSectionsLeft;
 
-                pModMachO->LinkAddress = u.pSeg64->vmaddr;
+                kHlpAssert(u.pSeg64->vmaddr >= pModMachO->LinkAddress);
 
                 /*
@@ -1332 +1348 @@
                                 pSeg->MapAddress = 0;
 
+                                pSegExtra->iOrgSegNo = pSegExtra - &pModMachO->aSegments[0];
                                 pSegExtra->cSections = 0;
                                 pSegExtra->paSections = pSectExtra;
@@ -1408 +1425 @@
     if (pSegExtra != &pModMachO->aSegments[0])
         pSegExtra[-1].cSections = pSectExtra - pSegExtra[-1].paSections;
+
+    /*
+     * Make sure the segments are sorted, or we'll get screwed further down.
+     */
+    c = pSeg - &pModMachO->pMod->aSegments[0];
+    pSeg = &pModMachO->pMod->aSegments[0];
+    for (i = 0; i < c - 1; i++)
+    {
+        KLDRADDR LinkAddress = pSeg[i + 1].LinkAddress;
+        if (LinkAddress < pSeg[i].LinkAddress)
+        {
+            /* Gotta move the next segment, find the correct location. */
+            KLDRMODMACHOSEG TmpSegExtra;
+            KLDRSEG TmpSeg;
+            KU32 j = i;
+            KU32 cShift = 1;
+
+            while (j > 0 && LinkAddress < pSeg[j - 1].LinkAddress)
+                j--, cShift++;
+
+            TmpSegExtra = pModMachO->aSegments[i + 1];
+            kHlpMemMove(&pModMachO->aSegments[j + 1], &pModMachO->aSegments[j],
+                        cShift * sizeof(pModMachO->aSegments[0]));
+            pModMachO->aSegments[j] = TmpSegExtra;
+
+            TmpSeg = pSeg[i + 1];
+            kHlpMemMove(&pSeg[j + 1], &pSeg[j], cShift * sizeof(pSeg[0]));
+            pSeg[j] = TmpSeg;
+        }
+    }
+    pSeg = &pModMachO->pMod->aSegments[c];
 
     /*
@@ -1454 +1502 @@
         pSeg->MapAddress = 0;
 
+        pSegExtra->iOrgSegNo = KU32_MAX;
         pSegExtra->cSections = 0;
         pSegExtra->paSections = NULL;