simple-object-xcoff.c (simple_object_xcoff_find_sections): Improve .go_export csect...
authorTony Reix <tony.reix@atos.net>
Wed, 30 Aug 2017 14:08:00 +0000 (14:08 +0000)
committerIan Lance Taylor <ian@gcc.gnu.org>
Wed, 30 Aug 2017 14:08:00 +0000 (14:08 +0000)
* simple-object-xcoff.c (simple_object_xcoff_find_sections):
Improve .go_export csect handling.  Don't make assumptions
on containing section or number of auxiliary entries.

From-SVN: r251533

libiberty/ChangeLog
libiberty/simple-object-xcoff.c

index 58d2816a1416c36ea969285acfc48d1a44f7f1de..e8165a0911a9b68dc20e66b5092bf82fe66210e6 100644 (file)
@@ -1,3 +1,9 @@
+2017-08-29  Tony Reix  <tony.reix@atos.net>
+
+       * simple-object-xcoff.c (simple_object_xcoff_find_sections):
+       Improve .go_export csect handling.  Don't make assumptions
+       on containing section or number of auxiliary entries.
+
 2017-08-28  Richard Biener  <rguenther@suse.de>
 
        PR lto/81968
index 2adebe37107f68180a9ca649377513786ecd1694..9a8f581563f0e9c83828c3ec1742e4773c37a2a0 100644 (file)
@@ -255,10 +255,14 @@ union external_auxent
 #define IMAGE_SYM_TYPE \
   ((IMAGE_SYM_DTYPE_NULL << 4) | IMAGE_SYM_TYPE_NULL)
 
+#define C_EXT          (2)
 #define C_STAT         (3)
 #define C_FILE         (103)
+#define C_HIDEXT       (107)
 
-#define DBXMASK                0x80
+#define XTY_SD         (1)     /* section definition */
+
+#define XMC_XO         (7)     /* extended operation */
 
 /* Private data for an simple_object_read.  */
 
@@ -400,6 +404,7 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
   size_t scnhdr_size;
   unsigned char *scnbuf;
   const char *errmsg;
+  unsigned short (*fetch_16) (const unsigned char *);
   unsigned int (*fetch_32) (const unsigned char *);
   ulong_type (*fetch_64) (const unsigned char *);
   unsigned int nscns;
@@ -407,7 +412,6 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
   size_t strtab_size;
   struct external_syment *symtab = NULL;
   unsigned int i;
-  off_t textptr = 0;
 
   scnhdr_size = u64 ? SCNHSZ64 : SCNHSZ32;
   scnbuf = XNEWVEC (unsigned char, scnhdr_size * ocr->nscns);
@@ -420,6 +424,7 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
       return errmsg;
     }
 
+  fetch_16 = simple_object_fetch_big_16;
   fetch_32 = simple_object_fetch_big_32;
   fetch_64 = simple_object_fetch_big_64;
 
@@ -433,7 +438,7 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
       char namebuf[SCNNMLEN + 1];
       char *name;
       off_t scnptr;
-      unsigned int size;
+      off_t size;
 
       scnhdr = scnbuf + i * scnhdr_size;
       scnname = scnhdr + offsetof (struct external_scnhdr, s_name);
@@ -489,24 +494,24 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
                                              u.xcoff32.s_size));
        }
 
-      if (strcmp (name, ".text") == 0)
-       textptr = scnptr;
       if (!(*pfn) (data, name, scnptr, size))
        break;
     }
 
-  /* Special handling for .go_export CSECT. */
-  if (textptr != 0 && ocr->nsyms > 0)
+  /* Special handling for .go_export csect.  */
+  if (ocr->nsyms > 0)
     {
-      unsigned char *sym, *aux;
+      unsigned char *sym;
       const char *n_name;
-      unsigned long n_value, n_offset, n_zeroes, x_scnlen;
+      off_t size, n_value;
+      unsigned int n_numaux, n_offset, n_zeroes;
+      short n_scnum;
 
-      /* Read symbol table. */
+      /* Read symbol table.  */
       symtab = XNEWVEC (struct external_syment, ocr->nsyms * SYMESZ);
       if (!simple_object_internal_read (sobj->descriptor,
                                        sobj->offset + ocr->symptr,
-                                       (unsigned char *)symtab,
+                                       (unsigned char *) symtab,
                                        ocr->nsyms * SYMESZ,
                                        &errmsg, err))
        {
@@ -515,17 +520,25 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
          return NULL;
        }
 
-      /* Search in symbol table if we have a ".go_export" symbol. */
-      for (i = 0; i < ocr->nsyms; ++i)
+      /* Search in symbol table if we have a ".go_export" symbol.  */
+      for (i = 0; i < ocr->nsyms; i += n_numaux + 1)
        {
-         sym = (unsigned char *)&symtab[i];
+         sym = (unsigned char *) &symtab[i];
+         n_numaux = symtab[i].n_numaux[0];
+
+         if (symtab[i].n_sclass[0] != C_EXT
+             && symtab[i].n_sclass[0] != C_HIDEXT)
+           continue;
+
+         /* Must have at least one csect auxiliary entry.  */
+         if (n_numaux < 1 || i + n_numaux >= ocr->nsyms)
+           continue;
+
+         n_scnum = fetch_16 (sym + offsetof (struct external_syment,
+                                             n_scnum));
+         if (n_scnum < 1 || (unsigned int) n_scnum > nscns)
+           continue;
 
-         if (symtab[i].n_sclass[0] & DBXMASK)
-           {
-             /* Skip debug symbols whose names are in stabs. */
-             i += symtab[i].n_numaux[0];
-             continue;
-           }
          if (u64)
            {
              n_value = fetch_64 (sym + offsetof (struct external_syment,
@@ -535,67 +548,96 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
            }
          else
            {
-             /* ".go_export" is longer than N_SYMNMLEN */
+             /* ".go_export" is longer than N_SYMNMLEN */
              n_zeroes = fetch_32 (sym + offsetof (struct external_syment,
                                                   u.xcoff32.n.n.n_zeroes));
              if (n_zeroes != 0)
-               {
-                 /* Skip auxiliary entries. */
-                 i += symtab[i].n_numaux[0];
-                 continue;
-               }
+               continue;
+
              n_value = fetch_32 (sym + offsetof (struct external_syment,
                                                  u.xcoff32.n_value));
              n_offset = fetch_32 (sym + offsetof (struct external_syment,
                                                   u.xcoff32.n.n.n_offset));
            }
 
-         /* The real section name is found in the string table.  */
+         /* The real symbol name is found in the string table.  */
          if (strtab == NULL)
            {
              strtab = simple_object_xcoff_read_strtab (sobj,
-                                                       &strtab_size,
+                                                       &strtab_size,
                                                        &errmsg, err);
              if (strtab == NULL)
-               {
-                  XDELETEVEC (symtab);
-                 XDELETEVEC (scnbuf);
+               {
+                 XDELETEVEC (symtab);
+                 XDELETEVEC (scnbuf);
                  return errmsg;
-               }
+               }
            }
 
          if (n_offset >= strtab_size)
-            {
+           {
              XDELETEVEC (strtab);
              XDELETEVEC (symtab);
              XDELETEVEC (scnbuf);
              *err = 0;
-             return "section string index out of range";
-            }
-          n_name = strtab + n_offset;
+             return "symbol string index out of range";
+           }
+         n_name = strtab + n_offset;
 
-         if (!strcmp(n_name, ".go_export"))
+         if (!strcmp (n_name, ".go_export"))
            {
-             /* Found .go_export symbol, read auxiliary entry. */
-             if (i + 1 >= ocr->nsyms)
-               break;
-
-             aux = (unsigned char *)&symtab[i + 1];
+             union external_auxent *auxent;
+             unsigned char *aux, *scnhdr;
+             off_t scnptr, x_scnlen;
+
+             /* Found .go_export symbol, read its csect auxiliary entry.
+                By convention, it is the last auxiliary entry.  */
+             auxent = (union external_auxent *) &symtab[i + n_numaux];
+             aux = (unsigned char *) auxent;
              if (u64)
                {
+                 if ((auxent->u.xcoff64.x_csect.x_smtyp & 0x7) != XTY_SD
+                     || auxent->u.xcoff64.x_csect.x_smclas != XMC_XO)
+                   continue;
+
                  x_scnlen = fetch_32 (aux + offsetof (union external_auxent,
+                                                      u.xcoff64.x_csect.x_scnlen_hi));
+                 x_scnlen = x_scnlen << 32
+                          | fetch_32 (aux + offsetof (union external_auxent,
                                                       u.xcoff64.x_csect.x_scnlen_lo));
                }
              else
                {
+                 if ((auxent->u.xcoff32.x_csect.x_smtyp & 0x7) != XTY_SD
+                     || auxent->u.xcoff32.x_csect.x_smclas != XMC_XO)
+                   continue;
+
                  x_scnlen = fetch_32 (aux + offsetof (union external_auxent,
                                                       u.xcoff32.x_csect.x_scnlen));
                }
-             (*pfn) (data, ".go_export", textptr + n_value, x_scnlen);
+
+             /* Get header of containing section.  */
+             scnhdr = scnbuf + (n_scnum - 1) * scnhdr_size;
+             if (u64)
+               {
+                 scnptr = fetch_64 (scnhdr + offsetof (struct external_scnhdr,
+                                                       u.xcoff64.s_scnptr));
+                 size = fetch_64 (scnhdr + offsetof (struct external_scnhdr,
+                                                     u.xcoff64.s_size));
+               }
+             else
+               {
+                 scnptr = fetch_32 (scnhdr + offsetof (struct external_scnhdr,
+                                                       u.xcoff32.s_scnptr));
+                 size = fetch_32 (scnhdr + offsetof (struct external_scnhdr,
+                                                     u.xcoff32.s_size));
+               }
+             if (n_value + x_scnlen > size)
+               break;
+
+             (*pfn) (data, ".go_export", scnptr + n_value, x_scnlen);
              break;
            }
-         /* Skip auxiliary entries. */
-         i += symtab[i].n_numaux[0];
        }
     }