[Emacs-diffs] emacs/src unexelf.c

[YAMAMOTO Mitsuharu]

CVSROOT:        /cvsroot/emacs
Module name:    emacs
Changes by:     YAMAMOTO Mitsuharu <mituharu>   09/05/06 02:27:21

Modified files:
        src            : unexelf.c 

Log message:
        (unexec): Consider a section to precede the .bss section
        if its addresses overlap that of .bss.
        (unexec) [NS_IMPL_GNUSTEP]: Copy ObjC-related data from old file
        instead of dumping process.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/emacs/src/unexelf.c?cvsroot=emacs&r1=1.71&r2=1.72

Patches:
Index: unexelf.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/unexelf.c,v
retrieving revision 1.71
retrieving revision 1.72
diff -u -b -r1.71 -r1.72
--- unexelf.c   7 Feb 2009 13:07:39 -0000       1.71
+++ unexelf.c   6 May 2009 02:27:20 -0000       1.72
@@ -985,9 +985,29 @@
             placed after the .bss section.  Overlap can occur if the
             section just before .bss has less-strict alignment; this
             was observed between .symtab and .bss on Solaris 2.5.1
-            (sparc) with GCC snapshot 960602.  */
+            (sparc) with GCC snapshot 960602.
 
-         if (NEW_SECTION_H (nn).sh_offset >= old_bss_offset)
+> dump -h temacs
+
+temacs:
+
+          **** SECTION HEADER TABLE ****
+[No]   Type    Flags   Addr         Offset       Size          Name
+       Link    Info    Adralgn      Entsize
+
+[22]   1       3       0x335150     0x315150     0x4           .data.rel.local
+       0       0       0x4          0            
+
+[23]   8       3       0x335158     0x315158     0x42720       .bss
+       0       0       0x8          0            
+
+[24]   2       0       0            0x315154     0x1c9d0       .symtab
+       25      1709    0x4          0x10         
+         */
+
+         if (NEW_SECTION_H (nn).sh_offset >= old_bss_offset
+             || (NEW_SECTION_H (nn).sh_offset + NEW_SECTION_H (nn).sh_size
+                 > new_data2_offset))
            NEW_SECTION_H (nn).sh_offset += new_data2_incr;
 
          /* Any section that was originally placed after the section
@@ -1206,11 +1226,41 @@
       symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
 
       for (; symp < symendp; symp ++)
+       {
        if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
            || strcmp ((char *) (symnames + symp->st_name), "end") == 0
            || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
            || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
          memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
+
+         /* Strictly speaking, #ifdef below is not necessary.  But we
+            keep it to indicate that this kind of change may also be
+            necessary for other unexecs to support GNUstep.  */
+#ifdef NS_IMPL_GNUSTEP
+         /* ObjC runtime modifies the values of some data structures
+            such as classes and selectors in the .data section after
+            loading.  As the dump process copies the .data section
+            from the current process, that causes problems when the
+            modified classes are reinitialized in the dumped
+            executable.  We copy such data from the old file, not
+            from the current process.  */
+         if (strncmp ((char *) (symnames + symp->st_name),
+                      "_OBJC_", sizeof ("_OBJC_") - 1) == 0)
+           {
+             caddr_t old, new;
+
+             new = ((symp->st_value - NEW_SECTION_H (symp->st_shndx).sh_addr)
+                    + NEW_SECTION_H (symp->st_shndx).sh_offset + new_base);
+             /* "Unpatch" index.  */
+             nn = symp->st_shndx;
+             if (nn > old_bss_index)
+               nn--;
+             old = ((symp->st_value - NEW_SECTION_H (symp->st_shndx).sh_addr)
+                    + OLD_SECTION_H (nn).sh_offset + old_base);
+             memcpy (new, old, symp->st_size);
+           }
+#endif
+       }
     }
 
   /* This loop seeks out relocation sections for the data section, so