summaryrefslogtreecommitdiff
path: root/src/unexalpha.c
diff options
context:
space:
mode:
authorRichard M. Stallman <rms@gnu.org>1996-08-21 20:18:00 +0000
committerRichard M. Stallman <rms@gnu.org>1996-08-21 20:18:00 +0000
commitd7b43eaa00c71f48a19134bf89751820f1ccf17b (patch)
tree900c40c728c9d75078025f924f0ffb196b978174 /src/unexalpha.c
parent18aa68c389251d4a2b9cafa5b49a4cfe41fae480 (diff)
downloademacs-d7b43eaa00c71f48a19134bf89751820f1ccf17b.tar.gz
Conditionalize the changes below on not __linux__.
Include reloc.h and elf_abi.h. (rel_dyn_section, dynstr_section, dynsym_section): New variables. (old_data_scnhdr): New variable. (CHECK_SCNHDR): Compare just 8 chars of section name. (unexec): Check for rel_dyn_section, dynsym_section, dynstr_section. Do call update_dynamic_symbols. (update_dynamic_symbols): Finish it up and take away #if 0.
Diffstat (limited to 'src/unexalpha.c')
-rw-r--r--src/unexalpha.c151
1 files changed, 91 insertions, 60 deletions
diff --git a/src/unexalpha.c b/src/unexalpha.c
index 48b4059fcaf..2adfd1fa57e 100644
--- a/src/unexalpha.c
+++ b/src/unexalpha.c
@@ -31,6 +31,10 @@ Boston, MA 02111-1307, USA. */
#include <aouthdr.h>
#include <scnhdr.h>
#include <syms.h>
+#ifndef __linux__
+# include <reloc.h>
+# include <elf_abi.h>
+#endif
static void fatal_unexec ();
static void mark_x ();
@@ -52,11 +56,14 @@ static void mark_x ();
extern int errno;
extern char *strerror ();
-void *sbrk();
+void *sbrk ();
#define EEOF -1
static struct scnhdr *text_section;
+static struct scnhdr *rel_dyn_section;
+static struct scnhdr *dynstr_section;
+static struct scnhdr *dynsym_section;
static struct scnhdr *init_section;
static struct scnhdr *finit_section;
static struct scnhdr *rdata_section;
@@ -71,6 +78,8 @@ static struct scnhdr *sdata_section;
static struct scnhdr *sbss_section;
static struct scnhdr *bss_section;
+static struct scnhdr old_data_scnhdr;
+
static unsigned long Brk;
struct headers {
@@ -157,7 +166,7 @@ unexec (new_name, a_name, data_start, bss_start, entry_address)
#define CHECK_SCNHDR(ptr, name, flags) \
ptr = NULL; \
for (i = 0; i < nhdr.fhdr.f_nscns && !ptr; i++) \
- if (strcmp (nhdr.section[i].s_name, name) == 0) \
+ if (strncmp (nhdr.section[i].s_name, name, 8) == 0) \
{ \
if (nhdr.section[i].s_flags != flags) \
fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \
@@ -167,6 +176,15 @@ unexec (new_name, a_name, data_start, bss_start, entry_address)
CHECK_SCNHDR (text_section, _TEXT, STYP_TEXT);
CHECK_SCNHDR (init_section, _INIT, STYP_INIT);
+#ifdef _REL_DYN
+ CHECK_SCNHDR (rel_dyn_section, _REL_DYN, STYP_REL_DYN);
+#endif /* _REL_DYN */
+#ifdef _DYNSYM
+ CHECK_SCNHDR (dynsym_section, _DYNSYM, STYP_DYNSYM);
+#endif /* _REL_DYN */
+#ifdef _DYNSTR
+ CHECK_SCNHDR (dynstr_section, _DYNSTR, STYP_DYNSTR);
+#endif /* _REL_DYN */
#ifdef _FINI
CHECK_SCNHDR (finit_section, _FINI, STYP_FINI);
#endif /* _FINI */
@@ -200,6 +218,8 @@ unexec (new_name, a_name, data_start, bss_start, entry_address)
Brk = brk;
+ bcopy (data_section, &old_data_scnhdr, sizeof (old_data_scnhdr));
+
nhdr.aout.dsize = brk - DATA_START;
nhdr.aout.bsize = 0;
if (entry_address == 0)
@@ -341,15 +361,8 @@ unexec (new_name, a_name, data_start, bss_start, entry_address)
stat.st_size - ohdr.fhdr.f_symptr - cbHDRR,
"writing symbol table of %s", new_name);
-#if 0
-
-/* Not needed for now */
-
- update_dynamic_symbols (oldptr, new_name, new, newsyms,
- ((pHDRR) (oldptr + ohdr.fhdr.f_symptr))->issExtMax,
- ((pHDRR) (oldptr + ohdr.fhdr.f_symptr))->cbExtOffset,
- ((pHDRR) (oldptr + ohdr.fhdr.f_symptr))->cbSsExtOffset);
-
+#ifndef __linux__
+ update_dynamic_symbols (oldptr, new_name, new, nhdr.aout);
#endif
#undef symhdr
@@ -364,69 +377,87 @@ unexec (new_name, a_name, data_start, bss_start, entry_address)
}
-#if 0
-
-/* Not needed for now */
-
-/* The following function updates the values of some symbols
- that are used by the dynamic loader:
-
- _edata
- _end
-*/
+#ifndef __linux__
-update_dynamic_symbols (old, new_name, new, newsyms, nsyms, symoff, stroff)
+update_dynamic_symbols (old, new_name, new, aout)
char *old; /* Pointer to old executable */
char *new_name; /* Name of new executable */
int new; /* File descriptor for new executable */
- long newsyms; /* Offset of Symbol table in new executable */
- int nsyms; /* Number of symbol table entries */
- long symoff; /* Offset of External Symbols in old file */
- long stroff; /* Offset of string table in old file */
+ struct aouthdr aout; /* a.out info from the file header */
{
- long i;
- int found = 0;
- EXTR n_end, n_edata;
+ typedef struct dynrel_info {
+ char * addr;
+ unsigned type:8;
+ unsigned index:24;
+ unsigned info:8;
+ unsigned pad:8;
+ } dr_info;
+
+ int nsyms = rel_dyn_section->s_size / sizeof (struct dynrel_info);
+ int i;
+ dr_info * rd_base = (dr_info *) (old + rel_dyn_section->s_scnptr);
+ Elf32_Sym * ds_base = (Elf32_Sym *) (old + dynsym_section->s_scnptr);
- /* We go through the symbol table entries until we have found the two
- symbols. */
+ for (i = 0; i < nsyms; i++) {
+ register Elf32_Sym x;
- /* cbEXTR is the size of an external symbol table entry */
+ if (rd_base[i].index == 0)
+ continue;
- for (i = 0; i < nsyms && found < 2; i += cbEXTR)
- {
- register pEXTR x = (pEXTR) (old + symoff + i);
- char *s;
-
- s = old + stroff + x->asym.iss; /* name of the symbol */
-
- if (!strcmp(s,"_edata"))
- {
- found++;
- bcopy (x, &n_edata, cbEXTR);
- n_edata.asym.value = Brk;
- SEEK (new, newsyms + cbHDRR + i,
- "seeking to symbol _edata in %s", new_name);
- WRITE (new, &n_edata, cbEXTR,
- "writing symbol table entry for _edata into %s", new_name);
- }
- else if (!strcmp(s,"_end"))
- {
- found++;
- bcopy (x, &n_end, cbEXTR);
- n_end.asym.value = Brk;
- SEEK (new, newsyms + cbHDRR + i,
- "seeking to symbol _end in %s", new_name);
- WRITE (new, &n_end, cbEXTR,
- "writing symbol table entry for _end into %s", new_name);
- }
+ x = ds_base[rd_base[i].index];
+
+#if 0
+ fprintf (stderr, "Object inspected: %s, addr = %lx, shndx = %x",
+ old + dynstr_section->s_scnptr + x.st_name, rd_base[i].addr, x.st_shndx);
+#endif
+
+
+ if ((ELF32_ST_BIND (x.st_info) == STB_GLOBAL)
+ && (x.st_shndx == 0)
+ /* && (x.st_value == NULL) */
+ ) {
+ /* OK, this is probably a reference to an object in a shared
+ library, so copy the old value. This is done in several steps:
+ 1. reladdr is the address of the location in question relative to
+ the start of the data section,
+ 2. oldref is the addr is the mapped in temacs executable,
+ 3. newref is the address of the location in question in the
+ undumped executable,
+ 4. len is the size of the object reference in bytes --
+ currently only 4 (long) and 8 (quad) are supported.
+ */
+ register unsigned long reladdr = rd_base[i].addr - old_data_scnhdr.s_vaddr;
+ char * oldref = old + old_data_scnhdr.s_scnptr + reladdr;
+ unsigned long newref = aout.tsize + reladdr;
+ int len;
+
+#if 0
+ fprintf (stderr, "...relocated\n");
+#endif
+
+ if (rd_base[i].type == R_REFLONG)
+ len = 4;
+ else if (rd_base[i].type == R_REFQUAD)
+ len = 8;
+ else
+ fatal_unexec ("unrecognized relocation type in .dyn.rel section (symbol #%d)", i);
+
+ SEEK (new, newref, "seeking to dynamic symbol in %s", new_name);
+ WRITE (new, oldref, len, "writing old dynrel info in %s", new_name);
}
+#if 0
+ else
+ fprintf (stderr, "...not relocated\n");
+#endif
+
+ }
+
}
-#endif
+#endif /* !__linux__ */
/*