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Re: PATCH: PR binutils/12639: nm/readelf failed to detect corrupted symtab
On Wed, Apr 6, 2011 at 7:43 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Tue, Apr 5, 2011 at 11:58 PM, Alan Modra <amodra@gmail.com> wrote:
>> On Tue, Apr 05, 2011 at 11:02:06PM -0700, H.J. Lu wrote:
>>> d) nm/readelf reports error on those bad input files.
>>>
>>> That is what my patch implements.
>>
>> Not exactly. ?Your elfcode.h:elf_slurp_symbol_table patch issues a
>> message but doesn't return an error. ?I think you ought to call
>> bfd_set_error and exit the function via error_return.
>
> Then we got
>
> [hjl@gnu-6 cq167859]$ make
> ./ld -o bad tr70098.bad.o start.o
> start.o: In function `_start':
> (.text+0x1): undefined reference to `main'
> make: *** [bad] Error 1
> [hjl@gnu-6 cq167859]$ ./nm tr70098.bad.o
> BFD: tr70098.bad.o: corrupted local symbol `main'
> ./nm: tr70098.bad.o: No symbols
> [hjl@gnu-6 cq167859]$
>
> "nm" won't display any symbols. I don't think it is very helpful.
>
>> On the readelf patch, I'd be inclined to report "Bad symtab" at the
>> end of the symbol table and not special case mips.
>>
>
> readelf displays many "<corrupt>" without something like
> "Bad XXXX" at the end. ?I don't think symtab is that special.
>
Here is the updated patch without special case for MIPS.
OK to install?
Thanks.
--
H.J.
---
bfd/
2011-04-06 H.J. Lu <hongjiu.lu@intel.com>
PR binutils/12639
* elfcode.h (elf_slurp_symbol_table): Check valid local symbols.
binutils/
2011-04-06 H.J. Lu <hongjiu.lu@intel.com>
PR binutils/12639
* readelf.c (process_symbol_table): Detect corrupted symtab.
diff --git a/bfd/elfcode.h b/bfd/elfcode.h
index 28b6b90..c56b4f1 100644
--- a/bfd/elfcode.h
+++ b/bfd/elfcode.h
@@ -1218,6 +1218,9 @@ elf_slurp_symbol_table (bfd *abfd, asymbol
**symptrs, bfd_boolean dynamic)
sym = symbase = NULL;
else
{
+ /* Start of global symbols */
+ Elf_Internal_Sym *start_global;
+
isymbuf = bfd_elf_get_elf_syms (abfd, hdr, symcount, 0,
NULL, NULL, NULL);
if (isymbuf == NULL)
@@ -1262,6 +1265,9 @@ elf_slurp_symbol_table (bfd *abfd, asymbol
**symptrs, bfd_boolean dynamic)
if (xver != NULL)
++xver;
isymend = isymbuf + symcount;
+ start_global = isymbuf;
+ if (!elf_bad_symtab (abfd))
+ start_global += hdr->sh_info;
for (isym = isymbuf + 1, sym = symbase; isym < isymend; isym++, sym++)
{
memcpy (&sym->internal_elf_sym, isym, sizeof (Elf_Internal_Sym));
@@ -1306,6 +1312,18 @@ elf_slurp_symbol_table (bfd *abfd, asymbol
**symptrs, bfd_boolean dynamic)
if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
sym->symbol.value -= sym->symbol.section->vma;
+ if (isym < start_global
+ && ELF_ST_BIND (isym->st_info) != STB_LOCAL)
+ {
+ (*_bfd_error_handler)
+ (_("%s: corrupted local symbol `%s'"),
+ abfd->filename, sym->symbol.name);
+
+ /* Force it to local symbol. */
+ isym->st_info = ELF_ST_INFO (STB_LOCAL,
+ ELF_ST_TYPE (isym->st_info));
+ }
+
switch (ELF_ST_BIND (isym->st_info))
{
case STB_LOCAL:
diff --git a/binutils/readelf.c b/binutils/readelf.c
index f8c6bb3..ebeddb7 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -8825,7 +8825,7 @@ process_symbol_table (FILE * file)
i < elf_header.e_shnum;
i++, section++)
{
- unsigned int si;
+ unsigned int si, start_global;
char * strtab = NULL;
unsigned long int strtab_size = 0;
Elf_Internal_Sym * symtab;
@@ -8857,6 +8857,7 @@ process_symbol_table (FILE * file)
if (symtab == NULL)
continue;
+ start_global = section->sh_info;
if (section->sh_link == elf_header.e_shstrndx)
{
strtab = string_table;
@@ -8883,7 +8884,11 @@ process_symbol_table (FILE * file)
putchar (' ');
print_vma (psym->st_size, DEC_5);
printf (" %-7s", get_symbol_type (ELF_ST_TYPE (psym->st_info)));
- printf (" %-6s", get_symbol_binding (ELF_ST_BIND (psym->st_info)));
+ if (si < start_global
+ && ELF_ST_BIND (psym->st_info) != STB_LOCAL)
+ printf (" %-6s", "<corrupt>");
+ else
+ printf (" %-6s", get_symbol_binding (ELF_ST_BIND (psym->st_info)));
printf (" %-7s", get_symbol_visibility (ELF_ST_VISIBILITY
(psym->st_other)));
/* Check to see if any other bits in the st_other field are set.
Note - displaying this information disrupts the layout of the