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Commit: Improve readelf's decoding or ARM unwind tables.
- From: Nick Clifton <nickc at redhat dot com>
- To: binutils at sourceware dot org
- Date: Fri, 02 Dec 2011 17:04:31 +0000
- Subject: Commit: Improve readelf's decoding or ARM unwind tables.
Hi Guys,
Whilst working on PR 13449, I found some problems with readelf's
decoding of ARM unwind tables. So I am applying this patch to make
things better.
Cheers
Nick
binutils/ChangeLog
2011-12-02 Nick Clifton <nickc@redhat.com>
* readelf.c (ia64_process_unwind): Turn into a void funtion.
(hppa_process_unwind): Likewise.
(arm_process_unwind): Likewise.
(process_unwind): Likewise.
(arm_get_section_word): Rename to get_unwind_section_word.
Add sym_name parameter to return the offset into the string table
of the symbol associated with the reloc applied to the word.
(decode_tic6x_unwind_regmask): Add NULL argument to invocation of
get_unwind_section_word.
(dump_arm_unwind): Likewise.
(decode_arm_unwind_bytecode): Prepend a comma when *not* the first
register in a list.
(decode_arm_unwind): If the returned function address is 0 and a
valid symname offset is provided use that to compute the name
associated with the entry.
Add extra checks of the compact model index entry.
Index: binutils/readelf.c
===================================================================
RCS file: /cvs/src/src/binutils/readelf.c,v
retrieving revision 1.562
diff -u -3 -p -r1.562 readelf.c
--- binutils/readelf.c 28 Nov 2011 16:51:09 -0000 1.562
+++ binutils/readelf.c 2 Dec 2011 16:52:50 -0000
@@ -5779,7 +5781,7 @@ slurp_ia64_unwind_table (FILE * file,
return 1;
}
-static int
+static void
ia64_process_unwind (FILE * file)
{
Elf_Internal_Shdr * sec;
@@ -5916,8 +5918,6 @@ ia64_process_unwind (FILE * file)
free (aux.symtab);
if (aux.strtab)
free ((char *) aux.strtab);
-
- return 1;
}
struct hppa_unw_table_entry
@@ -6189,7 +6189,7 @@ slurp_hppa_unwind_table (FILE * file,
return 1;
}
-static int
+static void
hppa_process_unwind (FILE * file)
{
struct hppa_unw_aux_info aux;
@@ -6198,10 +6198,10 @@ hppa_process_unwind (FILE * file)
Elf_Internal_Shdr * sec;
unsigned long i;
- memset (& aux, 0, sizeof (aux));
-
if (string_table == NULL)
- return 1;
+ return;
+
+ memset (& aux, 0, sizeof (aux));
for (i = 0, sec = section_headers; i < elf_header.e_shnum; ++i, ++sec)
{
@@ -6249,8 +6249,6 @@ hppa_process_unwind (FILE * file)
free (aux.symtab);
if (aux.strtab)
free ((char *) aux.strtab);
-
- return 1;
}
struct arm_section
@@ -6315,17 +6313,21 @@ arm_free_section (struct arm_section *ar
cached section and install SEC instead.
2) Locate the 32-bit word at WORD_OFFSET in unwind section SEC
and return its valued in * WORDP, relocating if necessary.
- 3) Update the NEXT_RELA field in ARM_SEC and stores the section index and
+ 3) Update the NEXT_RELA field in ARM_SEC and store the section index and
relocation's offset in ADDR.
- 4) Return TRUE upon success, FALSE otherwise. */
+ 4) If SYM_NAME is non-NULL and a relocation was applied, record the offset
+ into the string table of the symbol associated with the reloc. If no
+ reloc was applied store -1 there.
+ 5) Return TRUE upon success, FALSE otherwise. */
static bfd_boolean
-arm_section_get_word (struct arm_unw_aux_info * aux,
- struct arm_section * arm_sec,
- Elf_Internal_Shdr * sec,
- bfd_vma word_offset,
- unsigned int * wordp,
- struct absaddr * addr)
+get_unwind_section_word (struct arm_unw_aux_info * aux,
+ struct arm_section * arm_sec,
+ Elf_Internal_Shdr * sec,
+ bfd_vma word_offset,
+ unsigned int * wordp,
+ struct absaddr * addr,
+ bfd_vma * sym_name)
{
Elf_Internal_Rela *rp;
Elf_Internal_Sym *sym;
@@ -6336,6 +6338,9 @@ arm_section_get_word (struct arm_unw_aux
addr->section = SHN_UNDEF;
addr->offset = 0;
+ if (sym_name != NULL)
+ *sym_name = (bfd_vma) -1;
+
/* If necessary, update the section cache. */
if (sec != arm_sec->sec)
{
@@ -6465,6 +6470,8 @@ arm_section_get_word (struct arm_unw_aux
word = (word & ~ (bfd_vma) 0x7fffffff) | (prelval & 0x7fffffff);
addr->section = sym->st_shndx;
addr->offset = offset;
+ if (sym_name)
+ * sym_name = sym->st_name;
break;
}
@@ -6501,8 +6508,8 @@ decode_tic6x_unwind_regmask (unsigned in
if (remaining == 0 && more_words) \
{ \
data_offset += 4; \
- if (!arm_section_get_word (aux, data_arm_sec, data_sec, \
- data_offset, &word, &addr)) \
+ if (! get_unwind_section_word (aux, data_arm_sec, data_sec, \
+ data_offset, & word, & addr, NULL)) \
return; \
remaining = 4; \
more_words--; \
@@ -6606,7 +6613,7 @@ decode_arm_unwind_bytecode (struct arm_u
}
if (op & 0x08)
{
- if (first)
+ if (!first)
printf (", ");
printf ("r14");
}
@@ -6883,21 +6890,29 @@ arm_expand_prel31 (bfd_vma word, bfd_vma
}
static void
-decode_arm_unwind (struct arm_unw_aux_info *aux,
- unsigned int word, unsigned int remaining,
- bfd_vma data_offset, Elf_Internal_Shdr *data_sec,
- struct arm_section *data_arm_sec)
+decode_arm_unwind (struct arm_unw_aux_info * aux,
+ unsigned int word,
+ unsigned int remaining,
+ bfd_vma data_offset,
+ Elf_Internal_Shdr * data_sec,
+ struct arm_section * data_arm_sec)
{
int per_index;
unsigned int more_words = 0;
struct absaddr addr;
+ bfd_vma sym_name = (bfd_vma) -1;
if (remaining == 0)
{
- /* Fetch the first word. */
- if (!arm_section_get_word (aux, data_arm_sec, data_sec, data_offset,
- &word, &addr))
+ /* Fetch the first word.
+ Note - when decoding an object file the address extracted
+ here will always be 0. So we also pass in the sym_name
+ parameter so that we can find the symbol associated with
+ the personality routine. */
+ if (! get_unwind_section_word (aux, data_arm_sec, data_sec, data_offset,
+ & word, & addr, & sym_name))
return;
+
remaining = 4;
}
@@ -6909,7 +6924,21 @@ decode_arm_unwind (struct arm_unw_aux_in
fn = arm_expand_prel31 (word, data_sec->sh_addr + data_offset);
printf (_(" Personality routine: "));
- procname = arm_print_vma_and_name (aux, fn, addr);
+ if (fn == 0
+ && addr.section == SHN_UNDEF && addr.offset == 0
+ && sym_name != (bfd_vma) -1 && sym_name < aux->strtab_size)
+ {
+ procname = aux->strtab + sym_name;
+ print_vma (fn, PREFIX_HEX);
+ if (procname)
+ {
+ fputs (" <", stdout);
+ fputs (procname, stdout);
+ fputc ('>', stdout);
+ }
+ }
+ else
+ procname = arm_print_vma_and_name (aux, fn, addr);
fputc ('\n', stdout);
/* The GCC personality routines use the standard compact
@@ -6939,9 +6968,20 @@ decode_arm_unwind (struct arm_unw_aux_in
}
else
{
-
+ /* ARM EHABI Section 6.3:
+
+ An exception-handling table entry for the compact model looks like:
+
+ 31 30-28 27-24 23-0
+ -- ----- ----- ----
+ 1 0 index Data for personalityRoutine[index] */
+
+ if (elf_header.e_machine == EM_ARM
+ && (word & 0x70000000))
+ warn (_("Corrupt ARM compact model table entry (%08x)\n"), word);
+
per_index = (word >> 24) & 0x7f;
- printf (_(" Compact model %d\n"), per_index);
+ printf (_(" Compact model index: %d\n"), per_index);
if (per_index == 0)
{
more_words = 0;
@@ -6965,14 +7005,17 @@ decode_arm_unwind (struct arm_unw_aux_in
data_offset, data_sec, data_arm_sec);
}
else
- printf (" [reserved]\n");
+ {
+ warn (_("Unknown ARM compact model index encountered\n"));
+ printf (_(" [reserved]\n"));
+ }
break;
case EM_TI_C6000:
if (per_index < 3)
{
decode_tic6x_unwind_bytecode (aux, word, remaining, more_words,
- data_offset, data_sec, data_arm_sec);
+ data_offset, data_sec, data_arm_sec);
}
else if (per_index < 5)
{
@@ -6989,11 +7032,12 @@ decode_arm_unwind (struct arm_unw_aux_in
tic6x_unwind_regnames[word & 0xf]);
}
else
- printf (" [reserved]\n");
+ printf (_(" [reserved (%d)]\n"), per_index);
break;
default:
- abort ();
+ error (_("Unsupported architecture type %d encountered when decoding unwind table"),
+ elf_header.e_machine);
}
/* Decode the descriptors. Not implemented. */
@@ -7017,13 +7061,13 @@ dump_arm_unwind (struct arm_unw_aux_info
fputc ('\n', stdout);
- if (!arm_section_get_word (aux, &exidx_arm_sec, exidx_sec,
- 8 * i, &exidx_fn, &fn_addr)
- || !arm_section_get_word (aux, &exidx_arm_sec, exidx_sec,
- 8 * i + 4, &exidx_entry, &entry_addr))
+ if (! get_unwind_section_word (aux, & exidx_arm_sec, exidx_sec,
+ 8 * i, & exidx_fn, & fn_addr, NULL)
+ || ! get_unwind_section_word (aux, & exidx_arm_sec, exidx_sec,
+ 8 * i + 4, & exidx_entry, & entry_addr, NULL))
{
- arm_free_section (&exidx_arm_sec);
- arm_free_section (&extab_arm_sec);
+ arm_free_section (& exidx_arm_sec);
+ arm_free_section (& extab_arm_sec);
return;
}
@@ -7084,7 +7128,8 @@ dump_arm_unwind (struct arm_unw_aux_info
}
/* Used for both ARM and C6X unwinding tables. */
-static int
+
+static void
arm_process_unwind (FILE *file)
{
struct arm_unw_aux_info aux;
@@ -7094,9 +7139,6 @@ arm_process_unwind (FILE *file)
unsigned long i;
unsigned int sec_type;
- memset (& aux, 0, sizeof (aux));
- aux.file = file;
-
switch (elf_header.e_machine)
{
case EM_ARM:
@@ -7107,12 +7149,17 @@ arm_process_unwind (FILE *file)
sec_type = SHT_C6000_UNWIND;
break;
- default:
- abort();
+ default:
+ error (_("Unsupported architecture type %d encountered when processing unwind table"),
+ elf_header.e_machine);
+ return;
}
if (string_table == NULL)
- return 1;
+ return;
+
+ memset (& aux, 0, sizeof (aux));
+ aux.file = file;
for (i = 0, sec = section_headers; i < elf_header.e_shnum; ++i, ++sec)
{
@@ -7130,37 +7177,35 @@ arm_process_unwind (FILE *file)
unwsec = sec;
}
- if (!unwsec)
+ if (unwsec == NULL)
printf (_("\nThere are no unwind sections in this file.\n"));
+ else
+ for (i = 0, sec = section_headers; i < elf_header.e_shnum; ++i, ++sec)
+ {
+ if (sec->sh_type == sec_type)
+ {
+ printf (_("\nUnwind table index '%s' at offset 0x%lx contains %lu entries:\n"),
+ SECTION_NAME (sec),
+ (unsigned long) sec->sh_offset,
+ (unsigned long) (sec->sh_size / (2 * eh_addr_size)));
- for (i = 0, sec = section_headers; i < elf_header.e_shnum; ++i, ++sec)
- {
- if (sec->sh_type == sec_type)
- {
- printf (_("\nUnwind table index '%s' at offset 0x%lx contains %lu entries:\n"),
- SECTION_NAME (sec),
- (unsigned long) sec->sh_offset,
- (unsigned long) (sec->sh_size / (2 * eh_addr_size)));
-
- dump_arm_unwind (&aux, sec);
- }
- }
+ dump_arm_unwind (&aux, sec);
+ }
+ }
if (aux.symtab)
free (aux.symtab);
if (aux.strtab)
free ((char *) aux.strtab);
-
- return 1;
}
-static int
+static void
process_unwind (FILE * file)
{
struct unwind_handler
{
int machtype;
- int (* handler)(FILE *);
+ void (* handler)(FILE *);
} handlers[] =
{
{ EM_ARM, arm_process_unwind },
@@ -7172,14 +7217,14 @@ process_unwind (FILE * file)
int i;
if (!do_unwind)
- return 1;
+ return;
for (i = 0; handlers[i].handler != NULL; i++)
if (elf_header.e_machine == handlers[i].machtype)
return handlers[i].handler (file);
- printf (_("\nThere are no unwind sections in this file.\n"));
- return 1;
+ printf (_("\nThe decoding of unwind sections for machine type %s is not currently supported.\n"),
+ get_machine_name (elf_header.e_machine));
}
static void