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Re: _bfd_dwarf2_find_nearest_line returns wrong filename
- From: Daniel Jacobowitz <drow at mvista dot com>
- To: binutils at sources dot redhat dot com
- Date: Tue, 4 Feb 2003 10:37:05 -0500
- Subject: Re: _bfd_dwarf2_find_nearest_line returns wrong filename
- References: <m3smwoe46q.fsf@whitebox.local> <m3lm27rbpl.fsf@north-pole.nickc.cambridge.redhat.com> <m3r8bzp0s8.fsf@whitebox.local> <20021230231439.GA16750@nevyn.them.org> <20021230231641.GA16906@nevyn.them.org> <m3isx8aehk.fsf@whitebox.local> <20030103060814.GA10818@nevyn.them.org> <jey96270wj.fsf@sykes.suse.de> <20030116210239.GA30751@nevyn.them.org> <jed6mtcbx6.fsf@sykes.suse.de>
On Sun, Jan 19, 2003 at 06:00:21PM +0100, Andreas Schwab wrote:
> Daniel Jacobowitz <drow@mvista.com> writes:
>
> |> On Fri, Jan 03, 2003 at 03:39:40PM +0100, Andreas Schwab wrote:
> |> > Daniel Jacobowitz <drow@mvista.com> writes:
> |> >
> |> > |> No regressions, but some pertinent facts:
> |> > |>
> |> > |> - Examine the ld.log with this patch applied. Grep for BFD. You'll
> |> > |> find several assertion failures indicating that the DWARF-2 data
> |> > |> is incorrect. It's kind of sad that the testsuite doesn't notice any
> |> > |> of these.
> |> >
> |> > I have now tried it on ia64, and it is getting worse. They are using
> |> > R_IA64_SECREL32LS relocations in .debug_info, which is causing
> |> > bfd_perform_relocation to return bfd_reloc_outofrange, and
> |> > bfd_generic_get_relocated_section_contents is aborting on that.
> |>
> |> We needed to save and restore outputs in order to get the right answers
> |> on i386 in some cases. We also needed some other fixes to ia64 - I
> |> missed it when I swept the hash table create functions to make them use
> |> bfd_malloc, I guess - and to weaken an abort in elfNN_ia64_reloc. But
> |> now it works.
>
> This does not seem to work in the linker, it doesn't emit any filename
> prefixes any more. This also causes testsuite failures, the ld-elfvsb
> tests depend on the filename part of the error messages.
I had the right idea, but I wasn't thorough enough implementing it. In
addition to dummying the output offsets, we also have to dummy the
output sections. Otherwise .debug_info thinks that a function starts
up past 0x08400000, and the rest of the linker thinks that it starts at
0x18.
Andreas, thanks for your continued patience. Would you mind testing
this version?
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
2003-02-04 Andreas Schwab <schwab@suse.de>
Daniel Jacobowitz <drow@mvista.com>
* simple.c (bfd_simple_get_relocated_section_contents): Add
parameter symbol_table. Optionally use it instead of the symbol
table from the bfd. Save and restore output offsets and output
sections around bfd_get_relocated_section_contents. Fix a memory
leak.
(simple_save_output_info, simple_restore_output_info): New
functions.
* bfd-in2.h: Regenerate.
* dwarf2.c (read_abbrevs): Use
bfd_simple_get_relocated_section_contents instead of
bfd_get_section_contents.
(decode_line_info): Likewise.
(_bfd_dwarf2_find_nearest_line): Likewise. Don't call
find_rela_addend.
(find_rela_addend): Remove.
* elfxx-ia64.c (elfNN_ia64_reloc): Weaken sanity check for
debugging sections.
(elfNN_ia64_hash_table_create): Create the hash table with malloc,
not bfd_zalloc.
Index: bfd/dwarf2.c
===================================================================
RCS file: /big/fsf/rsync/src-cvs/src/bfd/dwarf2.c,v
retrieving revision 1.42
diff -u -p -r1.42 dwarf2.c
--- bfd/dwarf2.c 12 Dec 2002 10:26:01 -0000 1.42
+++ bfd/dwarf2.c 16 Jan 2003 20:52:45 -0000
@@ -245,8 +245,6 @@ static bfd_boolean lookup_address_in_lin
static bfd_boolean lookup_address_in_function_table
PARAMS ((struct funcinfo *, bfd_vma, struct funcinfo **, const char **));
static bfd_boolean scan_unit_for_functions PARAMS ((struct comp_unit *));
-static bfd_vma find_rela_addend
- PARAMS ((bfd *, asection *, bfd_size_type, asymbol**));
static struct comp_unit *parse_comp_unit
PARAMS ((bfd *, struct dwarf2_debug *, bfd_vma, unsigned int));
static bfd_boolean comp_unit_contains_address
@@ -546,13 +544,11 @@ read_abbrevs (abfd, offset, stash)
}
stash->dwarf_abbrev_size = msec->_raw_size;
- stash->dwarf_abbrev_buffer = (char*) bfd_alloc (abfd, msec->_raw_size);
+ stash->dwarf_abbrev_buffer
+ = bfd_simple_get_relocated_section_contents (abfd, msec, NULL,
+ stash->syms);
if (! stash->dwarf_abbrev_buffer)
return 0;
-
- if (! bfd_get_section_contents (abfd, msec, stash->dwarf_abbrev_buffer,
- (bfd_vma) 0, msec->_raw_size))
- return 0;
}
if (offset >= stash->dwarf_abbrev_size)
@@ -1019,21 +1015,15 @@ decode_line_info (unit, stash)
}
stash->dwarf_line_size = msec->_raw_size;
- stash->dwarf_line_buffer = (char *) bfd_alloc (abfd, msec->_raw_size);
+ stash->dwarf_line_buffer
+ = bfd_simple_get_relocated_section_contents (abfd, msec, NULL,
+ stash->syms);
if (! stash->dwarf_line_buffer)
return 0;
-
- if (! bfd_get_section_contents (abfd, msec, stash->dwarf_line_buffer,
- (bfd_vma) 0, msec->_raw_size))
- return 0;
-
- /* FIXME: We ought to apply the relocs against this section before
- we process it... */
}
- /* Since we are using un-relocated data, it is possible to get a bad value
- for the line_offset. Validate it here so that we won't get a segfault
- below. */
+ /* It is possible to get a bad value for the line_offset. Validate
+ it here so that we won't get a segfault below. */
if (unit->line_offset >= stash->dwarf_line_size)
{
(*_bfd_error_handler) (_("Dwarf Error: Line offset (%lu) greater than or equal to .debug_line size (%lu)."),
@@ -1521,60 +1511,6 @@ scan_unit_for_functions (unit)
return TRUE;
}
-/* Look for a RELA relocation to be applied on OFFSET of section SEC,
- and return the addend if such a relocation is found. Since this is
- only used to find relocations referring to the .debug_abbrev
- section, we make sure the relocation refers to this section, but
- this is not strictly necessary, and it can probably be safely
- removed if needed. However, it is important to note that this
- function only returns the addend, it doesn't serve the purpose of
- applying a generic relocation.
-
- If no suitable relocation is found, or if it is not a real RELA
- relocation, this function returns 0. */
-
-static bfd_vma
-find_rela_addend (abfd, sec, offset, syms)
- bfd* abfd;
- asection* sec;
- bfd_size_type offset;
- asymbol** syms;
-{
- long reloc_size = bfd_get_reloc_upper_bound (abfd, sec);
- arelent **relocs = NULL;
- long reloc_count, relc;
-
- if (reloc_size <= 0)
- return 0;
-
- relocs = (arelent **) bfd_malloc ((bfd_size_type) reloc_size);
- if (relocs == NULL)
- return 0;
-
- reloc_count = bfd_canonicalize_reloc (abfd, sec, relocs, syms);
-
- if (reloc_count <= 0)
- {
- free (relocs);
- return 0;
- }
-
- for (relc = 0; relc < reloc_count; relc++)
- if (relocs[relc]->address == offset
- && (*relocs[relc]->sym_ptr_ptr)->flags & BSF_SECTION_SYM
- && strcmp ((*relocs[relc]->sym_ptr_ptr)->name,
- ".debug_abbrev") == 0)
- {
- bfd_vma addend = (relocs[relc]->howto->partial_inplace
- ? 0 : relocs[relc]->addend);
- free (relocs);
- return addend;
- }
-
- free (relocs);
- return 0;
-}
-
/* Parse a DWARF2 compilation unit starting at INFO_PTR. This
includes the compilation unit header that proceeds the DIE's, but
does not include the length field that preceeds each compilation
@@ -1602,7 +1538,6 @@ parse_comp_unit (abfd, stash, unit_lengt
char *info_ptr = stash->info_ptr;
char *end_ptr = info_ptr + unit_length;
bfd_size_type amt;
- bfd_size_type off;
version = read_2_bytes (abfd, info_ptr);
info_ptr += 2;
@@ -1611,12 +1546,6 @@ parse_comp_unit (abfd, stash, unit_lengt
abbrev_offset = read_4_bytes (abfd, info_ptr);
else
abbrev_offset = read_8_bytes (abfd, info_ptr);
- /* The abbrev offset is generally a relocation pointing to
- .debug_abbrev+offset. On RELA targets, we have to find the
- relocation and extract the addend to obtain the actual
- abbrev_offset, so do it here. */
- off = info_ptr - stash->sec_info_ptr;
- abbrev_offset += find_rela_addend (abfd, stash->sec, off, stash->syms);
info_ptr += offset_size;
addr_size = read_1_byte (abfd, info_ptr);
info_ptr += 1;
@@ -1939,8 +1868,8 @@ _bfd_dwarf2_find_nearest_line (abfd, sec
start = stash->info_ptr_end - stash->info_ptr;
- if (! bfd_get_section_contents (abfd, msec, stash->info_ptr + start,
- (bfd_vma) 0, size))
+ if ((bfd_simple_get_relocated_section_contents
+ (abfd, msec, stash->info_ptr + start, symbols)) == NULL)
continue;
stash->info_ptr_end = stash->info_ptr + start + size;
@@ -1953,21 +1882,6 @@ _bfd_dwarf2_find_nearest_line (abfd, sec
stash->syms = symbols;
}
- /* FIXME: There is a problem with the contents of the
- .debug_info section. The 'low' and 'high' addresses of the
- comp_units are computed by relocs against symbols in the
- .text segment. We need these addresses in order to determine
- the nearest line number, and so we have to resolve the
- relocs. There is a similar problem when the .debug_line
- section is processed as well (e.g., there may be relocs
- against the operand of the DW_LNE_set_address operator).
-
- Unfortunately getting hold of the reloc information is hard...
-
- For now, this means that disassembling object files (as
- opposed to fully executables) does not always work as well as
- we would like. */
-
/* A null info_ptr indicates that there is no dwarf2 info
(or that an error occured while setting up the stash). */
if (! stash->info_ptr)
@@ -2034,10 +1948,10 @@ _bfd_dwarf2_find_nearest_line (abfd, sec
{
if (comp_unit_contains_address (each, addr))
return comp_unit_find_nearest_line (each, addr,
- filename_ptr,
- functionname_ptr,
- linenumber_ptr,
- stash);
+ filename_ptr,
+ functionname_ptr,
+ linenumber_ptr,
+ stash);
}
else
{
Index: bfd/elfxx-ia64.c
===================================================================
RCS file: /big/fsf/rsync/src-cvs/src/bfd/elfxx-ia64.c,v
retrieving revision 1.66
diff -u -p -r1.66 elfxx-ia64.c
--- bfd/elfxx-ia64.c 17 Jan 2003 23:27:55 -0000 1.66
+++ bfd/elfxx-ia64.c 4 Feb 2003 15:31:06 -0000
@@ -346,6 +346,10 @@ elfNN_ia64_reloc (abfd, reloc, sym, data
reloc->address += input_section->output_offset;
return bfd_reloc_ok;
}
+
+ if (input_section->flags & SEC_DEBUGGING)
+ return bfd_reloc_continue;
+
*error_message = "Unsupported call to elfNN_ia64_reloc";
return bfd_reloc_notsupported;
}
@@ -1701,19 +1705,25 @@ elfNN_ia64_hash_table_create (abfd)
{
struct elfNN_ia64_link_hash_table *ret;
- ret = bfd_zalloc (abfd, (bfd_size_type) sizeof (*ret));
+ ret = bfd_malloc ((bfd_size_type) sizeof (*ret));
if (!ret)
return 0;
+ memset (ret, 0, sizeof (*ret));
+
if (!_bfd_elf_link_hash_table_init (&ret->root, abfd,
elfNN_ia64_new_elf_hash_entry))
{
- bfd_release (abfd, ret);
+ free (ret);
return 0;
}
if (!elfNN_ia64_local_hash_table_init (&ret->loc_hash_table, abfd,
elfNN_ia64_new_loc_hash_entry))
- return 0;
+ {
+ free (ret);
+ return 0;
+ }
+
return &ret->root.root;
}
Index: bfd/simple.c
===================================================================
RCS file: /big/fsf/rsync/src-cvs/src/bfd/simple.c,v
retrieving revision 1.5
diff -u -p -r1.5 simple.c
--- bfd/simple.c 30 Nov 2002 08:39:40 -0000 1.5
+++ bfd/simple.c 4 Feb 2003 15:28:20 -0000
@@ -42,8 +42,14 @@ static bfd_boolean simple_dummy_reloc_da
static bfd_boolean simple_dummy_unattached_reloc
PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma));
+static void simple_save_output_info
+ PARAMS ((bfd *, asection *, PTR));
+
+static void simple_restore_output_info
+ PARAMS ((bfd *, asection *, PTR));
+
bfd_byte * bfd_simple_get_relocated_section_contents
- PARAMS ((bfd *, asection *, bfd_byte *));
+ PARAMS ((bfd *, asection *, bfd_byte *, asymbol **));
static bfd_boolean
simple_dummy_warning (link_info, warning, symbol, abfd, section, address)
@@ -105,17 +111,48 @@ simple_dummy_unattached_reloc (link_info
return TRUE;
}
+struct saved_output_info
+{
+ bfd_vma offset;
+ asection *section;
+};
+
+static void
+simple_save_output_info (abfd, section, ptr)
+ bfd *abfd ATTRIBUTE_UNUSED;
+ asection *section;
+ PTR ptr;
+{
+ struct saved_output_info *output_info = (struct saved_output_info *) ptr;
+ output_info[section->index].offset = section->output_offset;
+ output_info[section->index].section = section->output_section;
+ section->output_offset = 0;
+ section->output_section = section;
+}
+
+static void
+simple_restore_output_info (abfd, section, ptr)
+ bfd *abfd ATTRIBUTE_UNUSED;
+ asection *section;
+ PTR ptr;
+{
+ struct saved_output_info *output_info = (struct saved_output_info *) ptr;
+ section->output_offset = output_info[section->index].offset;
+ section->output_section = output_info[section->index].section;
+}
+
/*
FUNCTION
bfd_simple_relocate_secton
SYNOPSIS
- bfd_byte *bfd_simple_get_relocated_section_contents (bfd *abfd, asection *sec, bfd_byte *outbuf);
+ bfd_byte *bfd_simple_get_relocated_section_contents (bfd *abfd, asection *sec, bfd_byte *outbuf, asymbol **symbol_table);
DESCRIPTION
- Returns the relocated contents of section @var{sec}. Only symbols
- from @var{abfd} and the output offsets assigned to sections in
- @var{abfd} are used. The result will be stored at @var{outbuf}
+ Returns the relocated contents of section @var{sec}. The symbols in
+ @var{symbol_table} will be used, or the symbols from @var{abfd} if
+ @var{symbol_table} is NULL. The output offsets for all sections will
+ be temporarily reset to 0. The result will be stored at @var{outbuf}
or allocated with @code{bfd_malloc} if @var{outbuf} is @code{NULL}.
Generally all sections in @var{abfd} should have their
@@ -126,17 +163,18 @@ DESCRIPTION
*/
bfd_byte *
-bfd_simple_get_relocated_section_contents (abfd, sec, outbuf)
+bfd_simple_get_relocated_section_contents (abfd, sec, outbuf, symbol_table)
bfd *abfd;
asection *sec;
bfd_byte *outbuf;
+ asymbol **symbol_table;
{
struct bfd_link_info link_info;
struct bfd_link_order link_order;
struct bfd_link_callbacks callbacks;
bfd_byte *contents, *data;
int storage_needed, number_of_symbols;
- asymbol **symbol_table;
+ PTR saved_offsets;
if (! (sec->flags & SEC_RELOC))
{
@@ -183,11 +221,36 @@ bfd_simple_get_relocated_section_content
return NULL;
outbuf = data;
}
- bfd_link_add_symbols (abfd, &link_info);
- storage_needed = bfd_get_symtab_upper_bound (abfd);
- symbol_table = (asymbol **) bfd_malloc (storage_needed);
- number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
+ /* The sections in ABFD may already have output sections and offsets set.
+ Because this function is primarily for debug sections, and GCC uses the
+ knowledge that debug sections will generally have VMA 0 when emiting
+ relocations between DWARF-2 sections (which are supposed to be
+ section-relative offsets anyway), we need to reset the output offsets
+ to zero. We also need to arrange for section->output_section->vma plus
+ section->output_offset to equal section->vma, which we do by setting
+ section->output_section to point back to section. Save the original
+ output offset and output section to restore later. */
+ saved_offsets = malloc (sizeof (struct saved_output_info)
+ * abfd->section_count);
+ if (saved_offsets == NULL)
+ {
+ if (data)
+ free (data);
+ return NULL;
+ }
+ bfd_map_over_sections (abfd, simple_save_output_info, saved_offsets);
+
+ if (symbol_table == NULL)
+ {
+ bfd_link_add_symbols (abfd, &link_info);
+
+ storage_needed = bfd_get_symtab_upper_bound (abfd);
+ symbol_table = (asymbol **) bfd_malloc (storage_needed);
+ number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
+ }
+ else
+ storage_needed = 0;
contents = bfd_get_relocated_section_contents (abfd,
&link_info,
@@ -197,6 +260,12 @@ bfd_simple_get_relocated_section_content
symbol_table);
if (contents == NULL && data != NULL)
free (data);
+
+ if (storage_needed != 0)
+ free (symbol_table);
+
+ bfd_map_over_sections (abfd, simple_restore_output_info, saved_offsets);
+ free (saved_offsets);
/* Foul hack to prevent bfd_section_size aborts. This flag only controls
that macro (and the related size macros), selecting between _raw_size