PATCH bfd: Fix linker warning for recently introduced arm attributes

PATCH bfd: Fix linker warning for recently introduced arm attributes

[Andrea Corallo]

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Hi all,

this simple patch updates the value of 'NUM_KNOWN_OBJ_ATTRIBUTES' so
that when linking objects with 'Tag_BTI_use' or 'Tag_PACRET_use' set ld
does not emit the "unknown EABI object attribute" warning.

Regtested clean, okay for trunk?

Best Regards

  Andrea


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From 39c0c12b13fdeb07695def0af19e8ed760bd882b Mon Sep 17 00:00:00 2001
From: Andrea Corallo <andrea.corallo@arm.com>
Date: Mon, 27 Sep 2021 16:04:31 +0200
Subject: [PATCH] PATCH bfd: Fix linker warning for recently introduced arm
 attributes

2021-09-27  Andrea Corallo  <andrea.corallo@arm.com>

	* elf-bfd.h (NUM_KNOWN_OBJ_ATTRIBUTES): Update value to cover
	'Tag_BTI_use' and 'Tag_PACRET_use'.
---
 bfd/elf-bfd.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index c247d52c615..c7dedf522da 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -1814,7 +1814,7 @@ struct bfd_elf_section_data
 #define LEAST_KNOWN_OBJ_ATTRIBUTE 2
 
 /* The maximum number of known object attributes for any target.  */
-#define NUM_KNOWN_OBJ_ATTRIBUTES 71
+#define NUM_KNOWN_OBJ_ATTRIBUTES 77
 
 /* The value of an object attribute.  The type indicates whether the attribute
    holds and integer, a string, or both.  It can also indicate that there can
-- 
2.20.1

Re: PATCH bfd: Fix linker warning for recently introduced arm attributes

[Nick Clifton]

Hi Andrea,

> this simple patch updates the value of 'NUM_KNOWN_OBJ_ATTRIBUTES' so
> that when linking objects with 'Tag_BTI_use' or 'Tag_PACRET_use' set ld
> does not emit the "unknown EABI object attribute" warning.
> 
> Regtested clean, okay for trunk?

Approved - please apply.

Cheers
   Nick

Re: PATCH bfd: Fix linker warning for recently introduced arm attributes

[Andrea Corallo]

Nick Clifton <nickc@redhat.com> writes:

> Hi Andrea,
>
>> this simple patch updates the value of 'NUM_KNOWN_OBJ_ATTRIBUTES' so
>> that when linking objects with 'Tag_BTI_use' or 'Tag_PACRET_use' set ld
>> does not emit the "unknown EABI object attribute" warning.
>> Regtested clean, okay for trunk?
>
> Approved - please apply.
>
> Cheers
>   Nick

Hi Nick,

thanks for reviewing, in as 242fe37867c.

Regards

  Andrea

Re: PATCH bfd: Fix linker warning for recently introduced arm attributes

[Simon Marchi]

On 2021-09-27 10:40, Andrea Corallo wrote:> Hi all,
> 
> this simple patch updates the value of 'NUM_KNOWN_OBJ_ATTRIBUTES' so
> that when linking objects with 'Tag_BTI_use' or 'Tag_PACRET_use' set ld
> does not emit the "unknown EABI object attribute" warning.
> 
> Regtested clean, okay for trunk?
> 
> Best Regards
> 
>   Andrea
> 
Hi Andrea,

I get some GDB failures starting with this commit.  To run:

gdb/ $ make check TESTS="gdb.cp/ambiguous.exp"

And in gdb.log:

    49 (gdb) file /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.cp/ambiguous/ambiguous^M
    50 BFD: BFD (GNU Binutils) 2.37.50.20210924 assertion fail /home/simark/src/binutils-gdb/bfd/elf.c:240^M
    51 BFD: /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.cp/ambiguous/ambiguous: warning: multiple dynamic symbol tables detected - ignoring the table in section 6^M
    52 ^M
    53 ^M
    54 Fatal signal: Segmentation fault^M

Just loading the file in GDB is enough to reproduce:

  $ ./gdb -nx -q --data-directory=data-directory testsuite/outputs/gdb.cp/ambiguous/ambiguous

crashes here:

    #16 0x55695f64f856 in handle_sigsegv /home/simark/src/binutils-gdb/gdb/event-top.c:971
    #17 0x7fd2187fe86f  (/usr/lib/libpthread.so.0+0x1386f)
    #18 0x556960b22a45 in bfd_section_from_shdr /home/simark/src/binutils-gdb/bfd/elf.c:2308
    #19 0x556960b07f92 in bfd_elf64_object_p /home/simark/src/binutils-gdb/bfd/elfcode.h:834
    #20 0x556960aa5eec in bfd_check_format_matches /home/simark/src/binutils-gdb/bfd/format.c:343
    #21 0x55695f65703b in exec_file_attach(char const*, int) /home/simark/src/binutils-gdb/gdb/exec.c:471
    #22 0x55695fa8aa48 in catch_command_errors /home/simark/src/binutils-gdb/gdb/main.c:523
    #23 0x55695fa8db42 in captured_main_1 /home/simark/src/binutils-gdb/gdb/main.c:1233
    #24 0x55695fa8edbe in captured_main /home/simark/src/binutils-gdb/gdb/main.c:1343
    #25 0x55695fa8ee53 in gdb_main(captured_main_args*) /home/simark/src/binutils-gdb/gdb/main.c:1368
    #26 0x55695ecd5ad8 in main /home/simark/src/binutils-gdb/gdb/gdb.c:32
    #27 0x7fd217f11b24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
    #28 0x55695ecd58ad in _start (/home/simark/build/binutils-gdb/gdb/gdb+0x12ec8ad)

Simon

Re: PATCH bfd: Fix linker warning for recently introduced arm attributes

[Alan Modra]

On Mon, Oct 04, 2021 at 10:49:58PM -0400, Simon Marchi via Binutils wrote:
> On 2021-09-27 10:40, Andrea Corallo wrote:> Hi all,
> > 
> > this simple patch updates the value of 'NUM_KNOWN_OBJ_ATTRIBUTES' so
> > that when linking objects with 'Tag_BTI_use' or 'Tag_PACRET_use' set ld
> > does not emit the "unknown EABI object attribute" warning.
> > 
> > Regtested clean, okay for trunk?
> > 
> > Best Regards
> > 
> >   Andrea
> > 
> Hi Andrea,
> 
> I get some GDB failures starting with this commit.  To run:
> 
> gdb/ $ make check TESTS="gdb.cp/ambiguous.exp"
> 
> And in gdb.log:
> 
>     49 (gdb) file /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.cp/ambiguous/ambiguous^M
>     50 BFD: BFD (GNU Binutils) 2.37.50.20210924 assertion fail /home/simark/src/binutils-gdb/bfd/elf.c:240^M

Dependency problem?  I can't see that assert being hit unless you have
stale bfd object files.

-- 
Alan Modra
Australia Development Lab, IBM

Re: PATCH bfd: Fix linker warning for recently introduced arm attributes

[Simon Marchi]

On 2021-10-05 20:03, Alan Modra wrote:
> On Mon, Oct 04, 2021 at 10:49:58PM -0400, Simon Marchi via Binutils wrote:
>> On 2021-09-27 10:40, Andrea Corallo wrote:> Hi all,
>>>
>>> this simple patch updates the value of 'NUM_KNOWN_OBJ_ATTRIBUTES' so
>>> that when linking objects with 'Tag_BTI_use' or 'Tag_PACRET_use' set ld
>>> does not emit the "unknown EABI object attribute" warning.
>>>
>>> Regtested clean, okay for trunk?
>>>
>>> Best Regards
>>>
>>>   Andrea
>>>
>> Hi Andrea,
>>
>> I get some GDB failures starting with this commit.  To run:
>>
>> gdb/ $ make check TESTS="gdb.cp/ambiguous.exp"
>>
>> And in gdb.log:
>>
>>     49 (gdb) file /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.cp/ambiguous/ambiguous^M
>>     50 BFD: BFD (GNU Binutils) 2.37.50.20210924 assertion fail /home/simark/src/binutils-gdb/bfd/elf.c:240^M
> 
> Dependency problem?  I can't see that assert being hit unless you have
> stale bfd object files.

I tried rebuilding from scratch a few times and kept seeing it.  I
flushed my ccache cache and now I don't see it, so perhaps it was a
ccache issue (if so, that's quite rare).

So, sorry for the noise.

Simon

Re: PATCH bfd: Fix linker warning for recently introduced arm attributes

[Andrea Corallo]

Simon Marchi <simon.marchi@polymtl.ca> writes:

> On 2021-10-05 20:03, Alan Modra wrote:
>> On Mon, Oct 04, 2021 at 10:49:58PM -0400, Simon Marchi via Binutils wrote:
>>> On 2021-09-27 10:40, Andrea Corallo wrote:> Hi all,
>>>>
>>>> this simple patch updates the value of 'NUM_KNOWN_OBJ_ATTRIBUTES' so
>>>> that when linking objects with 'Tag_BTI_use' or 'Tag_PACRET_use' set ld
>>>> does not emit the "unknown EABI object attribute" warning.
>>>>
>>>> Regtested clean, okay for trunk?
>>>>
>>>> Best Regards
>>>>
>>>>   Andrea
>>>>
>>> Hi Andrea,
>>>
>>> I get some GDB failures starting with this commit.  To run:
>>>
>>> gdb/ $ make check TESTS="gdb.cp/ambiguous.exp"
>>>
>>> And in gdb.log:
>>>
>>>     49 (gdb) file /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.cp/ambiguous/ambiguous^M
>>>     50 BFD: BFD (GNU Binutils) 2.37.50.20210924 assertion fail /home/simark/src/binutils-gdb/bfd/elf.c:240^M
>> 
>> Dependency problem?  I can't see that assert being hit unless you have
>> stale bfd object files.
>
> I tried rebuilding from scratch a few times and kept seeing it.  I
> flushed my ccache cache and now I don't see it, so perhaps it was a
> ccache issue (if so, that's quite rare).
>
> So, sorry for the noise.

Hi Simon,

no issue, I was trying to reproduce it but it's certainly better a false
alarm than a real one :)

Best Regards

  Andrea