Re: [PATCH] elf: Don't call fatal_error in _dl_signal_error

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 03/04/24 17:00, H.J. Lu wrote:
> On Wed, Apr 3, 2024 at 12:54 PM Adhemerval Zanella Netto
> <adhemerval.zanella@linaro.org> wrote:
>>
>>
>>
>> On 03/04/24 09:39, H.J. Lu wrote:
>>> Don't call fatal_error in _dl_signal_error since _dl_signal_error should
>>> only be called from _dl_catch_exception and get_catch should never return
>>> NULL.  Otherwise, fatal_error should be called directly instead.
>>
>> Is this related to BZ#31596 or did you catch it by code review?  I think
> 
> Yes, it is related.  I noticed by code review.
> 
>> this is required for lazy binding being fatal error on initializer
>> functions (elf/dl-open.c:829).
> 
> elf/dl-open.c:829 calls _dl_catch_exception.

I think it because lazy binding errors from _dl_lookup_symbol_x calls
_dl_exception_create_format/_dl_signal_cexception instead of _dl_signal_error
mainly because it can not translate the message at the time. 

From _dl_catch_exception comment, it aims to support first argument being
NULL so all exceptions are fatal.  This change change this assumption,
meaning _dl_signal_error can not be called in this way (since now it always
expects to return the exception to caller).

> 
>>> ---
>>>  elf/dl-catch.c | 13 ++++---------
>>>  1 file changed, 4 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/elf/dl-catch.c b/elf/dl-catch.c
>>> index 2109516dba..a023555165 100644
>>> --- a/elf/dl-catch.c
>>> +++ b/elf/dl-catch.c
>>> @@ -117,16 +117,11 @@ _dl_signal_error (int errcode, const char *objname, const char *occasion,
>>>    if (! errstring)
>>>      errstring = N_("DYNAMIC LINKER BUG!!!");
>>>
>>> -  if (lcatch != NULL)
>>> -    {
>>> -      _dl_exception_create (lcatch->exception, objname, errstring);
>>> -      *lcatch->errcode = errcode;
>>> +  _dl_exception_create (lcatch->exception, objname, errstring);
>>> +  *lcatch->errcode = errcode;
>>>
>>> -      /* We do not restore the signal mask because none was saved.  */
>>> -      __longjmp (lcatch->env[0].__jmpbuf, 1);
>>> -    }
>>> -  else
>>> -    fatal_error (errcode, objname, occasion, errstring);
>>> +  /* We do not restore the signal mask because none was saved.  */
>>> +  __longjmp (lcatch->env[0].__jmpbuf, 1);
>>>  }
>>>  rtld_hidden_def (_dl_signal_error)
>>>
> 
> 
>