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From: "mehmetgelisin at aol dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug string/17279] strncat(..., ..., SIZE_MAX) behaves incorrectly
Date: Fri, 10 Sep 2021 19:36:49 +0000	[thread overview]
Message-ID: <bug-17279-131-2Q3tJ0l9xs@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-17279-131@http.sourceware.org/bugzilla/>

https://sourceware.org/bugzilla/show_bug.cgi?id=17279

Mehmet gelisin <mehmetgelisin at aol dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mehmetgelisin at aol dot com

--- Comment #3 from Mehmet gelisin <mehmetgelisin at aol dot com> ---
In collect_register() function of arc-linux-tdep.c, the "eret"
(exception return) register value is not being reported correctly.

Background: https://komiya-dental.com/ 
When asked for the "pc" value, we have to update the "eret" register
with GDB's STOP_PC.  The "eret" instructs the kernel code where to
jump back when an instruction has stopped due to a breakpoint.  This
is how collect_register() is doing so:

--------------8<--------------
  if (regnum == gdbarch_pc_regnum (gdbarch))
    regnum = ARC_ERET_REGNUM;
  regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]);
-------------->8--------------

Root cause: http://www.iu-bloomington.com/
Although this is using the correct offset (ERET register's), it is also
changing the REGNUM itself.  Therefore, raw_collect (regnum, ...) is
not reading from "pc" anymore.

Consequence:
This bug affects the "native ARC gdb" badly and causes kernel code to jump
to addresses after the breakpoint and not executing the "breakpoint"ed
instructions at all.  That "native ARC gdb" feature is not upstream yet and
is in review at the time of writing [1]. https://www.webb-dev.co.uk/ 

In collect_register() function of arc-linux-tdep.c, the "eret"
(exception return) register value is not being reported correctly.

Background: https://waytowhatsnext.com/  
When asked for the "pc" value, we have to update the "eret" register
with GDB's STOP_PC.  The "eret" instructs the kernel code where to
jump back when an instruction has stopped due to a breakpoint.  This
is how collect_register() is doing so:

--------------8<--------------
  if (regnum == gdbarch_pc_regnum (gdbarch))
    regnum = ARC_ERET_REGNUM; http://www.acpirateradio.co.uk/ 
  regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]);
-------------->8--------------

Root cause:
Although this is using the correct offset (ERET register's), it is also
changing the REGNUM itself.  Therefore, raw_collect (regnum, ...) is
not reading from "pc" anymore. http://www.logoarts.co.uk/ 

Consequence:
This bug affects the "native ARC gdb" badly and causes kernel code to jump
to addresses after the breakpoint and not executing the "breakpoint"ed
instructions at all.  That "native ARC gdb" feature is not upstream yet and
is in review at the time of writing [1].
In collect_register() function of arc-linux-tdep.c, the "eret"
http://www.slipstone.co.uk/ 
(exception return) register value is not being reported correctly.

Background:
When asked for the "pc" value, http://embermanchester.uk/  we have to update
the "eret" register
with GDB's STOP_PC.  The "eret" instructs the kernel code where to
jump back when an instruction has stopped due to a breakpoint.  This
is how collect_register() is doing so: http://connstr.net/ 

--------------8<--------------
  if (regnum == gdbarch_pc_regnum (gdbarch)) http://joerg.li/
    regnum = ARC_ERET_REGNUM;
  regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]);
-------------->8--------------
http://www.jopspeech.com/
Root cause:
Although this is using the correct offset (ERET register's), it is also
changing the REGNUM itself.  Therefore, raw_collect (regnum, ...) is
not reading from "pc" anymore. http://www.wearelondonmade.com/

Consequence:
This bug affects the "native ARC gdb" badly and causes kernel code to jump
to addresses http://www.compilatori.com/  after the breakpoint and not
executing the "breakpoint"ed
instructions at all.  That "native ARC gdb" feature is not upstream yet and
is in review at the time of writing [1]. http://www-look-4.com/

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  parent reply	other threads:[~2021-09-10 19:36 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-16  9:58 [Bug libc/17279] New: " roche at httrack dot com
2015-08-27 22:23 ` [Bug string/17279] " jsm28 at gcc dot gnu.org
2021-08-10 11:45 ` ucelsanicin at yahoo dot com
2021-09-10 19:36 ` mehmetgelisin at aol dot com [this message]
2021-09-10 19:53 ` mark at klomp dot org
2021-09-22 16:58 ` mervegunesli at aol dot com
2021-10-09 11:00 ` gulsenenginar at aol dot com
2021-11-08  8:08 ` richardsjenkins70 at gmail dot com

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