From: Jan Kratochvil <jan.kratochvil@redhat.com>
To: gdb-patches@sourceware.org
Cc: Ulrich Weigand <uweigand@de.ibm.com>,
Joel Brobecker <brobecker@adacore.com>
Subject: cancel: [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7 #4 [Re: [revert] Regression on PowerPC]
Date: Fri, 09 Mar 2012 07:22:00 -0000 [thread overview]
Message-ID: <20120309072125.GA517@host2.jankratochvil.net> (raw)
In-Reply-To: <20120308232345.GA32618@host2.jankratochvil.net>
On Fri, 09 Mar 2012 00:23:45 +0100, Jan Kratochvil wrote:
> 2012-03-09 Jan Kratochvil <jan.kratochvil@redhat.com>
>
> * amd64-linux-tdep.c: Include inferior.h.
> (amd64_linux_init_abi): Set ON_STACK and i386_linux_push_dummy_code.
> * i386-linux-tdep.c (i386_linux_push_dummy_code): New function.
> (i386_linux_init_abi): Set ON_STACK and i386_linux_push_dummy_code.
> * i386-tdep.h (i386_linux_push_dummy_code): New declaration.
FYI cancelling this patch, it has some issues:
(1) As i386-tdep.c already has OS-independent i386_push_dummy_call I believe
push_dummy_code can be also put into i386-tdep.c.
(2) At least on RHEL-5 i386 there is a regression:
FAIL: gdb.base/call-signal-resume.exp: continue to program exit
#0 null_hand_call () at ./gdb.base/call-signals.c:56
#1 <function called from gdb>
#2 0xf7fe0430 in __kernel_vsyscall ()
#3 0xf7e7d236 in kill () from /lib/libc.so.6
#4 0x080484f4 in gen_signal () at ./gdb.base/call-signals.c:35
#5 0x08048574 in main () at ./gdb.base/call-signals.c:81
->
#0 null_hand_call () at ./gdb.base/call-signals.c:56
#1 <function called from gdb>
#2 0xf7fe0430 in __kernel_vsyscall ()
#3 0xf7e7d236 in kill () from /lib/libc.so.6
#4 0xf70484f4 in ?? ()
#5 0x00004b03 in ?? ()
#6 0x00000006 in ?? ()
#7 0xffffd068 in ?? ()
#8 0x08048574 in main () at ./gdb.base/call-signals.c:81
This is because (a) the dummy frame has no associated DWARF/EH frame unwind
info and i386_push_dummy_call does not setup proper frame pointer in the new
frame. Moreover I believe it should be setup with 0 frame pointer / 0 return
address to indicate end of unwinding for possible inferior unwinders, IMO
inferior should not unwind through the dummy frame. And then therefore GDB
needs new frame_unwind to properly unwind that 0 return address / frame
pointer.
Regards,
Jan
next prev parent reply other threads:[~2012-03-09 7:22 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-22 20:49 [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7 Jan Kratochvil
2011-12-27 6:23 ` Joel Brobecker
2011-12-28 16:30 ` Jan Kratochvil
2011-12-28 18:47 ` [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7 #2 Jan Kratochvil
2011-12-28 20:40 ` Mark Kettenis
2011-12-30 2:45 ` [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7 #3 Jan Kratochvil
2011-12-30 8:46 ` Joel Brobecker
2011-12-30 11:11 ` Mark Kettenis
2011-12-30 14:16 ` Jan Kratochvil
2011-12-31 2:56 ` Peter Schauer
2011-12-30 11:25 ` Jan Kratochvil
2012-01-01 22:22 ` Jan Kratochvil
2012-01-02 2:45 ` Joel Brobecker
2012-01-02 2:58 ` Jan Kratochvil
2012-01-03 14:45 ` Regression on PowerPC (Re: [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7 #3) Ulrich Weigand
2012-01-03 15:52 ` Joel Brobecker
2012-01-04 14:01 ` [revert] " Jan Kratochvil
2012-01-04 14:09 ` Joel Brobecker
2012-03-08 23:24 ` [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7 #4 [Re: [revert] Regression on PowerPC] Jan Kratochvil
2012-03-09 7:22 ` Jan Kratochvil [this message]
2012-01-02 14:10 ` [patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7 Pedro Alves
2012-01-02 14:20 ` Jan Kratochvil
2012-01-02 14:44 ` Pedro Alves
2012-01-02 14:53 ` Jan Kratochvil
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