* Re: [PRecord] Memory gets set even if users responds 'n' to query
[not found] <6D19CA8D71C89C43A057926FE0D4ADAA07C00000@ecamlmw720.eamcs.ericsson.se>
@ 2009-07-21 3:38 ` Hui Zhu
2009-07-21 8:23 ` Marc Khouzam
0 siblings, 1 reply; 3+ messages in thread
From: Hui Zhu @ 2009-07-21 3:38 UTC (permalink / raw)
To: Marc Khouzam, Michael Snyder; +Cc: gdb-patches ml
[-- Attachment #1: Type: text/plain, Size: 2967 bytes --]
On Tue, Jul 21, 2009 at 10:15, Marc Khouzam<marc.khouzam@ericsson.com> wrote:
> Hi,
>
> while looking into the query stuff we have been discussing I ran into
> the weird behavior where PRecord sets memory even if I answer 'n' to the
> query. I've done a little troubleshooting and it seems that the query
> code is not the problem. So, I thought that maybe even though PRecord
> returns
> from its method right away when I say 'n' to the query, the memory
> has already been changed. Could that be? I didn't investigate further.
>
> Also, I didn't try it with changing registers.
>
> I'm pretty sure it used to work properly.
>
> Thanks
>
> Marc
>
> Here is the session:
>
> GNU gdb (GDB) 6.8.50.20090720-cvs
> Copyright (C) 2009 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later
> <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law. Type "show
> copying"
> and "show warranty" for details.
> This GDB was configured as "i686-pc-linux-gnu".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>...
> (gdb) l
> 1 int main() {
> 2 int a = 1;
> 3 int b = 10;
> 4
> 5 a++;
> 6 b++;
> 7
> 8 return a;
> 9 }
> 10
> (gdb) start
> Temporary breakpoint 1 at 0x80483f5: file b.cc, line 2.
> Starting program: /home/marc/testing/a.out
> re
> Temporary breakpoint 1, main () at b.cc:2
> 2 int a = 1;
> (gdb) record
> (gdb) n
> 3 int b = 10;
> (gdb) n
> 5 a++;
> (gdb) n
> 6 b++;
> (gdb) n
> 8 return a;
> (gdb) rn
> 6 b++;
> (gdb) p a
> $1 = 2
> (gdb) set var a = 8
> Because GDB is in replay mode, writing to memory will make the execution
> log unusable from this point onward. Write memory at address
> 0xbffff6b0?(y or [n]) n
> (gdb) p a
> $2 = 8
> (gdb)
>
>
Thanks Marc.
This issue is because when user answer n, function record_xfer_partial
return -1 will not really cancel the memory change operation.
I make a patch to change it to error.
And I have check the code about register, it works OK. Because it
already use error.
Please help me review it.
Thanks,
Hui
2009-07-21 Hui Zhu <teawater@gmail.com>
* record.c (record_xfer_partial): Call error When nquery
return "n".
---
record.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/record.c
+++ b/record.c
@@ -997,7 +997,7 @@ record_xfer_partial (struct target_ops *
"will make the execution log unusable from this "
"point onward. Write memory at address %s?"),
paddress (target_gdbarch, offset)))
- return -1;
+ error (_("Process record canceled the operation."));
/* Destroy the record from here forward. */
record_list_release_next ();
[-- Attachment #2: reverse-fix-change-memory.txt --]
[-- Type: text/plain, Size: 490 bytes --]
---
record.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/record.c
+++ b/record.c
@@ -997,7 +997,7 @@ record_xfer_partial (struct target_ops *
"will make the execution log unusable from this "
"point onward. Write memory at address %s?"),
paddress (target_gdbarch, offset)))
- return -1;
+ error (_("Process record canceled the operation."));
/* Destroy the record from here forward. */
record_list_release_next ();
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