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[patch] More suggestive displaced-stepping memory error message
- From: Jan Kratochvil <jan dot kratochvil at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Tue, 10 Apr 2012 21:19:55 +0200
- Subject: [patch] More suggestive displaced-stepping memory error message
Hi,
with
gdbserver ld-linux-x86-64.so.2 /bin/prog
and
gdb /bin/prog
in non-stop mode during ld.so initialization happens an error as
displaced-stepping buffer at /bin/prog's _start is not yet available.
Also I think in single-threaded mode displaced-stepping is not useful.
But I understand turning off displaced-stepping if inferior has only one
thread would be too complicating all the troubleshooting.
With all the races and errors I would definitely find this message helpful.
It should at least state the error occured for the displaced-stepping buffer,
not just generic
Cannot access memory at address %s
No regressions on {x86_64,x86_64-m32,i686}-fedora17-linux-gnu.
I may check it in on my own without the "you may want .*" part.
Thanks,
Jan
gdb/
2012-04-10 Jan Kratochvil <jan.kratochvil@redhat.com>
Provide more specific displaced-stepping memory error message.
* infrun.c (displaced_step_prepare): New variable status. Call
target_read_memory instead of read_memory, provide more specific
error message.
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -1296,6 +1296,7 @@ displaced_step_prepare (ptid_t ptid)
ULONGEST len;
struct displaced_step_closure *closure;
struct displaced_step_inferior_state *displaced;
+ int status;
/* We should never reach this function if the architecture does not
support displaced stepping. */
@@ -1356,7 +1357,13 @@ displaced_step_prepare (ptid_t ptid)
displaced->step_saved_copy = xmalloc (len);
ignore_cleanups = make_cleanup (free_current_contents,
&displaced->step_saved_copy);
- read_memory (copy, displaced->step_saved_copy, len);
+ status = target_read_memory (copy, displaced->step_saved_copy, len);
+ if (status != 0)
+ throw_error (MEMORY_ERROR,
+ _("Error accessing memory address %s (%s) for "
+ "displaced-stepping buffer, you may want to temporarily "
+ "turn it off if there is only one inferior thread."),
+ paddress (target_gdbarch, copy), safe_strerror (status));
if (debug_displaced)
{
fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",