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Re: RFC: Updates support for breakpoints that generate SIGILL
- From: "Ulrich Weigand" <uweigand at de dot ibm dot com>
- To: dan at codesourcery dot com (Daniel Jacobowitz)
- Cc: gdb-patches at sourceware dot org
- Date: Mon, 8 Feb 2010 20:35:17 +0100 (CET)
- Subject: Re: RFC: Updates support for breakpoints that generate SIGILL
Daniel Jacobowitz wrote:
> 2010-01-28 Daniel Jacobowitz <dan@codesourcery.com>
>
> * infrun.c (prepare_to_proceed): Handle other signals which might
> match a breakpoint.
> (handle_inferior_event): Move the check for unusual breakpoint
> signals earlier.
Unfortunately this change broke Cell/B.E. debugging.
The problem is that with the change, handle_inferior_event will now
*always* look up a regcache, even when the process has exited.
Before the patch, the code has always taken care to avoid that; while
some targets don't mind, others will break (in particular, the Cell/B.E.
multi-arch target does).
The patch below changes this to only look up the regcache when needed
(in particular, this implies the process is still there).
Tested on Cell/B.E. (ppc32 and ppc64) with no regressions.
Does this look OK to you?
Bye,
Ulricu
ChangeLog:
* infrun.c (handle_inferior_event): Do not look up regcache
for exited processes.
Index: gdb/infrun.c
===================================================================
RCS file: /cvs/src/src/gdb/infrun.c,v
retrieving revision 1.428
diff -u -p -r1.428 infrun.c
--- gdb/infrun.c 29 Jan 2010 15:40:21 -0000 1.428
+++ gdb/infrun.c 8 Feb 2010 18:03:29 -0000
@@ -2664,7 +2664,6 @@ handle_inferior_event (struct execution_
{
struct frame_info *frame;
struct gdbarch *gdbarch;
- struct regcache *regcache;
int sw_single_step_trap_p = 0;
int stopped_by_watchpoint;
int stepped_after_stopped_by_watchpoint = 0;
@@ -2735,18 +2734,21 @@ handle_inferior_event (struct execution_
non-executable stack. This happens for call dummy breakpoints
for architectures like SPARC that place call dummies on the
stack. */
- regcache = get_thread_regcache (ecs->ptid);
if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
&& (ecs->ws.value.sig == TARGET_SIGNAL_ILL
|| ecs->ws.value.sig == TARGET_SIGNAL_SEGV
- || ecs->ws.value.sig == TARGET_SIGNAL_EMT)
- && breakpoint_inserted_here_p (get_regcache_aspace (regcache),
- regcache_read_pc (regcache)))
+ || ecs->ws.value.sig == TARGET_SIGNAL_EMT))
{
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog,
- "infrun: Treating signal as SIGTRAP\n");
- ecs->ws.value.sig = TARGET_SIGNAL_TRAP;
+ struct regcache *regcache = get_thread_regcache (ecs->ptid);
+
+ if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
+ regcache_read_pc (regcache)))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: Treating signal as SIGTRAP\n");
+ ecs->ws.value.sig = TARGET_SIGNAL_TRAP;
+ }
}
/* Mark the non-executing threads accordingly. In all-stop, all
--
Dr. Ulrich Weigand
GNU Toolchain for Linux on System z and Cell BE
Ulrich.Weigand@de.ibm.com