I see the internal error below in gdb.base/bp-permanent.exp in aarch64-linux-gnu target. (gdb) PASS: gdb.base/bp-permanent.exp: always_inserted=off, sw_watchpoint=0: stepi signal with handler: stop at permanent breakpoint queue-signal SIGUSR1^M (gdb) PASS: gdb.base/bp-permanent.exp: always_inserted=off, sw_watchpoint=0: stepi signal with handler: queue-signal SIGUSR1 stepi^M gdb/infrun.c:2114: internal-error: resume: Assertion `tp->control.step_resume_breakpoint->loc->permanent' failed.^M A problem internal to GDB has been detected,^M further debugging may prove unreliable.^M Quit this debugging session? (y or n) FAIL: gdb.base/bp-permanent.exp: always_inserted=off, sw_watchpoint=0: stepi signal with handler: single-step to handler (GDB internal error) Resyncing due to internal error. Further analysis is needed.
This internal error is only shown on remote/cross testing. In the native testing (without gdbserver), the internal error goes away: (gdb) PASS: gdb.base/bp-permanent.exp: always_inserted=on, sw_watchpoint=1: stepi signal with handler: stop at permanent breakpoint queue-signal SIGUSR1^M (gdb) PASS: gdb.base/bp-permanent.exp: always_inserted=on, sw_watchpoint=1: stepi signal with handler: queue-signal SIGUSR1 stepi^M 47 NOP; /* after permanent bp */^M (gdb) FAIL: gdb.base/bp-permanent.exp: always_inserted=on, sw_watchpoint=1: stepi signal with handler: single-step to handler
The ppc64 buildbots are showing this as well. I've got a patch.
Mine.
The master branch has been updated by Pedro Alves <palves@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=68901c4d439ebceecab927932c17ea1504747c02 commit 68901c4d439ebceecab927932c17ea1504747c02 Author: Pedro Alves <palves@redhat.com> Date: Thu Mar 5 23:39:45 2015 +0000 PR gdb/18002: Fix reinsert of a permanent breakpoints When we find out that a breakpoint is set on top of a program breakpoint, we mark it as "permanent". E.g.,: ... if (bp_loc_is_permanent (loc)) { loc->inserted = 1; loc->permanent = 1; } ... Note we didn't fill in the breakpoint's shadow (shadow_len remains 0). In case the target claims support for evaluating breakpoint conditions, GDB sometimes reinserts breakpoints that are already inserted (to update the conditions on the target side). Since GDB doesn't know whether the target supports evaluating conditions _of_ software breakpoints (vs hardware breakpoints, etc.) until it actually tries it, if the target doesn't actually support z0 breakpoints, GDB ends up reinserting a GDB-managed software/memory breakpoint (mem-break.c). And that is the case that is buggy: breakpoints that are marked inserted contribute their shadows (if any) to the memory returned by target_read_memory, to mask out breakpoints. Permanent breakpoints are always marked as inserted. So if the permanent breakpoint doesn't have a shadow yet in its shadow buffer, but we set shadow_len before calling target_read_memory, then the still clear shadow_contents buffer will be used by the breakpoint masking code... And then from there on, the permanent breakpoint has a broken shadow buffer, and thus any memory read out of that address will read bogus code, and many random bad things fall out from that. The fix is just to set shadow_len at the same time shadow_contents is set, not one before and another after... Fixes all gdb.base/bp-permanent.exp FAILs on PPC64 GNU/Linux gdbserver and probably any other gdbserver port that doesn't do z0 breakpoints. gdb/ChangeLog: 2015-03-05 Pedro Alves <palves@redhat.com> PR gdb/18002 * mem-break.c (default_memory_insert_breakpoint): Set shadow_len after reading the breakpoint's shadow memory.
Fixed.