From 71d378ae60a4f072ce392046878d471255f6c8a1 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 11 Jan 2018 17:50:31 +0000 Subject: [PATCH] gdb.base/breakpoint-in-ro-region.exp regression on sss targets (PR gdb/22583) As Maciej reported at , this commit: commit d930703d68ae160ddfe8ebe5fdcf416fb6090e1e Date: Thu Nov 16 18:44:43 2017 +0000 Subject: Don't ever Quit out of resume caused regressions on software single-set targets, specifically: FAIL: gdb.base/breakpoint-in-ro-region.exp: always-inserted off: auto-hw off: single-step breakpoint is not left behind FAIL: gdb.base/breakpoint-in-ro-region.exp: always-inserted off: auto-hw on: single-step breakpoint is not left behind FAIL: gdb.base/breakpoint-in-ro-region.exp: always-inserted on: auto-hw off: step in ro region (cannot insert hw break) FAIL: gdb.base/breakpoint-in-ro-region.exp: always-inserted on: auto-hw off: single-step breakpoint is not left behind FAIL: gdb.base/breakpoint-in-ro-region.exp: always-inserted on: auto-hw on: single-step breakpoint is not left behind and indeed detailed logs indicate a breakpoint is left lingering, e.g.: (gdb) PASS: gdb.base/breakpoint-in-ro-region.exp: always-inserted off: auto-hw off: step in ro region (cannot insert sw break) maint info breakpoints 0 Num Type Disp Enb Address What 0 sw single-step keep y 0x00400774 in main at [...]/gdb/testsuite/gdb.base/breakpoint-in-ro-region.c:24 inf 1 thread 1 stop only in thread 1 (gdb) FAIL: gdb.base/breakpoint-in-ro-region.exp: always-inserted off: auto-hw off: single-step breakpoint is not left behind vs: (gdb) PASS: gdb.base/breakpoint-in-ro-region.exp: always-inserted off: auto-hw off: step in ro region (cannot insert sw break) maint info breakpoints 0 No breakpoint or watchpoint matching '0'. (gdb) PASS: gdb.base/breakpoint-in-ro-region.exp: always-inserted off: auto-hw off: single-step breakpoint is not left behind as at commit d930703d68ae^. Before commit d930703d68ae, we had a cleanup installed in 'resume' that would delete single-step breakpoints on error: /* Resuming. */ /* Things to clean up if we QUIT out of resume (). */ static void resume_cleanups (void *ignore) { if (!ptid_equal (inferior_ptid, null_ptid)) delete_single_step_breakpoints (inferior_thread ()); normal_stop (); } That whole function was removed by d930703d68ae mainly to eliminate the normal_stop call: ~~~~ Note that the exception called from within resume ends up calling normal_stop via resume_cleanups. That's very borked though, because normal_stop is going to re-handle whatever was the last reported event, possibly even re-running a hook stop... ~~~~ But as the regression shows, removing resume_cleanups completely went a bit too far, as the delete_single_step_breakpoints call is still necessary. So fix the regression by reinstating the delete_single_step_breakpoints call on error. However, since we're trying to eliminate cleanups, restore it in a different form (using TRY/CATCH). Tested on x86-64 GNU/Linux both top of master and on top of a series that implements software single-step on x86. gdb/ChangeLog: 2018-01-11 Pedro Alves PR gdb/22583 * infrun.c (resume): Rename to ... (resume_1): ... this. (resume): Reimplement as wrapper around resume_1. --- gdb/ChangeLog | 7 +++++++ gdb/infrun.c | 33 ++++++++++++++++++++++++++++++--- 2 files changed, 37 insertions(+), 3 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 4c629e548c..4f9bb8d86a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2018-01-11 Pedro Alves + + PR gdb/22583 + * infrun.c (resume): Rename to ... + (resume_1): ... this. + (resume): Reimplement as wrapper around resume_1. + 2018-01-11 Pedro Alves PR remote/22597 diff --git a/gdb/infrun.c b/gdb/infrun.c index 7e8d8da588..7d6aa7d069 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -2355,10 +2355,11 @@ do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig) } /* Resume the inferior. SIG is the signal to give the inferior - (GDB_SIGNAL_0 for none). */ + (GDB_SIGNAL_0 for none). Note: don't call this directly; instead + call 'resume', which handles exceptions. */ -void -resume (enum gdb_signal sig) +static void +resume_1 (enum gdb_signal sig) { struct regcache *regcache = get_current_regcache (); struct gdbarch *gdbarch = regcache->arch (); @@ -2730,6 +2731,32 @@ resume (enum gdb_signal sig) do_target_resume (resume_ptid, step, sig); tp->resumed = 1; } + +/* Resume the inferior. SIG is the signal to give the inferior + (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that + rolls back state on error. */ + +void +resume (gdb_signal sig) +{ + TRY + { + resume_1 (sig); + } + CATCH (ex, RETURN_MASK_ALL) + { + /* If resuming is being aborted for any reason, delete any + single-step breakpoint resume_1 may have created, to avoid + confusing the following resumption, and to avoid leaving + single-step breakpoints perturbing other threads, in case + we're running in non-stop mode. */ + if (inferior_ptid != null_ptid) + delete_single_step_breakpoints (inferior_thread ()); + throw_exception (ex); + } + END_CATCH +} + /* Proceeding. */