From 8550d3b32f4ac17bdb9e4768bb905da181b77ded Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Thu, 16 Apr 2015 13:48:10 +0100 Subject: Honour software single step in fallback of displaced stepping Hi, When I run gdb.threads/non-stop-fair-events.exp on arm-linux target, I see the following message in the debugging log, displaced: breakpoint is gone: Thread 22518, step(1)^M Sending packet: $vCont;s:p57f3.57f6#9d... ^^^^^^^^^ GDB sends vCont;s by mistake, and GDBserver fails on assert. GDB doesn't consider software single step in infrun.c:displaced_step_fixup, /* Go back to what we were trying to do. */ step = currently_stepping (tp); if (debug_displaced) fprintf_unfiltered (gdb_stdlog, "displaced: breakpoint is gone: %s, step(%d)\n", target_pid_to_str (tp->ptid), step); target_resume (ptid, step, GDB_SIGNAL_0); The patch is to let GDB consider software single step here. It fixes fails in gdb.threads/non-stop-fair-events.exp on arm. gdb: 2015-04-16 Yao Qi * infrun.c (maybe_software_singlestep): Declare. (displaced_step_fixup): Call maybe_software_singlestep. --- gdb/ChangeLog | 5 +++++ gdb/infrun.c | 8 ++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) (limited to 'gdb') diff --git a/gdb/ChangeLog b/gdb/ChangeLog index efee416..7f9c96a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2015-04-16 Yao Qi + + * infrun.c (maybe_software_singlestep): Declare. + (displaced_step_fixup): Call maybe_software_singlestep. + 2015-04-15 Doug Evans * psymtab.c (psym_expand_symtabs_matching): Add QUIT call. diff --git a/gdb/infrun.c b/gdb/infrun.c index 4164a00..7870f70 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -98,6 +98,8 @@ static void insert_step_resume_breakpoint_at_caller (struct frame_info *); static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR); +static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc); + /* When set, stop the 'step' command if we enter a function which has no line number information. The normal behavior is that we step over such function. */ @@ -1863,6 +1865,7 @@ displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal) regcache = get_thread_regcache (ptid); actual_pc = regcache_read_pc (regcache); aspace = get_regcache_aspace (regcache); + gdbarch = get_regcache_arch (regcache); if (breakpoint_here_p (aspace, actual_pc)) { @@ -1873,8 +1876,6 @@ displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal) displaced_step_prepare (ptid); - gdbarch = get_regcache_arch (regcache); - if (debug_displaced) { CORE_ADDR actual_pc = regcache_read_pc (regcache); @@ -1907,6 +1908,9 @@ displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal) /* Go back to what we were trying to do. */ step = currently_stepping (tp); + if (step) + step = maybe_software_singlestep (gdbarch, actual_pc); + if (debug_displaced) fprintf_unfiltered (gdb_stdlog, "displaced: breakpoint is gone: %s, step(%d)\n", -- cgit v1.1