From 48f9886d473c936907a5d1647cd5f1dd4bb9e36c Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Mon, 6 Sep 2010 14:22:07 +0000 Subject: [PATCH] * infrun.c (resume): Extend comment on ignoring single-step requests on vfork parents waiting for a vfork-done. --- gdb/ChangeLog | 5 +++++ gdb/infrun.c | 16 +++++++++++----- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 6a28be1e26a..8eca93ad780 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2010-09-06 Pedro Alves + + * infrun.c (resume): Extend comment on ignoring single-step + requests on vfork parents waiting for a vfork-done. + 2010-09-06 Jan Kratochvil Pedro Alves diff --git a/gdb/infrun.c b/gdb/infrun.c index b21fd3f33e4..a6f8fd13242 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -1560,13 +1560,19 @@ resume (int step, enum target_signal sig) QUIT; - /* Don't consider single-stepping when the inferior is - waiting_for_vfork_done, either software or hardware step. In - software step, child process will hit the software single step - breakpoint inserted in parent process. In hardware step, GDB - can resumes inferior, and wait for vfork_done event. */ if (current_inferior ()->waiting_for_vfork_done) { + /* Don't try to single-step a vfork parent that is waiting for + the child to get out of the shared memory region (by exec'ing + or exiting). This is particularly important on software + single-step archs, as the child process would trip on the + software single step breakpoint inserted for the parent + process. Since the parent will not actually execute any + instruction until the child is out of the shared region (such + are vfork's semantics), it is safe to simply continue it. + Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for + the parent, and tell it to `keep_going', which automatically + re-sets it stepping. */ if (debug_infrun) fprintf_unfiltered (gdb_stdlog, "infrun: resume : clear step\n"); -- 2.30.2