diff options
| -rw-r--r-- | gdb/ChangeLog | 9 | ||||
| -rw-r--r-- | gdb/common/linux-ptrace.c | 9 | ||||
| -rw-r--r-- | gdb/common/linux-ptrace.h | 1 | ||||
| -rw-r--r-- | gdb/linux-nat.c | 25 |
4 files changed, 43 insertions, 1 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index dc63863..79aded4 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,12 @@ +2014-06-08 Hui Zhu <hui@codesourcery.com> + + * common/linux-ptrace.c (linux_disable_event_reporting): New + function. + * common/linux-ptrace.h (linux_disable_event_reporting): New + declaration. + * linux-nat.c (linux_child_follow_fork): Do a single step before + detach. + 2014-06-07 Keith Seitz <keiths@redhat.com> Revert: diff --git a/gdb/common/linux-ptrace.c b/gdb/common/linux-ptrace.c index efbd1ea..b140b08 100644 --- a/gdb/common/linux-ptrace.c +++ b/gdb/common/linux-ptrace.c @@ -476,6 +476,15 @@ linux_enable_event_reporting (pid_t pid) (PTRACE_TYPE_ARG4) (uintptr_t) current_ptrace_options); } +/* Disable reporting of all currently supported ptrace events. */ + +void +linux_disable_event_reporting (pid_t pid) +{ + /* Set the options. */ + ptrace (PTRACE_SETOPTIONS, pid, (PTRACE_TYPE_ARG3) 0, 0); +} + /* Returns non-zero if PTRACE_OPTIONS is contained within CURRENT_PTRACE_OPTIONS, therefore supported. Returns 0 otherwise. */ diff --git a/gdb/common/linux-ptrace.h b/gdb/common/linux-ptrace.h index 881d9c9..cffb5ce 100644 --- a/gdb/common/linux-ptrace.h +++ b/gdb/common/linux-ptrace.h @@ -86,6 +86,7 @@ struct buffer; extern void linux_ptrace_attach_fail_reason (pid_t pid, struct buffer *buffer); extern void linux_ptrace_init_warnings (void); extern void linux_enable_event_reporting (pid_t pid); +extern void linux_disable_event_reporting (pid_t pid); extern int linux_supports_tracefork (void); extern int linux_supports_traceclone (void); extern int linux_supports_tracevforkdone (void); diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index 6ca5c7e..3b117b5 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -414,6 +414,7 @@ holding the child stopped. Try \"set detach-on-fork\" or \ if (detach_fork) { struct cleanup *old_chain; + int status = 0; /* Before detaching from the child, remove all breakpoints from it. If we forked, then this has already been taken @@ -447,7 +448,29 @@ holding the child stopped. Try \"set detach-on-fork\" or \ if (linux_nat_prepare_to_resume != NULL) linux_nat_prepare_to_resume (child_lp); - ptrace (PTRACE_DETACH, child_pid, 0, 0); + + /* When debugging an inferior in an architecture that supports + hardware single stepping on a kernel without commit + 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child + process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits + set if the parent process had them set. + To work around this, single step the child process + once before detaching to clear the flags. */ + + if (!gdbarch_software_single_step_p (target_thread_architecture + (child_lp->ptid))) + { + int status; + + linux_disable_event_reporting (child_pid); + if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) + perror_with_name (_("Couldn't do single step")); + if (my_waitpid (child_pid, &status, 0) < 0) + perror_with_name (_("Couldn't wait vfork process")); + } + + if (WIFSTOPPED (status)) + ptrace (PTRACE_DETACH, child_pid, 0, WSTOPSIG (status)); do_cleanups (old_chain); } |