From c077881afaedb9b74063bee992b3e472b4b6e9ca Mon Sep 17 00:00:00 2001 From: Hui Zhu Date: Sun, 8 Jun 2014 19:11:09 +0800 Subject: Fix gdb.base/watch-vfork.exp: Watchpoint triggers after vfork (sw) (timeout) with Linux 2.6.32 and older version https://sourceware.org/ml/gdb-patches/2014-04/msg00047.html Got gdb.base/watch-vfork.exp: Watchpoint triggers after vfork (sw) (timeout) with Linux 2.6.32 and older version. The rootcause is after the test use "set can-use-hw-watchpoints 0" let GDB doesn't use hardware breakpoint and set a watchpoint on "global", GDB continue will keep single step inside function "vfork". The Linux 2.6.32 and older version doesn't have commit 6580807da14c423f0d0a708108e6df6ebc8bc83d (get more info please goto http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=6580807da14c423f0d0a708108e6df6ebc8bc83d). When the function "vfork" do syscall, the single step flag TIF_SINGLESTEP will copy to child process. Then GDB detach it, child process and parent process will be hanged. So I make a patch that do a single step before detach. Then TIF_SINGLESTEP of child process in old Linux kernel will be cleared before detach. Child process in new Linux kernel will not be affected by this single step. 2014-06-08 Hui Zhu * 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. --- gdb/common/linux-ptrace.c | 9 +++++++++ gdb/common/linux-ptrace.h | 1 + 2 files changed, 10 insertions(+) (limited to 'gdb/common') 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); -- cgit v1.1