[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [6095] User-mode GDB stub improvements - handle fork
From: |
Aurelien Jarno |
Subject: |
[Qemu-devel] [6095] User-mode GDB stub improvements - handle fork |
Date: |
Thu, 18 Dec 2008 22:44:05 +0000 |
Revision: 6095
http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6095
Author: aurel32
Date: 2008-12-18 22:44:04 +0000 (Thu, 18 Dec 2008)
Log Message:
-----------
User-mode GDB stub improvements - handle fork
Close gdbserver in child processes, so that only one stub tries to talk
to GDB at a time. Updated from an earlier patch by Paul Brook.
Signed-off-by: Daniel Jacobowitz <address@hidden>
Signed-off-by: Aurelien Jarno <address@hidden>
Modified Paths:
--------------
trunk/gdbstub.c
trunk/gdbstub.h
trunk/linux-user/main.c
trunk/linux-user/syscall.c
Modified: trunk/gdbstub.c
===================================================================
--- trunk/gdbstub.c 2008-12-18 22:43:56 UTC (rev 6094)
+++ trunk/gdbstub.c 2008-12-18 22:44:04 UTC (rev 6095)
@@ -1996,6 +1996,18 @@
gdb_accept();
return 0;
}
+
+/* Disable gdb stub for child processes. */
+void gdbserver_fork(CPUState *env)
+{
+ GDBState *s = gdbserver_state;
+ if (s->fd < 0)
+ return;
+ close(s->fd);
+ s->fd = -1;
+ cpu_breakpoint_remove_all(env, BP_GDB);
+ cpu_watchpoint_remove_all(env, BP_GDB);
+}
#else
static int gdb_chr_can_receive(void *opaque)
{
Modified: trunk/gdbstub.h
===================================================================
--- trunk/gdbstub.h 2008-12-18 22:43:56 UTC (rev 6094)
+++ trunk/gdbstub.h 2008-12-18 22:44:04 UTC (rev 6095)
@@ -13,6 +13,7 @@
int gdb_handlesig (CPUState *, int);
void gdb_exit(CPUState *, int);
int gdbserver_start(int);
+void gdbserver_fork(CPUState *);
#else
int gdbserver_start(const char *port);
#endif
Modified: trunk/linux-user/main.c
===================================================================
--- trunk/linux-user/main.c 2008-12-18 22:43:56 UTC (rev 6094)
+++ trunk/linux-user/main.c 2008-12-18 22:44:04 UTC (rev 6095)
@@ -162,6 +162,7 @@
pthread_cond_init(&exclusive_cond, NULL);
pthread_cond_init(&exclusive_resume, NULL);
pthread_mutex_init(&tb_lock, NULL);
+ gdbserver_fork(thread_env);
} else {
pthread_mutex_unlock(&exclusive_lock);
pthread_mutex_unlock(&tb_lock);
@@ -254,6 +255,9 @@
void fork_end(int child)
{
+ if (child) {
+ gdbserver_fork(thread_env);
+ }
}
#endif
Modified: trunk/linux-user/syscall.c
===================================================================
--- trunk/linux-user/syscall.c 2008-12-18 22:43:56 UTC (rev 6094)
+++ trunk/linux-user/syscall.c 2008-12-18 22:44:04 UTC (rev 6095)
@@ -2960,17 +2960,17 @@
return -EINVAL;
fork_start();
ret = fork();
-#if defined(USE_NPTL)
- /* There is a race condition here. The parent process could
- theoretically read the TID in the child process before the child
- tid is set. This would require using either ptrace
- (not implemented) or having *_tidptr to point at a shared memory
- mapping. We can't repeat the spinlock hack used above because
- the child process gets its own copy of the lock. */
if (ret == 0) {
+ /* Child Process. */
cpu_clone_regs(env, newsp);
fork_end(1);
- /* Child Process. */
+#if defined(USE_NPTL)
+ /* There is a race condition here. The parent process could
+ theoretically read the TID in the child process before the child
+ tid is set. This would require using either ptrace
+ (not implemented) or having *_tidptr to point at a shared memory
+ mapping. We can't repeat the spinlock hack used above because
+ the child process gets its own copy of the lock. */
if (flags & CLONE_CHILD_SETTID)
put_user_u32(gettid(), child_tidptr);
if (flags & CLONE_PARENT_SETTID)
@@ -2979,14 +2979,10 @@
if (flags & CLONE_SETTLS)
cpu_set_tls (env, newtls);
/* TODO: Implement CLONE_CHILD_CLEARTID. */
+#endif
} else {
fork_end(0);
}
-#else
- if (ret == 0) {
- cpu_clone_regs(env, newsp);
- }
-#endif
}
return ret;
}
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Qemu-devel] [6095] User-mode GDB stub improvements - handle fork,
Aurelien Jarno <=