From 1e9fa730163c2a445014ff8324b169cd82a50df1 Mon Sep 17 00:00:00 2001 From: Nathan Froyd Date: Wed, 3 Jun 2009 11:33:08 -0700 Subject: fix gdbstub support for multiple threads in usermode, v3 When debugging multi-threaded programs, QEMU's gdb stub would report the correct number of threads (the qfThreadInfo and qsThreadInfo packets). However, the stub was unable to actually switch between threads (the T packet), since it would report every thread except the first as being dead. Furthermore, the stub relied upon cpu_index as a reliable means of assigning IDs to the threads. This was a bad idea; if you have this sequence of events: initial thread created new thread #1 new thread #2 thread #1 exits new thread #3 thread #3 will have the same cpu_index as thread #1, which would confuse GDB. (This problem is partly due to the remote protocol not having a good way to send thread creation/destruction events.) We fix this by using the host thread ID for the identifier passed to GDB when debugging a multi-threaded userspace program. The thread ID might wrap, but the same sort of problems with wrapping thread IDs would come up with debugging programs natively, so this doesn't represent a problem. Signed-off-by: Nathan Froyd --- exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'exec.c') diff --git a/exec.c b/exec.c index 723de89..52f4e89 100644 --- a/exec.c +++ b/exec.c @@ -553,7 +553,7 @@ void cpu_exec_init(CPUState *env) penv = &first_cpu; cpu_index = 0; while (*penv != NULL) { - penv = (CPUState **)&(*penv)->next_cpu; + penv = &(*penv)->next_cpu; cpu_index++; } env->cpu_index = cpu_index; -- cgit v1.1