Ping. Patchwork: http://patchwork.ozlabs.org/patch/488073/
v1 discussion: http://lists.nongnu.org/archive/html/qemu-devel/2015-06/msg05791.html and patchworks: http://patchwork.ozlabs.org/patch/487438/ http://patchwork.ozlabs.org/patch/487566/ On Wed, Jun 24, 2015 at 3:25 PM, Zavadovsky Yan <zavadovsky....@gmail.com> wrote: > Calling SuspendThread() is not enough to suspend Win32 thread. > We need to call GetThreadContext() after SuspendThread() > to make sure that OS have really suspended target thread. > But GetThreadContext() needs for THREAD_GET_CONTEXT > access right on thread object. > More info about this technique can be found here: > http://blogs.msdn.com/b/oldnewthing/archive/2015/02/05/10591215.aspx > > This patch adds THREAD_GET_CONTEXT to OpenThread() arguments > and change oddity 'while(GetThreadContext() == SUCCESS)' to > 'if(GetThreadContext() == FAILED){exit(1);}'. > So this block of code will continue only after successful > grabbing of thread context(i.e. when thread is really suspended). > And halts otherwise with more verbose error message than previous. > > Signed-off-by: Zavadovsky Yan <zavadovsky....@gmail.com> > --- > cpus.c | 14 ++++++++------ > util/qemu-thread-win32.c | 4 ++-- > 2 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/cpus.c b/cpus.c > index 4f0e54d..0df6a7d 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -1089,8 +1089,8 @@ static void qemu_cpu_kick_thread(CPUState *cpu) > CONTEXT tcgContext; > > if (SuspendThread(cpu->hThread) == (DWORD)-1) { > - fprintf(stderr, "qemu:%s: GetLastError:%lu\n", __func__, > - GetLastError()); > + fprintf(stderr, "qemu:%s: SuspendThread GetLastError:%lu\n", > + __func__, GetLastError()); > exit(1); > } > > @@ -1098,15 +1098,17 @@ static void qemu_cpu_kick_thread(CPUState *cpu) > * suspended until we can get the context. > */ > tcgContext.ContextFlags = CONTEXT_CONTROL; > - while (GetThreadContext(cpu->hThread, &tcgContext) != 0) { > - continue; > + if (GetThreadContext(cpu->hThread, &tcgContext) == 0) { > + fprintf(stderr, "qemu:%s: GetThreadContext > GetLastError:%lu\n", > + __func__, GetLastError()); > + exit(1); > } > > cpu_signal(0); > > if (ResumeThread(cpu->hThread) == (DWORD)-1) { > - fprintf(stderr, "qemu:%s: GetLastError:%lu\n", __func__, > - GetLastError()); > + fprintf(stderr, "qemu:%s: ResumeThread GetLastError:%lu\n", > + __func__, GetLastError()); > exit(1); > } > } > diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c > index 406b52f..823eca1 100644 > --- a/util/qemu-thread-win32.c > +++ b/util/qemu-thread-win32.c > @@ -406,8 +406,8 @@ HANDLE qemu_thread_get_handle(QemuThread *thread) > > EnterCriticalSection(&data->cs); > if (!data->exited) { > - handle = OpenThread(SYNCHRONIZE | THREAD_SUSPEND_RESUME, FALSE, > - thread->tid); > + handle = OpenThread(SYNCHRONIZE | THREAD_SUSPEND_RESUME | > THREAD_GET_CONTEXT, > + FALSE, thread->tid); > } else { > handle = NULL; > } > -- > 2.4.4.windows.2 > >
