diff options
| author | davidbuckley <davidbuckley@unity3d.com> | 2018-10-31 22:51:59 +0300 |
|---|---|---|
| committer | davidbuckley <davidbuckley@unity3d.com> | 2018-10-31 22:51:59 +0300 |
| commit | 09716ca3d0aec2da0010bebd7c17ee2ccf67555b (patch) | |
| tree | c497eeec198b4689cd21eff15cf205795f35bb25 | |
| parent | f40bf2ab729fa043a20e400839aae1ffce03e2ca (diff) | |
use SP saved in contexthandle-suspend-on-altstack
| -rw-r--r-- | pthread_stop_world.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/pthread_stop_world.c b/pthread_stop_world.c index c20ec17b..335e2d3b 100644 --- a/pthread_stop_world.c +++ b/pthread_stop_world.c @@ -262,7 +262,7 @@ STATIC void GC_suspend_handler_inner(ptr_t dummy, void *context); # define GC_lookup_thread_async GC_lookup_thread #endif -GC_INLINE void GC_store_stack_ptr(GC_thread me) +GC_INLINE void GC_store_stack_ptr(GC_thread me, void * context GC_ATTR_UNUSED) { /* There is no data race between the suspend handler (storing */ /* stack_ptr) and GC_push_all_stacks (fetching stack_ptr) because */ @@ -277,8 +277,20 @@ GC_INLINE void GC_store_stack_ptr(GC_thread me) # else # ifdef IA64 me -> backing_store_ptr = GC_save_regs_in_stack(); + /* For known architectures we support, use SP stored in context. */ + /* This prevents disaster if we are running an alternate stack. */ +# elif defined(LINUX) && (defined(X86_64) || defined(I386)) + ucontext_t* uc = (ucontext_t*)context; + AO_store((volatile AO_t *)&me->stop_info.stack_ptr, +# ifdef X86_64 + (AO_t)uc->uc_mcontext.gregs[REG_RSP] +# else + (AO_t)uc->uc_mcontext.gregs[REG_ESP] +# endif + ); +# else + AO_store((volatile AO_t *)&me->stop_info.stack_ptr, (AO_t)GC_approx_sp()); # endif - AO_store((volatile AO_t *)&me->stop_info.stack_ptr, (AO_t)GC_approx_sp()); # endif } @@ -310,7 +322,7 @@ STATIC void GC_suspend_handler_inner(ptr_t dummy GC_ATTR_UNUSED, # ifdef GC_ENABLE_SUSPEND_THREAD if (AO_load(&me->suspended_ext)) { - GC_store_stack_ptr(me); + GC_store_stack_ptr(me, context); sem_post(&GC_suspend_ack_sem); suspend_self_inner(me); # ifdef DEBUG_THREADS @@ -330,7 +342,7 @@ STATIC void GC_suspend_handler_inner(ptr_t dummy GC_ATTR_UNUSED, RESTORE_CANCEL(cancel_state); return; } - GC_store_stack_ptr(me); + GC_store_stack_ptr(me, context); # ifdef THREAD_SANITIZER /* TSan disables signals around signal handlers. Without */ |