Fix original stack when running signal handler on alternate stack

        * autoload.cc (SetThreadStackGuarantee): Import.
        * cygtls.h (struct _cygtls): Replace thread_context with a ucontext_t
        called context.
        * exceptions.cc (exception::handle): Exit from process via signal_exit
        in case sig_send returns from handling a stack overflow SIGSEGV.
        Explain why.
        (dumpstack_overflow_wrapper): Thread wrapper to create a stackdump
        from another thread.
        (signal_exit): Fix argument list to reflect three-arg signal handler.
        In case we have to create a stackdump for a stack overflow condition,
        do so from a separate thread.  Explain why.
        (sigpacket::process): Don't run signal_exit on alternate stack.
        (altstack_wrapper): Wrapper function to do stack correction when
        calling the signal handler on an alternate stack to handle a stack
        overflow.  Make sure to have lots of comments.
        (_cygtls::call_signal_handler): Drop local context variable to reduce
        stack pressure.  Use this->context instead.  Change inline assembler
        to call altstack_wrapper.
        (_cygtls::signal_debugger): Accommodate aforementioned change to
        struct _cygtls.
        * tlsoffset.h: Regenerate.
        * tlsoffset64.h: Regenerate.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

1 files changed, 60 insertions, 56 deletions

diff --git a/winsup/cygwin/tlsoffsets64.h b/winsup/cygwin/tlsoffsets64.h
index 3f171b0ff..d137408d0 100644
--- a/winsup/cygwin/tlsoffsets64.h
+++ b/winsup/cygwin/tlsoffsets64.h
@@ -31,34 +31,36 @@
 //; $tls::psignal_arrived = 4152;
 //; $tls::will_wait_for_signal = -8640;
 //; $tls::pwill_wait_for_signal = 4160;
-//; $tls::thread_context = -8632;
-//; $tls::pthread_context = 4168;
-//; $tls::thread_id = -7400;
-//; $tls::pthread_id = 5400;
-//; $tls::infodata = -7396;
-//; $tls::pinfodata = 5404;
-//; $tls::tid = -7248;
-//; $tls::ptid = 5552;
-//; $tls::_ctinfo = -7240;
-//; $tls::p_ctinfo = 5560;
-//; $tls::andreas = -7232;
-//; $tls::pandreas = 5568;
-//; $tls::wq = -7224;
-//; $tls::pwq = 5576;
-//; $tls::sig = -7176;
-//; $tls::psig = 5624;
-//; $tls::incyg = -7172;
-//; $tls::pincyg = 5628;
-//; $tls::spinning = -7168;
-//; $tls::pspinning = 5632;
-//; $tls::stacklock = -7164;
-//; $tls::pstacklock = 5636;
-//; $tls::stackptr = -7160;
-//; $tls::pstackptr = 5640;
-//; $tls::stack = -7152;
-//; $tls::pstack = 5648;
-//; $tls::initialized = -5104;
-//; $tls::pinitialized = 7696;
+//; $tls::__align = -8632;
+//; $tls::p__align = 4168;
+//; $tls::context = -8624;
+//; $tls::pcontext = 4176;
+//; $tls::thread_id = -7328;
+//; $tls::pthread_id = 5472;
+//; $tls::infodata = -7324;
+//; $tls::pinfodata = 5476;
+//; $tls::tid = -7176;
+//; $tls::ptid = 5624;
+//; $tls::_ctinfo = -7168;
+//; $tls::p_ctinfo = 5632;
+//; $tls::andreas = -7160;
+//; $tls::pandreas = 5640;
+//; $tls::wq = -7152;
+//; $tls::pwq = 5648;
+//; $tls::sig = -7104;
+//; $tls::psig = 5696;
+//; $tls::incyg = -7100;
+//; $tls::pincyg = 5700;
+//; $tls::spinning = -7096;
+//; $tls::pspinning = 5704;
+//; $tls::stacklock = -7092;
+//; $tls::pstacklock = 5708;
+//; $tls::stackptr = -7088;
+//; $tls::pstackptr = 5712;
+//; $tls::stack = -7080;
+//; $tls::pstack = 5720;
+//; $tls::initialized = -5032;
+//; $tls::pinitialized = 7768;
 //; __DATA__
 
 #define tls_locals (-12800)
@@ -91,31 +93,33 @@
 #define tls_psignal_arrived (4152)
 #define tls_will_wait_for_signal (-8640)
 #define tls_pwill_wait_for_signal (4160)
-#define tls_thread_context (-8632)
-#define tls_pthread_context (4168)
-#define tls_thread_id (-7400)
-#define tls_pthread_id (5400)
-#define tls_infodata (-7396)
-#define tls_pinfodata (5404)
-#define tls_tid (-7248)
-#define tls_ptid (5552)
-#define tls__ctinfo (-7240)
-#define tls_p_ctinfo (5560)
-#define tls_andreas (-7232)
-#define tls_pandreas (5568)
-#define tls_wq (-7224)
-#define tls_pwq (5576)
-#define tls_sig (-7176)
-#define tls_psig (5624)
-#define tls_incyg (-7172)
-#define tls_pincyg (5628)
-#define tls_spinning (-7168)
-#define tls_pspinning (5632)
-#define tls_stacklock (-7164)
-#define tls_pstacklock (5636)
-#define tls_stackptr (-7160)
-#define tls_pstackptr (5640)
-#define tls_stack (-7152)
-#define tls_pstack (5648)
-#define tls_initialized (-5104)
-#define tls_pinitialized (7696)
+#define tls___align (-8632)
+#define tls_p__align (4168)
+#define tls_context (-8624)
+#define tls_pcontext (4176)
+#define tls_thread_id (-7328)
+#define tls_pthread_id (5472)
+#define tls_infodata (-7324)
+#define tls_pinfodata (5476)
+#define tls_tid (-7176)
+#define tls_ptid (5624)
+#define tls__ctinfo (-7168)
+#define tls_p_ctinfo (5632)
+#define tls_andreas (-7160)
+#define tls_pandreas (5640)
+#define tls_wq (-7152)
+#define tls_pwq (5648)
+#define tls_sig (-7104)
+#define tls_psig (5696)
+#define tls_incyg (-7100)
+#define tls_pincyg (5700)
+#define tls_spinning (-7096)
+#define tls_pspinning (5704)
+#define tls_stacklock (-7092)
+#define tls_pstacklock (5708)
+#define tls_stackptr (-7088)
+#define tls_pstackptr (5712)
+#define tls_stack (-7080)
+#define tls_pstack (5720)
+#define tls_initialized (-5032)
+#define tls_pinitialized (7768)