Commit Graph

461 Commits

Author SHA1 Message Date
Corinna Vinschen 60f10c64aa x86_64: Handle myfault exceptions when running on alternate signal stack
x86_64 only:
        * cygtls.cc (san::leave): Restore _my_tls.andreas.
        * cygtls.h (class san):  Add _clemente as in 32 bit case.  Add ret and
        frame members.
        (san::san): Handle _my_tls.andreas as on 32 bit.  Take parameter and
        write it to new member ret.  Store current stack pointer in frame.
        (san::~san): New destructor to restore _my_tls.andreas.
        (__try): Use __l_except address as parameter to san::san.
        * dcrt0.cc (dll_crt0_0): Add myfault_altstack_handler as vectored
        continuation handler.
        * exception.h (myfault_altstack_handler): Declare.
        * exceptions.cc (myfault_altstack_handler): New function.  Explain what
        it's good for.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-07-07 20:45:06 +02:00
Corinna Vinschen 2cd7eb7f60 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>
2015-07-04 22:49:30 +02:00
Corinna Vinschen c2c1b84309 Handle ss_flags value longjmp safe.
* exceptions.cc (_cygtls::call_signal_handler): Drop manipulating
	thread's ss_flags here.  It's not safe against longjmp.
	* signal.cc (sigaltstack): Check if we're running on the alternate
	stack and set ss_flags returned in oss to SS_ONSTACK.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-06-27 12:08:07 +02:00
Corinna Vinschen f4abb28ea8 Don't push on original stack during alternate signal stack setup
* exceptions.cc (_cygtls::call_signal_handler): Drop pushing a register
	on the original stack, it confuses GCC.  Rearrange the assembler code
	so that $rax/$eax is not used by GCC to prepare an argument value.
	Use $rax/$eax without saving.  Drop clearing $rbp/$epb.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-06-22 13:09:55 +02:00
Corinna Vinschen b6c18f2a64 Safe all clobbered volatile registers when using alternate stack
* exceptions.cc (_cygtls::call_signal_handler): Drop subtracting 16
	bytes from the alternate stack, it's not necessary.  Safe all clobbered
	registers.  Safe one on the orignal stack, the others on the alternate
	stack on both platforms.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-06-21 13:58:57 +02:00
Corinna Vinschen 44745e3165 Fix comments
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-06-20 20:56:55 +02:00
Corinna Vinschen 0cbf19283b Implement using alternate signal stack in Cygwin
* exceptions.cc (_cygtls::call_signal_handler): Implement alternate
	signal stack handling.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-06-20 20:21:02 +02:00
Corinna Vinschen 22465796ed Preliminary infrastructure to implement alternate stack
* libc/include/sys/signal.h: Define SS_ONSTACK and SS_DISABLE
	unconditionally.
	(sigaltstack): Enable prototype on Cygwin.

	* common.din (sigaltstack): Export.
	* cygtls.cc (_cygtls::init_thread): Initialize altstack.
	* cygtls.h (__tlsstack_t): Rename from __stack_t to distinguish
	more clearly from stack_t.  Accommodate throughout.
	(_cygtls): Add altstack member.
	* exceptions.cc (exception::handle): Set SIGSEGV handler to SIG_DFL
	if we encounter a stack overflow, and no alternate stack has been
	defined.
	* include/cygwin/signal.h (MINSIGSTKSZ): Define
	(SIGSTKSZ): Define.
	(SA_ONSTACK): Define.
	* signal.cc (sigaltstack): New function.
	* tlsoffset.h: Regenerate.
	* tlsoffset64.h: Ditto.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-06-19 16:12:45 +02:00
Corinna Vinschen 715ac1e872 Formatting fixes in exceptions.cc
* Makefile.in (install-man): Exclude release subdir from search paths.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-06-19 16:12:10 +02:00
Corinna Vinschen 95c5a3f6b7 Don't enforce SA_RESTART in non-main threads
* exceptions.cc (_cygtls::call_signal_handler): Disable enforcing
	SA_RESTART in non-main threads to allow returning with EINTR from
	system calls.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-06-15 16:15:54 +02:00
Jon TURNEY bccc0e83e8 Set mcontext.cr2 to the faulting address
* exceptions.cc (call_signal_handler): Set mcontext.cr2 to the
	faulting address.

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
2015-04-23 21:58:33 +02:00
Jon TURNEY 9043956ce8 Only construct ucontext for SA_SIGINFO signal handlers
* exceptions.cc (call_signal_handler): Only bother to construct
	the ucontext for signal handlers with SA_SIGINFO set.  Set
	mcontext.oldmask.

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
2015-04-23 21:58:32 +02:00
Jon TURNEY 65c071bc4d Initialize context before RtlContextCapture
* exceptions.cc (call_signal_handler): Zero initialize context and set
	context flags, as RlCaptureContext doesn't.

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
2015-04-23 21:58:32 +02:00
Jon TURNEY 9e8932d6da Provide ucontext to signal handlers
Add ucontext.h header, defining ucontext_t and mcontext_t types.

Provide sigaction sighandlers with a ucontext_t parameter, containing stack and
context information.

	* include/sys/ucontext.h : New header.
	* include/ucontext.h : Ditto.
	* exceptions.cc (call_signal_handler): Provide ucontext_t
	parameter to signal handler function.

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
2015-04-23 21:57:10 +02:00
Corinna Vinschen 3fb21f9143 Prepare to rename/reuse struct ucontext.
* cygtls.h (struct _cygtls): Convert thread_context to type CONTEXT.
	* exceptions.cc (_cygtls::signal_debugger): Use sizeof (CONTEXT) for
	size of CONTEXT copied for GDB's digestion.
	* include/cygwin/signal.h: Add a preliminary comment.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2015-04-23 21:57:07 +02:00
Jon TURNEY e9e47b8ce6 Teach stackinfo::walk() how to virtually unwind the tls sigstack
This improves how stackinfo::dumpstack() dumps _sigbe and sigdelayed frames

	* exceptions.cc (stack_info): Add sigstackptr member.
	(walk): Unwind sigstackptr inside _sigbe and sigdelayed.
	* gendef (_sigdelayed_end): Add symbol to mark end of sigdelayed.

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
2015-03-13 13:05:52 +00:00
Corinna Vinschen 26158dc3e9 * cygheap.cc (init_cygheap::init_tls_list): Accommodate threadlist
having a new type threadlist_t *.  Convert commented out code into an
	#if 0.  Create thread mutex.  Explain why.
	(init_cygheap::remove_tls): Drop timeout value.  Always wait infinitely
	for tls_sentry.  Return mutex HANDLE of just deleted threadlist entry.
	(init_cygheap::find_tls): New implementation taking tls pointer as
	search parameter.  Return threadlist_t *.
	(init_cygheap::find_tls): Return threadlist_t *.  Define ix as auto
	variable.  Drop exception handling since crash must be made impossible
	due to correct synchronization.  Return with locked mutex.
	* cygheap.h (struct threadlist_t): Define.
	(struct init_cygheap): Convert threadlist to threadlist_t type.
	(init_cygheap::remove_tls): Align declaration to above change.
	(init_cygheap::find_tls): Ditto.
	(init_cygheap::unlock_tls): Define.
	* cygtls.cc (_cygtls::remove): Unlock and close mutex when finishing.
	* exceptions.cc (sigpacket::process): Lock _cygtls area of thread before
	accessing it.
	* fhandler_termios.cc (fhandler_termios::bg_check): Ditto.
	* sigproc.cc (sig_send): Ditto.
	* thread.cc (pthread::exit): Ditto.  Add comment.
	(pthread::cancel): Ditto.
2014-11-28 20:46:13 +00:00
Corinna Vinschen 3f3bd10104 * Throughout, use __try/__except/__endtry blocks, rather than myfault
handler.
	* cygtls.cc (_cygtls::remove): Accommodate the fact that pathbufs
	has been moved from _local_storage to _cygtls.
	* cygtls.h (class tls_pathbuf): Add comment to hint to gendef usage
	of counters.  Change type of counters to uint32_t for clarity.
	Remove _cygtls as friend class.
	(struct _local_storage): Move pathbufs from here...
	(struct _cygtls): ...to here, allowing to access it from _sigbe.
	(class san): Only define on 32 bit.  Remove errno, _c_cnt and _w_cnt
	members.
	(san::setup): Drop parameter.  Don't initialize removed members.
	(san::leave): Don't set removed members.
	(class myfault): Only define on 32 bit.
	(myfault::faulted): Only keep implementation not taking any parameter.
	Drop argument in call to sebastian.setup.
	(__try/__leave/__except/__endtry): Implement to support real SEH.  For
	now stick to SJLJ on 32 bit.
	* dcrt0.cc (dll_crt0_0): Drop 64 bit call to
	exception::install_myfault_handler.
	* exception.h (exception_handler): Define with EXCEPTION_DISPOSITION
	as return type.
	(PDISPATCHER_CONTEXT): Define as void * on 32 bit.  Define as pointer
	to _DISPATCHER_CONTEXT on 64 bit.
	(class exception): Define separately for 32 and 64 bit.
	(exception::myfault): Add handler for myfault SEH handling on 64 bit.
	(exception::exception): Fix mangled method name to account for change
	in type of last parameter.
	(exception::install_myfault_handler): Remove.
	* exceptions.cc (exception::myfault_handle): Remove.
	(exception::myfault): New SEH handler for 64 bit.
	* gendef (_sigbe): Set tls_pathbuf counters to 0 explicitely when
	returning to the caller.
	* ntdll.h: Move a comment to a better place.
	(struct _SCOPE_TABLE): Define on 64 bit.
	* thread.cc (verifyable_object_isvalid): Remove gcc 4.7 workaround.
	* tls_pbuf.cc (tls_pbuf): Fix to accommodate new place of pathbufs.
	(tls_pathbuf::destroy): Change type of loop variables to uint32_t.
	* tls_pbuf.h (class tmp_pathbuf): Change type of buffer counters to
	uint32_t.  Accommodate new place of pathbufs.
	* tlsoffsets.h: Regenerate.
	* tlsoffsets64.h: Regenerate.
2014-08-22 09:21:33 +00:00
Corinna Vinschen 3dab1e488a * exceptions.cc (exception::myfault_handle): Rephrase comment. 2014-07-09 10:41:11 +00:00
Corinna Vinschen 64cfc4ac5a * exceptions.cc (exception::myfault_handle): Fix typo in comment. 2014-07-09 10:21:05 +00:00
Corinna Vinschen e1d158a04f * exceptions.cc (exception::myfault_handle): Disable handling
STATUS_STACK_OVERFLOW.  Explain why.
2014-07-07 19:58:16 +00:00
Corinna Vinschen 4337e28e62 * exceptions.cc (try_to_debug): Free environment pointer when not used
anymore (CID 59968).
2014-06-23 13:23:14 +00:00
Corinna Vinschen f2e040ce76 * exceptions.cc (try_to_debug): Fix size of dbg_cmd (CID 59929). 2014-05-19 10:28:54 +00:00
Corinna Vinschen 09a7cdcc4b * exceptions.cc (exception::myfault_handle): Only handle the minimum
amount of exceptions the myfault handler was designed for.
2014-04-09 19:20:01 +00:00
Christopher Faylor c6eaf1f3f7 * DevNotes: Add entry cgf-000025.
* exceptions.cc (_cygtls::signal_debugger): Reorganize to avoid contacting the
debugger if we have already done so via the exception handler.  Eliminate need
for goto.  Remove an ifdef in favor of just allocating a larger buffer.
2014-03-29 21:16:09 +00:00
Corinna Vinschen 20738749f6 * dcrt0.cc (dll_crt0_0): Install myfault exception handler on x86_64.
* exception.h (exception_list): Typedef as void on x86_64.
	(exception::handler_installed): Remove.
	(exception::handle_while_being_debugged): Remove.
	(exception::myfault_handle): Declare for x86_64.
	(exception::handle): Declare as ordinary exception handler on x86_64
	as well.
	(exception::exception): Drop previous code (again).  Install
	exception::handle as SEH handler.
	(exception::install_myfault_handler): New x86_64-only method to
	install exception::myfault_handle as VEH handler.  Explain why.
	(exception::~exception): For x86_64, define frame end label (again).
	* exceptions.cc (CYG_EXC_CONTINUE_EXECUTION): Drop definition.
	(CYG_EXC_CONTINUE_SEARCH): Ditto.
	(exception::myfault_handle): New x86_64-only method, VEH handler to
	handle myfault exceptions.
	(exception::handle): Define as ordinary exception handler on x86_64
	as well.  Use ExceptionContinueExecution and ExceptionContinueSearch
	throughout instead of deleted Cygwin macros.  Don't handle myfault
	exceptions on x86_64.
2014-03-28 22:31:53 +00:00
Corinna Vinschen c16097ed26 * exceptions.cc (_cygtls::signal_debugger): Move memcpy to copy context
from incoming siginfo_t to thread_context, too.
2014-03-28 16:56:03 +00:00
Corinna Vinschen 2c1e724ba4 * exception.h (exception::handle_while_being_debugged): Declare.
(exception::exception): Install unhandled exception filter.
	* exceptions.cc (exception::handle_while_being_debugged): New method.
2014-03-19 16:08:21 +00:00
Corinna Vinschen 8c0389d330 Partially revert patch from 2014-03-04.
* exception.h (exception::handler_installed): Declare.
	(exception::exception): Install vectored exception handler on x86_64.
	(exception::~exception): Remove for x86_64.
	* exceptions.cc (exception::handler_installed): Define.
2014-03-18 13:51:18 +00:00
Corinna Vinschen 4e3c8d9425 * exception.h (exception::handler_installed): Remove.
(exception::exception): Remove old code.  Manually install SEH handler
	instead.
	(exception::~exception): For x86_64, define frame end label.
	* exceptions.cc (exception::handler_installed): Remove.
2014-03-04 11:56:42 +00:00
Christopher Faylor 8aca67421d * exceptions.h (cygwin_exception::open_stackdumpfile): Move old function into
class.
(cygwin_exception::h): New member.
(cygwin_exception::cygwin_exception): Initialize h to NULL.
* exceptions.cc (cygwin_exception::open_stackdumpfile): Move into
cygwin_exception class.  Use 'h' class member.
(cygwin_exception::dumpstack): Close stack dump file handle if opened.
2014-01-08 16:51:20 +00:00
Christopher Faylor ae8456bdf2 * globals.cc (hntdll): Define/declare.
* exceptions.cc (inside_kernel): Don't call GetModuleFileName if we know we're
in ntdll.
* sigproc.cc (wait_sig): Initialize hntdll.
2013-12-09 20:32:24 +00:00
Corinna Vinschen d2a88d9792 Throughout, drop unnecessary explicit includes of windows header files
included by default.
	* winlean.h: Add long comment to explain why we have to define certain
	symbols.
	(_NORMALIZE_): Define.
	(_WINNLS_): Drop definition and subsequent undef.
	(_WINNETWK_): Ditto.
	(_WINSVC_): Ditto.

2013-11-23  Eric Blake  <eblake@redhat.com>
2013-11-24 12:13:36 +00:00
Christopher Faylor d31805a14c * exceptions.cc (signal_exit): Remove comment. Use __builtin_frame_address. 2013-07-20 17:11:44 +00:00
Christopher Faylor 5ce53ae0ea * exceptions.cc (signal_exit): Nope. Nevermind. Dump core unconditionally. 2013-07-20 16:19:51 +00:00
Christopher Faylor efe8407eca reword comment 2013-07-19 23:19:27 +00:00
Christopher Faylor fb6cf945f9 * exceptions.cc (signal_exit): Add a FIXME comment. 2013-07-19 23:13:58 +00:00
Christopher Faylor 3a4dab46c3 * exceptions.cc (signal_exit): Only dump core when it's a "kernel" signal.
Only use RtlCaptureContext on x86_64.  It doesn't seem to do what's expected on
x86.
2013-07-19 23:04:32 +00:00
Christopher Faylor 62003f180a * exceptions.cc (try_to_debug): Don't use yield() when waiting for another
process.
(sigpacket::setup_handler): Fix long-standing problem where loop could exit
with lock held.
2013-06-08 16:54:41 +00:00
Christopher Faylor 5d35299e51 * cygwait.cc (cygwait): Remove lock around sig retrieval since this code is
essentially guarded by thread-specific signal_arrived.
* exceptions.cc (_cygtls::handle_SIGCONT): Simplify.  Eliminate lock/unlock
since code is guarded by signal_arrived.
2013-06-08 14:38:20 +00:00
Christopher Faylor da6461a4d5 * exceptions.cc (_cygtls::handle_SIGCONT): Reinstate previous behavior but make
sure that yield() isn't called when signal stack is locked.
2013-06-07 17:09:56 +00:00
Christopher Faylor 0f38043d8b * exceptions.cc (exception::handle): Add comment explaining si_addr behavior. 2013-06-07 16:05:12 +00:00
Corinna Vinschen b3f0fb6baa * exceptions.cc (_cygtls::handle_SIGCONT): Simplify loop waiting for
sig_handle_tty_stop to wake up.  Make sure to unlock before calling
	yield to avoid starvation of sig_handle_tty_stop.  Add comments.
	* miscfuncs.cc (yield): Explain why yield should never be called under
	_cygtls::lock conditions.  Call SleepEx with 1ms timeout.  Explain why.
2013-06-06 15:29:41 +00:00
Corinna Vinschen fa35814af1 * exceptions.cc (exception::handle): Resurrect accidentally lost
patch from 2009-07-22: Set si_addr according to POSIX for SIGSEGV.
2013-06-02 09:11:09 +00:00
Christopher Faylor cc5bdf003f * exceptions.cc (cygwin_exception::dumpstack): Guard against wild pointer
dereference.
(CYG_EXC_CONTINUE_EXECUTION): Define based on standard Windows definition.
(CYG_EXC_CONTINUE_SEARCH): Ditto.
(exception::handle): Move andreas detection earlier.  Make comment clearer.
(signal_exit): Set core-dumped flag.
2013-04-30 23:47:01 +00:00
Corinna Vinschen 61522196c7 * Merge in cygwin-64bit-branch. 2013-04-23 09:44:36 +00:00
Christopher Faylor 9d2155089e * cygtls.h (_cygtls::reset_signal_arrived): Actually reset the signal_arrived
event.
(_cygtls::handle_SIGCONT): Declare ew function.
* cygwait.cc (is_cw_sig_handle): Delete.
(is_cw_sig_cont): New convenience define.
(cygwait): Clear signal if is_cw_sig_cont and we got a SIGCONT.
* cygwait.h (cw_wait_mask): Add cw_sig_cont.
* exceptions.cc (sig_handle_tty_stop): Tighten "incyg" region.  Use cw_sig_cont
param for cygwait.  Don't zero signal here outside of lock.
(sigpacket::setup_handler): Don't check for in_forkee since we will now never
get here in that state.
(_cygtls::handle_SIGCONT): Define new function.
(sigpacket::process): Call handle_SIGCONT early to deal with SIGCONT.  Nuke
continue_now handling.  Allow SIGKILL to kill a suspended process.  Delete a
couple of now-unneeded labels.
(_cygtls::call_signal_handler): Reorganize setting of incyg within lock.
* sigproc.cc (pending_signals): Simplify.
(pending_signals::clear): New method.
(_cygtls::remove_wq): Reorganize to always close wq.thread_ev if it exists to
avoid handle leaks.
(sig_clear): Simplify by just calling sigq.clear().
(sig_dispatch_pending): Always call sigq.pending even in signal thread to force
another loop in wait_sig.
(sig_send): Remove a "goto out" just before out: label.
(pending_signals::add): Simplify.
(pending_signals::del): Delete.
(pending_signals::next): Delete.
(wait_sig): Define variable q to be the start of the signal queue.  Just
iterate through sigq queue, deleting processed or zeroed signals.  Only set
clearwait when the current signal is SIGCHLD.
* sigproc.h: Add a comment about an unused enum.
2013-04-09 01:01:19 +00:00
Christopher Faylor 8f8eeb70ba * child_info.h (cygheap_exec_info::sigmask): Declare new field.
* cygheap.cc (init_cygheap::find_tls): Rename threadlist_ix -> ix.  Only take
one pass through thread list, looking for eligible threads to signal.  Set a
new param indicating that function has found a sigwait* mask.
* cygheap.h (init_cygheap::find_tls): Reflect new parameter.
* dcrt0.cc (parent_sigmask): New variable.
(child_info_spawn::handle_spawn): Save parent's signal mask here.
(dll_crt0_1): Restore parent's signal mask to tls sigmask as appropriate.  Call
sig_dispatch_pending to flush signal queue when we can finally do something
with signals.
* exceptions.cc (sigpacket::process): Avoid attempting to handle signals if we
haven't finished initializing.  Rely on the fact that find_tls will do mask
checking and don't do it again.  Delete ill-named 'dummy' variable.
* sigproc.cc (cygheap_exec_info::alloc): Save calling thread's signal mask in
new sigmask field.
(wait_sig): Try to debug when WFSO fails and DEBUGGING is defined.
* thread.cc (pthread::set_tls_self_pointer): Make this a true automatic method
rather than inexplicably relying on a thread parameter.
(pthread::thread_init_wrapper): Accommodate set_tls_self_pointer change to
non-static.  Initialize sigmask before setting tid or suffer signal races.
* ehread.h (pthread::set_tls_self_pointer): Make non-static, delete parameter.
2013-03-31 12:35:44 +00:00
Christopher Faylor 1a863e04b3 * exceptions.cc (exception::handle): Generalize comment. 2013-03-28 16:14:53 +00:00
Christopher Faylor 56bc657ce4 * cygtls.h (_cygtls::signal_debugger): Change argument type.
(_cygtls::copy_context): Delete declaration.
* exceptions.cc (exception::handle): Don't call copy_context() here.  Move
signal_handler call earlier and always call it.
(_cygtls::copy_context): Delete definition.
(_cygtls::signal_debugger): Move copy_context logic here.  Suspend thread
receiving signal before gathering context information.
2013-03-09 21:55:18 +00:00