In case SA_SIGINFO flag is given, the signal handler may change
the context and the application is supposed to pick up from the
changed context. So far we don't do that, so the context given
to the signal handler is basically read-only, unless the signal
handler calls setcontext or swapcontext.
For a start, restore the thread's signal mask from the uc_sigmask
value of the context given to the signal handler.
If that's feasible for Cygwin, we restore the entire context from
the context changed by the signal handler in a followup patch.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Rename files timer.* to posix_timer.*.
- Reimplement using an OS timer rather than a handcrafted wait loop.
- Use a Slim R/W Lock for synchronization.
- Drop timer chaining. It doesn't server a purpose since all timers
are local only.
- Rename ttstart to itimer_tracker to better reflect its purpose.
It's not the anchor for a timer chain anymore anyway.
- Drop fixup_timers_after_fork. Everything is process-local, nothing
gets inherited.
- Rename timer_tracker::disarm_event to disarm_overrun_event for
better readability.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Allow the signal thread to recognize we're called in consequence of
select on a signalfd. If the signal is part of the wait mask, don't
call any signal handler and don't remove the signal from the queue,
so a subsequent read (or sigwaitinfo/sigtimedwait) still gets the
signal. Instead, just signal the event object at
_cygtls::signalfd_select_wait for the thread running select.
The addition of signalfd_select_wait to _cygtls unearthed the alignment
problem of the context member again. To make sure this doesn't get lost,
improve the related comment in the header file so that this (hopefully)
doesn't get lost (again).
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This new function returns the name of the calling thread; works for both
cygthreads and pthreads. All calls to cygthread::name(/*void*/) replaced
by calls to mythreadname(/*void*/).
The third argument of RtlLookupFunctionEntry actually is documented as
_Inout_opt_ for both x64 and ARM, although generic doc says _Out_ only.
* exceptions.cc (__unwind_single_frame): Initialize hist variable.
GDB since commit 24cdb46e [1] can report and use these names.
Add utility function SetThreadName(), which sends a thread name to the
debugger.
Use that:
- to set the default thread name for main thread and newly created pthreads.
- in pthread_setname_np() for user thread names.
- for helper thread names in cygthread::create()
- for helper threads which are created directly with CreateThread.
Note that there can still be anonymous threads, created by system or
injected DLLs.
[1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=24cdb46e9f0a694b4fbc11085e094857f08c0419
Bump GPLv2+ to GPLv3+ for some files, clarify BSD 2-clause.
Everything else stays under GPLv3+.
New Linking Exception exempts resulting executables from LGPLv3 section 4.
Add CONTRIBUTORS file to keep track of licensing.
Remove 'Copyright Red Hat Inc' comments.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Don't use u_char, u_short, u_int or u_long in Cygwin, unless it refers
to the Winsock types. Use u_intN_t in BSD-based sources, unsigned char
where strings are concerned, uintN_t otherwise. Also:
* net.cc: Fix comment, we're not using u_long anymore.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
GCC 5 switched from C89 to C11 by default. This implies a change from
GNU to C99 inline by default, which have very different meanings of
extern inline vs. static inline:
https://gcc.gnu.org/onlinedocs/gcc/Inline.html
Marking these as gnu_inline retains the previous behaviour.
winsup/cygwin/
* exceptions.cc (exception::handle): Change debugging to int to fix
an always-true boolean comparison warning.
* include/cygwin/config.h (__getreent): Mark gnu_inline.
* winbase.h (ilockcmpexch, ilockcmpexch64): Ditto.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
* cygtls.h (_cygtls::wait_signal_arrived): Renamed from
set_signal_arrived.
(_cygtls::set_signal_arrived): New function signalling signal_arrived.
(_cygtls::reset_signal_arrived): Don't reset will_wait_for_signal.
(_cygtls::unwait_signal_arrived): New function only resetting
will_wait_for_signal.
(class wait_signal_arrived): Rename from set_signal_arrived.
Accommodate name change throughout Cygwin.
(wait_signal_arrived::~wait_signal_arrived): Call
_cygtls::unwait_signal_arrived. Add comment.
* cygserver_ipc.h (ipc_set_proc_info): Fetch signal_arrived handle
via call to _cygtls::get_signal_arrived.
* exceptions.cc (_cygtls::interrupt_setup): Signal signal_arrived via
call to _cygtls::set_signal_arrived.
(_cygtls::handle_SIGCONT): Ditto.
* fhandler_socket.cc (fhandler_socket::wait_for_events): Generate
WSAEVENT array prior to entering wait loop. Add cancel event object
if available. Remove calls to pthread_testcancel and just call
pthread::static_cancel_self if the cancel event object is signalled.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
glibc's tst-makecontext2 testcase uncovered a bug in
__cont_link_context. If the function misses to reserve
shadow space for the calls to setcontext/cygwin_exit,
both functions could overwrite memory beyond the stack
configured in uc_stack.
* exceptions.cc (__cont_link_context): x86_64: align stack and reserve
shadow space for subsequent function calls, otherwise suffer potential
buffer overflow.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* dcrt0.cc (initial_env): Reduce size of local path buffers to
PATH_MAX. Allocate debugger_command from process heap.
(init_windows_system_directory): Very early initialize new global
variable global_progname.
* dll_init.cc (dll_list::alloc): Make path buffer static. Explain why.
(dll_list::populate_deps): Use tmp_pathbuf for local path buffer.
* exceptions.cc (debugger_command): Convert to PWCHAR.
(error_start_init): Allocate debugger_command and fill with wide char
strings. Only allocate if NULL.
(try_to_debug): Just check if debugger_command is a NULL pointer to
return. Drop conversion from char to WCHAR and drop local variable
dbg_cmd.
* globals.cc (global_progname): New global variable to store Windows
application path.
* pinfo.cc (pinfo_basic::pinfo_basic): Just copy progname over from
global_progname.
(pinfo::status_exit): Let path_conv create the POSIX path to
avoid local buffer.
* pseudo_reloc.cc (__report_error): Utilize global_progname, drop local
buffer.
* smallprint.cc (__small_vsprintf): Just utilize global_progname for
%P format specifier.
(__small_vswprintf): Ditto.
* strace.cc (PROTECT): Change to reflect x being a pointer. Reformat.
(CHECK): Ditto. Reformat.
(strace::activate): Utilize global_progname, drop local buffer.
Fix formatting.
(strace::vsprntf): Reduce size of local progname buffer to NAME_MAX.
Copy and, if necessary, convert only the last path component to
progname.
(strace_buf_guard): New muto.
(buf): New static pointer.
(strace::vprntf): Use buf under strace_buf_guard lock only. Allocate
buffer space for buf on Windows heap.
* wow64.cc (wow64_respawn_process): Utilize global_progname, drop
local path buffer.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* exceptions.cc (__unwind_single_frame): Define empty macro on i686.
(_cygtls::call_signal_handler): Try to make sure signal context makes
sense in case we're generating context here. Add comment to explain.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* exceptions.cc (__unwind_single_frame): Move up in file to be
accessible from other places. Move comment to getcontext.
(stack_info::walk): Call __unwind_single_frame in 64 bit case. Fix
preceeding comment.
(myfault_altstack_handler): Call __unwind_single_frame.
(getcontext): Give comment from __unwind_single_frame a new home.
(swapcontext): Fix comment.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
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>
* 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>
* 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>
* 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>
* 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>
* 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>
* 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>
* 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>
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>
* 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>
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>
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.
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.
Corinna Vinschen
Mark Geisert
Michael Haubenwallner
Jon Turney
Yaakov Selkowitz