128 lines
3.2 KiB
C++
128 lines
3.2 KiB
C++
/* init.cc
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This file is part of Cygwin.
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This software is a copyrighted work licensed under the terms of the
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Cygwin license. Please consult the file "CYGWIN_LICENSE" for
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details. */
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#include "winsup.h"
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#include "cygtls.h"
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#include "ntdll.h"
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#include "shared_info.h"
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static DWORD _my_oldfunc;
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static char *search_for = (char *) cygthread::stub;
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unsigned threadfunc_ix[8];
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static bool dll_finished_loading;
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#define OLDFUNC_OFFSET -1
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static void WINAPI
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threadfunc_fe (VOID *arg)
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{
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#ifdef __i386__
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#if __GNUC_PREREQ(6,0)
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#pragma GCC diagnostic ignored "-Wframe-address"
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#endif
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(void)__builtin_return_address(1);
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#if __GNUC_PREREQ(6,0)
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#pragma GCC diagnostic pop
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#endif
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asm volatile ("andl $-16,%%esp" ::: "%esp");
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#endif
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_cygtls::call ((DWORD (*) (void *, void *)) TlsGetValue (_my_oldfunc), arg);
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}
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/* If possible, redirect the thread entry point to a cygwin routine which
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adds tls stuff to the stack. */
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static void
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munge_threadfunc ()
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{
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int i;
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char **ebp = (char **) __builtin_frame_address (0);
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if (!threadfunc_ix[0])
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{
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char **peb;
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char **top = (char **) NtCurrentTeb()->Tib.StackBase;
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for (peb = ebp, i = 0; peb < top && i < 7; peb++)
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if (*peb == search_for)
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threadfunc_ix[i++] = peb - ebp;
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if (0 && !threadfunc_ix[0])
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{
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try_to_debug ();
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return;
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}
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}
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if (threadfunc_ix[0])
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{
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char *threadfunc = NULL;
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NtQueryInformationThread (NtCurrentThread (),
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ThreadQuerySetWin32StartAddress,
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&threadfunc, sizeof threadfunc, NULL);
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if (!search_for || threadfunc == search_for)
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{
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search_for = NULL;
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for (i = 0; threadfunc_ix[i]; i++)
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if (!threadfunc || ebp[threadfunc_ix[i]] == threadfunc)
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ebp[threadfunc_ix[i]] = (char *) threadfunc_fe;
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TlsSetValue (_my_oldfunc, threadfunc);
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}
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}
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}
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void dll_crt0_0 ();
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/* Non-static fake variable so GCC doesn't second-guess if we *really*
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need the alloca'd space in the DLL_PROCESS_ATTACH case below... */
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void *alloca_dummy;
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extern "C" BOOL WINAPI
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dll_entry (HANDLE h, DWORD reason, void *static_load)
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{
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BOOL test_stack_marker;
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switch (reason)
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{
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case DLL_PROCESS_ATTACH:
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init_console_handler (false);
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cygwin_hmodule = (HMODULE) h;
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dynamically_loaded = (static_load == NULL);
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/* Starting with adding the POSIX-1.2008 per-thread locale functionality,
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we need an initalized _REENT area even for the functions called from
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dll_crt0_0. Most importantly, we need the _REENT->_locale pointer
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initialized to NULL, so subsequent calls to locale-specific functions
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will always fall back to __global_locale, rather then crash due to
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_REENT->_locale having an arbitrary value. */
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alloca_dummy = alloca (CYGTLS_PADSIZE);
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ZeroMemory (alloca_dummy, CYGTLS_PADSIZE);
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memcpy (_REENT, _GLOBAL_REENT, sizeof (struct _reent));
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dll_crt0_0 ();
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_my_oldfunc = TlsAlloc ();
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dll_finished_loading = true;
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break;
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case DLL_PROCESS_DETACH:
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if (dynamically_loaded)
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shared_destroy ();
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break;
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case DLL_THREAD_ATTACH:
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if (dll_finished_loading)
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munge_threadfunc ();
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break;
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case DLL_THREAD_DETACH:
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if (dll_finished_loading
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&& (PVOID) &_my_tls > (PVOID) &test_stack_marker
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&& _my_tls.isinitialized ())
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_my_tls.remove (0);
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break;
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}
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return TRUE;
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}
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