c019a66c32
* dcrt0.cc (cygwin_exit): Set exit_state to ES_EXIT_STARTING prior to calling real exit. * dll_init.cc (dll_list::detach): Remove dll from linked list and call destructors even if exiting. Don't call __cxa_finalize in exiting case.
428 lines
12 KiB
C++
428 lines
12 KiB
C++
/* dll_init.cc
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Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
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2007, 2008, 2009, 2010 Red Hat, Inc.
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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 "cygerrno.h"
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#include "perprocess.h"
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#include "dll_init.h"
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#include "environ.h"
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#include "security.h"
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#include "path.h"
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#include "fhandler.h"
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#include "dtable.h"
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#include "cygheap.h"
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#include "pinfo.h"
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#include "cygtls.h"
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#include "exception.h"
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#include <wchar.h>
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#include <sys/reent.h>
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extern void __stdcall check_sanity_and_sync (per_process *);
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dll_list dlls;
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static bool dll_global_dtors_recorded;
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/* Run destructors for all DLLs on exit. */
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void
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dll_global_dtors ()
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{
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int recorded = dll_global_dtors_recorded;
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dll_global_dtors_recorded = false;
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if (recorded && dlls.start.next)
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for (dll *d = dlls.end; d != &dlls.start; d = d->prev)
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d->run_dtors ();
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}
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/* Run all constructors associated with a dll */
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void
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per_module::run_ctors ()
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{
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void (**pfunc)() = ctors;
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/* Run ctors backwards, so skip the first entry and find how many
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there are, then run them. */
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if (pfunc)
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{
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int i;
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for (i = 1; pfunc[i]; i++);
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for (int j = i - 1; j > 0; j--)
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(pfunc[j]) ();
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}
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}
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/* Run all destructors associated with a dll */
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void
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per_module::run_dtors ()
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{
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void (**pfunc)() = dtors;
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while (*++pfunc)
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(*pfunc) ();
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}
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/* Initialize an individual DLL */
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int
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dll::init ()
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{
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int ret = 1;
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/* Why didn't we just import this variable? */
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*(p.envptr) = __cygwin_environ;
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/* Don't run constructors or the "main" if we've forked. */
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if (!in_forkee)
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{
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/* global contructors */
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p.run_ctors ();
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/* entry point of dll (use main of per_process with null args...) */
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if (p.main)
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ret = (*(p.main)) (0, 0, 0);
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}
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return ret;
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}
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/* Look for a dll based on name */
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dll *
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dll_list::operator[] (const PWCHAR name)
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{
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dll *d = &start;
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while ((d = d->next) != NULL)
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if (!wcscasecmp (name, d->name))
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return d;
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return NULL;
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}
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#define RETRIES 1000
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/* Allocate space for a dll struct. */
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dll *
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dll_list::alloc (HINSTANCE h, per_process *p, dll_type type)
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{
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WCHAR name[NT_MAX_PATH];
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DWORD namelen = GetModuleFileNameW (h, name, sizeof (name));
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/* Already loaded? */
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dll *d = dlls[name];
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if (d)
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{
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if (!in_forkee)
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d->count++; /* Yes. Bump the usage count. */
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return d; /* Return previously allocated pointer. */
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}
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/* FIXME: Change this to new at some point. */
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d = (dll *) cmalloc (HEAP_2_DLL, sizeof (*d) + (namelen * sizeof (*name)));
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/* Now we've allocated a block of information. Fill it in with the supplied
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info about this DLL. */
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d->count = 1;
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wcscpy (d->name, name);
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d->handle = h;
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d->has_dtors = true;
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d->p = p;
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d->type = type;
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if (end == NULL)
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end = &start; /* Point to "end" of dll chain. */
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end->next = d; /* Standard linked list stuff. */
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d->next = NULL;
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d->prev = end;
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end = d;
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tot++;
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if (type == DLL_LOAD)
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loaded_dlls++;
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return d;
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}
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dll *
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dll_list::find (void *retaddr)
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{
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MEMORY_BASIC_INFORMATION m;
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if (!VirtualQuery (retaddr, &m, sizeof m))
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return NULL;
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HMODULE h = (HMODULE) m.AllocationBase;
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dll *d = &start;
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while ((d = d->next))
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if (d->handle == h)
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break;
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return d;
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}
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/* Detach a DLL from the chain. */
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void
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dll_list::detach (void *retaddr)
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{
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dll *d;
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if (!myself || !(d = find (retaddr)))
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return;
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if (d->count <= 0)
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system_printf ("WARNING: trying to detach an already detached dll ...");
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if (--d->count == 0)
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{
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/* Ensure our exception handler is enabled for destructors */
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exception protect;
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/* Call finalize function if we are not already exiting */
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if (!exit_state)
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__cxa_finalize (d);
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d->run_dtors ();
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d->prev->next = d->next;
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if (d->next)
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d->next->prev = d->prev;
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if (d->type == DLL_LOAD)
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loaded_dlls--;
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if (end == d)
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end = d->prev;
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cfree (d);
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}
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}
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/* Initialization for all linked DLLs, called by dll_crt0_1. */
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void
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dll_list::init ()
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{
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/* Walk the dll chain, initializing each dll */
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dll *d = &start;
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dll_global_dtors_recorded = d->next != NULL;
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while ((d = d->next))
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d->init ();
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}
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#define A64K (64 * 1024)
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/* Mark every memory address up to "here" as reserved. This may force
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Windows NT to load a DLL in the next available, lowest slot. */
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static void
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reserve_upto (const PWCHAR name, DWORD here)
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{
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DWORD size;
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MEMORY_BASIC_INFORMATION mb;
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for (DWORD start = 0x10000; start < here; start += size)
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if (!VirtualQuery ((void *) start, &mb, sizeof (mb)))
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size = A64K;
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else
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{
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size = A64K * ((mb.RegionSize + A64K - 1) / A64K);
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start = A64K * (((DWORD) mb.BaseAddress + A64K - 1) / A64K);
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if (start + size > here)
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size = here - start;
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if (mb.State == MEM_FREE &&
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!VirtualAlloc ((void *) start, size, MEM_RESERVE, PAGE_NOACCESS))
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api_fatal ("couldn't allocate memory %p(%d) for '%W' alignment, %E\n",
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start, size, name);
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}
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}
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/* Release all of the memory previously allocated by "upto" above.
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Note that this may also free otherwise reserved memory. If that becomes
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a problem, we'll have to keep track of the memory that we reserve above. */
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static void
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release_upto (const PWCHAR name, DWORD here)
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{
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DWORD size;
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MEMORY_BASIC_INFORMATION mb;
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for (DWORD start = 0x10000; start < here; start += size)
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if (!VirtualQuery ((void *) start, &mb, sizeof (mb)))
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size = 64 * 1024;
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else
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{
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size = mb.RegionSize;
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if (!(mb.State == MEM_RESERVE && mb.AllocationProtect == PAGE_NOACCESS
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&& (((void *) start < cygheap->user_heap.base
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|| (void *) start > cygheap->user_heap.top)
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&& ((void *) start < (void *) cygheap
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|| (void *) start
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> (void *) ((char *) cygheap + CYGHEAPSIZE)))))
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continue;
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if (!VirtualFree ((void *) start, 0, MEM_RELEASE))
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api_fatal ("couldn't release memory %p(%d) for '%W' alignment, %E\n",
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start, size, name);
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}
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}
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/* Reload DLLs after a fork. Iterates over the list of dynamically loaded
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DLLs and attempts to load them in the same place as they were loaded in the
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parent. */
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void
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dll_list::load_after_fork (HANDLE parent)
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{
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for (dll *d = &dlls.start; (d = d->next) != NULL; )
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if (d->type == DLL_LOAD)
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for (int i = 0; i < 2; i++)
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{
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/* See if DLL will load in proper place. If so, free it and reload
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it the right way.
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It stinks that we can't invert the order of the initial LoadLibrary
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and FreeLibrar since Microsoft documentation seems to imply that
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should do what we want. However, once a library is loaded as
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above, the second LoadLibrary will not execute its startup code
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unless it is first unloaded. */
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HMODULE h = LoadLibraryExW (d->name, NULL, DONT_RESOLVE_DLL_REFERENCES);
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if (!h)
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system_printf ("can't reload %W, %E", d->name);
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else
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{
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FreeLibrary (h);
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if (h == d->handle)
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h = LoadLibraryW (d->name);
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}
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/* If we reached here on the second iteration of the for loop
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then there is a lot of memory to release. */
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if (i > 0)
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release_upto (d->name, (DWORD) d->handle);
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if (h == d->handle)
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break; /* Success */
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if (i > 0)
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/* We tried once to relocate the dll and it failed. */
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api_fatal ("unable to remap %W to same address as parent: %p != %p",
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d->name, d->handle, h);
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/* Dll loaded in the wrong place. Dunno why this happens but it
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always seems to happen when there are multiple DLLs attempting to
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load into the same address space. In the "forked" process, the
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second DLL always loads into a different location. So, block all
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of the memory up to the new load address and try again. */
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reserve_upto (d->name, (DWORD) d->handle);
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}
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in_forkee = false;
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}
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struct dllcrt0_info
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{
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HMODULE h;
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per_process *p;
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int res;
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dllcrt0_info (HMODULE h0, per_process *p0): h(h0), p(p0) {}
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};
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extern "C" int
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dll_dllcrt0 (HMODULE h, per_process *p)
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{
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dllcrt0_info x (h, p);
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if (_my_tls.isinitialized ())
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dll_dllcrt0_1 (&x);
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else
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_my_tls.call ((DWORD (*) (void *, void *)) dll_dllcrt0_1, &x);
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return x.res;
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}
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void
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dll_dllcrt0_1 (VOID *x)
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{
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HMODULE& h = ((dllcrt0_info *)x)->h;
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per_process*& p = ((dllcrt0_info *)x)->p;
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int& res = ((dllcrt0_info *)x)->res;
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if (p == NULL)
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p = &__cygwin_user_data;
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else
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*(p->impure_ptr_ptr) = __cygwin_user_data.impure_ptr;
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bool linked = !in_forkee && !cygwin_finished_initializing;
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/* Broken DLLs built against Cygwin versions 1.7.0-49 up to 1.7.0-57
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override the cxx_malloc pointer in their DLL initialization code,
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when loaded either statically or dynamically. Because this leaves
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a stale pointer into demapped memory space if the DLL is unloaded
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by a call to dlclose, we prevent this happening for dynamically
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loaded DLLS in dlopen by saving and restoring cxx_malloc around
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the call to LoadLibrary, which invokes the DLL's startup sequence.
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Modern DLLs won't even attempt to override the pointer when loaded
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statically, but will write their overrides directly into the
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struct it points to. With all modern DLLs, this will remain the
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default_cygwin_cxx_malloc struct in cxx.cc, but if any broken DLLs
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are in the mix they will have overridden the pointer and subsequent
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overrides will go into their embedded cxx_malloc structs. This is
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almost certainly not a problem as they can never be unloaded, but
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if we ever did want to do anything about it, we could check here to
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see if the pointer had been altered in the early parts of the DLL's
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startup, and if so copy back the new overrides and reset it here.
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However, that's just a note for the record; at the moment, we can't
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see any need to worry about this happening. */
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/* Partially initialize Cygwin guts for non-cygwin apps. */
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if (dynamically_loaded && user_data->magic_biscuit == 0)
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dll_crt0 (p);
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else
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check_sanity_and_sync (p);
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dll_type type;
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/* If this function is called before cygwin has finished
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initializing, then the DLL must be a cygwin-aware DLL
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that was explicitly linked into the program rather than
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a dlopened DLL. */
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if (linked)
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type = DLL_LINK;
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else
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{
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type = DLL_LOAD;
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dlls.reload_on_fork = 1;
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}
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/* Allocate and initialize space for the DLL. */
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dll *d = dlls.alloc (h, p, type);
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/* If d == NULL, then something is broken.
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Otherwise, if we've finished initializing, it's ok to
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initialize the DLL. If we haven't finished initializing,
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it may not be safe to call the dll's "main" since not
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all of cygwin's internal structures may have been set up. */
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if (!d || (!linked && !d->init ()))
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res = -1;
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else
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res = (DWORD) d;
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}
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/* OBSOLETE: This function is obsolete and will go away in the
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future. Cygwin can now handle being loaded from a noncygwin app
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using the same entry point. */
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extern "C" int
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dll_noncygwin_dllcrt0 (HMODULE h, per_process *p)
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{
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return dll_dllcrt0 (h, p);
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}
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extern "C" void
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cygwin_detach_dll (dll *)
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{
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HANDLE retaddr;
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if (_my_tls.isinitialized ())
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retaddr = (void *) _my_tls.retaddr ();
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else
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retaddr = __builtin_return_address (0);
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dlls.detach (retaddr);
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}
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extern "C" void
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dlfork (int val)
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{
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dlls.reload_on_fork = val;
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}
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/* Called from various places to update all of the individual
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ideas of the environ block. Explain to me again why we didn't
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just import __cygwin_environ? */
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void __stdcall
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update_envptrs ()
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{
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for (dll *d = dlls.istart (DLL_ANY); d; d = dlls.inext ())
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*(d->p.envptr) = __cygwin_environ;
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*main_environ = __cygwin_environ;
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}
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