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* dll_init.cc (dll_list::find_by_modname): New function to search the dll list

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for a module name only (no path).
(dll_list::alloc): Initialize newly-added members of struct dll.
(dll_list::append): New function to factor out the append operation
(used by dll_list::topsort).
(dll_list::populate_deps): New function to identify dll dependencies.
(dll_list::topsort): New function to sort the dll list topologically by
dependencies.
(dll_list::topsort_visit): New helper function for the above.
* dll_init.h (dll::ndeps): New class member.
(dll::deps): Ditto.
(dll::modname): Ditto.
(dll_list::find_by_modname): New function related to topsort.
(dll_list::populate_all_deps): Ditto.
(dll_list::populate_deps): Ditto.
(dll_list::topsort): Ditto.
(dll_list::topsort_visit): Ditto.
(dll_list::append): Ditto.
(pefile): New struct allowing simple introspection of dll images.
* fork.cc (fork): Topologically sort the dll list before forking
* child_info.h (CURR_CHILD_INFO_MAGIC): Refresh.
(child_info::refresh_cygheap): New function.
* spawn.cc (spawn_guts): Call refresh_cygheap before creating a new process to
ensure that cygheap_max is up-to-date.
* fork.cc (frok::parent): Ditto.
This commit is contained in:
Christopher Faylor
2011-05-30 06:52:12 +00:00
parent 3a88e09e7f
commit 977ad5434c
6 changed files with 207 additions and 35 deletions
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176
winsup/cygwin/dll_init.cc
View File

@@ -116,6 +116,18 @@ dll_list::operator[] (const PWCHAR name)
return NULL;
}
/* Look for a dll based on is short name only (no path) */
dll *
dll_list::find_by_modname (const PWCHAR name)
{
dll *d = &start;
while ((d = d->next) != NULL)
if (!wcscasecmp (name, d->modname))
return d;
return NULL;
}
#define RETRIES 1000
/* Allocate space for a dll struct. */
@@ -161,15 +173,14 @@ dll_list::alloc (HINSTANCE h, per_process *p, dll_type type)
d->handle = h;
d->has_dtors = true;
d->p = p;
d->ndeps = 0;
d->deps = NULL;
d->modname = wcsrchr (d->name, L'\\');
if (d->modname)
d->modname++;
d->image_size = ((pefile*)h)->optional_hdr ()->SizeOfImage;
d->type = type;
if (end == NULL)
end = &start; /* Point to "end" of dll chain. */
end->next = d; /* Standard linked list stuff. */
d->next = NULL;
d->prev = end;
end = d;
tot++;
append (d);
if (type == DLL_LOAD)
loaded_dlls++;
}
@@ -178,6 +189,119 @@ dll_list::alloc (HINSTANCE h, per_process *p, dll_type type)
return d;
}
void
dll_list::append (dll* d)
{
if (end == NULL)
end = &start; /* Point to "end" of dll chain. */
end->next = d; /* Standard linked list stuff. */
d->next = NULL;
d->prev = end;
end = d;
tot++;
}
void dll_list::populate_deps (dll* d)
{
WCHAR wmodname[NT_MAX_PATH];
pefile* pef = (pefile*) d->handle;
PIMAGE_DATA_DIRECTORY dd = pef->idata_dir (IMAGE_DIRECTORY_ENTRY_IMPORT);
/* Annoyance: calling crealloc with a NULL pointer will use the
wrong heap and crash, so we have to replicate some code */
long maxdeps = 4;
d->deps = (dll**) cmalloc (HEAP_2_DLL, maxdeps*sizeof (dll*));
d->ndeps = 0;
for (PIMAGE_IMPORT_DESCRIPTOR id=
(PIMAGE_IMPORT_DESCRIPTOR) pef->rva (dd->VirtualAddress);
dd->Size && id->Name;
id++)
{
char* modname = pef->rva (id->Name);
sys_mbstowcs (wmodname, NT_MAX_PATH, modname);
if (dll* dep = find_by_modname (wmodname))
{
if (d->ndeps >= maxdeps)
{
maxdeps = 2*(1+maxdeps);
d->deps = (dll**) crealloc (d->deps, maxdeps*sizeof (dll*));
}
d->deps[d->ndeps++] = dep;
}
}
/* add one to differentiate no deps from unknown */
d->ndeps++;
}
void
dll_list::topsort ()
{
/* Anything to do? */
if (!end)
return;
/* make sure we have all the deps available */
dll* d = &start;
while ((d = d->next))
if (!d->ndeps)
populate_deps (d);
/* unlink head and tail pointers so the sort can rebuild the list */
d = start.next;
start.next = end = NULL;
topsort_visit (d, true);
/* clear node markings made by the sort */
d = &start;
while ((d = d->next))
{
debug_printf ("%W", d->modname);
for (int i=1; i < -d->ndeps; i++)
debug_printf ("-> %W", d->deps[i-1]->modname);
/* It would be really nice to be able to keep this information
around for next time, but we don't have an easy way to
invalidate cached dependencies when a module unloads. */
d->ndeps = 0;
cfree (d->deps);
d->deps = NULL;
}
}
/* A recursive in-place topological sort. The result is ordered so that
dependencies of a dll appear before it in the list.
NOTE: this algorithm is guaranteed to terminate with a "partial
order" of dlls but does not do anything smart about cycles: an
arbitrary dependent dll will necessarily appear first. Perhaps not
surprisingly, Windows ships several dlls containing dependency
cycles, including SspiCli/RPCRT4.dll and a lovely tangle involving
USP10/LPK/GDI32/USER32.dll). Fortunately, we don't care about
Windows DLLs here, and cygwin dlls should behave better */
void
dll_list::topsort_visit (dll* d, bool seek_tail)
{
/* Recurse to the end of the dll chain, then visit nodes as we
unwind. We do this because once we start visiting nodes we can no
longer trust any _next_ pointers.
We "mark" visited nodes (to avoid revisiting them) by negating
ndeps (undone once the sort completes). */
if (seek_tail && d->next)
topsort_visit (d->next, true);
if (d->ndeps > 0)
{
d->ndeps = -d->ndeps;
for (long i=1; i < -d->ndeps; i++)
topsort_visit (d->deps[i-1], false);
append (d);
}
}
dll *
dll_list::find (void *retaddr)
{
@@ -322,7 +446,7 @@ reserve_at (const PWCHAR name, DWORD here, DWORD dll_base, DWORD dll_size)
size = end - here;
if (!VirtualAlloc ((void *) here, size, MEM_RESERVE, PAGE_NOACCESS))
api_fatal ("couldn't allocate memory %p(%d) for '%W' alignment, %E\n",
here, size, name);
here, size, name);
return here;
}
@@ -332,7 +456,7 @@ release_at (const PWCHAR name, DWORD here)
{
if (!VirtualFree ((void *) here, 0, MEM_RELEASE))
api_fatal ("couldn't release memory %p for '%W' alignment, %E\n",
here, name);
here, name);
}
/* Reload DLLs after a fork. Iterates over the list of dynamically loaded
@@ -368,13 +492,13 @@ dll_list::load_after_fork (HANDLE parent)
/* If we reached here on the second iteration of the for loop
then there is a lot of memory to release. */
if (i > 0)
{
release_upto (d->name, (DWORD) d->handle);
{
release_upto (d->name, (DWORD) d->handle);
if (preferred_block)
release_at (d->name, preferred_block);
preferred_block = 0;
}
if (preferred_block)
release_at (d->name, preferred_block);
preferred_block = 0;
}
if (h == d->handle)
break; /* Success */
@@ -385,19 +509,19 @@ dll_list::load_after_fork (HANDLE parent)
d->name, d->handle, h);
/* Dll loaded in the wrong place. Dunno why this happens but it
always seems to happen when there are multiple DLLs with the
same base address. In the "forked" process, the relocated DLL
may load at a different address. So, block all of the memory up
to the relocated load address and try again. */
always seems to happen when there are multiple DLLs with the
same base address. In the "forked" process, the relocated DLL
may load at a different address. So, block all of the memory up
to the relocated load address and try again. */
reserve_upto (d->name, (DWORD) d->handle);
/* Also, if the DLL loaded at a higher address than wanted (probably
it's base address), reserve the memory at that address. This can
happen if it couldn't load at the preferred base in the parent, but
can in the child, due to differences in the load ordering.
Block memory at it's preferred address and try again. */
if ((DWORD) h > (DWORD) d->handle)
preferred_block = reserve_at (d->name, (DWORD) h,
/* Also, if the DLL loaded at a higher address than wanted (probably
it's base address), reserve the memory at that address. This can
happen if it couldn't load at the preferred base in the parent, but
can in the child, due to differences in the load ordering.
Block memory at it's preferred address and try again. */
if ((DWORD) h > (DWORD) d->handle)
preferred_block = reserve_at (d->name, (DWORD) h,
(DWORD) d->handle, d->image_size);
}