diff options
Diffstat (limited to 'winsup/cygwin/dll_init.cc')
| -rw-r--r-- | winsup/cygwin/dll_init.cc | 176 |
1 files changed, 150 insertions, 26 deletions
diff --git a/winsup/cygwin/dll_init.cc b/winsup/cygwin/dll_init.cc index 060ff497e..44d7b7a52 100644 --- a/winsup/cygwin/dll_init.cc +++ b/winsup/cygwin/dll_init.cc @@ -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); } |