Fixes racy access to LDR lists in lookup_function_info().
Signed-off-by: Paul Gofman pgofman@codeweavers.com --- dlls/ntdll/actctx.c | 6 ------ dlls/ntdll/loader.c | 21 ++++++++++++++++++--- 2 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/dlls/ntdll/actctx.c b/dlls/ntdll/actctx.c index f9afb655885..bc222dadf27 100644 --- a/dlls/ntdll/actctx.c +++ b/dlls/ntdll/actctx.c @@ -705,10 +705,8 @@ static inline const char* debugstr_version(const struct assembly_version *ver) static NTSTATUS get_module_filename( HMODULE module, UNICODE_STRING *str, unsigned int extra_len ) { NTSTATUS status; - ULONG_PTR magic; LDR_DATA_TABLE_ENTRY *pldr;
- LdrLockLoaderLock(0, NULL, &magic); status = LdrFindEntryForAddress( module, &pldr ); if (status == STATUS_SUCCESS) { @@ -721,7 +719,6 @@ static NTSTATUS get_module_filename( HMODULE module, UNICODE_STRING *str, unsign } else status = STATUS_NO_MEMORY; } - LdrUnlockLoaderLock(0, magic); return status; }
@@ -3301,12 +3298,10 @@ static NTSTATUS find_query_actctx( HANDLE *handle, DWORD flags, ULONG class ) } else if (flags & (QUERY_ACTCTX_FLAG_ACTCTX_IS_ADDRESS|QUERY_ACTCTX_FLAG_ACTCTX_IS_HMODULE)) { - ULONG_PTR magic; LDR_DATA_TABLE_ENTRY *pldr;
if (!*handle) return STATUS_INVALID_PARAMETER;
- LdrLockLoaderLock( 0, NULL, &magic ); if (!LdrFindEntryForAddress( *handle, &pldr )) { if ((flags & QUERY_ACTCTX_FLAG_ACTCTX_IS_HMODULE) && *handle != pldr->DllBase) @@ -3315,7 +3310,6 @@ static NTSTATUS find_query_actctx( HANDLE *handle, DWORD flags, ULONG class ) *handle = pldr->ActivationContext; } else status = STATUS_DLL_NOT_FOUND; - LdrUnlockLoaderLock( 0, magic ); } else if (!*handle && (class != ActivationContextBasicInformation)) *handle = process_actctx; diff --git a/dlls/ntdll/loader.c b/dlls/ntdll/loader.c index 797d72aedb6..e363c060ab1 100644 --- a/dlls/ntdll/loader.c +++ b/dlls/ntdll/loader.c @@ -176,6 +176,10 @@ static PEB_LDR_DATA ldr = { &ldr.InMemoryOrderModuleList, &ldr.InMemoryOrderModuleList }, { &ldr.InInitializationOrderModuleList, &ldr.InInitializationOrderModuleList } }; +/* Ldr lists are modified with loader locked and exclusive ldr_data_srw_lock held. + * Taking shared ldr_data_srw_lock to access the data is required outside of + * loader lock only. */ +static RTL_SRWLOCK ldr_data_srw_lock = RTL_SRWLOCK_INIT;
static RTL_BITMAP tls_bitmap; static RTL_BITMAP tls_expansion_bitmap; @@ -1245,10 +1249,12 @@ static WINE_MODREF *alloc_module( HMODULE hModule, const UNICODE_STRING *nt_name wm->ldr.EntryPoint = (char *)hModule + nt->OptionalHeader.AddressOfEntryPoint; }
+ RtlAcquireSRWLockExclusive( &ldr_data_srw_lock ); InsertTailList(&NtCurrentTeb()->Peb->LdrData->InLoadOrderModuleList, &wm->ldr.InLoadOrderLinks); InsertTailList(&NtCurrentTeb()->Peb->LdrData->InMemoryOrderModuleList, &wm->ldr.InMemoryOrderLinks); + RtlReleaseSRWLockExclusive( &ldr_data_srw_lock ); /* wait until init is called for inserting into InInitializationOrderModuleList */
if (!(nt->OptionalHeader.DllCharacteristics & IMAGE_DLLCHARACTERISTICS_NX_COMPAT)) @@ -1454,8 +1460,12 @@ static NTSTATUS process_attach( WINE_MODREF *wm, LPVOID lpReserved ) }
if (!wm->ldr.InInitializationOrderLinks.Flink) + { + RtlAcquireSRWLockExclusive( &ldr_data_srw_lock ); InsertTailList(&NtCurrentTeb()->Peb->LdrData->InInitializationOrderModuleList, &wm->ldr.InInitializationOrderLinks); + RtlReleaseSRWLockExclusive( &ldr_data_srw_lock ); + }
/* Call DLL entry point */ if (status == STATUS_SUCCESS) @@ -1578,13 +1588,14 @@ NTSTATUS WINAPI LdrDisableThreadCalloutsForDll(HMODULE hModule) /****************************************************************** * LdrFindEntryForAddress (NTDLL.@) * - * The loader_section must be locked while calling this function */ NTSTATUS WINAPI LdrFindEntryForAddress( const void *addr, PLDR_DATA_TABLE_ENTRY *pmod ) { + NTSTATUS ret = STATUS_NO_MORE_ENTRIES; PLIST_ENTRY mark, entry; PLDR_DATA_TABLE_ENTRY mod;
+ RtlAcquireSRWLockShared( &ldr_data_srw_lock ); mark = &NtCurrentTeb()->Peb->LdrData->InMemoryOrderModuleList; for (entry = mark->Flink; entry != mark; entry = entry->Flink) { @@ -1593,10 +1604,12 @@ NTSTATUS WINAPI LdrFindEntryForAddress( const void *addr, PLDR_DATA_TABLE_ENTRY (const char *)addr < (char*)mod->DllBase + mod->SizeOfImage) { *pmod = mod; - return STATUS_SUCCESS; + ret = STATUS_SUCCESS; + break; } } - return STATUS_NO_MORE_ENTRIES; + RtlReleaseSRWLockShared( &ldr_data_srw_lock ); + return ret; }
/****************************************************************** @@ -3510,10 +3523,12 @@ void WINAPI LdrShutdownThread(void) */ static void free_modref( WINE_MODREF *wm ) { + RtlAcquireSRWLockExclusive( &ldr_data_srw_lock ); RemoveEntryList(&wm->ldr.InLoadOrderLinks); RemoveEntryList(&wm->ldr.InMemoryOrderLinks); if (wm->ldr.InInitializationOrderLinks.Flink) RemoveEntryList(&wm->ldr.InInitializationOrderLinks); + RtlReleaseSRWLockExclusive( &ldr_data_srw_lock );
TRACE(" unloading %s\n", debugstr_w(wm->ldr.FullDllName.Buffer)); if (!TRACE_ON(module))