Reduce stack pressure throughout Cygwin

* dcrt0.cc (initial_env): Reduce size of local path buffers to
        PATH_MAX.  Allocate debugger_command from process heap.
        (init_windows_system_directory): Very early initialize new global
        variable global_progname.
        * dll_init.cc (dll_list::alloc): Make path buffer static.  Explain why.
        (dll_list::populate_deps): Use tmp_pathbuf for local path buffer.
        * exceptions.cc (debugger_command): Convert to PWCHAR.
        (error_start_init): Allocate debugger_command and fill with wide char
        strings.  Only allocate if NULL.
        (try_to_debug): Just check if debugger_command is a NULL pointer to
        return.  Drop conversion from char to WCHAR and drop local variable
        dbg_cmd.
        * globals.cc (global_progname): New global variable to store Windows
        application path.
        * pinfo.cc (pinfo_basic::pinfo_basic): Just copy progname over from
        global_progname.
        (pinfo::status_exit): Let path_conv create the POSIX path to
        avoid local buffer.
        * pseudo_reloc.cc (__report_error): Utilize global_progname, drop local
        buffer.
        * smallprint.cc (__small_vsprintf): Just utilize global_progname for
        %P format specifier.
        (__small_vswprintf): Ditto.
        * strace.cc (PROTECT): Change to reflect x being a pointer.  Reformat.
        (CHECK): Ditto.  Reformat.
        (strace::activate): Utilize global_progname, drop local buffer.
        Fix formatting.
        (strace::vsprntf): Reduce size of local progname buffer to NAME_MAX.
        Copy and, if necessary, convert only the last path component to
        progname.
        (strace_buf_guard): New muto.
        (buf): New static pointer.
        (strace::vprntf): Use buf under strace_buf_guard lock only.  Allocate
        buffer space for buf on Windows heap.
        * wow64.cc (wow64_respawn_process): Utilize global_progname, drop
        local path buffer.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/ChangeLog

@@ -1,3 +1,42 @@
+2015-07-19  Corinna Vinschen  <corinna@vinschen.de>
+
+	* dcrt0.cc (initial_env): Reduce size of local path buffers to
+	PATH_MAX.  Allocate debugger_command from process heap.
+	(init_windows_system_directory): Very early initialize new global
+	variable global_progname.
+	* dll_init.cc (dll_list::alloc): Make path buffer static.  Explain why.
+	(dll_list::populate_deps): Use tmp_pathbuf for local path buffer.
+	* exceptions.cc (debugger_command): Convert to PWCHAR.
+	(error_start_init): Allocate debugger_command and fill with wide char
+	strings.  Only allocate if NULL.
+	(try_to_debug): Just check if debugger_command is a NULL pointer to
+	return.  Drop conversion from char to WCHAR and drop local variable
+	dbg_cmd.
+	* globals.cc (global_progname): New global variable to store Windows
+	application path.
+	* pinfo.cc (pinfo_basic::pinfo_basic): Just copy progname over from
+	global_progname.
+	(pinfo::status_exit): Let path_conv create the POSIX path to
+	avoid local buffer.
+	* pseudo_reloc.cc (__report_error): Utilize global_progname, drop local
+	buffer.
+	* smallprint.cc (__small_vsprintf): Just utilize global_progname for
+	%P format specifier.
+	(__small_vswprintf): Ditto.
+	* strace.cc (PROTECT): Change to reflect x being a pointer.  Reformat.
+	(CHECK): Ditto.  Reformat.
+	(strace::activate): Utilize global_progname, drop local buffer.
+	Fix formatting.
+	(strace::vsprntf): Reduce size of local progname buffer to NAME_MAX.
+	Copy and, if necessary, convert only the last path component to
+	progname.
+	(strace_buf_guard): New muto.
+	(buf): New static pointer.
+	(strace::vprntf): Use buf under strace_buf_guard lock only.  Allocate
+	buffer space for buf on Windows heap.
+	* wow64.cc (wow64_respawn_process): Utilize global_progname, drop
+	local path buffer.
+
 2015-07-18  Corinna Vinschen  <corinna@vinschen.de>
 
 	* gendef: Remove unused 64 bit versions of __sjfault and __ljfault.

winsup/cygwin/dcrt0.cc

@@ -509,11 +509,11 @@ initial_env ()
     _cygwin_testing = 1;
 
 #ifdef DEBUGGING
-  char buf[NT_MAX_PATH];
+  char buf[PATH_MAX];
   if (GetEnvironmentVariableA ("CYGWIN_DEBUG", buf, sizeof (buf) - 1))
     {
-      char buf1[NT_MAX_PATH];
+      char buf1[PATH_MAX];
-      GetModuleFileName (NULL, buf1, NT_MAX_PATH);
+      GetModuleFileName (NULL, buf1, PATH_MAX);
       char *p = strpbrk (buf, ":=");
       if (!p)
 	p = (char *) "gdb.exe -nw";
@@ -521,6 +521,13 @@ initial_env ()
 	*p++ = '\0';
       if (strcasestr (buf1, buf))
 	{
+	  extern PWCHAR debugger_command;
+
+	  debugger_command = (PWCHAR) HeapAlloc (GetProcessHeap (), 0,
+						 (2 * NT_MAX_PATH + 20)
+						 * sizeof (WCHAR));
+	  if (!debugger_command)
+	    return;
 	  error_start_init (p);
 	  jit_debug = true;
 	  try_to_debug ();
@@ -736,6 +743,7 @@ void
 dll_crt0_0 ()
 {
   wincap.init ();
+  GetModuleFileNameW (NULL, global_progname, NT_MAX_PATH);
   child_proc_info = get_cygwin_startup_info ();
   init_windows_system_directory ();
   initial_env ();

winsup/cygwin/dll_init.cc

@@ -25,6 +25,7 @@ details. */
 #include <wchar.h>
 #include <sys/reent.h>
 #include <assert.h>
+#include <tls_pbuf.h>
 
 extern void __stdcall check_sanity_and_sync (per_process *);
 
@@ -178,7 +179,9 @@ dll_list::find_by_modname (const PWCHAR modname)
 dll *
 dll_list::alloc (HINSTANCE h, per_process *p, dll_type type)
 {
-  WCHAR buf[NT_MAX_PATH];
+  /* Called under loader lock conditions so this function can't be called
+     multiple times in parallel.  A static buffer is safe. */
+  static WCHAR buf[NT_MAX_PATH];
   GetModuleFileNameW (h, buf, NT_MAX_PATH);
   PWCHAR name = buf;
   if (!wcsncmp (name, L"\\\\?\\", 4))
@@ -264,7 +267,9 @@ dll_list::append (dll* d)
 
 void dll_list::populate_deps (dll* d)
 {
-  WCHAR wmodname[NT_MAX_PATH];
+  tmp_pathbuf tp;
+
+  PWCHAR wmodname = tp.w_get ();
   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

winsup/cygwin/exceptions.cc

@@ -46,7 +46,7 @@ details. */
 #define CALL_HANDLER_RETRY_OUTER 10
 #define CALL_HANDLER_RETRY_INNER 10
 
-char debugger_command[2 * NT_MAX_PATH + 20];
+PWCHAR debugger_command;
 extern u_char _sigbe;
 extern u_char _sigdelayed_end;
 
@@ -112,18 +112,19 @@ extern "C" void
 error_start_init (const char *buf)
 {
   if (!buf || !*buf)
-    {
-      debugger_command[0] = '\0';
     return;
-    }
+  if (!debugger_command &&
+      !(debugger_command = (PWCHAR) malloc ((2 * NT_MAX_PATH + 20)
+					    * sizeof (WCHAR))))
+    return;
 
-  char pgm[NT_MAX_PATH];
+  PWCHAR cp = debugger_command
-  if (!GetModuleFileName (NULL, pgm, NT_MAX_PATH))
+	      + sys_mbstowcs (debugger_command, NT_MAX_PATH, buf) - 1;
-    strcpy (pgm, "cygwin1.dll");
+  cp = wcpcpy (cp, L" \"");
-  for (char *p = strchr (pgm, '\\'); p; p = strchr (p, '\\'))
+  wcpcpy (cp, global_progname);
-    *p = '/';
+  for (PWCHAR p = wcschr (cp, L'\\'); p; p = wcschr (p, L'\\'))
-
+    *p = L'/';
-  __small_sprintf (debugger_command, "%s \"%s\"", buf, pgm);
+  wcscat (cp, L"\"");
 }
 
 void
@@ -474,9 +475,9 @@ cygwin_stackdump ()
 extern "C" int
 try_to_debug (bool waitloop)
 {
-  debug_printf ("debugger_command '%s'", debugger_command);
+  if (!debugger_command)
-  if (*debugger_command == '\0')
     return 0;
+  debug_printf ("debugger_command '%W'", debugger_command);
   if (being_debugged ())
     {
       extern void break_here ();
@@ -484,8 +485,8 @@ try_to_debug (bool waitloop)
       return 0;
     }
 
-  __small_sprintf (strchr (debugger_command, '\0'), " %u",
+  PWCHAR dbg_end = wcschr (debugger_command, L'\0');
-		   GetCurrentProcessId ());
+  __small_swprintf (dbg_end, L" %u", GetCurrentProcessId ());
 
   LONG prio = GetThreadPriority (GetCurrentThread ());
   SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_HIGHEST);
@@ -529,10 +530,8 @@ try_to_debug (bool waitloop)
   console_printf ("*** starting debugger for pid %u, tid %u\n",
 		  cygwin_pid (GetCurrentProcessId ()), GetCurrentThreadId ());
   BOOL dbg;
-  WCHAR dbg_cmd[strlen(debugger_command) + 1];
-  sys_mbstowcs (dbg_cmd, strlen(debugger_command) + 1, debugger_command);
   dbg = CreateProcessW (NULL,
-			dbg_cmd,
+			debugger_command,
 			NULL,
 			NULL,
 			FALSE,
@@ -542,6 +541,7 @@ try_to_debug (bool waitloop)
 			&si,
 			&pi);
 
+  *dbg_end = L'\0';
   if (!dbg)
     system_printf ("Failed to start debugger, %E");
   else

winsup/cygwin/globals.cc

@@ -31,6 +31,7 @@ UINT windows_system_directory_length;
 WCHAR system_wow64_directory[MAX_PATH];
 UINT system_wow64_directory_length;
 #endif /* !__x86_64__ */
+WCHAR global_progname[NT_MAX_PATH];
 
 /* program exit the program */
 

winsup/cygwin/pinfo.cc

@@ -38,7 +38,9 @@ public:
 pinfo_basic::pinfo_basic ()
 {
   pid = dwProcessId = GetCurrentProcessId ();
-  GetModuleFileNameW (NULL, progname, sizeof (progname) / sizeof (WCHAR));
+  PWCHAR pend = wcpncpy (progname, global_progname,
+			 sizeof (progname) / sizeof (WCHAR) - 1);
+  *pend = L'\0';
   /* Default uid/gid are needed very early to initialize shared user info. */
   uid = ILLEGAL_UID;
   gid = ILLEGAL_GID;
@@ -120,20 +122,18 @@ pinfo::status_exit (DWORD x)
     {
     case STATUS_DLL_NOT_FOUND:
       {
-	char posix_prog[NT_MAX_PATH];
 	path_conv pc;
 	if (!procinfo)
-	   pc.check ("/dev/null");
+	   pc.check ("/dev/null", PC_NOWARN | PC_POSIX);
 	else
 	  {
 	    UNICODE_STRING uc;
 	    RtlInitUnicodeString(&uc, procinfo->progname);
-	    pc.check (&uc, PC_NOWARN);
+	    pc.check (&uc, PC_NOWARN | PC_POSIX);
 	  }
-	mount_table->conv_to_posix_path (pc.get_win32 (), posix_prog, 1);
 	small_printf ("%s: error while loading shared libraries: %s: cannot "
 		      "open shared object file: No such file or directory\n",
-		      posix_prog, find_first_notloaded_dll (pc));
+		      pc.get_posix (), find_first_notloaded_dll (pc));
 	x = 127 << 8;
       }
       break;

winsup/cygwin/pseudo-reloc.cc

@@ -85,20 +85,18 @@ __report_error (const char *msg, ...)
    * cygwin ptys.
    */
   char buf[128];
-  WCHAR module[PATH_MAX];
   char *posix_module = NULL;
   static const char UNKNOWN_MODULE[] = "<unknown module>: ";
   static const char CYGWIN_FAILURE_MSG[] = "Cygwin runtime failure: ";
   HANDLE errh = GetStdHandle (STD_ERROR_HANDLE);
-  ssize_t modulelen = GetModuleFileNameW (NULL, module, PATH_MAX);
   va_list args;
 
   /* FIXME: cleanup further to avoid old use of cygwin_internal */
   if (errh == INVALID_HANDLE_VALUE)
     cygwin_internal (CW_EXIT_PROCESS, STATUS_ILLEGAL_DLL_PSEUDO_RELOCATION, 1);
 
-  if (modulelen > 0)
+  posix_module = (char *) cygwin_create_path (CCP_WIN_W_TO_POSIX,
-    posix_module = (char *) cygwin_create_path (CCP_WIN_W_TO_POSIX, module);
+					      global_progname);
 
   va_start (args, msg);
   vsnprintf (buf, sizeof (buf), msg, args);

winsup/cygwin/smallprint.cc

@@ -284,12 +284,6 @@ gen_decimalLL:
 		  dst = rnarg (dst, 16, 0, len, pad);
 #endif
 		  break;
-		case 'P':
-		  if (!GetModuleFileName (NULL, tmp, NT_MAX_PATH))
-		    s = "cygwin program";
-		  else
-		    s = tmp;
-		  goto fillin;
 		case '.':
 		  n = strtol (fmt, (char **) &fmt, 10);
 		  if (*fmt++ != 's')
@@ -311,6 +305,9 @@ gen_decimalLL:
 		    else
 		      *dst++ = *s++;
 		  break;
+		case 'P':
+		  RtlInitUnicodeString (us = &uw, global_progname);
+		  goto wfillin;
 		case 'W':
 		  w = va_arg (ap, PWCHAR);
 		  RtlInitUnicodeString (us = &uw, w ?: L"(null)");
@@ -613,10 +610,7 @@ gen_decimalLL:
 #endif
 		  break;
 		case L'P':
-		  if (!GetModuleFileNameW (NULL, tmp, NT_MAX_PATH))
+		  RtlInitUnicodeString (us = &uw, global_progname);
-		    RtlInitUnicodeString (us = &uw, L"cygwin program");
-		  else
-		    RtlInitUnicodeString (us = &uw, tmp);
 		  goto fillin;
 		case L'.':
 		  n = wcstoul (fmt, (wchar_t **) &fmt, 10);

winsup/cygwin/strace.cc

@@ -21,9 +21,13 @@ details. */
 #include "dtable.h"
 #include "cygheap.h"
 #include "child_info.h"
+#include "sync.h"
 
-#define PROTECT(x) x[sizeof (x)-1] = 0
+#define PROTECT(x) {x[NT_MAX_PATH - 1] = '\0';}
-#define CHECK(x) if (x[sizeof (x)-1] != 0) { small_printf ("array bound exceeded %d\n", __LINE__); ExitProcess (1); }
+#define CHECK(x) if (x[NT_MAX_PATH - 1] != '\0') \
+		   { small_printf ("array bound exceeded %d\n", __LINE__); \
+		     ExitProcess (1); \
+		   }
 
 class strace NO_COPY strace;
 
@@ -35,25 +39,25 @@ strace::activate (bool isfork)
   if (!_active && being_debugged ())
     {
       char buf[30];
-      __small_sprintf (buf, "cYg%8x %lx %d", _STRACE_INTERFACE_ACTIVATE_ADDR, &_active, isfork);
+      __small_sprintf (buf, "cYg%8x %lx %d",
+		       _STRACE_INTERFACE_ACTIVATE_ADDR, &_active, isfork);
       OutputDebugString (buf);
       if (_active)
 	{
 	  char pidbuf[80];
-	  WCHAR progname_buf[NT_MAX_PATH - 512];
+	  PWCHAR progname;
-	  WCHAR *progname;
 	  if (myself)
 	    {
-	      __small_sprintf (pidbuf, "(pid %d, ppid %d, windows pid %u)", myself->pid,
+	      __small_sprintf (pidbuf, "(pid %d, ppid %d, windows pid %u)",
-			       myself->ppid ?: 1, GetCurrentProcessId ());
+			       myself->pid, myself->ppid ?: 1,
+			       GetCurrentProcessId ());
 	      progname = myself->progname;
 	    }
 	  else
 	    {
-	      GetModuleFileNameW (NULL, progname_buf,
+	      __small_sprintf (pidbuf, "(windows pid %u)",
-	      			  sizeof progname_buf / sizeof (WCHAR));
+			       GetCurrentProcessId ());
-	      __small_sprintf (pidbuf, "(windows pid %u)", GetCurrentProcessId ());
+	      progname = global_progname;
-	      progname = progname_buf;
 	    }
 	  prntf (1, NULL, "**********************************************");
 	  prntf (1, NULL, "Program name: %W %s", progname, pidbuf);
@@ -151,32 +155,32 @@ strace::vsprntf (char *buf, const char *func, const char *infmt, va_list ap)
   else
     {
       PWCHAR pn = NULL;
-      WCHAR progname[NT_MAX_PATH];
+      WCHAR progname[NAME_MAX];
-      if (!cygwin_finished_initializing)
+      if (cygwin_finished_initializing && __progname)
-	pn = (myself) ? myself->progname : NULL;
+	{
-      else if (__progname)
+	  char *p = strrchr (__progname, '/');
-	sys_mbstowcs(pn = progname, NT_MAX_PATH, __progname);
+	  if (p)
-
+	    ++p;
-      WCHAR empty[1] = {};
-      PWCHAR p;
-      if (!pn)
-	GetModuleFileNameW (NULL, pn = progname, sizeof (progname));
-      if (!pn)
-	p = empty;
-      else if ((p = wcsrchr (pn, L'\\')) != NULL)
-	p++;
-      else if ((p = wcsrchr (pn, L'/')) != NULL)
-	p++;
 	  else
-	p = pn;
+	    p = __progname;
-      if (p != progname)
+	  char *pe = strrchr (p, '.');
-	wcscpy (progname, p);
+	  if (!pe || !ascii_strcasematch (pe, ".exe"))
-      if ((p = wcsrchr (progname, '.')) != NULL
+	    pe = strrchr (p, '\0');
-	  && !wcscasecmp (p, L".exe"))
+	  sys_mbstowcs (pn = progname, NAME_MAX, p, pe - p);
-	*p = '\000';
+	}
-      p = progname;
+      else
+	{
+	  PWCHAR p = wcsrchr (global_progname, L'\\');
+	  ++p;
+	  PWCHAR pe = wcsrchr (p, '.');
+	  if (!pe || wcscasecmp (pe, L".exe"))
+	    pe = wcsrchr (p, L'\0');
+	  pe = wcpncpy (progname, p, pe - p);
+	  *pe = L'\0';
+	  pn = progname;
+	}
       char tmpbuf[20];
-      count = __small_sprintf (buf, fmt, *p ? p : L"?", mypid (tmpbuf),
+      count = __small_sprintf (buf, fmt, pn, mypid (tmpbuf),
 			       execing ? "!" : "");
       if (func)
 	count += getfunc (buf + count, func);
@@ -235,14 +239,22 @@ strace::write_childpid (pid_t pid)
 
 /* Printf function used when tracing system calls.
    Warning: DO NOT SET ERRNO HERE! */
+static NO_COPY muto strace_buf_guard;
+static NO_COPY char *buf;
 
 void
 strace::vprntf (unsigned category, const char *func, const char *fmt, va_list ap)
 {
   DWORD err = GetLastError ();
   int len;
-  char buf[NT_MAX_PATH];
 
+  strace_buf_guard.init ("smallprint_buf")->acquire ();
+  /* Creating buffer on Windows process heap to drop stack pressure and
+     keeping our .bss small. */
+  if (!buf)
+    buf = (char *) HeapAlloc (GetProcessHeap (), 0, NT_MAX_PATH);
+  if (!buf)
+    return;
   PROTECT (buf);
   SetLastError (err);
 
@@ -272,6 +284,7 @@ strace::vprntf (unsigned category, const char *func, const char *fmt, va_list ap
   if (active ())
     write (category, buf, len);
 #endif
+  strace_buf_guard.release ();
   SetLastError (err);
 }
 

winsup/cygwin/wow64.cc

@@ -192,19 +192,17 @@ wow64_revert_to_original_stack (PVOID &allocationbase)
 void
 wow64_respawn_process ()
 {
-  WCHAR path[PATH_MAX];
   PROCESS_INFORMATION pi;
   STARTUPINFOW si;
   DWORD ret = 0;
 
-  GetModuleFileNameW (NULL, path, PATH_MAX);
   GetStartupInfoW (&si);
-  if (!CreateProcessW (path, GetCommandLineW (), NULL, NULL, TRUE,
+  if (!CreateProcessW (global_progname, GetCommandLineW (), NULL, NULL, TRUE,
 		       CREATE_DEFAULT_ERROR_MODE
 		       | GetPriorityClass (GetCurrentProcess ()),
 		       NULL, NULL, &si, &pi))
     api_fatal ("Failed to create process <%W> <%W>, %E",
-	       path, GetCommandLineW ());
+	       global_progname, GetCommandLineW ());
   CloseHandle (pi.hThread);
   if (WaitForSingleObject (pi.hProcess, INFINITE) == WAIT_FAILED)
     api_fatal ("Waiting for process %u failed, %E", pi.dwProcessId);