Set default stack size from program environment

New environment variable GLIBC_PTHREAD_DEFAULT_STACKSIZE to do this.

ChangeLog

@@ -1,3 +1,9 @@
+2013-03-01  Siddhesh Poyarekar  <siddhesh@redhat.com>
+
+	* csu/libc-start.c (__pthread_initialize_minimal): Change
+	function arguments.
+	* csu/libc-tls.c (__pthread_initialize_minimal): Likewise.
+
 2013-02-28  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #13550]

NEWS

@@ -17,6 +17,10 @@ Version 2.18
   and program exit.  This needs compiler support for offloading C++11
   destructor calls to glibc.
 
+* Add support for setting thread stack sizes from the program environment,
+  independently of the process stack size using the
+  GLIBC_PTHREAD_DEFAULT_STACKSIZE environment variable.
+
 
 Version 2.17
 

csu/libc-start.c

@@ -30,7 +30,7 @@ extern int __libc_multiple_libcs;
 #include <tls.h>
 #ifndef SHARED
 # include <dl-osinfo.h>
-extern void __pthread_initialize_minimal (void);
+extern void __pthread_initialize_minimal (int, char **, char **);
 # ifndef THREAD_SET_STACK_GUARD
 /* Only exported for architectures that don't store the stack guard canary
    in thread local area.  */
@@ -167,7 +167,7 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
   /* Initialize the thread library at least a bit since the libgcc
      functions are using thread functions if these are available and
      we need to setup errno.  */
-  __pthread_initialize_minimal ();
+  __pthread_initialize_minimal (argc, argv, __environ);
 
   /* Set up the stack checker's canary.  */
   uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random);

csu/libc-tls.c

@@ -243,7 +243,7 @@ _dl_tls_setup (void)
    not used.  */
 void
 __attribute__ ((weak))
-__pthread_initialize_minimal (void)
+__pthread_initialize_minimal (int argc, char **argv, char **envp)
 {
   __libc_setup_tls (TLS_INIT_TCB_SIZE, TLS_INIT_TCB_ALIGN);
 }

nptl/ChangeLog

@@ -1,3 +1,12 @@
+2013-03-01  Siddhesh Poyarekar  <siddhesh@redhat.com>
+
+	* Makefile (tests): Add tst-pthread-stack-env.
+	(tst-pthread-stack-env-ENV): Set environment for test.
+	* nptl-init.c (set_default_stacksize): New function.
+	(__pthread_initialize_minimal_internal): Accept ARGC, ARGV and
+	ENVP.  Initialize __ENVIRON and set __DEFAULT_STACKSIZE.
+	* tst-pthread-stack-env.c: New test case.
+
 2013-02-21  David S. Miller  <davem@davemloft.net>
 
 	* sysdeps/unix/sysv/linux/sparc/lowlevellock.h

nptl/Makefile

@@ -251,7 +251,8 @@ tests = tst-typesizes \
 	tst-exec1 tst-exec2 tst-exec3 tst-exec4 \
 	tst-exit1 tst-exit2 tst-exit3 \
 	tst-stdio1 tst-stdio2 \
-	tst-stack1 tst-stack2 tst-stack3 tst-pthread-getattr \
+	tst-stack1 tst-stack2 tst-stack3 \
+	tst-pthread-getattr tst-pthread-stack-env \
 	tst-unload \
 	tst-dlsym1 \
 	tst-sysconf \
@@ -441,6 +442,8 @@ tst-cancel7-ARGS = --command "exec $(host-test-program-cmd)"
 tst-cancelx7-ARGS = $(tst-cancel7-ARGS)
 tst-umask1-ARGS = $(objpfx)tst-umask1.temp
 
+tst-pthread-stack-env-ENV = GLIBC_PTHREAD_DEFAULT_STACKSIZE=1048576
+
 $(objpfx)tst-atfork2: $(libdl) $(shared-thread-library)
 LDFLAGS-tst-atfork2 = -rdynamic
 tst-atfork2-ENV = MALLOC_TRACE=$(objpfx)tst-atfork2.mtrace

nptl/nptl-init.c

@@ -276,8 +276,26 @@ extern void **__libc_dl_error_tsd (void) __attribute__ ((const));
 /* This can be set by the debugger before initialization is complete.  */
 static bool __nptl_initial_report_events __attribute_used__;
 
+static void
+set_default_stacksize (size_t stacksize)
+{
+  if (stacksize < PTHREAD_STACK_MIN)
+    stacksize = PTHREAD_STACK_MIN;
+
+  /* Make sure it meets the minimum size that allocate_stack
+     (allocatestack.c) will demand, which depends on the page size.  */
+  const uintptr_t pagesz = GLRO(dl_pagesize);
+  const size_t minstack = pagesz + __static_tls_size + MINIMAL_REST_STACK;
+
+  if (stacksize < minstack)
+    stacksize = minstack;
+
+  /* Round the resource limit up to page size.  */
+  stacksize = (stacksize + pagesz - 1) & -pagesz;
+  __default_stacksize = stacksize;
+}
 void
-__pthread_initialize_minimal_internal (void)
+__pthread_initialize_minimal_internal (int argc, char **argv, char **envp)
 {
 #ifndef SHARED
   /* Unlike in the dynamically linked case the dynamic linker has not
@@ -401,29 +419,41 @@ __pthread_initialize_minimal_internal (void)
 
   __static_tls_size = roundup (__static_tls_size, static_tls_align);
 
-  /* Determine the default allowed stack size.  This is the size used
-     in case the user does not specify one.  */
-  struct rlimit limit;
-  if (getrlimit (RLIMIT_STACK, &limit) != 0
-      || limit.rlim_cur == RLIM_INFINITY)
-    /* The system limit is not usable.  Use an architecture-specific
-       default.  */
-    limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE;
-  else if (limit.rlim_cur < PTHREAD_STACK_MIN)
-    /* The system limit is unusably small.
-       Use the minimal size acceptable.  */
-    limit.rlim_cur = PTHREAD_STACK_MIN;
+  /* Initialize the environment.  libc.so gets initialized after us due to a
+     circular dependency and hence __environ is not available otherwise.  */
+    __environ = envp;
 
-  /* Make sure it meets the minimum size that allocate_stack
-     (allocatestack.c) will demand, which depends on the page size.  */
-  const uintptr_t pagesz = GLRO(dl_pagesize);
-  const size_t minstack = pagesz + __static_tls_size + MINIMAL_REST_STACK;
-  if (limit.rlim_cur < minstack)
-    limit.rlim_cur = minstack;
+#ifndef SHARED
+    __libc_init_secure ();
+#endif
 
-  /* Round the resource limit up to page size.  */
-  limit.rlim_cur = (limit.rlim_cur + pagesz - 1) & -pagesz;
-  __default_stacksize = limit.rlim_cur;
+  size_t stacksize = 0;
+  char *envval = __libc_secure_getenv ("GLIBC_PTHREAD_DEFAULT_STACKSIZE");
+
+  if (__glibc_unlikely (envval != NULL && envval[0] != '\0'))
+    {
+      char *env_conv = envval;
+      size_t ret = strtoul (envval, &env_conv, 0);
+
+      if (*env_conv == '\0' && env_conv != envval)
+	stacksize = ret;
+    }
+
+  if (stacksize == 0)
+    {
+      /* Determine the default allowed stack size.  This is the size used
+	 in case the user does not specify one.  */
+      struct rlimit limit;
+      if (getrlimit (RLIMIT_STACK, &limit) != 0
+	  || limit.rlim_cur == RLIM_INFINITY)
+	/* The system limit is not usable.  Use an architecture-specific
+	   default.  */
+	stacksize = ARCH_STACK_DEFAULT_SIZE;
+      else
+	stacksize = limit.rlim_cur;
+    }
+
+  set_default_stacksize (stacksize);
 
 #ifdef SHARED
   /* Transfer the old value from the dynamic linker's internal location.  */

nptl/tst-pthread-stack-env.c

@@ -0,0 +1,77 @@
+/* Verify that pthreads uses the default thread stack size set with the
+   GLIBC_PTHREAD_DEFAULT_STACKSIZE environment variable.
+   Copyright (C) 2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <stdio.h>
+#include <string.h>
+
+/* It is possible that the default stack size somehow ends up being 1MB, thus
+   giving a false positive.  The ideal way to test this would be to get the
+   current stacksize fork a process with the default stack size set to
+   something different to the current stack size and verify in the child
+   process that the environment variable worked.  */
+#define STACKSIZE 1024 * 1024L
+
+void *
+thr (void *u)
+{
+  size_t stacksize, guardsize;
+  pthread_attr_t attr;
+  pthread_getattr_np (pthread_self (), &attr);
+
+  pthread_attr_getstacksize (&attr, &stacksize);
+  pthread_attr_getguardsize (&attr, &guardsize);
+
+  /* FIXME once guardsize is excluded from stacksize.  */
+  if (stacksize - guardsize != STACKSIZE)
+    {
+      printf ("Stack size is %zu, should be %zu\n", stacksize - guardsize,
+	      STACKSIZE);
+      return (void *) 1;
+    }
+
+  return NULL;
+}
+
+int
+do_test (int argc, char **argv)
+{
+  pthread_t t;
+  void *thr_ret;
+  int ret;
+
+  if ((ret = pthread_create (&t, NULL, thr, NULL)) != 0)
+    {
+      printf ("thread create failed: %s\n", strerror (ret));
+      return 1;
+    }
+
+  if ((ret = pthread_join (t, &thr_ret)) != 0)
+    {
+      printf ("join failed: %s\n", strerror (ret));
+      return 1;
+    }
+
+  if (thr_ret != NULL && thr_ret != PTHREAD_CANCELED)
+    return 1;
+
+  return 0;
+}
+
+#include "../test-skeleton.c"