Update.

2002-03-21  Ulrich Drepper  <drepper@redhat.com>

	* nscd/grpcache.c (addgrbyname): Improve buffer allocate with alloca.
	Use realloc if too large.
	(addgrbyid): Likewise.
	* nscd/hstcache.c (addhstbyname): Likewise.
	(addhstbyaddr): Likewise.
	(addhstbynamev6): Likewise.
	(addhstbyaddrv6): Likewise.
	* nscd/pwdcache.c (addpwbyname): Likewise.
	(addpwbyuid): Likewise.

ChangeLog

@@ -1,3 +1,15 @@
+2002-03-21  Ulrich Drepper  <drepper@redhat.com>
+
+	* nscd/grpcache.c (addgrbyname): Improve buffer allocate with alloca.
+	Use realloc if too large.
+	(addgrbyid): Likewise.
+	* nscd/hstcache.c (addhstbyname): Likewise.
+	(addhstbyaddr): Likewise.
+	(addhstbynamev6): Likewise.
+	(addhstbyaddrv6): Likewise.
+	* nscd/pwdcache.c (addpwbyname): Likewise.
+	(addpwbyuid): Likewise.
+
 2002-03-21  Andreas Jaeger  <aj@suse.de>
 
 	* sysdeps/unix/sysv/linux/x86_64/bits/sigcontext.h (struct

nscd/grpcache.c

@@ -207,13 +207,13 @@ addgrbyname (struct database *db, int fd, request_header *req,
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
   int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct group resultbuf;
   struct group *grp;
   uid_t oldeuid = 0;
   bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     dbg_log (_("Haven't found \"%s\" in group cache!"), (char *) key);
 
   if (secure[grpdb])
@@ -245,7 +245,7 @@ addgrbyname (struct database *db, int fd, request_header *req,
 	}
       else
 	{
-	  buffer = alloca (buflen);
+	  buffer = (char *) alloca (buflen);
 #if _STACK_GROWS_DOWN
 	  if (buffer + buflen == old_buffer)
 	    buflen = 2 * buflen - 1024;
@@ -278,7 +278,7 @@ addgrbygid (struct database *db, int fd, request_header *req,
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
   int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct group resultbuf;
   struct group *grp;
   uid_t oldeuid = 0;
@@ -295,7 +295,7 @@ addgrbygid (struct database *db, int fd, request_header *req,
       return;
     }
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     dbg_log (_("Haven't found \"%d\" in group cache!"), gid);
 
   if (secure[grpdb])
@@ -327,7 +327,7 @@ addgrbygid (struct database *db, int fd, request_header *req,
 	}
       else
 	{
-	  buffer = alloca (buflen);
+	  buffer = (char *) alloca (buflen);
 #if _STACK_GROWS_DOWN
 	  if (buffer + buflen == old_buffer)
 	    buflen = 2 * buflen - 1024;

nscd/hstcache.c

@@ -1,5 +1,5 @@
 /* Cache handling for host lookup.
-   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
 
@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <error.h>
 #include <netdb.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -31,6 +32,7 @@
 #include <libintl.h>
 #include <arpa/inet.h>
 #include <arpa/nameser.h>
+#include <stackinfo.h>
 
 #include "nscd.h"
 #include "dbg_log.h"
@@ -289,13 +291,14 @@ addhstbyname (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 512;
+  int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct hostent resultbuf;
   struct hostent *hst;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     dbg_log (_("Haven't found \"%s\" in hosts cache!"), (char *) key);
 
   if (secure[hstdb])
@@ -309,15 +312,47 @@ addhstbyname (struct database *db, int fd, request_header *req,
 	 && h_errno == NETDB_INTERNAL
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
+      buflen += 1024;
-      buffer = alloca (buflen);
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      hst = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[hstdb])
     seteuid (oldeuid);
 
   cache_addhst (db, fd, req, key, hst, uid);
+
+  if (use_malloc)
+    free (buffer);
 }
 
 
@@ -329,13 +364,14 @@ addhstbyaddr (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 512;
+  int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct hostent resultbuf;
   struct hostent *hst;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     {
       char buf[INET_ADDRSTRLEN];
       dbg_log (_("Haven't found \"%s\" in hosts cache!"),
@@ -353,15 +389,47 @@ addhstbyaddr (struct database *db, int fd, request_header *req,
 	 && h_errno == NETDB_INTERNAL
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
+      buflen += 1024;
-      buffer = alloca (buflen);
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      hst = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[hstdb])
     seteuid (oldeuid);
 
   cache_addhst (db, fd, req, key, hst, uid);
+
+  if (use_malloc)
+    free (buffer);
 }
 
 
@@ -373,13 +441,14 @@ addhstbynamev6 (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 512;
+  int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct hostent resultbuf;
   struct hostent *hst;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     {
       char buf[INET6_ADDRSTRLEN];
 
@@ -398,15 +467,47 @@ addhstbynamev6 (struct database *db, int fd, request_header *req,
 	 && h_errno == NETDB_INTERNAL
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
+      buflen += 1024;
-      buffer = alloca (buflen);
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      hst = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[hstdb])
     seteuid (oldeuid);
 
   cache_addhst (db, fd, req, key, hst, uid);
+
+  if (use_malloc)
+    free (buffer);
 }
 
 
@@ -418,13 +519,14 @@ addhstbyaddrv6 (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 512;
+  int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct hostent resultbuf;
   struct hostent *hst;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     {
       char buf[INET6_ADDRSTRLEN];
       dbg_log (_("Haven't found \"%s\" in hosts cache!"),
@@ -442,13 +544,45 @@ addhstbyaddrv6 (struct database *db, int fd, request_header *req,
 	 && h_errno == NETDB_INTERNAL
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
+      buflen += 1024;
-      buffer = alloca (buflen);
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      hst = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[hstdb])
     seteuid (oldeuid);
 
   cache_addhst (db, fd, req, key, hst, uid);
+
+  if (use_malloc)
+    free (buffer);
 }

nscd/pwdcache.c

@@ -1,5 +1,5 @@
 /* Cache handling for passwd lookup.
-   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
 
@@ -21,6 +21,7 @@
 #include <errno.h>
 #include <error.h>
 #include <pwd.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -28,6 +29,7 @@
 #include <time.h>
 #include <unistd.h>
 #include <libintl.h>
+#include <stackinfo.h>
 
 #include "nscd.h"
 #include "dbg_log.h"
@@ -200,13 +202,14 @@ addpwbyname (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 256;
+  int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct passwd resultbuf;
   struct passwd *pwd;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     dbg_log (_("Haven't found \"%s\" in password cache!"), (char *) key);
 
   if (secure[pwddb])
@@ -218,15 +221,47 @@ addpwbyname (struct database *db, int fd, request_header *req,
   while (__getpwnam_r (key, &resultbuf, buffer, buflen, &pwd) != 0
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
+      buflen += 1024;
-      buffer = alloca (buflen);
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      pwd = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[pwddb])
     seteuid (oldeuid);
 
   cache_addpw (db, fd, req, key, pwd, c_uid);
+
+  if (use_malloc)
+    free (buffer);
 }
 
 
@@ -239,12 +274,13 @@ addpwbyuid (struct database *db, int fd, request_header *req,
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
   int buflen = 256;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct passwd resultbuf;
   struct passwd *pwd;
   uid_t oldeuid = 0;
   char *ep;
   uid_t uid = strtoul ((char *) key, &ep, 10);
+  bool use_malloc = false;
 
   if (*(char *) key == '\0' || *ep != '\0')  /* invalid numeric uid */
     {
@@ -255,7 +291,7 @@ addpwbyuid (struct database *db, int fd, request_header *req,
       return;
     }
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     dbg_log (_("Haven't found \"%d\" in password cache!"), uid);
 
   if (secure[pwddb])
@@ -267,13 +303,45 @@ addpwbyuid (struct database *db, int fd, request_header *req,
   while (__getpwuid_r (uid, &resultbuf, buffer, buflen, &pwd) != 0
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
+      buflen += 1024;
-      buffer = alloca (buflen);
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      pwd = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[pwddb])
     seteuid (oldeuid);
 
   cache_addpw (db, fd, req, key, pwd, c_uid);
+
+  if (use_malloc)
+    free (buffer);
 }