2009-04-15  Ulrich Drepper  <drepper@redhat.com>

	* sysdeps/unix/sysv/linux/getsysstats.c (next_line): Make sure there
	are always at least 4 bytes in the returned line.

2009-04-15  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/unix/sysv/linux/getsysstats.c (__get_nprocs): Check
	__libc_use_alloca (8192), if the stack is too small use 512 bytes
	instead of 8K.  Stop searching in /proc/stat after hitting first
	line not starting with cpu.
	(next_line): Truncate too long
	lines at buffer size * 3/4 instead of pretending there were line
	breaks inside of large lines.

2009-02-15  Ulrich Drepper  <drepper@redhat.com>

	* sysdeps/unix/sysv/linux/getsysstats.c (next_line): New function.
	(GET_NPROCS_PARSER): Change parameters and use next_line.
	(__get_nprocs): Rewrite to not use stdio routines.
	* sysdeps/unix/sysv/linux/sparc/getsysstats.c (GET_NPROCS_PARSER):
	Change parameters and use next_line.

--- libc/sysdeps/unix/sysv/linux/getsysstats.c	1 Aug 2007 21:23:37 -0000	1.31
+++ libc/sysdeps/unix/sysv/linux/getsysstats.c	15 Apr 2009 15:57:29 -0000	1.33
@@ -22,6 +22,7 @@
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <mntent.h>
 #include <paths.h>
 #include <stdio.h>
@@ -46,10 +47,13 @@
    But not all systems have support for the /proc filesystem.  If it
    is not available we simply return 1 since there is no way.  */
 
+#include <not-cancel.h>
+
+
 /* Other architectures use different formats for /proc/cpuinfo.  This
    provides a hook for alternative parsers.  */
 #ifndef GET_NPROCS_PARSER
-# define GET_NPROCS_PARSER(FP, BUFFER, RESULT)				\
+# define GET_NPROCS_PARSER(FD, BUFFER, CP, RE, BUFFER_END, RESULT) \
   do									\
     {									\
       (RESULT) = 0;							\
@@ -57,44 +61,116 @@
 	 "processor".  We don't have to fear extremely long lines since	\
 	 the kernel will not generate them.  8192 bytes are really	\
 	 enough.  */							\
-      while (fgets_unlocked (BUFFER, sizeof (BUFFER), FP) != NULL)	\
-	if (strncmp (BUFFER, "processor", 9) == 0)			\
+      char *l;								\
+      while ((l = next_line (FD, BUFFER, &CP, &RE, BUFFER_END)) != NULL) \
+	if (strncmp (l, "processor", 9) == 0)				\
 	  ++(RESULT);							\
     }									\
   while (0)
 #endif
 
+
+static char *
+next_line (int fd, char *const buffer, char **cp, char **re,
+	   char *const buffer_end)
+{
+  char *res = *cp;
+  char *nl = memchr (*cp, '\n', *re - *cp);
+  if (nl == NULL)
+    {
+      if (*cp != buffer)
+	{
+	  if (*re == buffer_end)
+	    {
+	      memmove (buffer, *cp, *re - *cp);
+	      *re = buffer + (*re - *cp);
+	      *cp = buffer;
+
+	      ssize_t n = read_not_cancel (fd, *re, buffer_end - *re);
+	      if (n < 0)
+		return NULL;
+
+	      *re += n;
+
+	      nl = memchr (*cp, '\n', *re - *cp);
+	      while (nl == NULL && *re == buffer_end)
+		{
+		  /* Truncate too long lines.  */
+		  *re = buffer + 3 * (buffer_end - buffer) / 4;
+		  n = read_not_cancel (fd, *re, buffer_end - *re);
+		  if (n < 0)
+		    return NULL;
+
+		  nl = memchr (*re, '\n', n);
+		  **re = '\n';
+		  *re += n;
+		}
+	    }
+	  else
+	    nl = memchr (*cp, '\n', *re - *cp);
+
+	  res = *cp;
+	}
+
+      if (nl == NULL)
+	nl = *re - 1;
+    }
+  else if (nl + 5 >= *re)
+    {
+      memmove (buffer, nl, *re - nl);
+      *re = buffer + (*re - nl);
+      nl = *cp = buffer;
+
+      ssize_t n = read_not_cancel (fd, *re, buffer_end - *re);
+      if (n < 0)
+	return NULL;
+
+      *re += n;
+    }
+
+  *cp = nl + 1;
+  assert (*cp <= *re);
+
+  return res == *re ? NULL : res;
+}
+
+
 int
 __get_nprocs ()
 {
-  char buffer[8192];
-  int result = 1;
-
   /* XXX Here will come a test for the new system call.  */
 
-  /* The /proc/stat format is more uniform, use it by default.  */
-  FILE *fp = fopen ("/proc/stat", "rc");
-  if (fp != NULL)
-    {
-      /* No threads use this stream.  */
-      __fsetlocking (fp, FSETLOCKING_BYCALLER);
+  const size_t buffer_size = __libc_use_alloca (8192) ? 8192 : 512;
+  char *buffer = alloca (buffer_size);
+  char *buffer_end = buffer + buffer_size;
+  char *cp = buffer_end;
+  char *re = buffer_end;
+  int result = 1;
 
+    /* The /proc/stat format is more uniform, use it by default.  */
+  int fd = open_not_cancel_2 ("/proc/stat", O_RDONLY);
+  if (fd != -1)
+    {
       result = 0;
-      while (fgets_unlocked (buffer, sizeof (buffer), fp) != NULL)
-	if (strncmp (buffer, "cpu", 3) == 0 && isdigit (buffer[3]))
+
+      char *l;
+      while ((l = next_line (fd, buffer, &cp, &re, buffer_end)) != NULL)
+	/* The current format of /proc/stat has all the cpu* entries
+	   at the front.  We assume here that stays this way.  */
+	if (strncmp (l, "cpu", 3) != 0)
+	  break;
+	else if (isdigit (l[3]))
 	  ++result;
 
-      fclose (fp);
+      close_not_cancel_no_status (fd);
     }
   else
     {
-      fp = fopen ("/proc/cpuinfo", "rc");
-      if (fp != NULL)
+      fd = open_not_cancel_2 ("/proc/cpuinfo", O_RDONLY);
+      if (fd != -1)
 	{
-	  /* No threads use this stream.  */
-	  __fsetlocking (fp, FSETLOCKING_BYCALLER);
-	  GET_NPROCS_PARSER (fp, buffer, result);
-	  fclose (fp);
+	  GET_NPROCS_PARSER (fd, buffer, cp, re, buffer_end, result);
+	  close_not_cancel_no_status (fd);
 	}
     }
 
--- libc/sysdeps/unix/sysv/linux/sparc/getsysstats.c	6 Jul 2001 04:56:21 -0000	1.2
+++ libc/sysdeps/unix/sysv/linux/sparc/getsysstats.c	15 Feb 2009 23:40:33 -0000	1.3
@@ -21,7 +21,7 @@
 
 
 /* We need to define a special parser for /proc/cpuinfo.  */
-#define GET_NPROCS_PARSER(FP, BUFFER, RESULT)				  \
+#define GET_NPROCS_PARSER(FD, BUFFER, CP, RE, BUFFER_END, RESULT)	  \
   do									  \
     {									  \
       (RESULT) = 0;							  \
@@ -29,8 +29,9 @@
 	 active cpus.  We don't have to fear extremely long lines since	  \
 	 the kernel will not generate them.  8192 bytes are really	  \
 	 enough.  */							  \
-      while (fgets_unlocked (BUFFER, sizeof (BUFFER), FP) != NULL)	  \
-	if (sscanf (BUFFER, "ncpus active : %d", &(RESULT)) == 1)	  \
+      char *l;								  \
+      while ((l = next_line (FD, BUFFER, &CP, &RE, BUFFER_END)) != NULL)  \
+	if (sscanf (l, "ncpus active : %d", &(RESULT)) == 1)		  \
 	  break;							  \
     }									  \
   while (0)