patch-2.1.16 linux/arch/ppc/kernel/usercpy.c

• Lines: 117
• Date: Wed Dec 18 10:49:52 1996
• Orig file: v2.1.15/linux/arch/ppc/kernel/usercpy.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.15/linux/arch/ppc/kernel/usercpy.c linux/arch/ppc/kernel/usercpy.c
@@ -0,0 +1,116 @@
+#include <linux/types.h>
+#include <asm/string.h>
+#include <asm/errno.h>
+#include <linux/sched.h>
+
+/*
+ * bad data accesses from these functions should be handled specially 
+ * since they are to user areas and may or may not be valid.
+ * on error -EFAULT should be returned.  -- Cort
+ */
+int __copy_tofrom_user_failure(void)
+{
+  current->tss.excount = 0;
+  return -EFAULT;
+}
+
+int __copy_tofrom_user(unsigned long to, unsigned long from, int size)
+{
+  /* setup exception handling stuff */
+  current->tss.excount++;
+  current->tss.expc = (unsigned long )__copy_tofrom_user_failure;
+  
+  if (memcpy( (void *)to, (void *)from, (size_t) size) == -EFAULT )
+  {
+    /* take down exception handler stuff */
+    current->tss.excount = 0;
+    return -EFAULT;
+  }
+  current->tss.excount = 0;
+  return 0; /* successful return */
+}
+
+/* Just like strncpy except in the return value:
+ *
+ * -EFAULT       if an exception occurs before the terminator is copied.
+ * N             if the buffer filled.
+ *
+ * Otherwise the length of the string is returned.
+ */
+asmlinkage int __strncpy_from_user_failure(void)
+{
+  current->tss.excount = 0;
+  return -EFAULT;
+}
+
+int __strncpy_from_user(unsigned long dest, unsigned long src, int count)
+{
+  int i = 0;
+  /* setup exception handling stuff */
+  current->tss.excount++;
+  current->tss.expc = (unsigned long )__strncpy_from_user_failure;
+  
+  while ( i != count )
+  {
+    *(char *)(dest+i) = *(char *)(src+i);
+    if ( *(char *)(src+i) == 0 )
+    {
+      return i;
+    }
+    i++;
+  }
+  *(char *)(dest+i) = (char)0;
+  /* take down exception handler stuff */
+  current->tss.excount = 0;
+  return i;
+}
+
+int __clear_user_failure(void)
+{
+  current->tss.excount = 0;
+  return -EFAULT;
+}
+int __clear_user(unsigned long addr, int size)
+{
+  /* setup exception handling stuff */
+  current->tss.excount++;
+  current->tss.expc = (unsigned long )__clear_user_failure;
+
+  if ((int)memset((void *)addr,(int)0, (__kernel_size_t)size) == -EFAULT )
+    {
+      /* take down exception handler stuff */
+      current->tss.excount = 0;
+      return -EFAULT;
+    }
+  /* take down exception handler stuff */
+  current->tss.excount = 0;
+  return size;
+}
+
+/*
+ * Return the length of the string including the NUL terminator
+ * (strlen+1) or zero if an error occured.
+ */
+size_t strlen_user_failure(void)
+{
+  current->tss.excount = 0;
+  return -EFAULT;
+}
+size_t strlen_user(char * s)
+{
+  size_t i;
+  /* setup exception handling stuff */
+  current->tss.excount++;
+  current->tss.expc = (unsigned long )strlen_user_failure;
+  
+  i = strlen(s)+1;
+  
+  if ( i == -EFAULT)
+    return -EFAULT;
+  
+  /* take down exception handler stuff */
+  current->tss.excount = 0;
+
+  return(i);
+}
+