[PATCH]: trivial sys_mincore cleanup

[PATCH]: trivial sys_mincore cleanup

[Gianni Tedesco]

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Patch makes 2 simple cleanups:
 - Checks the syscall parameters before grabbing mmap semaphore.
 - Tidy up a comment.

BTW. How comes mincore() doesn't return a bit vector? :P

diff -urN linux-2.4.19.orig/mm/filemap.c linux-2.4.19/mm/filemap.c
--- linux-2.4.19.orig/mm/filemap.c      Sat Aug  3 00:39:46 2002
+++ linux-2.4.19/mm/filemap.c   Fri Dec 20 11:11:56 2002
@@ -2736,21 +2736,21 @@
        int unmapped_error = 0;
        long error = -EINVAL;
 
-       down_read(&current->mm->mmap_sem);
-
        if (start & ~PAGE_CACHE_MASK)
-               goto out;
+               return error;
        len = (len + ~PAGE_CACHE_MASK) & PAGE_CACHE_MASK;
        end = start + len;
        if (end < start)
-               goto out;
+               return error;
 
        error = 0;
        if (end == start)
-               goto out;
+               return error;
+
+       down_read(&current->mm->mmap_sem);
 
        /*
-        * If the interval [start,end) covers some unmapped address
+        * If the interval [start,end] covers some unmapped address
         * ranges, just ignore them, but return -ENOMEM at the end.
         */
        vma = find_vma(current->mm, start);

-- 
// Gianni Tedesco (gianni at ecsc dot co dot uk)
lynx --source www.scaramanga.co.uk/gianni-at-ecsc.asc | gpg --import
8646BE7D: 6D9F 2287 870E A2C9 8F60 3A3C 91B5 7669 8646 BE7D

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Re: [PATCH]: trivial sys_mincore cleanup

[Alex Riesen]

Gianni Tedesco, Fri, Dec 20, 2002 12:17:54 +0100:
> Patch makes 2 simple cleanups:
>  - Checks the syscall parameters before grabbing mmap semaphore.
>  - Tidy up a comment.

The comment is actually right: it is an old mathematical notation
to describe regions - from start until end, but not including the end.

>         /*
> -        * If the interval [start,end) covers some unmapped address
> +        * If the interval [start,end] covers some unmapped address
>          * ranges, just ignore them, but return -ENOMEM at the end.
>          */

-alex