[PATCH] uml: eliminate use of libc PAGE_SIZE

On some systems, libc PAGE_SIZE calls getpagesize, which can't happen from a
stub.  So, I use UM_KERN_PAGE_SIZE, which is less variable in its definition,
instead.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c
index 39c0d7145d310b946d4b82425754c64b9949bfdc..cb37ce9124a6f4a01702f260cab102f8a332b017 100644 (file)
--- a/arch/um/kernel/skas/clone.c
+++ b/arch/um/kernel/skas/clone.c
@@ -9,9 +9,13 @@
 #include "stub-data.h"
 #include "uml-config.h"
 #include "sysdep/stub.h"
+#include "kern_constants.h"
 
 /* This is in a separate file because it needs to be compiled with any
  * extraneous gcc flags (-pg, -fprofile-arcs, -ftest-coverage) disabled
+ *
+ * Use UM_KERN_PAGE_SIZE instead of PAGE_SIZE because that calls getpagesize
+ * on some systems.
  */
 
 #define STUB_DATA(field) (((struct stub_data *) UML_CONFIG_STUB_DATA)->field)
@@ -22,7 +26,7 @@ stub_clone_handler(void)
        long err;
 
        err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
-                           UML_CONFIG_STUB_DATA + PAGE_SIZE / 2 -
+                           UML_CONFIG_STUB_DATA + UM_KERN_PAGE_SIZE / 2 -
                            sizeof(void *));
        if(err != 0)
                goto out;
@@ -36,9 +40,10 @@ stub_clone_handler(void)
        if(err)
                goto out;
 
-       err = stub_syscall6(STUB_MMAP_NR, UML_CONFIG_STUB_DATA, PAGE_SIZE,
-                           PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED,
-                           STUB_DATA(fd), STUB_DATA(offset));
+       err = stub_syscall6(STUB_MMAP_NR, UML_CONFIG_STUB_DATA,
+                           UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
+                           MAP_FIXED | MAP_SHARED, STUB_DATA(fd),
+                           STUB_DATA(offset));
  out:
        /* save current result. Parent: pid; child: retcode of mmap */
        STUB_DATA(err) = err;