Commit aa1a64ee authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

[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: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 17d46971

arch/um/kernel/skas/clone.c

+9 −4
Original line number Diff line number Diff line
@@ -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;

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