Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull initial set_fs() removal from Al Viro:
 "Christoph's set_fs base series + fixups"

* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Allow a NULL pos pointer to __kernel_read
  fs: Allow a NULL pos pointer to __kernel_write
  powerpc: remove address space overrides using set_fs()
  powerpc: use non-set_fs based maccess routines
  x86: remove address space overrides using set_fs()
  x86: make TASK_SIZE_MAX usable from assembly code
  x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h
  lkdtm: remove set_fs-based tests
  test_bitmap: remove user bitmap tests
  uaccess: add infrastructure for kernel builds with set_fs()
  fs: don't allow splice read/write without explicit ops
  fs: don't allow kernel reads and writes without iter ops
  sysctl: Convert to iter interfaces
  proc: add a read_iter method to proc proc_ops
  proc: cleanup the compat vs no compat file ops
  proc: remove a level of indentation in proc_get_inode

1 files changed, 21 insertions, 46 deletions

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 604d705f1bb8..916daa4b4d0d 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -8,62 +8,21 @@
 #include <asm/extable.h>
 #include <asm/kup.h>
 
-/*
- * The fs value determines whether argument validity checking should be
- * performed or not.  If get_fs() == USER_DS, checking is performed, with
- * get_fs() == KERNEL_DS, checking is bypassed.
- *
- * For historical reasons, these macros are grossly misnamed.
- *
- * The fs/ds values are now the highest legal address in the "segment".
- * This simplifies the checking in the routines below.
- */
-
-#define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
-
-#define KERNEL_DS	MAKE_MM_SEG(~0UL)
 #ifdef __powerpc64__
 /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
-#define USER_DS		MAKE_MM_SEG(TASK_SIZE_USER64 - 1)
+#define TASK_SIZE_MAX		TASK_SIZE_USER64
 #else
-#define USER_DS		MAKE_MM_SEG(TASK_SIZE - 1)
+#define TASK_SIZE_MAX		TASK_SIZE
 #endif
 
-#define get_fs()	(current->thread.addr_limit)
-
-static inline void set_fs(mm_segment_t fs)
+static inline bool __access_ok(unsigned long addr, unsigned long size)
 {
-	current->thread.addr_limit = fs;
-	/* On user-mode return check addr_limit (fs) is correct */
-	set_thread_flag(TIF_FSCHECK);
+	return addr < TASK_SIZE_MAX && size <= TASK_SIZE_MAX - addr;
 }
 
-#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-#define user_addr_max()	(get_fs().seg)
-
-#ifdef __powerpc64__
-/*
- * This check is sufficient because there is a large enough
- * gap between user addresses and the kernel addresses
- */
-#define __access_ok(addr, size, segment)	\
-	(((addr) <= (segment).seg) && ((size) <= (segment).seg))
-
-#else
-
-static inline int __access_ok(unsigned long addr, unsigned long size,
-			mm_segment_t seg)
-{
-	if (addr > seg.seg)
-		return 0;
-	return (size == 0 || size - 1 <= seg.seg - addr);
-}
-
-#endif
-
 #define access_ok(addr, size)		\
 	(__chk_user_ptr(addr),		\
-	 __access_ok((__force unsigned long)(addr), (size), get_fs()))
+	 __access_ok((unsigned long)(addr), (size)))
 
 /*
  * These are the main single-value transfer routines.  They automatically
@@ -604,4 +563,20 @@ do {									\
 		__put_user_goto(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e);\
 } while (0)
 
+#define HAVE_GET_KERNEL_NOFAULT
+
+#define __get_kernel_nofault(dst, src, type, err_label)			\
+do {									\
+	int __kr_err;							\
+									\
+	__get_user_size_allowed(*((type *)(dst)), (__force type __user *)(src),\
+			sizeof(type), __kr_err);			\
+	if (unlikely(__kr_err))						\
+		goto err_label;						\
+} while (0)
+
+#define __put_kernel_nofault(dst, src, type, err_label)			\
+	__put_user_size_goto(*((type *)(src)),				\
+		(__force type __user *)(dst), sizeof(type), err_label)
+
 #endif	/* _ARCH_POWERPC_UACCESS_H */