Merge branch 'set_fs-4' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic into asm-generic

Christoph Hellwig and a few others spent a huge effort on removing
set_fs() from most of the important architectures, but about half the
other architectures were never completed even though most of them don't
actually use set_fs() at all.

I did a patch for microblaze at some point, which turned out to be fairly
generic, and now ported it to most other architectures, using new generic
implementations of access_ok() and __{get,put}_kernel_nocheck().

Three architectures (sparc64, ia64, and sh) needed some extra work,
which I also completed.

* 'set_fs-4' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  uaccess: remove CONFIG_SET_FS
  ia64: remove CONFIG_SET_FS support
  sh: remove CONFIG_SET_FS support
  sparc64: remove CONFIG_SET_FS support
  lib/test_lockup: fix kernel pointer check for separate address spaces
  uaccess: generalize access_ok()
  uaccess: fix type mismatch warnings from access_ok()
  arm64: simplify access_ok()
  m68k: fix access_ok for coldfire
  MIPS: use simpler access_ok()
  MIPS: Handle address errors for accesses above CPU max virtual user address
  uaccess: add generic __{get,put}_kernel_nofault
  nios2: drop access_ok() check from __put_user()
  x86: use more conventional access_ok() definition
  x86: remove __range_not_ok()
  sparc64: add __{get,put}_kernel_nofault()
  nds32: fix access_ok() checks in get/put_user
  uaccess: fix nios2 and microblaze get_user_8()
  uaccess: fix integer overflow on access_ok()

14 files changed, 90 insertions, 98 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 1cab1b284f1a..9200bc04701c 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -46,7 +46,6 @@ config SPARC
 	select LOCKDEP_SMALL if LOCKDEP
 	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
-	select SET_FS
 	select TRACE_IRQFLAGS_SUPPORT
 
 config SPARC32
@@ -62,6 +61,7 @@ config SPARC32
 
 config SPARC64
 	def_bool 64BIT
+	select ALTERNATE_USER_ADDRESS_SPACE
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_KRETPROBES
diff --git a/arch/sparc/include/asm/processor_32.h b/arch/sparc/include/asm/processor_32.h
index 647bf0ac7beb..b26c35336b51 100644
--- a/arch/sparc/include/asm/processor_32.h
+++ b/arch/sparc/include/asm/processor_32.h
@@ -32,10 +32,6 @@ struct fpq {
 };
 #endif
 
-typedef struct {
-	int seg;
-} mm_segment_t;
-
 /* The Sparc processor specific thread struct. */
 struct thread_struct {
 	struct pt_regs *kregs;
@@ -50,11 +46,9 @@ struct thread_struct {
 	unsigned long   fsr;
 	unsigned long   fpqdepth;
 	struct fpq	fpqueue[16];
-	mm_segment_t current_ds;
 };
 
 #define INIT_THREAD  { \
-	.current_ds = KERNEL_DS, \
 	.kregs = (struct pt_regs *)(init_stack+THREAD_SIZE)-1 \
 }
 
diff --git a/arch/sparc/include/asm/processor_64.h b/arch/sparc/include/asm/processor_64.h
index ae851e8fce4c..89850dff6b03 100644
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -47,10 +47,6 @@
 
 #ifndef __ASSEMBLY__
 
-typedef struct {
-	unsigned char seg;
-} mm_segment_t;
-
 /* The Sparc processor specific thread struct. */
 /* XXX This should die, everything can go into thread_info now. */
 struct thread_struct {
diff --git a/arch/sparc/include/asm/switch_to_64.h b/arch/sparc/include/asm/switch_to_64.h
index b1d4e2e3210f..14f3c49bfdbc 100644
--- a/arch/sparc/include/asm/switch_to_64.h
+++ b/arch/sparc/include/asm/switch_to_64.h
@@ -20,10 +20,8 @@ do {						\
 	 */
 #define switch_to(prev, next, last)					\
 do {	save_and_clear_fpu();						\
-	/* If you are tempted to conditionalize the following */	\
-	/* so that ASI is only written if it changes, think again. */	\
 	__asm__ __volatile__("wr %%g0, %0, %%asi"			\
-	: : "r" (task_thread_info(next)->current_ds));\
+	: : "r" (ASI_AIUS));						\
 	trap_block[current_thread_info()->cpu].thread =			\
 		task_thread_info(next);					\
 	__asm__ __volatile__(						\
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index 8047a9caab2f..1a44372e2bc0 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -46,7 +46,7 @@ struct thread_info {
 	struct pt_regs		*kregs;
 	int			preempt_count;	/* 0 => preemptable, <0 => BUG */
 	__u8			new_child;
-	__u8			current_ds;
+	__u8			__pad;
 	__u16			cpu;
 
 	unsigned long		*utraps;
@@ -81,7 +81,6 @@ struct thread_info {
 #define TI_KREGS	0x00000028
 #define TI_PRE_COUNT	0x00000030
 #define TI_NEW_CHILD	0x00000034
-#define TI_CURRENT_DS	0x00000035
 #define TI_CPU		0x00000036
 #define TI_UTRAPS	0x00000038
 #define TI_REG_WINDOW	0x00000040
@@ -116,7 +115,6 @@ struct thread_info {
 #define INIT_THREAD_INFO(tsk)				\
 {							\
 	.task		=	&tsk,			\
-	.current_ds	=	ASI_P,			\
 	.preempt_count	=	INIT_PREEMPT_COUNT,	\
 	.kregs		=	(struct pt_regs *)(init_stack+THREAD_SIZE)-1 \
 }
diff --git a/arch/sparc/include/asm/uaccess.h b/arch/sparc/include/asm/uaccess.h
index 390094200fc4..ee75f69e3fcd 100644
--- a/arch/sparc/include/asm/uaccess.h
+++ b/arch/sparc/include/asm/uaccess.h
@@ -10,9 +10,6 @@
 #include <asm/uaccess_32.h>
 #endif
 
-#define user_addr_max() \
-	(uaccess_kernel() ? ~0UL : TASK_SIZE)
-
 long strncpy_from_user(char *dest, const char __user *src, long count);
 
 #endif
diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index 4a12346bb69c..9fd6c53644b6 100644
--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h
@@ -12,30 +12,7 @@
 #include <linux/string.h>
 
 #include <asm/processor.h>
-
-/* Sparc is not segmented, however we need to be able to fool access_ok()
- * when doing system calls from kernel mode legitimately.
- *
- * "For historical reasons, these macros are grossly misnamed." -Linus
- */
-
-#define KERNEL_DS   ((mm_segment_t) { 0 })
-#define USER_DS     ((mm_segment_t) { -1 })
-
-#define get_fs()	(current->thread.current_ds)
-#define set_fs(val)	((current->thread.current_ds) = (val))
-
-#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-
-/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
- * can be fairly lightweight.
- * No one can read/write anything from userland in the kernel space by setting
- * large size and address near to PAGE_OFFSET - a fault will break his intentions.
- */
-#define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; })
-#define __kernel_ok (uaccess_kernel())
-#define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size)))
-#define access_ok(addr, size) __access_ok((unsigned long)(addr), size)
+#include <asm-generic/access_ok.h>
 
 /* Uh, these should become the main single-value transfer routines..
  * They automatically use the right size if we just have the right
@@ -47,13 +24,13 @@
  * and hide all the ugliness from the user.
  */
 #define put_user(x, ptr) ({ \
-	unsigned long __pu_addr = (unsigned long)(ptr); \
+	void __user *__pu_addr = (ptr); \
 	__chk_user_ptr(ptr); \
 	__put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \
 })
 
 #define get_user(x, ptr) ({ \
-	unsigned long __gu_addr = (unsigned long)(ptr); \
+	const void __user *__gu_addr = (ptr); \
 	__chk_user_ptr(ptr); \
 	__get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \
 })
@@ -232,7 +209,7 @@ static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 
 static inline unsigned long clear_user(void __user *addr, unsigned long n)
 {
-	if (n && __access_ok((unsigned long) addr, n))
+	if (n && __access_ok(addr, n))
 		return __clear_user(addr, n);
 	else
 		return n;
diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index 30eb4c6414d1..94266a5c5b04 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -12,33 +12,15 @@
 #include <asm/spitfire.h>
 
 #include <asm/processor.h>
+#include <asm-generic/access_ok.h>
 
 /*
  * Sparc64 is segmented, though more like the M68K than the I386.
  * We use the secondary ASI to address user memory, which references a
  * completely different VM map, thus there is zero chance of the user
  * doing something queer and tricking us into poking kernel memory.
- *
- * What is left here is basically what is needed for the other parts of
- * the kernel that expect to be able to manipulate, erum, "segments".
- * Or perhaps more properly, permissions.
- *
- * "For historical reasons, these macros are grossly misnamed." -Linus
  */
 
-#define KERNEL_DS   ((mm_segment_t) { ASI_P })
-#define USER_DS     ((mm_segment_t) { ASI_AIUS })	/* har har har */
-
-#define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
-
-#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-
-#define set_fs(val)								\
-do {										\
-	current_thread_info()->current_ds = (val).seg;				\
-	__asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));	\
-} while(0)
-
 /*
  * Test whether a block of memory is a valid user space address.
  * Returns 0 if the range is valid, nonzero otherwise.
@@ -61,16 +43,6 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un
 	__chk_range_not_ok((unsigned long __force)(addr), size, limit); \
 })
 
-static inline int __access_ok(const void __user * addr, unsigned long size)
-{
-	return 1;
-}
-
-static inline int access_ok(const void __user * addr, unsigned long size)
-{
-	return 1;
-}
-
 void __retl_efault(void);
 
 /* Uh, these should become the main single-value transfer routines..
@@ -100,6 +72,42 @@ void __retl_efault(void);
 struct __large_struct { unsigned long buf[100]; };
 #define __m(x) ((struct __large_struct *)(x))
 
+#define __put_kernel_nofault(dst, src, type, label)			\
+do {									\
+	type *addr = (type __force *)(dst);				\
+	type data = *(type *)src;					\
+	register int __pu_ret;						\
+	switch (sizeof(type)) {						\
+	case 1: __put_kernel_asm(data, b, addr, __pu_ret); break;	\
+	case 2: __put_kernel_asm(data, h, addr, __pu_ret); break;	\
+	case 4: __put_kernel_asm(data, w, addr, __pu_ret); break;	\
+	case 8: __put_kernel_asm(data, x, addr, __pu_ret); break;	\
+	default: __pu_ret = __put_user_bad(); break;			\
+	}								\
+	if (__pu_ret)							\
+		goto label;						\
+} while (0)
+
+#define __put_kernel_asm(x, size, addr, ret)				\
+__asm__ __volatile__(							\
+		"/* Put kernel asm, inline. */\n"			\
+	"1:\t"	"st"#size " %1, [%2]\n\t"				\
+		"clr	%0\n"						\
+	"2:\n\n\t"							\
+		".section .fixup,#alloc,#execinstr\n\t"			\
+		".align	4\n"						\
+	"3:\n\t"							\
+		"sethi	%%hi(2b), %0\n\t"				\
+		"jmpl	%0 + %%lo(2b), %%g0\n\t"			\
+		" mov	%3, %0\n\n\t"					\
+		".previous\n\t"						\
+		".section __ex_table,\"a\"\n\t"				\
+		".align	4\n\t"						\
+		".word	1b, 3b\n\t"					\
+		".previous\n\n\t"					\
+	       : "=r" (ret) : "r" (x), "r" (__m(addr)),			\
+		 "i" (-EFAULT))
+
 #define __put_user_nocheck(data, addr, size) ({			\
 	register int __pu_ret;					\
 	switch (size) {						\
@@ -134,6 +142,46 @@ __asm__ __volatile__(							\
 
 int __put_user_bad(void);
 
+#define __get_kernel_nofault(dst, src, type, label)			     \
+do {									     \
+	type *addr = (type __force *)(src);		     		     \
+	register int __gu_ret;						     \
+	register unsigned long __gu_val;				     \
+	switch (sizeof(type)) {						     \
+		case 1: __get_kernel_asm(__gu_val, ub, addr, __gu_ret); break; \
+		case 2: __get_kernel_asm(__gu_val, uh, addr, __gu_ret); break; \
+		case 4: __get_kernel_asm(__gu_val, uw, addr, __gu_ret); break; \
+		case 8: __get_kernel_asm(__gu_val, x, addr, __gu_ret); break;  \
+		default:						     \
+			__gu_val = 0;					     \
+			__gu_ret = __get_user_bad();			     \
+			break;						     \
+	} 								     \
+	if (__gu_ret)							     \
+		goto label;						     \
+	*(type *)dst = (__force type) __gu_val;				     \
+} while (0)
+#define __get_kernel_asm(x, size, addr, ret)				\
+__asm__ __volatile__(							\
+		"/* Get kernel asm, inline. */\n"			\
+	"1:\t"	"ld"#size " [%2], %1\n\t"				\
+		"clr	%0\n"						\
+	"2:\n\n\t"							\
+		".section .fixup,#alloc,#execinstr\n\t"			\
+		".align	4\n"						\
+	"3:\n\t"							\
+		"sethi	%%hi(2b), %0\n\t"				\
+		"clr	%1\n\t"						\
+		"jmpl	%0 + %%lo(2b), %%g0\n\t"			\
+		" mov	%3, %0\n\n\t"					\
+		".previous\n\t"						\
+		".section __ex_table,\"a\"\n\t"				\
+		".align	4\n\t"						\
+		".word	1b, 3b\n\n\t"					\
+		".previous\n\t"						\
+	       : "=r" (ret), "=r" (x) : "r" (__m(addr)),		\
+		 "i" (-EFAULT))
+
 #define __get_user_nocheck(data, addr, size, type) ({			     \
 	register int __gu_ret;						     \
 	register unsigned long __gu_val;				     \
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index 2dc0bf9fe62e..88c0c14aaff0 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -300,7 +300,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
 		extern int nwindows;
 		unsigned long psr;
 		memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
-		p->thread.current_ds = KERNEL_DS;
 		ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
 		childregs->u_regs[UREG_G1] = sp; /* function */
 		childregs->u_regs[UREG_G2] = arg;
@@ -311,7 +310,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
 	}
 	memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
 	childregs->u_regs[UREG_FP] = sp;
-	p->thread.current_ds = USER_DS;
 	ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
 	ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
 	ti->kwim = current->thread.fork_kwim;
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index f5b2cac8669f..9a2ceb080ac9 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -106,18 +106,13 @@ static void show_regwindow32(struct pt_regs *regs)
 {
 	struct reg_window32 __user *rw;
 	struct reg_window32 r_w;
-	mm_segment_t old_fs;
 	
 	__asm__ __volatile__ ("flushw");
 	rw = compat_ptr((unsigned int)regs->u_regs[14]);
-	old_fs = get_fs();
-	set_fs (USER_DS);
 	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
-		set_fs (old_fs);
 		return;
 	}
 
-	set_fs (old_fs);			
 	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
@@ -136,7 +131,6 @@ static void show_regwindow(struct pt_regs *regs)
 	struct reg_window __user *rw;
 	struct reg_window *rwk;
 	struct reg_window r_w;
-	mm_segment_t old_fs;
 
 	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 		__asm__ __volatile__ ("flushw");
@@ -145,14 +139,10 @@ static void show_regwindow(struct pt_regs *regs)
 		rwk = (struct reg_window *)
 			(regs->u_regs[14] + STACK_BIAS);
 		if (!(regs->tstate & TSTATE_PRIV)) {
-			old_fs = get_fs();
-			set_fs (USER_DS);
 			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
-				set_fs (old_fs);
 				return;
 			}
 			rwk = &r_w;
-			set_fs (old_fs);			
 		}
 	} else {
 		show_regwindow32(regs);
@@ -598,7 +588,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
 		memset(child_trap_frame, 0, child_stack_sz);
 		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
 			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
-		t->current_ds = ASI_P;
 		t->kregs->u_regs[UREG_G1] = sp; /* function */
 		t->kregs->u_regs[UREG_G2] = arg;
 		return 0;
@@ -613,7 +602,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
 	t->kregs->u_regs[UREG_FP] = sp;
 	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
 		(regs->tstate + 1) & TSTATE_CWP;
-	t->current_ds = ASI_AIUS;
 	if (sp != regs->u_regs[UREG_FP]) {
 		unsigned long csp;
 
diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c
index ffab16369bea..74f80443b195 100644
--- a/arch/sparc/kernel/signal_32.c
+++ b/arch/sparc/kernel/signal_32.c
@@ -65,7 +65,7 @@ struct rt_signal_frame {
  */
 static inline bool invalid_frame_pointer(void __user *fp, int fplen)
 {
-	if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen))
+	if ((((unsigned long) fp) & 15) || !access_ok(fp, fplen))
 		return true;
 
 	return false;
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 21077821f427..5b4de4a89dec 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -2857,8 +2857,6 @@ void __init trap_init(void)
 		     TI_PRE_COUNT != offsetof(struct thread_info,
 					      preempt_count) ||
 		     TI_NEW_CHILD != offsetof(struct thread_info, new_child) ||
-		     TI_CURRENT_DS != offsetof(struct thread_info,
-						current_ds) ||
 		     TI_KUNA_REGS != offsetof(struct thread_info,
 					      kern_una_regs) ||
 		     TI_KUNA_INSN != offsetof(struct thread_info,
diff --git a/arch/sparc/lib/NGmemcpy.S b/arch/sparc/lib/NGmemcpy.S
index 8e4d22a6ba0b..ee51c1230689 100644
--- a/arch/sparc/lib/NGmemcpy.S
+++ b/arch/sparc/lib/NGmemcpy.S
@@ -10,8 +10,7 @@
 #include <asm/thread_info.h>
 #define GLOBAL_SPARE	%g7
 #define RESTORE_ASI(TMP)	\
-	ldub	[%g6 + TI_CURRENT_DS], TMP;  \
-	wr	TMP, 0x0, %asi;
+	wr	%g0, ASI_AIUS, %asi
 #else
 #define GLOBAL_SPARE	%g5
 #define RESTORE_ASI(TMP)	\
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 1b23639e2fcd..8b1911591581 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -709,9 +709,10 @@ static void __init inherit_prom_mappings(void)
 
 void prom_world(int enter)
 {
-	if (!enter)
-		set_fs(get_fs());
-
+	/*
+	 * No need to change the address space any more, just flush
+	 * the register windows
+	 */
 	__asm__ __volatile__("flushw");
 }