Merge tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic updates from Arnd Bergmann:
 "There are three sets of updates for 5.18 in the asm-generic tree:

   - The set_fs()/get_fs() infrastructure gets removed for good.

     This was already gone from all major architectures, but now we can
     finally remove it everywhere, which loses some particularly tricky
     and error-prone code. There is a small merge conflict against a
     parisc cleanup, the solution is to use their new version.

   - The nds32 architecture ends its tenure in the Linux kernel.

     The hardware is still used and the code is in reasonable shape, but
     the mainline port is not actively maintained any more, as all
     remaining users are thought to run vendor kernels that would never
     be updated to a future release.

   - A series from Masahiro Yamada cleans up some of the uapi header
     files to pass the compile-time checks"

* tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits)
  nds32: Remove the architecture
  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()
  sparc64: fix building assembly files
  ...

8 files changed, 22 insertions, 80 deletions

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 1c2b53bf3093..5f220e903e5a 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -66,7 +66,6 @@ config SUPERH
 	select PERF_EVENTS
 	select PERF_USE_VMALLOC
 	select RTC_LIB
-	select SET_FS
 	select SPARSE_IRQ
 	select TRACE_IRQFLAGS_SUPPORT
 	help
diff --git a/arch/sh/include/asm/processor.h b/arch/sh/include/asm/processor.h
index 3820d698846e..85a6c1c3c16e 100644
--- a/arch/sh/include/asm/processor.h
+++ b/arch/sh/include/asm/processor.h
@@ -3,7 +3,6 @@
 #define __ASM_SH_PROCESSOR_H
 
 #include <asm/cpu-features.h>
-#include <asm/segment.h>
 #include <asm/cache.h>
 
 #ifndef __ASSEMBLY__
diff --git a/arch/sh/include/asm/segment.h b/arch/sh/include/asm/segment.h
deleted file mode 100644
index 02e54a3335d6..000000000000
--- a/arch/sh/include/asm/segment.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ASM_SH_SEGMENT_H
-#define __ASM_SH_SEGMENT_H
-
-#ifndef __ASSEMBLY__
-
-typedef struct {
-	unsigned long seg;
-} mm_segment_t;
-
-#define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })
-
-/*
- * 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.
- */
-#define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFFUL)
-#ifdef CONFIG_MMU
-#define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)
-#else
-#define USER_DS		KERNEL_DS
-#endif
-
-#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-
-#define get_fs()	(current_thread_info()->addr_limit)
-#define set_fs(x)	(current_thread_info()->addr_limit = (x))
-
-#endif /* __ASSEMBLY__ */
-#endif /* __ASM_SH_SEGMENT_H */
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index 598d0184ffea..b119b859a0a3 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -30,7 +30,6 @@ struct thread_info {
 	__u32			status;		/* thread synchronous flags */
 	__u32			cpu;
 	int			preempt_count; /* 0 => preemptable, <0 => BUG */
-	mm_segment_t		addr_limit;	/* thread address space */
 	unsigned long		previous_sp;	/* sp of previous stack in case
 						   of nested IRQ stacks */
 	__u8			supervisor_stack[0];
@@ -58,7 +57,6 @@ struct thread_info {
 	.status		= 0,			\
 	.cpu		= 0,			\
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
-	.addr_limit	= KERNEL_DS,		\
 }
 
 /* how to get the current stack pointer from C */
diff --git a/arch/sh/include/asm/uaccess.h b/arch/sh/include/asm/uaccess.h
index 8867bb04b00e..a79609eb14be 100644
--- a/arch/sh/include/asm/uaccess.h
+++ b/arch/sh/include/asm/uaccess.h
@@ -2,30 +2,8 @@
 #ifndef __ASM_SH_UACCESS_H
 #define __ASM_SH_UACCESS_H
 
-#include <asm/segment.h>
 #include <asm/extable.h>
-
-#define __addr_ok(addr) \
-	((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)
-
-/*
- * __access_ok: Check if address with size is OK or not.
- *
- * Uhhuh, this needs 33-bit arithmetic. We have a carry..
- *
- * sum := addr + size;  carry? --> flag = true;
- * if (sum >= addr_limit) flag = true;
- */
-#define __access_ok(addr, size)	({				\
-	unsigned long __ao_a = (addr), __ao_b = (size);		\
-	unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b;	\
-	__ao_end >= __ao_a && __addr_ok(__ao_end); })
-
-#define access_ok(addr, size)	\
-	(__chk_user_ptr(addr),		\
-	 __access_ok((unsigned long __force)(addr), (size)))
-
-#define user_addr_max()	(current_thread_info()->addr_limit.seg)
+#include <asm-generic/access_ok.h>
 
 /*
  * Uh, these should become the main single-value transfer routines ...
diff --git a/arch/sh/kernel/io_trapped.c b/arch/sh/kernel/io_trapped.c
index 004ad0130b10..e803b14ef12e 100644
--- a/arch/sh/kernel/io_trapped.c
+++ b/arch/sh/kernel/io_trapped.c
@@ -270,7 +270,6 @@ static struct mem_access trapped_io_access = {
 
 int handle_trapped_io(struct pt_regs *regs, unsigned long address)
 {
-	mm_segment_t oldfs;
 	insn_size_t instruction;
 	int tmp;
 
@@ -281,16 +280,12 @@ int handle_trapped_io(struct pt_regs *regs, unsigned long address)
 
 	WARN_ON(user_mode(regs));
 
-	oldfs = get_fs();
-	set_fs(KERNEL_DS);
-	if (copy_from_user(&instruction, (void *)(regs->pc),
-			   sizeof(instruction))) {
-		set_fs(oldfs);
+	if (copy_from_kernel_nofault(&instruction, (void *)(regs->pc),
+				     sizeof(instruction))) {
 		return 0;
 	}
 
 	tmp = handle_unaligned_access(instruction, regs,
 				      &trapped_io_access, 1, address);
-	set_fs(oldfs);
 	return tmp == 0;
 }
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 1c28e3cddb60..ca01286a0610 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -123,7 +123,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
 #if defined(CONFIG_SH_FPU)
 		childregs->sr |= SR_FD;
 #endif
-		ti->addr_limit = KERNEL_DS;
 		ti->status &= ~TS_USEDFPU;
 		p->thread.fpu_counter = 0;
 		return 0;
@@ -132,7 +131,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
 
 	if (usp)
 		childregs->regs[15] = usp;
-	ti->addr_limit = USER_DS;
 
 	if (clone_flags & CLONE_SETTLS)
 		childregs->gbr = tls;
diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c
index b3c715bc254b..6cdda3a621a1 100644
--- a/arch/sh/kernel/traps_32.c
+++ b/arch/sh/kernel/traps_32.c
@@ -75,6 +75,23 @@ static struct mem_access user_mem_access = {
 	copy_to_user,
 };
 
+static unsigned long copy_from_kernel_wrapper(void *dst, const void __user *src,
+					      unsigned long cnt)
+{
+	return copy_from_kernel_nofault(dst, (const void __force *)src, cnt);
+}
+
+static unsigned long copy_to_kernel_wrapper(void __user *dst, const void *src,
+					    unsigned long cnt)
+{
+	return copy_to_kernel_nofault((void __force *)dst, src, cnt);
+}
+
+static struct mem_access kernel_mem_access = {
+	copy_from_kernel_wrapper,
+	copy_to_kernel_wrapper,
+};
+
 /*
  * handle an instruction that does an unaligned memory access by emulating the
  * desired behaviour
@@ -473,7 +490,6 @@ asmlinkage void do_address_error(struct pt_regs *regs,
 				 unsigned long address)
 {
 	unsigned long error_code = 0;
-	mm_segment_t oldfs;
 	insn_size_t instruction;
 	int tmp;
 
@@ -489,13 +505,10 @@ asmlinkage void do_address_error(struct pt_regs *regs,
 		local_irq_enable();
 		inc_unaligned_user_access();
 
-		oldfs = force_uaccess_begin();
 		if (copy_from_user(&instruction, (insn_size_t __user *)(regs->pc & ~1),
 				   sizeof(instruction))) {
-			force_uaccess_end(oldfs);
 			goto uspace_segv;
 		}
-		force_uaccess_end(oldfs);
 
 		/* shout about userspace fixups */
 		unaligned_fixups_notify(current, instruction, regs);
@@ -518,11 +531,9 @@ fixup:
 			goto uspace_segv;
 		}
 
-		oldfs = force_uaccess_begin();
 		tmp = handle_unaligned_access(instruction, regs,
 					      &user_mem_access, 0,
 					      address);
-		force_uaccess_end(oldfs);
 
 		if (tmp == 0)
 			return; /* sorted */
@@ -538,21 +549,18 @@ uspace_segv:
 		if (regs->pc & 1)
 			die("unaligned program counter", regs, error_code);
 
-		set_fs(KERNEL_DS);
-		if (copy_from_user(&instruction, (void __user *)(regs->pc),
+		if (copy_from_kernel_nofault(&instruction, (void *)(regs->pc),
 				   sizeof(instruction))) {
 			/* Argh. Fault on the instruction itself.
 			   This should never happen non-SMP
 			*/
-			set_fs(oldfs);
 			die("insn faulting in do_address_error", regs, 0);
 		}
 
 		unaligned_fixups_notify(current, instruction, regs);
 
-		handle_unaligned_access(instruction, regs, &user_mem_access,
+		handle_unaligned_access(instruction, regs, &kernel_mem_access,
 					0, address);
-		set_fs(oldfs);
 	}
 }