uaccess: remove CONFIG_SET_FS

There are no remaining callers of set_fs(), so CONFIG_SET_FS
can be removed globally, along with the thread_info field and
any references to it.

This turns access_ok() into a cheaper check against TASK_SIZE_MAX.

As CONFIG_SET_FS is now gone, drop all remaining references to
set_fs()/get_fs(), mm_segment_t, user_addr_max() and uaccess_kernel().

Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Tested-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> # for arc changes
Acked-by: Stafford Horne <shorne@gmail.com> # [openrisc, asm-generic]
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

5 files changed, 3 insertions, 25 deletions

diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig
index 4d1421b18734..013249430fa3 100644
--- a/arch/nds32/Kconfig
+++ b/arch/nds32/Kconfig
@@ -44,7 +44,6 @@ config NDS32
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_DYNAMIC_FTRACE
-	select SET_FS
 	select TRACE_IRQFLAGS_SUPPORT
 	help
 	  Andes(nds32) Linux support.
diff --git a/arch/nds32/include/asm/thread_info.h b/arch/nds32/include/asm/thread_info.h
index d3967ad184f0..bd8f81cf2ce5 100644
--- a/arch/nds32/include/asm/thread_info.h
+++ b/arch/nds32/include/asm/thread_info.h
@@ -16,8 +16,6 @@ struct task_struct;
 #include <asm/ptrace.h>
 #include <asm/types.h>
 
-typedef unsigned long mm_segment_t;
-
 /*
  * low level task data that entry.S needs immediate access to.
  * __switch_to() assumes cpu_context follows immediately after cpu_domain.
@@ -25,12 +23,10 @@ typedef unsigned long mm_segment_t;
 struct thread_info {
 	unsigned long flags;	/* low level flags */
 	__s32 preempt_count;	/* 0 => preemptable, <0 => bug */
-	mm_segment_t addr_limit;	/* address limit */
 };
 #define INIT_THREAD_INFO(tsk)						\
 {									\
 	.preempt_count	= INIT_PREEMPT_COUNT,				\
-	.addr_limit	= KERNEL_DS,					\
 }
 #define thread_saved_pc(tsk) ((unsigned long)(tsk->thread.cpu_context.pc))
 #define thread_saved_fp(tsk) ((unsigned long)(tsk->thread.cpu_context.fp))
diff --git a/arch/nds32/include/asm/uaccess.h b/arch/nds32/include/asm/uaccess.h
index 832d642a4068..377548d4451a 100644
--- a/arch/nds32/include/asm/uaccess.h
+++ b/arch/nds32/include/asm/uaccess.h
@@ -11,6 +11,7 @@
 #include <asm/errno.h>
 #include <asm/memory.h>
 #include <asm/types.h>
+#include <asm-generic/access_ok.h>
 
 #define __asmeq(x, y)  ".ifnc " x "," y " ; .err ; .endif\n\t"
 
@@ -33,20 +34,6 @@ struct exception_table_entry {
 
 extern int fixup_exception(struct pt_regs *regs);
 
-#define KERNEL_DS 	((mm_segment_t) { ~0UL })
-#define USER_DS		((mm_segment_t) {TASK_SIZE - 1})
-
-#define get_fs()	(current_thread_info()->addr_limit)
-#define user_addr_max	get_fs
-#define uaccess_kernel() (get_fs() == KERNEL_DS)
-
-static inline void set_fs(mm_segment_t fs)
-{
-	current_thread_info()->addr_limit = fs;
-}
-
-#include <asm-generic/access_ok.h>
-
 /*
  * Single-value transfer routines.  They automatically use the right
  * size if we just have the right pointer type.  Note that the functions
diff --git a/arch/nds32/kernel/process.c b/arch/nds32/kernel/process.c
index 49fab9e39cbf..d35c1f63fa11 100644
--- a/arch/nds32/kernel/process.c
+++ b/arch/nds32/kernel/process.c
@@ -119,9 +119,8 @@ void show_regs(struct pt_regs *regs)
 		regs->uregs[7], regs->uregs[6], regs->uregs[5], regs->uregs[4]);
 	pr_info("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 		regs->uregs[3], regs->uregs[2], regs->uregs[1], regs->uregs[0]);
-	pr_info("  IRQs o%s  Segment %s\n",
-		interrupts_enabled(regs) ? "n" : "ff",
-		uaccess_kernel() ? "kernel" : "user");
+	pr_info("  IRQs o%s  Segment user\n",
+		interrupts_enabled(regs) ? "n" : "ff");
 }
 
 EXPORT_SYMBOL(show_regs);
diff --git a/arch/nds32/mm/alignment.c b/arch/nds32/mm/alignment.c
index 1eb7ded6992b..9c2c0a454da8 100644
--- a/arch/nds32/mm/alignment.c
+++ b/arch/nds32/mm/alignment.c
@@ -512,7 +512,6 @@ int do_unaligned_access(unsigned long addr, struct pt_regs *regs)
 {
 	unsigned long inst;
 	int ret = -EFAULT;
-	mm_segment_t seg;
 
 	inst = get_inst(regs->ipc);
 
@@ -520,12 +519,10 @@ int do_unaligned_access(unsigned long addr, struct pt_regs *regs)
 	      "Faulting addr: 0x%08lx, pc: 0x%08lx [inst: 0x%08lx ]\n", addr,
 	      regs->ipc, inst);
 
-	seg = force_uaccess_begin();
 	if (inst & NDS32_16BIT_INSTRUCTION)
 		ret = do_16((inst >> 16) & 0xffff, regs);
 	else
 		ret = do_32(inst, regs);
-	force_uaccess_end(seg);
 
 	return ret;
 }