uaccess: remove segment_eq

segment_eq is only used to implement uaccess_kernel.  Just open code
uaccess_kernel in the arch uaccess headers and remove one layer of
indirection.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Greentime Hu <green.hu@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Link: http://lkml.kernel.org/r/20200710135706.537715-5-hch@lst.deSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/include/asm/uaccess.h

@@ -20,7 +20,7 @@
 #define get_fs()  (current_thread_info()->addr_limit)
 #define set_fs(x) (current_thread_info()->addr_limit = (x))
 
-#define segment_eq(a, b)	((a).seg == (b).seg)
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
 
 /*
  * Is a address valid? This does a straightforward calculation rather

arch/arc/include/asm/segment.h

@@ -14,8 +14,7 @@ typedef unsigned long mm_segment_t;
 
 #define KERNEL_DS		MAKE_MM_SEG(0)
 #define USER_DS			MAKE_MM_SEG(TASK_SIZE)
-
-#define segment_eq(a, b)	((a) == (b))
+#define uaccess_kernel()	(get_fs() == KERNEL_DS)
 
 #endif /* __ASSEMBLY__ */
 #endif /* __ASMARC_SEGMENT_H */

arch/arm/include/asm/uaccess.h

@@ -76,7 +76,7 @@ static inline void set_fs(mm_segment_t fs)
 	modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
 }
 
-#define segment_eq(a, b)	((a) == (b))
+#define uaccess_kernel()	(get_fs() == KERNEL_DS)
 
 /*
  * We use 33-bit arithmetic here.  Success returns zero, failure returns
@@ -267,7 +267,7 @@ extern int __put_user_8(void *, unsigned long long);
  */
 #define USER_DS			KERNEL_DS
 
-#define segment_eq(a, b)		(1)
+#define uaccess_kernel()	(true)
 #define __addr_ok(addr)		((void)(addr), 1)
 #define __range_ok(addr, size)	((void)(addr), 0)
 #define get_fs()		(KERNEL_DS)

arch/arm64/include/asm/uaccess.h

@@ -50,7 +50,7 @@ static inline void set_fs(mm_segment_t fs)
 				CONFIG_ARM64_UAO));
 }
 
-#define segment_eq(a, b)	((a) == (b))
+#define uaccess_kernel()	(get_fs() == KERNEL_DS)
 
 /*
  * Test whether a block of memory is a valid user space address.

arch/csky/include/asm/segment.h

@@ -13,6 +13,6 @@ typedef struct {
 #define USER_DS			((mm_segment_t) { 0x80000000UL })
 #define get_fs()		(current_thread_info()->addr_limit)
 #define set_fs(x)		(current_thread_info()->addr_limit = (x))
-#define segment_eq(a, b)	((a).seg == (b).seg)
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
 
 #endif /* __ASM_CSKY_SEGMENT_H */

arch/h8300/include/asm/segment.h

@@ -33,7 +33,7 @@ static inline mm_segment_t get_fs(void)
 	return USER_DS;
 }
 
-#define segment_eq(a, b)	((a).seg == (b).seg)
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
 
 #endif /* __ASSEMBLY__ */
 

arch/ia64/include/asm/uaccess.h

@@ -50,7 +50,7 @@
 #define get_fs()  (current_thread_info()->addr_limit)
 #define set_fs(x) (current_thread_info()->addr_limit = (x))
 
-#define segment_eq(a, b)	((a).seg == (b).seg)
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
 
 /*
  * When accessing user memory, we need to make sure the entire area really is in

arch/m68k/include/asm/segment.h

@@ -52,7 +52,7 @@ static inline void set_fs(mm_segment_t val)
 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
 #endif
 
-#define segment_eq(a, b) ((a).seg == (b).seg)
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
 
 #endif /* __ASSEMBLY__ */
 

arch/microblaze/include/asm/uaccess.h

@@ -41,7 +41,7 @@
 # define get_fs()	(current_thread_info()->addr_limit)
 # define set_fs(val)	(current_thread_info()->addr_limit = (val))
 
-# define segment_eq(a, b)	((a).seg == (b).seg)
+# define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
 
 #ifndef CONFIG_MMU
 

arch/mips/include/asm/uaccess.h

@@ -72,7 +72,7 @@ extern u64 __ua_limit;
 #define get_fs()	(current_thread_info()->addr_limit)
 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
 
-#define segment_eq(a, b)	((a).seg == (b).seg)
+#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
 
 /*
  * eva_kernel_access() - determine whether kernel memory access on an EVA system

arch/nds32/include/asm/uaccess.h

@@ -44,7 +44,7 @@ static inline void set_fs(mm_segment_t fs)
 	current_thread_info()->addr_limit = fs;
 }
 
-#define segment_eq(a, b)	((a) == (b))
+#define uaccess_kernel()	(get_fs() == KERNEL_DS)
 
 #define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs() -size))
 

arch/nios2/include/asm/uaccess.h

@@ -30,7 +30,7 @@
 #define get_fs()		(current_thread_info()->addr_limit)
 #define set_fs(seg)		(current_thread_info()->addr_limit = (seg))
 
-#define segment_eq(a, b)	((a).seg == (b).seg)
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
 
 #define __access_ok(addr, len)			\
 	(((signed long)(((long)get_fs().seg) &	\

arch/openrisc/include/asm/uaccess.h

@@ -43,7 +43,7 @@
 #define get_fs()	(current_thread_info()->addr_limit)
 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
 
-#define segment_eq(a, b)	((a) == (b))
+#define uaccess_kernel()	(get_fs() == KERNEL_DS)
 
 /* Ensure that the range from addr to addr+size is all within the process'
  * address space

arch/parisc/include/asm/uaccess.h

@@ -14,7 +14,7 @@
 #define KERNEL_DS	((mm_segment_t){0})
 #define USER_DS 	((mm_segment_t){1})
 
-#define segment_eq(a, b) ((a).seg == (b).seg)
+#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))

arch/powerpc/include/asm/uaccess.h

@@ -38,8 +38,7 @@ static inline void set_fs(mm_segment_t fs)
 	set_thread_flag(TIF_FSCHECK);
 }
 
-#define segment_eq(a, b)	((a).seg == (b).seg)
-
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
 #define user_addr_max()	(get_fs().seg)
 
 #ifdef __powerpc64__

arch/riscv/include/asm/uaccess.h

@@ -64,11 +64,9 @@ static inline void set_fs(mm_segment_t fs)
 	current_thread_info()->addr_limit = fs;
 }
 
-#define segment_eq(a, b) ((a).seg == (b).seg)
-
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
 #define user_addr_max()	(get_fs().seg)
 
-
 /**
  * access_ok: - Checks if a user space pointer is valid
  * @addr: User space pointer to start of block to check

arch/s390/include/asm/uaccess.h

@@ -32,7 +32,7 @@
 #define USER_DS_SACF	(3)
 
 #define get_fs()        (current->thread.mm_segment)
-#define segment_eq(a,b) (((a) & 2) == ((b) & 2))
+#define uaccess_kernel() ((get_fs() & 2) == KERNEL_DS)
 
 void set_fs(mm_segment_t fs);
 

arch/sh/include/asm/segment.h

@@ -24,8 +24,7 @@ typedef struct {
 #define USER_DS		KERNEL_DS
 #endif
 
-#define segment_eq(a, b) ((a).seg == (b).seg)
-
+#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))

arch/sparc/include/asm/uaccess_32.h

@@ -28,7 +28,7 @@
 #define get_fs()	(current->thread.current_ds)
 #define set_fs(val)	((current->thread.current_ds) = (val))
 
-#define segment_eq(a, b) ((a).seg == (b).seg)
+#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.

arch/sparc/include/asm/uaccess_64.h

@@ -32,7 +32,7 @@
 
 #define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
 
-#define segment_eq(a, b)  ((a).seg == (b).seg)
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
 
 #define set_fs(val)								\
 do {										\

arch/x86/include/asm/uaccess.h

@@ -33,7 +33,7 @@ static inline void set_fs(mm_segment_t fs)
 	set_thread_flag(TIF_FSCHECK);
 }
 
-#define segment_eq(a, b)	((a).seg == (b).seg)
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
 #define user_addr_max() (current->thread.addr_limit.seg)
 
 /*

arch/xtensa/include/asm/uaccess.h

@@ -35,7 +35,7 @@
 #define get_fs()	(current->thread.current_ds)
 #define set_fs(val)	(current->thread.current_ds = (val))
 
-#define segment_eq(a, b)	((a).seg == (b).seg)
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
 
 #define __kernel_ok (uaccess_kernel())
 #define __user_ok(addr, size) \

include/asm-generic/uaccess.h

@@ -86,8 +86,8 @@ static inline void set_fs(mm_segment_t fs)
 }
 #endif
 
-#ifndef segment_eq
-#define segment_eq(a, b) ((a).seg == (b).seg)
+#ifndef uaccess_kernel
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
 #endif
 
 #define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))

include/linux/uaccess.h

@@ -6,8 +6,6 @@
 #include <linux/sched.h>
 #include <linux/thread_info.h>
 
-#define uaccess_kernel() segment_eq(get_fs(), KERNEL_DS)
-
 #include <asm/uaccess.h>
 
 /*