kill strlen_user()

no callers, no consistent semantics, no sane way to use it...

Signed-off-by: Al Viro <[e-mail]>

arch/alpha/include/asm/uaccess.h

···
         (uaccess_kernel() ? ~0UL : TASK_SIZE)
 
 extern long strncpy_from_user(char *dest, const char __user *src, long count);
-extern __must_check long strlen_user(const char __user *str);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 #include <asm/extable.h>

arch/arm/include/asm/uaccess.h

···
 /* These are from lib/ code, and use __get_user() and friends */
 extern long strncpy_from_user(char *dest, const char __user *src, long count);
 
-extern __must_check long strlen_user(const char __user *str);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 #endif /* _ASMARM_UACCESS_H */

arch/arm64/include/asm/uaccess.h

···
 
 extern long strncpy_from_user(char *dest, const char __user *src, long count);
 
-extern __must_check long strlen_user(const char __user *str);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 #endif /* __ASM_UACCESS_H */

arch/blackfin/include/asm/uaccess.h

···
 	return strnlen((const char __force *)src, n) + 1;
 }
 
-static inline long __must_check strlen_user(const char __user *src)
-{
-	if (!access_ok(VERIFY_READ, src, 1))
-		return 0;
-	return strlen((const char __force *)src) + 1;
-}
-
 /*
  * Zero Userspace
  */

arch/cris/include/asm/uaccess.h

···
 	return __do_clear_user(to, n);
 }
 
-#define strlen_user(str)	strnlen_user((str), 0x7ffffffe)
-
 #endif	/* _CRIS_UACCESS_H */

arch/frv/include/asm/uaccess.h

···
 extern long strncpy_from_user(char *dst, const char __user *src, long count);
 extern long strnlen_user(const char __user *src, long count);
 
-#define strlen_user(str) strnlen_user(str, 32767)
-
 #endif /* _ASM_UACCESS_H */

arch/ia64/include/asm/uaccess.h

···
 	__sfu_ret;							\
 })
 
-/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
-extern unsigned long __strlen_user (const char __user *);
-
-#define strlen_user(str)				\
-({							\
-	const char __user *__su_str = (str);		\
-	unsigned long __su_ret = 0;			\
-	if (__access_ok(__su_str, 0))			\
-		__su_ret = __strlen_user(__su_str);	\
-	__su_ret;					\
-})
-
 /*
  * Returns: 0 if exception before NUL or reaching the supplied limit
  * (N), a value greater than N if the limit would be exceeded, else

arch/ia64/lib/Makefile

···
 lib-y := io.o __divsi3.o __udivsi3.o __modsi3.o __umodsi3.o		\
 	__divdi3.o __udivdi3.o __moddi3.o __umoddi3.o			\
 	checksum.o clear_page.o csum_partial_copy.o			\
-	clear_user.o strncpy_from_user.o strlen_user.o strnlen_user.o	\
+	clear_user.o strncpy_from_user.o strnlen_user.o			\
 	flush.o ip_fast_csum.o do_csum.o				\
 	memset.o strlen.o xor.o
 

arch/ia64/lib/strlen_user.S

···
-/*
- * Optimized version of the strlen_user() function
- *
- * Inputs:
- *	in0	address of buffer
- *
- * Outputs:
- *	ret0	0 in case of fault, strlen(buffer)+1 otherwise
- *
- * Copyright (C) 1998, 1999, 2001 Hewlett-Packard Co
- *	David Mosberger-Tang <[e-mail]>
- *	Stephane Eranian <[e-mail]>
- *
- * 01/19/99 S.Eranian heavily enhanced version (see details below)
- * 09/24/99 S.Eranian added speculation recovery code
- */
-
-#include <asm/asmmacro.h>
-#include <asm/export.h>
-
-//
-// int strlen_user(char *)
-// ------------------------
-// Returns:
-//	- length of string + 1
-//	- 0 in case an exception is raised
-//
-// This is an enhanced version of the basic strlen_user. it includes a
-// combination of compute zero index (czx), parallel comparisons, speculative
-// loads and loop unroll using rotating registers.
-//
-// General Ideas about the algorithm:
-//	  The goal is to look at the string in chunks of 8 bytes.
-//	  so we need to do a few extra checks at the beginning because the
-//	  string may not be 8-byte aligned. In this case we load the 8byte
-//	  quantity which includes the start of the string and mask the unused
-//	  bytes with 0xff to avoid confusing czx.
-//	  We use speculative loads and software pipelining to hide memory
-//	  latency and do read ahead safely. This way we defer any exception.
-//
-//	  Because we don't want the kernel to be relying on particular
-//	  settings of the DCR register, we provide recovery code in case
-//	  speculation fails. The recovery code is going to "redo" the work using
-//	  only normal loads. If we still get a fault then we return an
-//	  error (ret0=0). Otherwise we return the strlen+1 as usual.
-//	  The fact that speculation may fail can be caused, for instance, by
-//	  the DCR.dm bit being set. In this case TLB misses are deferred, i.e.,
-//	  a NaT bit will be set if the translation is not present. The normal
-//	  load, on the other hand, will cause the translation to be inserted
-//	  if the mapping exists.
-//
-//	  It should be noted that we execute recovery code only when we need
-//	  to use the data that has been speculatively loaded: we don't execute
-//	  recovery code on pure read ahead data.
-//
-// Remarks:
-//	- the cmp r0,r0 is used as a fast way to initialize a predicate
-//	  register to 1. This is required to make sure that we get the parallel
-//	  compare correct.
-//
-//	- we don't use the epilogue counter to exit the loop but we need to set
-//	  it to zero beforehand.
-//
-//	- after the loop we must test for Nat values because neither the
-//	  czx nor cmp instruction raise a NaT consumption fault. We must be
-//	  careful not to look too far for a Nat for which we don't care.
-//	  For instance we don't need to look at a NaT in val2 if the zero byte
-//	  was in val1.
-//
-//	- Clearly performance tuning is required.
-//
-
-#define saved_pfs	r11
-#define	tmp		r10
-#define base		r16
-#define orig		r17
-#define saved_pr	r18
-#define src		r19
-#define mask		r20
-#define val		r21
-#define val1		r22
-#define val2		r23
-
-GLOBAL_ENTRY(__strlen_user)
-	.prologue
-	.save ar.pfs, saved_pfs
-	alloc saved_pfs=ar.pfs,11,0,0,8
-
-	.rotr v[2], w[2]	// declares our 4 aliases
-
-	extr.u tmp=in0,0,3	// tmp=least significant 3 bits
-	mov orig=in0		// keep trackof initial byte address
-	dep src=0,in0,0,3	// src=8byte-aligned in0 address
-	.save pr, saved_pr
-	mov saved_pr=pr		// preserve predicates (rotation)
-	;;
-
-	.body
-
-	ld8.s v[1]=[src],8	// load the initial 8bytes (must speculate)
-	shl tmp=tmp,3		// multiply by 8bits/byte
-	mov mask=-1		// our mask
-	;;
-	ld8.s w[1]=[src],8	// load next 8 bytes in 2nd pipeline
-	cmp.eq p6,p0=r0,r0	// sets p6 (required because of // cmp.and)
-	sub tmp=64,tmp		// how many bits to shift our mask on the right
-	;;
-	shr.u	mask=mask,tmp	// zero enough bits to hold v[1] valuable part
-	mov ar.ec=r0		// clear epilogue counter (saved in ar.pfs)
-	;;
-	add base=-16,src	// keep track of aligned base
-	chk.s v[1], .recover	// if already NaT, then directly skip to recover
-	or v[1]=v[1],mask	// now we have a safe initial byte pattern
-	;;
-1:
-	ld8.s v[0]=[src],8	// speculatively load next
-	czx1.r val1=v[1]	// search 0 byte from right
-	czx1.r val2=w[1]	// search 0 byte from right following 8bytes
-	;;
-	ld8.s w[0]=[src],8	// speculatively load next to next
-	cmp.eq.and p6,p0=8,val1	// p6 = p6 and val1==8
-	cmp.eq.and p6,p0=8,val2	// p6 = p6 and mask==8
-(p6)	br.wtop.dptk.few 1b	// loop until p6 == 0
-	;;
-	//
-	// We must return try the recovery code iff
-	// val1_is_nat || (val1==8 && val2_is_nat)
-	//
-	// XXX Fixme
-	//	- there must be a better way of doing the test
-	//
-	cmp.eq  p8,p9=8,val1	// p6 = val1 had zero (disambiguate)
-	tnat.nz p6,p7=val1	// test NaT on val1
-(p6)	br.cond.spnt .recover	// jump to recovery if val1 is NaT
-	;;
-	//
-	// if we come here p7 is true, i.e., initialized for // cmp
-	//
-	cmp.eq.and  p7,p0=8,val1// val1==8?
-	tnat.nz.and p7,p0=val2	// test NaT if val2
-(p7)	br.cond.spnt .recover	// jump to recovery if val2 is NaT
-	;;
-(p8)	mov val1=val2		// val2 contains the value
-(p8)	adds src=-16,src	// correct position when 3 ahead
-(p9)	adds src=-24,src	// correct position when 4 ahead
-	;;
-	sub ret0=src,orig	// distance from origin
-	sub tmp=7,val1		// 7=8-1 because this strlen returns strlen+1
-	mov pr=saved_pr,0xffffffffffff0000
-	;;
-	sub ret0=ret0,tmp	// length=now - back -1
-	mov ar.pfs=saved_pfs	// because of ar.ec, restore no matter what
-	br.ret.sptk.many rp	// end of normal execution
-
-	//
-	// Outlined recovery code when speculation failed
-	//
-	// This time we don't use speculation and rely on the normal exception
-	// mechanism. that's why the loop is not as good as the previous one
-	// because read ahead is not possible
-	//
-	// XXX Fixme
-	//	- today we restart from the beginning of the string instead
-	//	  of trying to continue where we left off.
-	//
-.recover:
-	EX(.Lexit1, ld8 val=[base],8)	// load the initial bytes
-	;;
-	or val=val,mask			// remask first bytes
-	cmp.eq p0,p6=r0,r0		// nullify first ld8 in loop
-	;;
-	//
-	// ar.ec is still zero here
-	//
-2:
-	EX(.Lexit1, (p6) ld8 val=[base],8)
-	;;
-	czx1.r val1=val		// search 0 byte from right
-	;;
-	cmp.eq p6,p0=8,val1	// val1==8 ?
-(p6)	br.wtop.dptk.few 2b	// loop until p6 == 0
-	;;
-	sub ret0=base,orig	// distance from base
-	sub tmp=7,val1		// 7=8-1 because this strlen returns strlen+1
-	mov pr=saved_pr,0xffffffffffff0000
-	;;
-	sub ret0=ret0,tmp	// length=now - back -1
-	mov ar.pfs=saved_pfs	// because of ar.ec, restore no matter what
-	br.ret.sptk.many rp	// end of successful recovery code
-
-	//
-	// We failed even on the normal load (called from exception handler)
-	//
-.Lexit1:
-	mov ret0=0
-	mov pr=saved_pr,0xffffffffffff0000
-	mov ar.pfs=saved_pfs	// because of ar.ec, restore no matter what
-	br.ret.sptk.many rp
-END(__strlen_user)
-EXPORT_SYMBOL(__strlen_user)

arch/m32r/include/asm/uaccess.h

···
  */
 unsigned long clear_user(void __user *mem, unsigned long len);
 
-/**
- * strlen_user: - Get the size of a string in user space.
- * @str: The string to measure.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Get the size of a NUL-terminated string in user space.
- *
- * Returns the size of the string INCLUDING the terminating NUL.
- * On exception, returns 0.
- *
- * If there is a limit on the length of a valid string, you may wish to
- * consider using strnlen_user() instead.
- */
-#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
 long strnlen_user(const char __user *str, long n);
 
 #endif /* _ASM_M32R_UACCESS_H */

arch/m68k/include/asm/uaccess_mm.h

···
 	(uaccess_kernel() ? ~0UL : TASK_SIZE)
 
 extern long strncpy_from_user(char *dst, const char __user *src, long count);
-extern __must_check long strlen_user(const char __user *str);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 unsigned long __clear_user(void __user *to, unsigned long n);

arch/m68k/include/asm/uaccess_no.h

···
 	return(strlen(src) + 1); /* DAVIDM make safer */
 }
 
-#define strlen_user(str) strnlen_user(str, 32767)
-
 /*
  * Zero Userspace
  */

arch/metag/include/asm/uaccess.h

···
  */
 extern long __must_check strnlen_user(const char __user *src, long count);
 
-#define strlen_user(str) strnlen_user(str, 32767)
-
 extern unsigned long raw_copy_from_user(void *to, const void __user *from,
 					unsigned long n);
 extern unsigned long raw_copy_to_user(void __user *to, const void *from,

arch/mips/include/asm/uaccess.h

···
 	return res;
 }
 
-extern long __strlen_kernel_asm(const char __user *s);
-extern long __strlen_user_asm(const char __user *s);
-
-/*
- * strlen_user: - Get the size of a string in user space.
- * @str: The string to measure.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Get the size of a NUL-terminated string in user space.
- *
- * Returns the size of the string INCLUDING the terminating NUL.
- * On exception, returns 0.
- *
- * If there is a limit on the length of a valid string, you may wish to
- * consider using strnlen_user() instead.
- */
-static inline long strlen_user(const char __user *s)
-{
-	long res;
-
-	if (eva_kernel_access()) {
-		__asm__ __volatile__(
-			"move\t$4, %1\n\t"
-			__MODULE_JAL(__strlen_kernel_asm)
-			"move\t%0, $2"
-			: "=r" (res)
-			: "r" (s)
-			: "$2", "$4", __UA_t0, "$31");
-	} else {
-		might_fault();
-		__asm__ __volatile__(
-			"move\t$4, %1\n\t"
-			__MODULE_JAL(__strlen_user_asm)
-			"move\t%0, $2"
-			: "=r" (res)
-			: "r" (s)
-			: "$2", "$4", __UA_t0, "$31");
-	}
-
-	return res;
-}
-
 extern long __strnlen_kernel_nocheck_asm(const char __user *s, long n);
 extern long __strnlen_user_nocheck_asm(const char __user *s, long n);
 

arch/mips/lib/Makefile

···
 #
 
 lib-y	+= bitops.o csum_partial.o delay.o memcpy.o memset.o \
-	   mips-atomic.o strlen_user.o strncpy_user.o \
+	   mips-atomic.o strncpy_user.o \
 	   strnlen_user.o uncached.o
 
 obj-y			+= iomap.o

arch/mips/lib/strlen_user.S

···
-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 1996, 1998, 1999, 2004 by Ralf Baechle
- * Copyright (C) 1999 Silicon Graphics, Inc.
- * Copyright (C) 2011 MIPS Technologies, Inc.
- */
-#include <asm/asm.h>
-#include <asm/asm-offsets.h>
-#include <asm/export.h>
-#include <asm/regdef.h>
-
-#define EX(insn,reg,addr,handler)			\
-9:	insn	reg, addr;				\
-	.section __ex_table,"a";			\
-	PTR	9b, handler;				\
-	.previous
-
-/*
- * Return the size of a string (including the ending 0)
- *
- * Return 0 for error
- */
-	.macro __BUILD_STRLEN_ASM func
-LEAF(__strlen_\func\()_asm)
-	LONG_L		v0, TI_ADDR_LIMIT($28)	# pointer ok?
-	and		v0, a0
-	bnez		v0, .Lfault\@
-
-	move		v0, a0
-.ifeqs "\func", "kernel"
-1:	EX(lbu, v1, (v0), .Lfault\@)
-.else
-1:	EX(lbue, v1, (v0), .Lfault\@)
-.endif
-	PTR_ADDIU	v0, 1
-	bnez		v1, 1b
-	PTR_SUBU	v0, a0
-	jr		ra
-	END(__strlen_\func\()_asm)
-
-.Lfault\@:	move		v0, zero
-	jr		ra
-	.endm
-
-#ifndef CONFIG_EVA
-	/* Set aliases */
-	.global __strlen_user_asm
-	.set __strlen_user_asm, __strlen_kernel_asm
-EXPORT_SYMBOL(__strlen_user_asm)
-#endif
-
-__BUILD_STRLEN_ASM kernel
-EXPORT_SYMBOL(__strlen_kernel_asm)
-
-#ifdef CONFIG_EVA
-
-	.set push
-	.set eva
-__BUILD_STRLEN_ASM user
-	.set pop
-EXPORT_SYMBOL(__strlen_user_asm)
-#endif

arch/mn10300/include/asm/uaccess.h

···
 extern long strncpy_from_user(char *dst, const char __user *src, long count);
 extern long __strncpy_from_user(char *dst, const char __user *src, long count);
 extern long strnlen_user(const char __user *str, long n);
-#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
 extern unsigned long clear_user(void __user *mem, unsigned long len);
 extern unsigned long __clear_user(void __user *mem, unsigned long len);
 

arch/openrisc/include/asm/uaccess.h

···
 
 extern long strncpy_from_user(char *dest, const char __user *src, long count);
 
-extern __must_check long strlen_user(const char __user *str);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 #endif /* __ASM_OPENRISC_UACCESS_H */

arch/parisc/include/asm/uaccess.h

···
 #define user_addr_max() (~0UL)
 
 #define strnlen_user lstrnlen_user
-#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
 #define clear_user lclear_user
 #define __clear_user lclear_user
 

arch/powerpc/include/asm/uaccess.h

···
 }
 
 extern long strncpy_from_user(char *dst, const char __user *src, long count);
-extern __must_check long strlen_user(const char __user *str);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 #endif	/* _ARCH_POWERPC_UACCESS_H */

arch/s390/include/asm/uaccess.h

···
 	return __strnlen_user(src, n);
 }
 
-/**
- * strlen_user: - Get the size of a string in user space.
- * @str: The string to measure.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Get the size of a NUL-terminated string in user space.
- *
- * Returns the size of the string INCLUDING the terminating NUL.
- * On exception, returns 0.
- *
- * If there is a limit on the length of a valid string, you may wish to
- * consider using strnlen_user() instead.
- */
-#define strlen_user(str) strnlen_user(str, ~0UL)
-
 /*
  * Zero Userspace
  */

arch/score/include/asm/uaccess.h

···
 	return -EFAULT;
 }
 
-extern int __strlen_user(const char *src);
-static inline long strlen_user(const char __user *src)
-{
-	return __strlen_user(src);
-}
-
 extern int __strnlen_user(const char *str, long len);
 static inline long strnlen_user(const char __user *str, long len)
 {

arch/score/lib/string.S

···
 	.previous
 
 	.align 2
-ENTRY(__strlen_user)
-0:	lb	r6, [r4]
-	mv	r7, r4
-	extsb	r6, r6
-	cmpi.c	r6, 0
-	mv	r4, r6
-	beq	.L27
-.L28:
-1:	lb	r6, [r7, 1]+
-	addi	r6, 1
-	cmpi.c	r6, 0
-	bne	.L28
-.L27:
-	br	r3
-	.section .fixup, "ax"
-	ldi	r4, 0x0
-	br	r3
-99:
-	ldi	r4, 0
-	br	r3
-	.previous
-	.section __ex_table, "a"
-	.align	2
-	.word	0b ,99b
-	.word	1b ,99b
-	.previous
-
-	.align 2
 ENTRY(__copy_tofrom_user)
 	cmpi.c	r6, 0
 	mv	r10,r6

arch/sh/include/asm/uaccess.h

···
 
 extern long strncpy_from_user(char *dest, const char __user *src, long count);
 
-extern __must_check long strlen_user(const char __user *str);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 /* Generic arbitrary sized copy.  */

arch/sparc/include/asm/uaccess_32.h

···
 		return n;
 }
 
-__must_check long strlen_user(const char __user *str);
 __must_check long strnlen_user(const char __user *str, long n);
 
 #endif /* _ASM_UACCESS_H */

arch/sparc/include/asm/uaccess_64.h

···
 
 #define clear_user __clear_user
 
-__must_check long strlen_user(const char __user *str);
 __must_check long strnlen_user(const char __user *str, long n);
 
 struct pt_regs;

arch/tile/include/asm/uaccess.h

···
 
 
 extern long strnlen_user(const char __user *str, long n);
-extern long strlen_user(const char __user *str);
 extern long strncpy_from_user(char *dst, const char __user *src, long);
 
 /**

arch/um/kernel/process.c

···
 	return clear_user(buf, size);
 }
 
-int strlen_user_proc(char __user *str)
-{
-	return strlen_user(str);
-}
-
 int cpu(void)
 {
 	return current_thread_info()->cpu;

arch/x86/include/asm/uaccess.h

···
 extern __must_check long
 strncpy_from_user(char *dst, const char __user *src, long count);
 
-extern __must_check long strlen_user(const char __user *str);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 unsigned long __must_check clear_user(void __user *mem, unsigned long len);

arch/xtensa/include/asm/uaccess.h

···
 	return -EFAULT;
 }
 
-
-#define strlen_user(str) strnlen_user((str), TASK_SIZE - 1)
-
 /*
  * Return the size of a string (including the ending 0!)
  */

include/asm-generic/uaccess.h

···
 	return __strnlen_user(src, n);
 }
 
-static inline long strlen_user(const char __user *src)
-{
-	return strnlen_user(src, 32767);
-}
-
 /*
  * Zero Userspace
  */

lib/strnlen_user.c

···
 	return 0;
 }
 EXPORT_SYMBOL(strnlen_user);
-
-/**
- * strlen_user: - Get the size of a user string INCLUDING final NUL.
- * @str: The string to measure.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Get the size of a NUL-terminated string in user space.
- *
- * Returns the size of the string INCLUDING the terminating NUL.
- * On exception, returns 0.
- *
- * If there is a limit on the length of a valid string, you may wish to
- * consider using strnlen_user() instead.
- */
-long strlen_user(const char __user *str)
-{
-	unsigned long max_addr, src_addr;
-
-	max_addr = user_addr_max();
-	src_addr = (unsigned long)str;
-	if (likely(src_addr < max_addr)) {
-		unsigned long max = max_addr - src_addr;
-		long retval;
-
-		user_access_begin();
-		retval = do_strnlen_user(str, ~0ul, max);
-		user_access_end();
-		return retval;
-	}
-	return 0;
-}
-EXPORT_SYMBOL(strlen_user);