hexagon: use generic strncpy/strnlen from_user

Remove the hexagon implementation of strncpy/strnlen and instead use
the generic version.  The hexagon version reads the data twice for
strncpy() by doing an extra strnlen(), and it apparently lacks a check
for user_addr_max().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index e5a8520..3bf4845 100644 (file)
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -19,6 +19,8 @@ config HEXAGON
        # GENERIC_ALLOCATOR is used by dma_alloc_coherent()
        select GENERIC_ALLOCATOR
        select GENERIC_IRQ_SHOW
+       select GENERIC_STRNCPY_FROM_USER
+       select GENERIC_STRNLEN_USER
        select HAVE_ARCH_KGDB
        select HAVE_ARCH_TRACEHOOK
        select NEED_SG_DMA_LENGTH

diff --git a/arch/hexagon/include/asm/uaccess.h b/arch/hexagon/include/asm/uaccess.h
index 59aa3a5..d950df1 100644 (file)
--- a/arch/hexagon/include/asm/uaccess.h
+++ b/arch/hexagon/include/asm/uaccess.h
@@ -57,42 +57,13 @@ unsigned long raw_copy_to_user(void __user *to, const void *from,
 __kernel_size_t __clear_user_hexagon(void __user *dest, unsigned long count);
 #define __clear_user(a, s) __clear_user_hexagon((a), (s))
 
-extern long __strnlen_user(const char __user *src, long n);
-
-static inline strnlen_user(const char __user *src, long n)
-{
-        if (!access_ok(src, 1))
-               return 0;
-
-       return __strnlen_user(src, n);
-}
-/*  get around the ifndef in asm-generic/uaccess.h  */
+extern long strnlen_user(const char __user *src, long n);
 #define strnlen_user strnlen_user
 
-static inline long strncpy_from_user(char *dst, const char __user *src, long n);
+extern long strncpy_from_user(char *dst, const char __user *src, long n)
 #define strncpy_from_user strncpy_from_user
 
 #include <asm-generic/uaccess.h>
 
-/*  Todo:  an actual accelerated version of this.  */
-static inline long strncpy_from_user(char *dst, const char __user *src, long n)
-{
-       long res = strnlen_user(src, n);
-
-       if (unlikely(!res))
-               return -EFAULT;
-
-       if (res > n) {
-               long left = raw_copy_from_user(dst, src, n);
-               if (unlikely(left))
-                       memset(dst + (n - left), 0, left);
-               return n;
-       } else {
-               long left = raw_copy_from_user(dst, src, res);
-               if (unlikely(left))
-                       memset(dst + (res - left), 0, left);
-               return res-1;
-       }
-}
 
 #endif

diff --git a/arch/hexagon/kernel/hexagon_ksyms.c b/arch/hexagon/kernel/hexagon_ksyms.c
index 35545a7..ec56ce2 100644 (file)
--- a/arch/hexagon/kernel/hexagon_ksyms.c
+++ b/arch/hexagon/kernel/hexagon_ksyms.c
@@ -15,7 +15,6 @@ EXPORT_SYMBOL(__clear_user_hexagon);
 EXPORT_SYMBOL(raw_copy_from_user);
 EXPORT_SYMBOL(raw_copy_to_user);
 EXPORT_SYMBOL(iounmap);
-EXPORT_SYMBOL(__strnlen_user);
 EXPORT_SYMBOL(__vmgetie);
 EXPORT_SYMBOL(__vmsetie);
 EXPORT_SYMBOL(__vmyield);

diff --git a/arch/hexagon/mm/Makefile b/arch/hexagon/mm/Makefile
index 8938384..49911a9 100644 (file)
--- a/arch/hexagon/mm/Makefile
+++ b/arch/hexagon/mm/Makefile
@@ -4,4 +4,4 @@
 #
 
 obj-y := init.o ioremap.o uaccess.o vm_fault.o cache.o
-obj-y += copy_to_user.o copy_from_user.o strnlen_user.o vm_tlb.o
+obj-y += copy_to_user.o copy_from_user.o vm_tlb.o

diff --git a/arch/hexagon/mm/strnlen_user.S b/arch/hexagon/mm/strnlen_user.S
deleted file mode 100644 (file)
index 4b5574a..0000000
--- a/arch/hexagon/mm/strnlen_user.S
+++ /dev/null
@@ -1,126 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * User string length functions for kernel
- *
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- */
-
-#define isrc   r0
-#define max    r1      /*  Do not change!  */
-
-#define end    r2
-#define tmp1   r3
-
-#define obo    r6      /*  off-by-one  */
-#define start  r7
-#define mod8   r8
-#define dbuf    r15:14
-#define dcmp   r13:12
-
-/*
- * The vector mask version of this turned out *really* badly.
- * The hardware loop version also turned out *really* badly.
- * Seems straight pointer arithmetic basically wins here.
- */
-
-#define fname __strnlen_user
-
-       .text
-       .global fname
-       .type fname, @function
-       .p2align 5  /*  why?  */
-fname:
-       {
-               mod8 = and(isrc,#7);
-               end = add(isrc,max);
-               start = isrc;
-       }
-       {
-               P0 = cmp.eq(mod8,#0);
-               mod8 = and(end,#7);
-               dcmp = #0;
-               if (P0.new) jump:t dw_loop;     /*  fire up the oven  */
-       }
-
-alignment_loop:
-fail_1:        {
-               tmp1 = memb(start++#1);
-       }
-       {
-               P0 = cmp.eq(tmp1,#0);
-               if (P0.new) jump:nt exit_found;
-               P1 = cmp.gtu(end,start);
-               mod8 = and(start,#7);
-       }
-       {
-               if (!P1) jump exit_error;  /*  hit the end  */
-               P0 = cmp.eq(mod8,#0);
-       }
-       {
-               if (!P0) jump alignment_loop;
-       }
-
-
-
-dw_loop:
-fail_2:        {
-               dbuf = memd(start);
-               obo = add(start,#1);
-       }
-       {
-               P0 = vcmpb.eq(dbuf,dcmp);
-       }
-       {
-               tmp1 = P0;
-               P0 = cmp.gtu(end,start);
-       }
-       {
-               tmp1 = ct0(tmp1);
-               mod8 = and(end,#7);
-               if (!P0) jump end_check;
-       }
-       {
-               P0 = cmp.eq(tmp1,#32);
-               if (!P0.new) jump:nt exit_found;
-               if (!P0.new) start = add(obo,tmp1);
-       }
-       {
-               start = add(start,#8);
-               jump dw_loop;
-       }       /*  might be nice to combine these jumps...   */
-
-
-end_check:
-       {
-               P0 = cmp.gt(tmp1,mod8);
-               if (P0.new) jump:nt exit_error; /*  neverfound!  */
-               start = add(obo,tmp1);
-       }
-
-exit_found:
-       {
-               R0 = sub(start,isrc);
-               jumpr R31;
-       }
-
-exit_error:
-       {
-               R0 = add(max,#1);
-               jumpr R31;
-       }
-
-       /*  Uh, what does the "fixup" return here?  */
-       .falign
-fix_1:
-       {
-               R0 = #0;
-               jumpr R31;
-       }
-
-       .size fname,.-fname
-
-
-.section __ex_table,"a"
-.long fail_1,fix_1
-.long fail_2,fix_1
-.previous