From 2820cfdc08178c55efa1c0fa402f082ef09bfe70 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 16 Jan 2020 15:58:41 +0100 Subject: 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 Signed-off-by: Arnd Bergmann --- arch/hexagon/Kconfig | 2 + arch/hexagon/include/asm/uaccess.h | 33 +--------- arch/hexagon/kernel/hexagon_ksyms.c | 1 - arch/hexagon/mm/Makefile | 2 +- arch/hexagon/mm/strnlen_user.S | 126 ------------------------------------ 5 files changed, 5 insertions(+), 159 deletions(-) delete mode 100644 arch/hexagon/mm/strnlen_user.S diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig index e5a852080730..3bf4845fed4b 100644 --- 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 59aa3a50744f..d950df12d8c5 100644 --- 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 -/* 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 35545a7386a0..ec56ce2d92a2 100644 --- 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 893838499591..49911a906fd0 100644 --- 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 index 4b5574a7cc9c..000000000000 --- 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 -- cgit v1.2.3