From e93a1cb8d2b3dccd31bde77373c8d5619f0e0a10 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 22 Jul 2021 22:07:30 +0200 Subject: s390: use generic strncpy/strnlen from_user The s390 variant of strncpy_from_user() is slightly faster than the generic variant, however convert to the generic variant now to follow most if not all other architectures. Converting to the generic variant was already considered a couple of years ago. See commit f5c8b9601036 ("s390/uaccess: use sane length for __strncpy_from_user()"). Signed-off-by: Heiko Carstens Signed-off-by: Arnd Bergmann --- arch/s390/Kconfig | 2 ++ arch/s390/include/asm/uaccess.h | 18 ++------------ arch/s390/lib/uaccess.c | 52 ----------------------------------------- 3 files changed, 4 insertions(+), 68 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index a0e2130f0100..e3988b538a0c 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -130,6 +130,8 @@ config S390 select GENERIC_GETTIMEOFDAY select GENERIC_PTDUMP select GENERIC_SMP_IDLE_THREAD + select GENERIC_STRNCPY_FROM_USER + select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL select GENERIC_VDSO_TIME_NS select HAVE_ALIGNED_STRUCT_PAGE if SLUB diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index 2316f2440881..9ed9aa37e836 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -233,23 +233,9 @@ raw_copy_in_user(void __user *to, const void __user *from, unsigned long n); /* * Copy a null terminated string from userspace. */ +long __must_check strncpy_from_user(char *dst, const char __user *src, long count); -long __strncpy_from_user(char *dst, const char __user *src, long count); - -static inline long __must_check -strncpy_from_user(char *dst, const char __user *src, long count) -{ - might_fault(); - return __strncpy_from_user(dst, src, count); -} - -unsigned long __must_check __strnlen_user(const char __user *src, unsigned long count); - -static inline unsigned long strnlen_user(const char __user *src, unsigned long n) -{ - might_fault(); - return __strnlen_user(src, n); -} +long __must_check strnlen_user(const char __user *src, long count); /* * Zero Userspace diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c index 7ec8b1fa0f08..94ca99bde59d 100644 --- a/arch/s390/lib/uaccess.c +++ b/arch/s390/lib/uaccess.c @@ -338,55 +338,3 @@ unsigned long __clear_user(void __user *to, unsigned long size) return clear_user_xc(to, size); } EXPORT_SYMBOL(__clear_user); - -static inline unsigned long strnlen_user_srst(const char __user *src, - unsigned long size) -{ - unsigned long tmp1, tmp2; - - asm volatile( - " lghi 0,0\n" - " la %2,0(%1)\n" - " la %3,0(%0,%1)\n" - " slgr %0,%0\n" - " sacf 256\n" - "0: srst %3,%2\n" - " jo 0b\n" - " la %0,1(%3)\n" /* strnlen_user results includes \0 */ - " slgr %0,%1\n" - "1: sacf 768\n" - EX_TABLE(0b,1b) - : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2) - : - : "cc", "memory", "0"); - return size; -} - -unsigned long __strnlen_user(const char __user *src, unsigned long size) -{ - if (unlikely(!size)) - return 0; - return strnlen_user_srst(src, size); -} -EXPORT_SYMBOL(__strnlen_user); - -long __strncpy_from_user(char *dst, const char __user *src, long size) -{ - size_t done, len, offset, len_str; - - if (unlikely(size <= 0)) - return 0; - done = 0; - do { - offset = (size_t)src & (L1_CACHE_BYTES - 1); - len = min(size - done, L1_CACHE_BYTES - offset); - if (copy_from_user(dst, src, len)) - return -EFAULT; - len_str = strnlen(dst, len); - done += len_str; - src += len_str; - dst += len_str; - } while ((len_str == len) && (done < size)); - return done; -} -EXPORT_SYMBOL(__strncpy_from_user); -- cgit v1.2.3 From e6226997ec5ac272fa76274c3675bd5b7b437c53 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 17 May 2021 09:22:34 +0200 Subject: asm-generic: reverse GENERIC_{STRNCPY_FROM,STRNLEN}_USER symbols Most architectures do not need a custom implementation, and in most cases the generic implementation is preferred, so change the polariy on these Kconfig symbols to require architectures to select them when they provide their own version. The new name is CONFIG_ARCH_HAS_{STRNCPY_FROM,STRNLEN}_USER. The remaining architectures at the moment are: ia64, mips, parisc, um and xtensa. We should probably convert these as well, but I was not sure how far to take this series. Thomas Bogendoerfer had some concerns about converting mips but may still do some more detailed measurements to see which version is better. Cc: "James E.J. Bottomley" Cc: Anton Ivanov Cc: Christian Borntraeger Cc: Heiko Carstens Cc: Helge Deller Cc: Jeff Dike Cc: Max Filippov Cc: Richard Weinberger Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Cc: linux-ia64@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-xtensa@linux-xtensa.org Acked-by: Geert Uytterhoeven Acked-by: Helge Deller # parisc Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann --- arch/s390/Kconfig | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index e3988b538a0c..a0e2130f0100 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -130,8 +130,6 @@ config S390 select GENERIC_GETTIMEOFDAY select GENERIC_PTDUMP select GENERIC_SMP_IDLE_THREAD - select GENERIC_STRNCPY_FROM_USER - select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL select GENERIC_VDSO_TIME_NS select HAVE_ALIGNED_STRUCT_PAGE if SLUB -- cgit v1.2.3