diff options
author | Heiko Carstens <hca@linux.ibm.com> | 2021-07-22 22:07:30 +0200 |
---|---|---|
committer | Arnd Bergmann <arnd@arndb.de> | 2021-07-27 23:01:13 +0200 |
commit | e93a1cb8d2b3dccd31bde77373c8d5619f0e0a10 (patch) | |
tree | c605308a2391826c39e9bd262262af33bb3f4895 /arch | |
parent | b26b181651f3214fa2383411fb85029b7f3e1788 (diff) |
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 <hca@linux.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/s390/Kconfig | 2 | ||||
-rw-r--r-- | arch/s390/include/asm/uaccess.h | 18 | ||||
-rw-r--r-- | arch/s390/lib/uaccess.c | 52 |
3 files changed, 4 insertions, 68 deletions
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); |