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authorHeiko Carstens <hca@linux.ibm.com>2021-07-22 22:07:30 +0200
committerArnd Bergmann <arnd@arndb.de>2021-07-27 23:01:13 +0200
commite93a1cb8d2b3dccd31bde77373c8d5619f0e0a10 (patch)
treec605308a2391826c39e9bd262262af33bb3f4895 /arch
parentb26b181651f3214fa2383411fb85029b7f3e1788 (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/Kconfig2
-rw-r--r--arch/s390/include/asm/uaccess.h18
-rw-r--r--arch/s390/lib/uaccess.c52
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);