diff options
Diffstat (limited to 'arch/s390/lib/uaccess.c')
| -rw-r--r-- | arch/s390/lib/uaccess.c | 90 |
1 files changed, 80 insertions, 10 deletions
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c index 802903c50de1..cae5a1e16cbd 100644 --- a/arch/s390/lib/uaccess.c +++ b/arch/s390/lib/uaccess.c @@ -40,10 +40,67 @@ static inline int copy_with_mvcos(void) } #endif +void set_fs(mm_segment_t fs) +{ + current->thread.mm_segment = fs; + if (fs == USER_DS) { + __ctl_load(S390_lowcore.user_asce, 1, 1); + clear_cpu_flag(CIF_ASCE_PRIMARY); + } else { + __ctl_load(S390_lowcore.kernel_asce, 1, 1); + set_cpu_flag(CIF_ASCE_PRIMARY); + } + if (fs & 1) { + if (fs == USER_DS_SACF) + __ctl_load(S390_lowcore.user_asce, 7, 7); + else + __ctl_load(S390_lowcore.kernel_asce, 7, 7); + set_cpu_flag(CIF_ASCE_SECONDARY); + } +} +EXPORT_SYMBOL(set_fs); + +mm_segment_t enable_sacf_uaccess(void) +{ + mm_segment_t old_fs; + unsigned long asce, cr; + + old_fs = current->thread.mm_segment; + if (old_fs & 1) + return old_fs; + current->thread.mm_segment |= 1; + asce = S390_lowcore.kernel_asce; + if (likely(old_fs == USER_DS)) { + __ctl_store(cr, 1, 1); + if (cr != S390_lowcore.kernel_asce) { + __ctl_load(S390_lowcore.kernel_asce, 1, 1); + set_cpu_flag(CIF_ASCE_PRIMARY); + } + asce = S390_lowcore.user_asce; + } + __ctl_store(cr, 7, 7); + if (cr != asce) { + __ctl_load(asce, 7, 7); + set_cpu_flag(CIF_ASCE_SECONDARY); + } + return old_fs; +} +EXPORT_SYMBOL(enable_sacf_uaccess); + +void disable_sacf_uaccess(mm_segment_t old_fs) +{ + if (old_fs == USER_DS && test_facility(27)) { + __ctl_load(S390_lowcore.user_asce, 1, 1); + clear_cpu_flag(CIF_ASCE_PRIMARY); + } + current->thread.mm_segment = old_fs; +} +EXPORT_SYMBOL(disable_sacf_uaccess); + static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr, unsigned long size) { - register unsigned long reg0 asm("0") = 0x81UL; + register unsigned long reg0 asm("0") = 0x01UL; unsigned long tmp1, tmp2; tmp1 = -4096UL; @@ -74,8 +131,9 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, unsigned long size) { unsigned long tmp1, tmp2; + mm_segment_t old_fs; - load_kernel_asce(); + old_fs = enable_sacf_uaccess(); tmp1 = -256UL; asm volatile( " sacf 0\n" @@ -102,6 +160,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) : : "cc", "memory"); + disable_sacf_uaccess(old_fs); return size; } @@ -116,7 +175,7 @@ EXPORT_SYMBOL(raw_copy_from_user); static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, unsigned long size) { - register unsigned long reg0 asm("0") = 0x810000UL; + register unsigned long reg0 asm("0") = 0x010000UL; unsigned long tmp1, tmp2; tmp1 = -4096UL; @@ -147,8 +206,9 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, unsigned long size) { unsigned long tmp1, tmp2; + mm_segment_t old_fs; - load_kernel_asce(); + old_fs = enable_sacf_uaccess(); tmp1 = -256UL; asm volatile( " sacf 0\n" @@ -175,6 +235,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) : : "cc", "memory"); + disable_sacf_uaccess(old_fs); return size; } @@ -189,7 +250,7 @@ EXPORT_SYMBOL(raw_copy_to_user); static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from, unsigned long size) { - register unsigned long reg0 asm("0") = 0x810081UL; + register unsigned long reg0 asm("0") = 0x010001UL; unsigned long tmp1, tmp2; tmp1 = -4096UL; @@ -212,9 +273,10 @@ static inline unsigned long copy_in_user_mvcos(void __user *to, const void __use static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from, unsigned long size) { + mm_segment_t old_fs; unsigned long tmp1; - load_kernel_asce(); + old_fs = enable_sacf_uaccess(); asm volatile( " sacf 256\n" " aghi %0,-1\n" @@ -238,6 +300,7 @@ static inline unsigned long copy_in_user_mvc(void __user *to, const void __user EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1) : : "cc", "memory"); + disable_sacf_uaccess(old_fs); return size; } @@ -251,7 +314,7 @@ EXPORT_SYMBOL(raw_copy_in_user); static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) { - register unsigned long reg0 asm("0") = 0x810000UL; + register unsigned long reg0 asm("0") = 0x010000UL; unsigned long tmp1, tmp2; tmp1 = -4096UL; @@ -279,9 +342,10 @@ static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size static inline unsigned long clear_user_xc(void __user *to, unsigned long size) { + mm_segment_t old_fs; unsigned long tmp1, tmp2; - load_kernel_asce(); + old_fs = enable_sacf_uaccess(); asm volatile( " sacf 256\n" " aghi %0,-1\n" @@ -310,6 +374,7 @@ static inline unsigned long clear_user_xc(void __user *to, unsigned long size) EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2) : : "cc", "memory"); + disable_sacf_uaccess(old_fs); return size; } @@ -345,10 +410,15 @@ static inline unsigned long strnlen_user_srst(const char __user *src, unsigned long __strnlen_user(const char __user *src, unsigned long size) { + mm_segment_t old_fs; + unsigned long len; + if (unlikely(!size)) return 0; - load_kernel_asce(); - return strnlen_user_srst(src, size); + old_fs = enable_sacf_uaccess(); + len = strnlen_user_srst(src, size); + disable_sacf_uaccess(old_fs); + return len; } EXPORT_SYMBOL(__strnlen_user); |