diff options
Diffstat (limited to 'arch/s390/lib/uaccess.c')
| -rw-r--r-- | arch/s390/lib/uaccess.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c new file mode 100644 index 000000000000..7416efe8eae4 --- /dev/null +++ b/arch/s390/lib/uaccess.c @@ -0,0 +1,406 @@ +/* + * Standard user space access functions based on mvcp/mvcs and doing + * interesting things in the secondary space mode. + * + * Copyright IBM Corp. 2006,2014 + * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), + * Gerald Schaefer (gerald.schaefer@de.ibm.com) + */ + +#include <linux/jump_label.h> +#include <linux/uaccess.h> +#include <linux/export.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <asm/mmu_context.h> +#include <asm/facility.h> + +#ifndef CONFIG_64BIT +#define AHI "ahi" +#define ALR "alr" +#define CLR "clr" +#define LHI "lhi" +#define SLR "slr" +#else +#define AHI "aghi" +#define ALR "algr" +#define CLR "clgr" +#define LHI "lghi" +#define SLR "slgr" +#endif + +static struct static_key have_mvcos = STATIC_KEY_INIT_FALSE; + +static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr, + unsigned long size) +{ + register unsigned long reg0 asm("0") = 0x81UL; + unsigned long tmp1, tmp2; + + tmp1 = -4096UL; + asm volatile( + "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n" + "9: jz 7f\n" + "1:"ALR" %0,%3\n" + " "SLR" %1,%3\n" + " "SLR" %2,%3\n" + " j 0b\n" + "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ + " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ + " "SLR" %4,%1\n" + " "CLR" %0,%4\n" /* copy crosses next page boundary? */ + " jnh 4f\n" + "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n" + "10:"SLR" %0,%4\n" + " "ALR" %2,%4\n" + "4:"LHI" %4,-1\n" + " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */ + " bras %3,6f\n" /* memset loop */ + " xc 0(1,%2),0(%2)\n" + "5: xc 0(256,%2),0(%2)\n" + " la %2,256(%2)\n" + "6:"AHI" %4,-256\n" + " jnm 5b\n" + " ex %4,0(%3)\n" + " j 8f\n" + "7:"SLR" %0,%0\n" + "8:\n" + EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b) + : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) + : "d" (reg0) : "cc", "memory"); + return size; +} + +static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, + unsigned long size) +{ + unsigned long tmp1, tmp2; + + update_primary_asce(current); + tmp1 = -256UL; + asm volatile( + " sacf 0\n" + "0: mvcp 0(%0,%2),0(%1),%3\n" + "10:jz 8f\n" + "1:"ALR" %0,%3\n" + " la %1,256(%1)\n" + " la %2,256(%2)\n" + "2: mvcp 0(%0,%2),0(%1),%3\n" + "11:jnz 1b\n" + " j 8f\n" + "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ + " "LHI" %3,-4096\n" + " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ + " "SLR" %4,%1\n" + " "CLR" %0,%4\n" /* copy crosses next page boundary? */ + " jnh 5f\n" + "4: mvcp 0(%4,%2),0(%1),%3\n" + "12:"SLR" %0,%4\n" + " "ALR" %2,%4\n" + "5:"LHI" %4,-1\n" + " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */ + " bras %3,7f\n" /* memset loop */ + " xc 0(1,%2),0(%2)\n" + "6: xc 0(256,%2),0(%2)\n" + " la %2,256(%2)\n" + "7:"AHI" %4,-256\n" + " jnm 6b\n" + " ex %4,0(%3)\n" + " j 9f\n" + "8:"SLR" %0,%0\n" + "9: sacf 768\n" + EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b) + EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b) + : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) + : : "cc", "memory"); + return size; +} + +unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) +{ + if (static_key_false(&have_mvcos)) + return copy_from_user_mvcos(to, from, n); + return copy_from_user_mvcp(to, from, n); +} +EXPORT_SYMBOL(__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; + unsigned long tmp1, tmp2; + + tmp1 = -4096UL; + asm volatile( + "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" + "6: jz 4f\n" + "1:"ALR" %0,%3\n" + " "SLR" %1,%3\n" + " "SLR" %2,%3\n" + " j 0b\n" + "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ + " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ + " "SLR" %4,%1\n" + " "CLR" %0,%4\n" /* copy crosses next page boundary? */ + " jnh 5f\n" + "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n" + "7:"SLR" %0,%4\n" + " j 5f\n" + "4:"SLR" %0,%0\n" + "5:\n" + EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) + : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) + : "d" (reg0) : "cc", "memory"); + return size; +} + +static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, + unsigned long size) +{ + unsigned long tmp1, tmp2; + + update_primary_asce(current); + tmp1 = -256UL; + asm volatile( + " sacf 0\n" + "0: mvcs 0(%0,%1),0(%2),%3\n" + "7: jz 5f\n" + "1:"ALR" %0,%3\n" + " la %1,256(%1)\n" + " la %2,256(%2)\n" + "2: mvcs 0(%0,%1),0(%2),%3\n" + "8: jnz 1b\n" + " j 5f\n" + "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ + " "LHI" %3,-4096\n" + " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ + " "SLR" %4,%1\n" + " "CLR" %0,%4\n" /* copy crosses next page boundary? */ + " jnh 6f\n" + "4: mvcs 0(%4,%1),0(%2),%3\n" + "9:"SLR" %0,%4\n" + " j 6f\n" + "5:"SLR" %0,%0\n" + "6: sacf 768\n" + EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) + EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) + : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) + : : "cc", "memory"); + return size; +} + +unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n) +{ + if (static_key_false(&have_mvcos)) + return copy_to_user_mvcos(to, from, n); + return copy_to_user_mvcs(to, from, n); +} +EXPORT_SYMBOL(__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; + unsigned long tmp1, tmp2; + + tmp1 = -4096UL; + /* FIXME: copy with reduced length. */ + asm volatile( + "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n" + " jz 2f\n" + "1:"ALR" %0,%3\n" + " "SLR" %1,%3\n" + " "SLR" %2,%3\n" + " j 0b\n" + "2:"SLR" %0,%0\n" + "3: \n" + EX_TABLE(0b,3b) + : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2) + : "d" (reg0) : "cc", "memory"); + return size; +} + +static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from, + unsigned long size) +{ + unsigned long tmp1; + + update_primary_asce(current); + asm volatile( + " sacf 256\n" + " "AHI" %0,-1\n" + " jo 5f\n" + " bras %3,3f\n" + "0:"AHI" %0,257\n" + "1: mvc 0(1,%1),0(%2)\n" + " la %1,1(%1)\n" + " la %2,1(%2)\n" + " "AHI" %0,-1\n" + " jnz 1b\n" + " j 5f\n" + "2: mvc 0(256,%1),0(%2)\n" + " la %1,256(%1)\n" + " la %2,256(%2)\n" + "3:"AHI" %0,-256\n" + " jnm 2b\n" + "4: ex %0,1b-0b(%3)\n" + "5: "SLR" %0,%0\n" + "6: sacf 768\n" + EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) + : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1) + : : "cc", "memory"); + return size; +} + +unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n) +{ + if (static_key_false(&have_mvcos)) + return copy_in_user_mvcos(to, from, n); + return copy_in_user_mvc(to, from, n); +} +EXPORT_SYMBOL(__copy_in_user); + +static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) +{ + register unsigned long reg0 asm("0") = 0x810000UL; + unsigned long tmp1, tmp2; + + tmp1 = -4096UL; + asm volatile( + "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n" + " jz 4f\n" + "1:"ALR" %0,%2\n" + " "SLR" %1,%2\n" + " j 0b\n" + "2: la %3,4095(%1)\n"/* %4 = to + 4095 */ + " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */ + " "SLR" %3,%1\n" + " "CLR" %0,%3\n" /* copy crosses next page boundary? */ + " jnh 5f\n" + "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n" + " "SLR" %0,%3\n" + " j 5f\n" + "4:"SLR" %0,%0\n" + "5:\n" + EX_TABLE(0b,2b) EX_TABLE(3b,5b) + : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2) + : "a" (empty_zero_page), "d" (reg0) : "cc", "memory"); + return size; +} + +static inline unsigned long clear_user_xc(void __user *to, unsigned long size) +{ + unsigned long tmp1, tmp2; + + update_primary_asce(current); + asm volatile( + " sacf 256\n" + " "AHI" %0,-1\n" + " jo 5f\n" + " bras %3,3f\n" + " xc 0(1,%1),0(%1)\n" + "0:"AHI" %0,257\n" + " la %2,255(%1)\n" /* %2 = ptr + 255 */ + " srl %2,12\n" + " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */ + " "SLR" %2,%1\n" + " "CLR" %0,%2\n" /* clear crosses next page boundary? */ + " jnh 5f\n" + " "AHI" %2,-1\n" + "1: ex %2,0(%3)\n" + " "AHI" %2,1\n" + " "SLR" %0,%2\n" + " j 5f\n" + "2: xc 0(256,%1),0(%1)\n" + " la %1,256(%1)\n" + "3:"AHI" %0,-256\n" + " jnm 2b\n" + "4: ex %0,0(%3)\n" + "5: "SLR" %0,%0\n" + "6: sacf 768\n" + EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b) + : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2) + : : "cc", "memory"); + return size; +} + +unsigned long __clear_user(void __user *to, unsigned long size) +{ + if (static_key_false(&have_mvcos)) + return clear_user_mvcos(to, 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) +{ + register unsigned long reg0 asm("0") = 0; + unsigned long tmp1, tmp2; + + asm volatile( + " la %2,0(%1)\n" + " la %3,0(%0,%1)\n" + " "SLR" %0,%0\n" + " sacf 256\n" + "0: srst %3,%2\n" + " jo 0b\n" + " la %0,1(%3)\n" /* strnlen_user results includes \0 */ + " "SLR" %0,%1\n" + "1: sacf 768\n" + EX_TABLE(0b,1b) + : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2) + : "d" (reg0) : "cc", "memory"); + return size; +} + +unsigned long __strnlen_user(const char __user *src, unsigned long size) +{ + if (unlikely(!size)) + return 0; + update_primary_asce(current); + 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 & ~PAGE_MASK; + len = min(size - done, PAGE_SIZE - 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); + +/* + * The "old" uaccess variant without mvcos can be enforced with the + * uaccess_primary kernel parameter. This is mainly for debugging purposes. + */ +static int uaccess_primary __initdata; + +static int __init parse_uaccess_pt(char *__unused) +{ + uaccess_primary = 1; + return 0; +} +early_param("uaccess_primary", parse_uaccess_pt); + +static int __init uaccess_init(void) +{ + if (IS_ENABLED(CONFIG_64BIT) && !uaccess_primary && test_facility(27)) + static_key_slow_inc(&have_mvcos); + return 0; +} +early_initcall(uaccess_init); |