// SPDX-License-Identifier: GPL-2.0 /* * 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/uaccess.h> #include <linux/export.h> #include <linux/mm.h> #include <asm/asm-extable.h> #ifdef CONFIG_DEBUG_ENTRY void debug_user_asce(int exit) { unsigned long cr1, cr7; __ctl_store(cr1, 1, 1); __ctl_store(cr7, 7, 7); if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce) return; panic("incorrect ASCE on kernel %s\n" "cr1: %016lx cr7: %016lx\n" "kernel: %016llx user: %016llx\n", exit ? "exit" : "entry", cr1, cr7, S390_lowcore.kernel_asce, S390_lowcore.user_asce); } #endif /*CONFIG_DEBUG_ENTRY */ static unsigned long raw_copy_from_user_key(void *to, const void __user *from, unsigned long size, unsigned long key) { unsigned long tmp1, tmp2; union oac spec = { .oac2.key = key, .oac2.as = PSW_BITS_AS_SECONDARY, .oac2.k = 1, .oac2.a = 1, }; tmp1 = -4096UL; asm volatile( " lr 0,%[spec]\n" "0: mvcos 0(%2),0(%1),%0\n" "6: jz 4f\n" "1: algr %0,%3\n" " slgr %1,%3\n" " slgr %2,%3\n" " j 0b\n" "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 5f\n" "3: mvcos 0(%2),0(%1),%4\n" "7: slgr %0,%4\n" " j 5f\n" "4: slgr %0,%0\n" "5:\n" EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) : "+a" (size), "+a" (from), "+a" (to), "+a" (tmp1), "=a" (tmp2) : [spec] "d" (spec.val) : "cc", "memory", "0"); return size; } unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { return raw_copy_from_user_key(to, from, n, 0); } EXPORT_SYMBOL(raw_copy_from_user); unsigned long _copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key) { unsigned long res = n; might_fault(); if (!should_fail_usercopy()) { instrument_copy_from_user_before(to, from, n); res = raw_copy_from_user_key(to, from, n, key); instrument_copy_from_user_after(to, from, n, res); } if (unlikely(res)) memset(to + (n - res), 0, res); return res; } EXPORT_SYMBOL(_copy_from_user_key); static unsigned long raw_copy_to_user_key(void __user *to, const void *from, unsigned long size, unsigned long key) { unsigned long tmp1, tmp2; union oac spec = { .oac1.key = key, .oac1.as = PSW_BITS_AS_SECONDARY, .oac1.k = 1, .oac1.a = 1, }; tmp1 = -4096UL; asm volatile( " lr 0,%[spec]\n" "0: mvcos 0(%1),0(%2),%0\n" "6: jz 4f\n" "1: algr %0,%3\n" " slgr %1,%3\n" " slgr %2,%3\n" " j 0b\n" "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */ " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 5f\n" "3: mvcos 0(%1),0(%2),%4\n" "7: slgr %0,%4\n" " j 5f\n" "4: slgr %0,%0\n" "5:\n" EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b) : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2) : [spec] "d" (spec.val) : "cc", "memory", "0"); return size; } unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) { return raw_copy_to_user_key(to, from, n, 0); } EXPORT_SYMBOL(raw_copy_to_user); unsigned long _copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key) { might_fault(); if (should_fail_usercopy()) return n; instrument_copy_to_user(to, from, n); return raw_copy_to_user_key(to, from, n, key); } EXPORT_SYMBOL(_copy_to_user_key); unsigned long __clear_user(void __user *to, unsigned long size) { unsigned long tmp1, tmp2; union oac spec = { .oac1.as = PSW_BITS_AS_SECONDARY, .oac1.a = 1, }; tmp1 = -4096UL; asm volatile( " lr 0,%[spec]\n" "0: mvcos 0(%1),0(%4),%0\n" "6: jz 4f\n" "1: algr %0,%2\n" " slgr %1,%2\n" " j 0b\n" "2: la %3,4095(%1)\n"/* %4 = to + 4095 */ " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */ " slgr %3,%1\n" " clgr %0,%3\n" /* copy crosses next page boundary? */ " jnh 5f\n" "3: mvcos 0(%1),0(%4),%3\n" "7: slgr %0,%3\n" " j 5f\n" "4: slgr %0,%0\n" "5:\n" EX_TABLE(0b,2b) EX_TABLE(6b,2b) EX_TABLE(3b,5b) EX_TABLE(7b,5b) : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2) : "a" (empty_zero_page), [spec] "d" (spec.val) : "cc", "memory", "0"); return size; } EXPORT_SYMBOL(__clear_user);