diff options
Diffstat (limited to 'arch/s390/lib/uaccess.c')
| -rw-r--r-- | arch/s390/lib/uaccess.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c new file mode 100644 index 000000000..e4a13d7ca --- /dev/null +++ b/arch/s390/lib/uaccess.c @@ -0,0 +1,185 @@ +// 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 rem; + union oac spec = { + .oac2.key = key, + .oac2.as = PSW_BITS_AS_SECONDARY, + .oac2.k = 1, + .oac2.a = 1, + }; + + asm volatile( + " lr 0,%[spec]\n" + "0: mvcos 0(%[to]),0(%[from]),%[size]\n" + "1: jz 5f\n" + " algr %[size],%[val]\n" + " slgr %[from],%[val]\n" + " slgr %[to],%[val]\n" + " j 0b\n" + "2: la %[rem],4095(%[from])\n" /* rem = from + 4095 */ + " nr %[rem],%[val]\n" /* rem = (from + 4095) & -4096 */ + " slgr %[rem],%[from]\n" + " clgr %[size],%[rem]\n" /* copy crosses next page boundary? */ + " jnh 6f\n" + "3: mvcos 0(%[to]),0(%[from]),%[rem]\n" + "4: slgr %[size],%[rem]\n" + " j 6f\n" + "5: slgr %[size],%[size]\n" + "6:\n" + EX_TABLE(0b, 2b) + EX_TABLE(1b, 2b) + EX_TABLE(3b, 6b) + EX_TABLE(4b, 6b) + : [size] "+&a" (size), [from] "+&a" (from), [to] "+&a" (to), [rem] "=&a" (rem) + : [val] "a" (-4096UL), [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 rem; + union oac spec = { + .oac1.key = key, + .oac1.as = PSW_BITS_AS_SECONDARY, + .oac1.k = 1, + .oac1.a = 1, + }; + + asm volatile( + " lr 0,%[spec]\n" + "0: mvcos 0(%[to]),0(%[from]),%[size]\n" + "1: jz 5f\n" + " algr %[size],%[val]\n" + " slgr %[to],%[val]\n" + " slgr %[from],%[val]\n" + " j 0b\n" + "2: la %[rem],4095(%[to])\n" /* rem = to + 4095 */ + " nr %[rem],%[val]\n" /* rem = (to + 4095) & -4096 */ + " slgr %[rem],%[to]\n" + " clgr %[size],%[rem]\n" /* copy crosses next page boundary? */ + " jnh 6f\n" + "3: mvcos 0(%[to]),0(%[from]),%[rem]\n" + "4: slgr %[size],%[rem]\n" + " j 6f\n" + "5: slgr %[size],%[size]\n" + "6:\n" + EX_TABLE(0b, 2b) + EX_TABLE(1b, 2b) + EX_TABLE(3b, 6b) + EX_TABLE(4b, 6b) + : [size] "+&a" (size), [to] "+&a" (to), [from] "+&a" (from), [rem] "=&a" (rem) + : [val] "a" (-4096UL), [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 rem; + union oac spec = { + .oac1.as = PSW_BITS_AS_SECONDARY, + .oac1.a = 1, + }; + + asm volatile( + " lr 0,%[spec]\n" + "0: mvcos 0(%[to]),0(%[zeropg]),%[size]\n" + "1: jz 5f\n" + " algr %[size],%[val]\n" + " slgr %[to],%[val]\n" + " j 0b\n" + "2: la %[rem],4095(%[to])\n" /* rem = to + 4095 */ + " nr %[rem],%[val]\n" /* rem = (to + 4095) & -4096 */ + " slgr %[rem],%[to]\n" + " clgr %[size],%[rem]\n" /* copy crosses next page boundary? */ + " jnh 6f\n" + "3: mvcos 0(%[to]),0(%[zeropg]),%[rem]\n" + "4: slgr %[size],%[rem]\n" + " j 6f\n" + "5: slgr %[size],%[size]\n" + "6:\n" + EX_TABLE(0b, 2b) + EX_TABLE(1b, 2b) + EX_TABLE(3b, 6b) + EX_TABLE(4b, 6b) + : [size] "+&a" (size), [to] "+&a" (to), [rem] "=&a" (rem) + : [val] "a" (-4096UL), [zeropg] "a" (empty_zero_page), [spec] "d" (spec.val) + : "cc", "memory", "0"); + return size; +} +EXPORT_SYMBOL(__clear_user); |