diff options
Diffstat (limited to 'arch/s390/lib/uaccess.c')
| -rw-r--r-- | arch/s390/lib/uaccess.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c new file mode 100644 index 000000000..0ac2f3998 --- /dev/null +++ b/arch/s390/lib/uaccess.c @@ -0,0 +1,203 @@ +// 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/kprobes.h> +#include <linux/uaccess.h> +#include <linux/export.h> +#include <linux/mm.h> +#include <asm/asm-extable.h> +#include <asm/ctlreg.h> +#include <asm/skey.h> + +#ifdef CONFIG_DEBUG_ENTRY +void debug_user_asce(int exit) +{ + struct lowcore *lc = get_lowcore(); + struct ctlreg cr1, cr7; + + local_ctl_store(1, &cr1); + local_ctl_store(7, &cr7); + if (cr1.val == lc->user_asce.val && cr7.val == lc->user_asce.val) + return; + panic("incorrect ASCE on kernel %s\n" + "cr1: %016lx cr7: %016lx\n" + "kernel: %016lx user: %016lx\n", + exit ? "exit" : "entry", cr1.val, cr7.val, + lc->kernel_asce.val, lc->user_asce.val); +} +#endif /*CONFIG_DEBUG_ENTRY */ + +#define CMPXCHG_USER_KEY_MAX_LOOPS 128 + +static nokprobe_inline int __cmpxchg_key_small(void *address, unsigned int *uval, + unsigned int old, unsigned int new, + unsigned int mask, unsigned long key) +{ + unsigned long count; + unsigned int prev; + int rc = 0; + + skey_regions_initialize(); + asm_inline volatile( + "20: spka 0(%[key])\n" + " llill %[count],%[max_loops]\n" + "0: l %[prev],%[address]\n" + "1: nr %[prev],%[mask]\n" + " xilf %[mask],0xffffffff\n" + " or %[new],%[prev]\n" + " or %[prev],%[tmp]\n" + "2: lr %[tmp],%[prev]\n" + "3: cs %[prev],%[new],%[address]\n" + "4: jnl 5f\n" + " xr %[tmp],%[prev]\n" + " xr %[new],%[tmp]\n" + " nr %[tmp],%[mask]\n" + " jnz 5f\n" + " brct %[count],2b\n" + "5: spka %[default_key]\n" + "21:\n" + EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev]) + EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev]) + EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev]) + EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev]) + SKEY_REGION(20b, 21b) + : [rc] "+&d" (rc), + [prev] "=&d" (prev), + [address] "+Q" (*(int *)address), + [tmp] "+&d" (old), + [new] "+&d" (new), + [mask] "+&d" (mask), + [count] "=a" (count) + : [key] "%[count]" (key << 4), + [default_key] "J" (PAGE_DEFAULT_KEY), + [max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS) + : "memory", "cc"); + *uval = prev; + if (!count) + rc = -EAGAIN; + return rc; +} + +int __kprobes __cmpxchg_key1(void *addr, unsigned char *uval, unsigned char old, + unsigned char new, unsigned long key) +{ + unsigned long address = (unsigned long)addr; + unsigned int prev, shift, mask, _old, _new; + int rc; + + shift = (3 ^ (address & 3)) << 3; + address ^= address & 3; + _old = (unsigned int)old << shift; + _new = (unsigned int)new << shift; + mask = ~(0xff << shift); + rc = __cmpxchg_key_small((void *)address, &prev, _old, _new, mask, key); + *uval = prev >> shift; + return rc; +} +EXPORT_SYMBOL(__cmpxchg_key1); + +int __kprobes __cmpxchg_key2(void *addr, unsigned short *uval, unsigned short old, + unsigned short new, unsigned long key) +{ + unsigned long address = (unsigned long)addr; + unsigned int prev, shift, mask, _old, _new; + int rc; + + shift = (2 ^ (address & 2)) << 3; + address ^= address & 2; + _old = (unsigned int)old << shift; + _new = (unsigned int)new << shift; + mask = ~(0xffff << shift); + rc = __cmpxchg_key_small((void *)address, &prev, _old, _new, mask, key); + *uval = prev >> shift; + return rc; +} +EXPORT_SYMBOL(__cmpxchg_key2); + +int __kprobes __cmpxchg_key4(void *address, unsigned int *uval, unsigned int old, + unsigned int new, unsigned long key) +{ + unsigned int prev = old; + int rc = 0; + + skey_regions_initialize(); + asm_inline volatile( + "20: spka 0(%[key])\n" + "0: cs %[prev],%[new],%[address]\n" + "1: spka %[default_key]\n" + "21:\n" + EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev]) + EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev]) + SKEY_REGION(20b, 21b) + : [rc] "+&d" (rc), + [prev] "+&d" (prev), + [address] "+Q" (*(int *)address) + : [new] "d" (new), + [key] "a" (key << 4), + [default_key] "J" (PAGE_DEFAULT_KEY) + : "memory", "cc"); + *uval = prev; + return rc; +} +EXPORT_SYMBOL(__cmpxchg_key4); + +int __kprobes __cmpxchg_key8(void *address, unsigned long *uval, unsigned long old, + unsigned long new, unsigned long key) +{ + unsigned long prev = old; + int rc = 0; + + skey_regions_initialize(); + asm_inline volatile( + "20: spka 0(%[key])\n" + "0: csg %[prev],%[new],%[address]\n" + "1: spka %[default_key]\n" + "21:\n" + EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev]) + EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev]) + SKEY_REGION(20b, 21b) + : [rc] "+&d" (rc), + [prev] "+&d" (prev), + [address] "+QS" (*(long *)address) + : [new] "d" (new), + [key] "a" (key << 4), + [default_key] "J" (PAGE_DEFAULT_KEY) + : "memory", "cc"); + *uval = prev; + return rc; +} +EXPORT_SYMBOL(__cmpxchg_key8); + +int __kprobes __cmpxchg_key16(void *address, __uint128_t *uval, __uint128_t old, + __uint128_t new, unsigned long key) +{ + __uint128_t prev = old; + int rc = 0; + + skey_regions_initialize(); + asm_inline volatile( + "20: spka 0(%[key])\n" + "0: cdsg %[prev],%[new],%[address]\n" + "1: spka %[default_key]\n" + "21:\n" + EX_TABLE_UA_LOAD_REGPAIR(0b, 1b, %[rc], %[prev]) + EX_TABLE_UA_LOAD_REGPAIR(1b, 1b, %[rc], %[prev]) + SKEY_REGION(20b, 21b) + : [rc] "+&d" (rc), + [prev] "+&d" (prev), + [address] "+QS" (*(__int128_t *)address) + : [new] "d" (new), + [key] "a" (key << 4), + [default_key] "J" (PAGE_DEFAULT_KEY) + : "memory", "cc"); + *uval = prev; + return rc; +} +EXPORT_SYMBOL(__cmpxchg_key16); |