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-rw-r--r--arch/s390/include/asm/uaccess.h601
1 files changed, 601 insertions, 0 deletions
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
new file mode 100644
index 0000000000..8a8c64a678
--- /dev/null
+++ b/arch/s390/include/asm/uaccess.h
@@ -0,0 +1,601 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * S390 version
+ * Copyright IBM Corp. 1999, 2000
+ * Author(s): Hartmut Penner (hp@de.ibm.com),
+ * Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ * Derived from "include/asm-i386/uaccess.h"
+ */
+#ifndef __S390_UACCESS_H
+#define __S390_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <asm/asm-extable.h>
+#include <asm/processor.h>
+#include <asm/ctl_reg.h>
+#include <asm/extable.h>
+#include <asm/facility.h>
+#include <asm-generic/access_ok.h>
+
+void debug_user_asce(int exit);
+
+unsigned long __must_check
+raw_copy_from_user(void *to, const void __user *from, unsigned long n);
+
+unsigned long __must_check
+raw_copy_to_user(void __user *to, const void *from, unsigned long n);
+
+#ifndef CONFIG_KASAN
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
+#endif
+
+unsigned long __must_check
+_copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key);
+
+static __always_inline unsigned long __must_check
+copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key)
+{
+ if (check_copy_size(to, n, false))
+ n = _copy_from_user_key(to, from, n, key);
+ return n;
+}
+
+unsigned long __must_check
+_copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key);
+
+static __always_inline unsigned long __must_check
+copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key)
+{
+ if (check_copy_size(from, n, true))
+ n = _copy_to_user_key(to, from, n, key);
+ return n;
+}
+
+union oac {
+ unsigned int val;
+ struct {
+ struct {
+ unsigned short key : 4;
+ unsigned short : 4;
+ unsigned short as : 2;
+ unsigned short : 4;
+ unsigned short k : 1;
+ unsigned short a : 1;
+ } oac1;
+ struct {
+ unsigned short key : 4;
+ unsigned short : 4;
+ unsigned short as : 2;
+ unsigned short : 4;
+ unsigned short k : 1;
+ unsigned short a : 1;
+ } oac2;
+ };
+};
+
+int __noreturn __put_user_bad(void);
+
+#define __put_user_asm(to, from, size) \
+({ \
+ union oac __oac_spec = { \
+ .oac1.as = PSW_BITS_AS_SECONDARY, \
+ .oac1.a = 1, \
+ }; \
+ int __rc; \
+ \
+ asm volatile( \
+ " lr 0,%[spec]\n" \
+ "0: mvcos %[_to],%[_from],%[_size]\n" \
+ "1: xr %[rc],%[rc]\n" \
+ "2:\n" \
+ EX_TABLE_UA_STORE(0b, 2b, %[rc]) \
+ EX_TABLE_UA_STORE(1b, 2b, %[rc]) \
+ : [rc] "=&d" (__rc), [_to] "+Q" (*(to)) \
+ : [_size] "d" (size), [_from] "Q" (*(from)), \
+ [spec] "d" (__oac_spec.val) \
+ : "cc", "0"); \
+ __rc; \
+})
+
+static __always_inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
+{
+ int rc;
+
+ switch (size) {
+ case 1:
+ rc = __put_user_asm((unsigned char __user *)ptr,
+ (unsigned char *)x,
+ size);
+ break;
+ case 2:
+ rc = __put_user_asm((unsigned short __user *)ptr,
+ (unsigned short *)x,
+ size);
+ break;
+ case 4:
+ rc = __put_user_asm((unsigned int __user *)ptr,
+ (unsigned int *)x,
+ size);
+ break;
+ case 8:
+ rc = __put_user_asm((unsigned long __user *)ptr,
+ (unsigned long *)x,
+ size);
+ break;
+ default:
+ __put_user_bad();
+ break;
+ }
+ return rc;
+}
+
+int __noreturn __get_user_bad(void);
+
+#define __get_user_asm(to, from, size) \
+({ \
+ union oac __oac_spec = { \
+ .oac2.as = PSW_BITS_AS_SECONDARY, \
+ .oac2.a = 1, \
+ }; \
+ int __rc; \
+ \
+ asm volatile( \
+ " lr 0,%[spec]\n" \
+ "0: mvcos 0(%[_to]),%[_from],%[_size]\n" \
+ "1: xr %[rc],%[rc]\n" \
+ "2:\n" \
+ EX_TABLE_UA_LOAD_MEM(0b, 2b, %[rc], %[_to], %[_ksize]) \
+ EX_TABLE_UA_LOAD_MEM(1b, 2b, %[rc], %[_to], %[_ksize]) \
+ : [rc] "=&d" (__rc), "=Q" (*(to)) \
+ : [_size] "d" (size), [_from] "Q" (*(from)), \
+ [spec] "d" (__oac_spec.val), [_to] "a" (to), \
+ [_ksize] "K" (size) \
+ : "cc", "0"); \
+ __rc; \
+})
+
+static __always_inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
+{
+ int rc;
+
+ switch (size) {
+ case 1:
+ rc = __get_user_asm((unsigned char *)x,
+ (unsigned char __user *)ptr,
+ size);
+ break;
+ case 2:
+ rc = __get_user_asm((unsigned short *)x,
+ (unsigned short __user *)ptr,
+ size);
+ break;
+ case 4:
+ rc = __get_user_asm((unsigned int *)x,
+ (unsigned int __user *)ptr,
+ size);
+ break;
+ case 8:
+ rc = __get_user_asm((unsigned long *)x,
+ (unsigned long __user *)ptr,
+ size);
+ break;
+ default:
+ __get_user_bad();
+ break;
+ }
+ return rc;
+}
+
+/*
+ * These are the main single-value transfer routines. They automatically
+ * use the right size if we just have the right pointer type.
+ */
+#define __put_user(x, ptr) \
+({ \
+ __typeof__(*(ptr)) __x = (x); \
+ int __pu_err = -EFAULT; \
+ \
+ __chk_user_ptr(ptr); \
+ switch (sizeof(*(ptr))) { \
+ case 1: \
+ case 2: \
+ case 4: \
+ case 8: \
+ __pu_err = __put_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ break; \
+ default: \
+ __put_user_bad(); \
+ break; \
+ } \
+ __builtin_expect(__pu_err, 0); \
+})
+
+#define put_user(x, ptr) \
+({ \
+ might_fault(); \
+ __put_user(x, ptr); \
+})
+
+#define __get_user(x, ptr) \
+({ \
+ int __gu_err = -EFAULT; \
+ \
+ __chk_user_ptr(ptr); \
+ switch (sizeof(*(ptr))) { \
+ case 1: { \
+ unsigned char __x; \
+ \
+ __gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ (x) = *(__force __typeof__(*(ptr)) *)&__x; \
+ break; \
+ }; \
+ case 2: { \
+ unsigned short __x; \
+ \
+ __gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ (x) = *(__force __typeof__(*(ptr)) *)&__x; \
+ break; \
+ }; \
+ case 4: { \
+ unsigned int __x; \
+ \
+ __gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ (x) = *(__force __typeof__(*(ptr)) *)&__x; \
+ break; \
+ }; \
+ case 8: { \
+ unsigned long __x; \
+ \
+ __gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ (x) = *(__force __typeof__(*(ptr)) *)&__x; \
+ break; \
+ }; \
+ default: \
+ __get_user_bad(); \
+ break; \
+ } \
+ __builtin_expect(__gu_err, 0); \
+})
+
+#define get_user(x, ptr) \
+({ \
+ might_fault(); \
+ __get_user(x, ptr); \
+})
+
+/*
+ * Copy a null terminated string from userspace.
+ */
+long __must_check strncpy_from_user(char *dst, const char __user *src, long count);
+
+long __must_check strnlen_user(const char __user *src, long count);
+
+/*
+ * Zero Userspace
+ */
+unsigned long __must_check __clear_user(void __user *to, unsigned long size);
+
+static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
+{
+ might_fault();
+ return __clear_user(to, n);
+}
+
+void *s390_kernel_write(void *dst, const void *src, size_t size);
+
+int __noreturn __put_kernel_bad(void);
+
+#define __put_kernel_asm(val, to, insn) \
+({ \
+ int __rc; \
+ \
+ asm volatile( \
+ "0: " insn " %[_val],%[_to]\n" \
+ "1: xr %[rc],%[rc]\n" \
+ "2:\n" \
+ EX_TABLE_UA_STORE(0b, 2b, %[rc]) \
+ EX_TABLE_UA_STORE(1b, 2b, %[rc]) \
+ : [rc] "=d" (__rc), [_to] "+Q" (*(to)) \
+ : [_val] "d" (val) \
+ : "cc"); \
+ __rc; \
+})
+
+#define __put_kernel_nofault(dst, src, type, err_label) \
+do { \
+ unsigned long __x = (unsigned long)(*((type *)(src))); \
+ int __pk_err; \
+ \
+ switch (sizeof(type)) { \
+ case 1: \
+ __pk_err = __put_kernel_asm(__x, (type *)(dst), "stc"); \
+ break; \
+ case 2: \
+ __pk_err = __put_kernel_asm(__x, (type *)(dst), "sth"); \
+ break; \
+ case 4: \
+ __pk_err = __put_kernel_asm(__x, (type *)(dst), "st"); \
+ break; \
+ case 8: \
+ __pk_err = __put_kernel_asm(__x, (type *)(dst), "stg"); \
+ break; \
+ default: \
+ __pk_err = __put_kernel_bad(); \
+ break; \
+ } \
+ if (unlikely(__pk_err)) \
+ goto err_label; \
+} while (0)
+
+int __noreturn __get_kernel_bad(void);
+
+#define __get_kernel_asm(val, from, insn) \
+({ \
+ int __rc; \
+ \
+ asm volatile( \
+ "0: " insn " %[_val],%[_from]\n" \
+ "1: xr %[rc],%[rc]\n" \
+ "2:\n" \
+ EX_TABLE_UA_LOAD_REG(0b, 2b, %[rc], %[_val]) \
+ EX_TABLE_UA_LOAD_REG(1b, 2b, %[rc], %[_val]) \
+ : [rc] "=d" (__rc), [_val] "=d" (val) \
+ : [_from] "Q" (*(from)) \
+ : "cc"); \
+ __rc; \
+})
+
+#define __get_kernel_nofault(dst, src, type, err_label) \
+do { \
+ int __gk_err; \
+ \
+ switch (sizeof(type)) { \
+ case 1: { \
+ unsigned char __x; \
+ \
+ __gk_err = __get_kernel_asm(__x, (type *)(src), "ic"); \
+ *((type *)(dst)) = (type)__x; \
+ break; \
+ }; \
+ case 2: { \
+ unsigned short __x; \
+ \
+ __gk_err = __get_kernel_asm(__x, (type *)(src), "lh"); \
+ *((type *)(dst)) = (type)__x; \
+ break; \
+ }; \
+ case 4: { \
+ unsigned int __x; \
+ \
+ __gk_err = __get_kernel_asm(__x, (type *)(src), "l"); \
+ *((type *)(dst)) = (type)__x; \
+ break; \
+ }; \
+ case 8: { \
+ unsigned long __x; \
+ \
+ __gk_err = __get_kernel_asm(__x, (type *)(src), "lg"); \
+ *((type *)(dst)) = (type)__x; \
+ break; \
+ }; \
+ default: \
+ __gk_err = __get_kernel_bad(); \
+ break; \
+ } \
+ if (unlikely(__gk_err)) \
+ goto err_label; \
+} while (0)
+
+void __cmpxchg_user_key_called_with_bad_pointer(void);
+
+#define CMPXCHG_USER_KEY_MAX_LOOPS 128
+
+static __always_inline int __cmpxchg_user_key(unsigned long address, void *uval,
+ __uint128_t old, __uint128_t new,
+ unsigned long key, int size)
+{
+ int rc = 0;
+
+ switch (size) {
+ case 1: {
+ unsigned int prev, shift, mask, _old, _new;
+ unsigned long count;
+
+ shift = (3 ^ (address & 3)) << 3;
+ address ^= address & 3;
+ _old = ((unsigned int)old & 0xff) << shift;
+ _new = ((unsigned int)new & 0xff) << shift;
+ mask = ~(0xff << shift);
+ asm volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\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: sacf 768\n"
+ " spka %[default_key]\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])
+ : [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");
+ *(unsigned char *)uval = prev >> shift;
+ if (!count)
+ rc = -EAGAIN;
+ return rc;
+ }
+ case 2: {
+ unsigned int prev, shift, mask, _old, _new;
+ unsigned long count;
+
+ shift = (2 ^ (address & 2)) << 3;
+ address ^= address & 2;
+ _old = ((unsigned int)old & 0xffff) << shift;
+ _new = ((unsigned int)new & 0xffff) << shift;
+ mask = ~(0xffff << shift);
+ asm volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\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: sacf 768\n"
+ " spka %[default_key]\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])
+ : [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");
+ *(unsigned short *)uval = prev >> shift;
+ if (!count)
+ rc = -EAGAIN;
+ return rc;
+ }
+ case 4: {
+ unsigned int prev = old;
+
+ asm volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: cs %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
+ : [rc] "+&d" (rc),
+ [prev] "+&d" (prev),
+ [address] "+Q" (*(int *)address)
+ : [new] "d" ((unsigned int)new),
+ [key] "a" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY)
+ : "memory", "cc");
+ *(unsigned int *)uval = prev;
+ return rc;
+ }
+ case 8: {
+ unsigned long prev = old;
+
+ asm volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: csg %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
+ : [rc] "+&d" (rc),
+ [prev] "+&d" (prev),
+ [address] "+QS" (*(long *)address)
+ : [new] "d" ((unsigned long)new),
+ [key] "a" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY)
+ : "memory", "cc");
+ *(unsigned long *)uval = prev;
+ return rc;
+ }
+ case 16: {
+ __uint128_t prev = old;
+
+ asm volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: cdsg %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ EX_TABLE_UA_LOAD_REGPAIR(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REGPAIR(1b, 1b, %[rc], %[prev])
+ : [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");
+ *(__uint128_t *)uval = prev;
+ return rc;
+ }
+ }
+ __cmpxchg_user_key_called_with_bad_pointer();
+ return rc;
+}
+
+/**
+ * cmpxchg_user_key() - cmpxchg with user space target, honoring storage keys
+ * @ptr: User space address of value to compare to @old and exchange with
+ * @new. Must be aligned to sizeof(*@ptr).
+ * @uval: Address where the old value of *@ptr is written to.
+ * @old: Old value. Compared to the content pointed to by @ptr in order to
+ * determine if the exchange occurs. The old value read from *@ptr is
+ * written to *@uval.
+ * @new: New value to place at *@ptr.
+ * @key: Access key to use for checking storage key protection.
+ *
+ * Perform a cmpxchg on a user space target, honoring storage key protection.
+ * @key alone determines how key checking is performed, neither
+ * storage-protection-override nor fetch-protection-override apply.
+ * The caller must compare *@uval and @old to determine if values have been
+ * exchanged. In case of an exception *@uval is set to zero.
+ *
+ * Return: 0: cmpxchg executed
+ * -EFAULT: an exception happened when trying to access *@ptr
+ * -EAGAIN: maxed out number of retries (byte and short only)
+ */
+#define cmpxchg_user_key(ptr, uval, old, new, key) \
+({ \
+ __typeof__(ptr) __ptr = (ptr); \
+ __typeof__(uval) __uval = (uval); \
+ \
+ BUILD_BUG_ON(sizeof(*(__ptr)) != sizeof(*(__uval))); \
+ might_fault(); \
+ __chk_user_ptr(__ptr); \
+ __cmpxchg_user_key((unsigned long)(__ptr), (void *)(__uval), \
+ (old), (new), (key), sizeof(*(__ptr))); \
+})
+
+#endif /* __S390_UACCESS_H */
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