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-rw-r--r--arch/powerpc/include/asm/uaccess.h493
1 files changed, 493 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
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+++ b/arch/powerpc/include/asm/uaccess.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ARCH_POWERPC_UACCESS_H
+#define _ARCH_POWERPC_UACCESS_H
+
+#include <asm/processor.h>
+#include <asm/page.h>
+#include <asm/extable.h>
+#include <asm/kup.h>
+
+#ifdef __powerpc64__
+/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
+#define TASK_SIZE_MAX TASK_SIZE_USER64
+#endif
+
+#include <asm-generic/access_ok.h>
+
+/*
+ * These are the main single-value transfer routines. They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * This gets kind of ugly. We want to return _two_ values in "get_user()"
+ * and yet we don't want to do any pointers, because that is too much
+ * of a performance impact. Thus we have a few rather ugly macros here,
+ * and hide all the ugliness from the user.
+ *
+ * The "__xxx" versions of the user access functions are versions that
+ * do not verify the address space, that must have been done previously
+ * with a separate "access_ok()" call (this is used when we do multiple
+ * accesses to the same area of user memory).
+ *
+ * As we use the same address space for kernel and user data on the
+ * PowerPC, we can just do these as direct assignments. (Of course, the
+ * exception handling means that it's no longer "just"...)
+ *
+ */
+#define __put_user(x, ptr) \
+({ \
+ long __pu_err; \
+ __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
+ __typeof__(*(ptr)) __pu_val = (__typeof__(*(ptr)))(x); \
+ __typeof__(sizeof(*(ptr))) __pu_size = sizeof(*(ptr)); \
+ \
+ might_fault(); \
+ do { \
+ __label__ __pu_failed; \
+ \
+ allow_write_to_user(__pu_addr, __pu_size); \
+ __put_user_size_goto(__pu_val, __pu_addr, __pu_size, __pu_failed); \
+ prevent_write_to_user(__pu_addr, __pu_size); \
+ __pu_err = 0; \
+ break; \
+ \
+__pu_failed: \
+ prevent_write_to_user(__pu_addr, __pu_size); \
+ __pu_err = -EFAULT; \
+ } while (0); \
+ \
+ __pu_err; \
+})
+
+#define put_user(x, ptr) \
+({ \
+ __typeof__(*(ptr)) __user *_pu_addr = (ptr); \
+ \
+ access_ok(_pu_addr, sizeof(*(ptr))) ? \
+ __put_user(x, _pu_addr) : -EFAULT; \
+})
+
+/*
+ * We don't tell gcc that we are accessing memory, but this is OK
+ * because we do not write to any memory gcc knows about, so there
+ * are no aliasing issues.
+ */
+/* -mprefixed can generate offsets beyond range, fall back hack */
+#ifdef CONFIG_PPC_KERNEL_PREFIXED
+#define __put_user_asm_goto(x, addr, label, op) \
+ asm_volatile_goto( \
+ "1: " op " %0,0(%1) # put_user\n" \
+ EX_TABLE(1b, %l2) \
+ : \
+ : "r" (x), "b" (addr) \
+ : \
+ : label)
+#else
+#define __put_user_asm_goto(x, addr, label, op) \
+ asm_volatile_goto( \
+ "1: " op "%U1%X1 %0,%1 # put_user\n" \
+ EX_TABLE(1b, %l2) \
+ : \
+ : "r" (x), "m<>" (*addr) \
+ : \
+ : label)
+#endif
+
+#ifdef __powerpc64__
+#define __put_user_asm2_goto(x, ptr, label) \
+ __put_user_asm_goto(x, ptr, label, "std")
+#else /* __powerpc64__ */
+#define __put_user_asm2_goto(x, addr, label) \
+ asm_volatile_goto( \
+ "1: stw%X1 %0, %1\n" \
+ "2: stw%X1 %L0, %L1\n" \
+ EX_TABLE(1b, %l2) \
+ EX_TABLE(2b, %l2) \
+ : \
+ : "r" (x), "m" (*addr) \
+ : \
+ : label)
+#endif /* __powerpc64__ */
+
+#define __put_user_size_goto(x, ptr, size, label) \
+do { \
+ __typeof__(*(ptr)) __user *__pus_addr = (ptr); \
+ \
+ switch (size) { \
+ case 1: __put_user_asm_goto(x, __pus_addr, label, "stb"); break; \
+ case 2: __put_user_asm_goto(x, __pus_addr, label, "sth"); break; \
+ case 4: __put_user_asm_goto(x, __pus_addr, label, "stw"); break; \
+ case 8: __put_user_asm2_goto(x, __pus_addr, label); break; \
+ default: BUILD_BUG(); \
+ } \
+} while (0)
+
+/*
+ * This does an atomic 128 byte aligned load from userspace.
+ * Upto caller to do enable_kernel_vmx() before calling!
+ */
+#define __get_user_atomic_128_aligned(kaddr, uaddr, err) \
+ __asm__ __volatile__( \
+ ".machine push\n" \
+ ".machine altivec\n" \
+ "1: lvx 0,0,%1 # get user\n" \
+ " stvx 0,0,%2 # put kernel\n" \
+ ".machine pop\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: li %0,%3\n" \
+ " b 2b\n" \
+ ".previous\n" \
+ EX_TABLE(1b, 3b) \
+ : "=r" (err) \
+ : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err))
+
+#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
+
+/* -mprefixed can generate offsets beyond range, fall back hack */
+#ifdef CONFIG_PPC_KERNEL_PREFIXED
+#define __get_user_asm_goto(x, addr, label, op) \
+ asm_volatile_goto( \
+ "1: "op" %0,0(%1) # get_user\n" \
+ EX_TABLE(1b, %l2) \
+ : "=r" (x) \
+ : "b" (addr) \
+ : \
+ : label)
+#else
+#define __get_user_asm_goto(x, addr, label, op) \
+ asm_volatile_goto( \
+ "1: "op"%U1%X1 %0, %1 # get_user\n" \
+ EX_TABLE(1b, %l2) \
+ : "=r" (x) \
+ : "m<>" (*addr) \
+ : \
+ : label)
+#endif
+
+#ifdef __powerpc64__
+#define __get_user_asm2_goto(x, addr, label) \
+ __get_user_asm_goto(x, addr, label, "ld")
+#else /* __powerpc64__ */
+#define __get_user_asm2_goto(x, addr, label) \
+ asm_volatile_goto( \
+ "1: lwz%X1 %0, %1\n" \
+ "2: lwz%X1 %L0, %L1\n" \
+ EX_TABLE(1b, %l2) \
+ EX_TABLE(2b, %l2) \
+ : "=&r" (x) \
+ : "m" (*addr) \
+ : \
+ : label)
+#endif /* __powerpc64__ */
+
+#define __get_user_size_goto(x, ptr, size, label) \
+do { \
+ BUILD_BUG_ON(size > sizeof(x)); \
+ switch (size) { \
+ case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \
+ case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \
+ case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \
+ case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \
+ default: x = 0; BUILD_BUG(); \
+ } \
+} while (0)
+
+#define __get_user_size_allowed(x, ptr, size, retval) \
+do { \
+ __label__ __gus_failed; \
+ \
+ __get_user_size_goto(x, ptr, size, __gus_failed); \
+ retval = 0; \
+ break; \
+__gus_failed: \
+ x = 0; \
+ retval = -EFAULT; \
+} while (0)
+
+#else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
+
+#define __get_user_asm(x, addr, err, op) \
+ __asm__ __volatile__( \
+ "1: "op"%U2%X2 %1, %2 # get_user\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: li %0,%3\n" \
+ " li %1,0\n" \
+ " b 2b\n" \
+ ".previous\n" \
+ EX_TABLE(1b, 3b) \
+ : "=r" (err), "=r" (x) \
+ : "m<>" (*addr), "i" (-EFAULT), "0" (err))
+
+#ifdef __powerpc64__
+#define __get_user_asm2(x, addr, err) \
+ __get_user_asm(x, addr, err, "ld")
+#else /* __powerpc64__ */
+#define __get_user_asm2(x, addr, err) \
+ __asm__ __volatile__( \
+ "1: lwz%X2 %1, %2\n" \
+ "2: lwz%X2 %L1, %L2\n" \
+ "3:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "4: li %0,%3\n" \
+ " li %1,0\n" \
+ " li %1+1,0\n" \
+ " b 3b\n" \
+ ".previous\n" \
+ EX_TABLE(1b, 4b) \
+ EX_TABLE(2b, 4b) \
+ : "=r" (err), "=&r" (x) \
+ : "m" (*addr), "i" (-EFAULT), "0" (err))
+#endif /* __powerpc64__ */
+
+#define __get_user_size_allowed(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ BUILD_BUG_ON(size > sizeof(x)); \
+ switch (size) { \
+ case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \
+ case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \
+ case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
+ case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \
+ default: x = 0; BUILD_BUG(); \
+ } \
+} while (0)
+
+#define __get_user_size_goto(x, ptr, size, label) \
+do { \
+ long __gus_retval; \
+ \
+ __get_user_size_allowed(x, ptr, size, __gus_retval); \
+ if (__gus_retval) \
+ goto label; \
+} while (0)
+
+#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
+
+/*
+ * This is a type: either unsigned long, if the argument fits into
+ * that type, or otherwise unsigned long long.
+ */
+#define __long_type(x) \
+ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
+
+#define __get_user(x, ptr) \
+({ \
+ long __gu_err; \
+ __long_type(*(ptr)) __gu_val; \
+ __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
+ __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \
+ \
+ might_fault(); \
+ allow_read_from_user(__gu_addr, __gu_size); \
+ __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
+ prevent_read_from_user(__gu_addr, __gu_size); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ \
+ __gu_err; \
+})
+
+#define get_user(x, ptr) \
+({ \
+ __typeof__(*(ptr)) __user *_gu_addr = (ptr); \
+ \
+ access_ok(_gu_addr, sizeof(*(ptr))) ? \
+ __get_user(x, _gu_addr) : \
+ ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \
+})
+
+/* more complex routines */
+
+extern unsigned long __copy_tofrom_user(void __user *to,
+ const void __user *from, unsigned long size);
+
+#ifdef __powerpc64__
+static inline unsigned long
+raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+ unsigned long ret;
+
+ allow_read_write_user(to, from, n);
+ ret = __copy_tofrom_user(to, from, n);
+ prevent_read_write_user(to, from, n);
+ return ret;
+}
+#endif /* __powerpc64__ */
+
+static inline unsigned long raw_copy_from_user(void *to,
+ const void __user *from, unsigned long n)
+{
+ unsigned long ret;
+
+ allow_read_from_user(from, n);
+ ret = __copy_tofrom_user((__force void __user *)to, from, n);
+ prevent_read_from_user(from, n);
+ return ret;
+}
+
+static inline unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ unsigned long ret;
+
+ allow_write_to_user(to, n);
+ ret = __copy_tofrom_user(to, (__force const void __user *)from, n);
+ prevent_write_to_user(to, n);
+ return ret;
+}
+
+unsigned long __arch_clear_user(void __user *addr, unsigned long size);
+
+static inline unsigned long __clear_user(void __user *addr, unsigned long size)
+{
+ unsigned long ret;
+
+ might_fault();
+ allow_write_to_user(addr, size);
+ ret = __arch_clear_user(addr, size);
+ prevent_write_to_user(addr, size);
+ return ret;
+}
+
+static inline unsigned long clear_user(void __user *addr, unsigned long size)
+{
+ return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size;
+}
+
+extern long strncpy_from_user(char *dst, const char __user *src, long count);
+extern __must_check long strnlen_user(const char __user *str, long n);
+
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+unsigned long __must_check
+copy_mc_generic(void *to, const void *from, unsigned long size);
+
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned long size)
+{
+ return copy_mc_generic(to, from, size);
+}
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+static inline unsigned long __must_check
+copy_mc_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (check_copy_size(from, n, true)) {
+ if (access_ok(to, n)) {
+ allow_write_to_user(to, n);
+ n = copy_mc_generic((void *)to, from, n);
+ prevent_write_to_user(to, n);
+ }
+ }
+
+ return n;
+}
+#endif
+
+extern long __copy_from_user_flushcache(void *dst, const void __user *src,
+ unsigned size);
+
+static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len)
+{
+ if (unlikely(!access_ok(ptr, len)))
+ return false;
+
+ might_fault();
+
+ allow_read_write_user((void __user *)ptr, ptr, len);
+ return true;
+}
+#define user_access_begin user_access_begin
+#define user_access_end prevent_current_access_user
+#define user_access_save prevent_user_access_return
+#define user_access_restore restore_user_access
+
+static __must_check __always_inline bool
+user_read_access_begin(const void __user *ptr, size_t len)
+{
+ if (unlikely(!access_ok(ptr, len)))
+ return false;
+
+ might_fault();
+
+ allow_read_from_user(ptr, len);
+ return true;
+}
+#define user_read_access_begin user_read_access_begin
+#define user_read_access_end prevent_current_read_from_user
+
+static __must_check __always_inline bool
+user_write_access_begin(const void __user *ptr, size_t len)
+{
+ if (unlikely(!access_ok(ptr, len)))
+ return false;
+
+ might_fault();
+
+ allow_write_to_user((void __user *)ptr, len);
+ return true;
+}
+#define user_write_access_begin user_write_access_begin
+#define user_write_access_end prevent_current_write_to_user
+
+#define unsafe_get_user(x, p, e) do { \
+ __long_type(*(p)) __gu_val; \
+ __typeof__(*(p)) __user *__gu_addr = (p); \
+ \
+ __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
+ (x) = (__typeof__(*(p)))__gu_val; \
+} while (0)
+
+#define unsafe_put_user(x, p, e) \
+ __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e)
+
+#define unsafe_copy_from_user(d, s, l, e) \
+do { \
+ u8 *_dst = (u8 *)(d); \
+ const u8 __user *_src = (const u8 __user *)(s); \
+ size_t _len = (l); \
+ int _i; \
+ \
+ for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
+ unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \
+ if (_len & 4) { \
+ unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \
+ _i += 4; \
+ } \
+ if (_len & 2) { \
+ unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \
+ _i += 2; \
+ } \
+ if (_len & 1) \
+ unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \
+} while (0)
+
+#define unsafe_copy_to_user(d, s, l, e) \
+do { \
+ u8 __user *_dst = (u8 __user *)(d); \
+ const u8 *_src = (const u8 *)(s); \
+ size_t _len = (l); \
+ int _i; \
+ \
+ for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
+ unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \
+ if (_len & 4) { \
+ unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \
+ _i += 4; \
+ } \
+ if (_len & 2) { \
+ unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \
+ _i += 2; \
+ } \
+ if (_len & 1) \
+ unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \
+} while (0)
+
+#define __get_kernel_nofault(dst, src, type, err_label) \
+ __get_user_size_goto(*((type *)(dst)), \
+ (__force type __user *)(src), sizeof(type), err_label)
+
+#define __put_kernel_nofault(dst, src, type, err_label) \
+ __put_user_size_goto(*((type *)(src)), \
+ (__force type __user *)(dst), sizeof(type), err_label)
+
+#endif /* _ARCH_POWERPC_UACCESS_H */