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Diffstat (limited to 'arch/powerpc/include/asm/uaccess.h')
| -rw-r--r-- | arch/powerpc/include/asm/uaccess.h | 479 |
1 files changed, 479 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h new file mode 100644 index 000000000..6ed40fcd8 --- /dev/null +++ b/arch/powerpc/include/asm/uaccess.h @@ -0,0 +1,479 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ARCH_POWERPC_UACCESS_H +#define _ARCH_POWERPC_UACCESS_H + +#include <asm/ppc_asm.h> +#include <asm/processor.h> +#include <asm/page.h> +#include <asm/extable.h> +#include <asm/kup.h> + +/* + * The fs value determines whether argument validity checking should be + * performed or not. If get_fs() == USER_DS, checking is performed, with + * get_fs() == KERNEL_DS, checking is bypassed. + * + * For historical reasons, these macros are grossly misnamed. + * + * The fs/ds values are now the highest legal address in the "segment". + * This simplifies the checking in the routines below. + */ + +#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) + +#define KERNEL_DS MAKE_MM_SEG(~0UL) +#ifdef __powerpc64__ +/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ +#define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1) +#else +#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) +#endif + +#define get_ds() (KERNEL_DS) +#define get_fs() (current->thread.addr_limit) + +static inline void set_fs(mm_segment_t fs) +{ + current->thread.addr_limit = fs; + /* On user-mode return check addr_limit (fs) is correct */ + set_thread_flag(TIF_FSCHECK); +} + +#define segment_eq(a, b) ((a).seg == (b).seg) + +#define user_addr_max() (get_fs().seg) + +#ifdef __powerpc64__ +/* + * This check is sufficient because there is a large enough + * gap between user addresses and the kernel addresses + */ +#define __access_ok(addr, size, segment) \ + (((addr) <= (segment).seg) && ((size) <= (segment).seg)) + +#else + +static inline int __access_ok(unsigned long addr, unsigned long size, + mm_segment_t seg) +{ + if (addr > seg.seg) + return 0; + return (size == 0 || size - 1 <= seg.seg - addr); +} + +#endif + +#define access_ok(type, addr, size) \ + (__chk_user_ptr(addr), (void)(type), \ + __access_ok((__force unsigned long)(addr), (size), get_fs())) + +/* + * 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 get_user(x, ptr) \ + __get_user_check((x), (ptr), sizeof(*(ptr))) +#define put_user(x, ptr) \ + __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) + +#define __get_user(x, ptr) \ + __get_user_nocheck((x), (ptr), sizeof(*(ptr)), true) +#define __put_user(x, ptr) \ + __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), true) + +#define __get_user_allowed(x, ptr) \ + __get_user_nocheck((x), (ptr), sizeof(*(ptr)), false) +#define __put_user_allowed(x, ptr) \ + __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), false) + +#define __get_user_inatomic(x, ptr) \ + __get_user_nosleep((x), (ptr), sizeof(*(ptr))) +#define __put_user_inatomic(x, ptr) \ + __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) + +extern long __put_user_bad(void); + +/* + * 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. + */ +#define __put_user_asm(x, addr, err, op) \ + __asm__ __volatile__( \ + "1: " op " %1,0(%2) # put_user\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: li %0,%3\n" \ + " b 2b\n" \ + ".previous\n" \ + EX_TABLE(1b, 3b) \ + : "=r" (err) \ + : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) + +#ifdef __powerpc64__ +#define __put_user_asm2(x, ptr, retval) \ + __put_user_asm(x, ptr, retval, "std") +#else /* __powerpc64__ */ +#define __put_user_asm2(x, addr, err) \ + __asm__ __volatile__( \ + "1: stw %1,0(%2)\n" \ + "2: stw %1+1,4(%2)\n" \ + "3:\n" \ + ".section .fixup,\"ax\"\n" \ + "4: li %0,%3\n" \ + " b 3b\n" \ + ".previous\n" \ + EX_TABLE(1b, 4b) \ + EX_TABLE(2b, 4b) \ + : "=r" (err) \ + : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) +#endif /* __powerpc64__ */ + +#define __put_user_size_allowed(x, ptr, size, retval) \ +do { \ + retval = 0; \ + switch (size) { \ + case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ + case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ + case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ + case 8: __put_user_asm2(x, ptr, retval); break; \ + default: __put_user_bad(); \ + } \ +} while (0) + +#define __put_user_size(x, ptr, size, retval) \ +do { \ + allow_write_to_user(ptr, size); \ + __put_user_size_allowed(x, ptr, size, retval); \ + prevent_write_to_user(ptr, size); \ +} while (0) + +#define __put_user_nocheck(x, ptr, size, do_allow) \ +({ \ + long __pu_err; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + __typeof__(*(ptr)) __pu_val = (x); \ + __typeof__(size) __pu_size = (size); \ + \ + if (!is_kernel_addr((unsigned long)__pu_addr)) \ + might_fault(); \ + __chk_user_ptr(__pu_addr); \ + if (do_allow) \ + __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \ + else \ + __put_user_size_allowed(__pu_val, __pu_addr, __pu_size, __pu_err); \ + \ + __pu_err; \ +}) + +#define __put_user_check(x, ptr, size) \ +({ \ + long __pu_err = -EFAULT; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + __typeof__(*(ptr)) __pu_val = (x); \ + __typeof__(size) __pu_size = (size); \ + \ + might_fault(); \ + if (access_ok(VERIFY_WRITE, __pu_addr, __pu_size)) \ + __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \ + \ + __pu_err; \ +}) + +#define __put_user_nosleep(x, ptr, size) \ +({ \ + long __pu_err; \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + __typeof__(*(ptr)) __pu_val = (x); \ + __typeof__(size) __pu_size = (size); \ + \ + __chk_user_ptr(__pu_addr); \ + __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \ + \ + __pu_err; \ +}) + + +extern long __get_user_bad(void); + +/* + * 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)) + +#define __get_user_asm(x, addr, err, op) \ + __asm__ __volatile__( \ + "1: "op" %1,0(%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) \ + : "b" (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 %1,0(%2)\n" \ + "2: lwz %1+1,4(%2)\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) \ + : "b" (addr), "i" (-EFAULT), "0" (err)) +#endif /* __powerpc64__ */ + +#define __get_user_size_allowed(x, ptr, size, retval) \ +do { \ + retval = 0; \ + __chk_user_ptr(ptr); \ + if (size > sizeof(x)) \ + (x) = __get_user_bad(); \ + switch (size) { \ + case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ + case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ + case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ + case 8: __get_user_asm2(x, ptr, retval); break; \ + default: (x) = __get_user_bad(); \ + } \ +} while (0) + +#define __get_user_size(x, ptr, size, retval) \ +do { \ + allow_read_from_user(ptr, size); \ + __get_user_size_allowed(x, ptr, size, retval); \ + prevent_read_from_user(ptr, size); \ +} while (0) + +/* + * 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_nocheck(x, ptr, size, do_allow) \ +({ \ + long __gu_err; \ + __long_type(*(ptr)) __gu_val; \ + __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ + __typeof__(size) __gu_size = (size); \ + \ + __chk_user_ptr(__gu_addr); \ + if (!is_kernel_addr((unsigned long)__gu_addr)) \ + might_fault(); \ + barrier_nospec(); \ + if (do_allow) \ + __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \ + else \ + __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \ + (x) = (__typeof__(*(ptr)))__gu_val; \ + \ + __gu_err; \ +}) + +#define __get_user_check(x, ptr, size) \ +({ \ + long __gu_err = -EFAULT; \ + __long_type(*(ptr)) __gu_val = 0; \ + __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ + __typeof__(size) __gu_size = (size); \ + \ + might_fault(); \ + if (access_ok(VERIFY_READ, __gu_addr, __gu_size)) { \ + barrier_nospec(); \ + __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \ + } \ + (x) = (__force __typeof__(*(ptr)))__gu_val; \ + \ + __gu_err; \ +}) + +#define __get_user_nosleep(x, ptr, size) \ +({ \ + long __gu_err; \ + __long_type(*(ptr)) __gu_val; \ + __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ + __typeof__(size) __gu_size = (size); \ + \ + __chk_user_ptr(__gu_addr); \ + barrier_nospec(); \ + __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \ + (x) = (__force __typeof__(*(ptr)))__gu_val; \ + \ + __gu_err; \ +}) + + +/* 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; + + barrier_nospec(); + allow_user_access(to, from, n); + ret = __copy_tofrom_user(to, from, n); + prevent_user_access(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; + if (__builtin_constant_p(n) && (n <= 8)) { + ret = 1; + + switch (n) { + case 1: + barrier_nospec(); + __get_user_size(*(u8 *)to, from, 1, ret); + break; + case 2: + barrier_nospec(); + __get_user_size(*(u16 *)to, from, 2, ret); + break; + case 4: + barrier_nospec(); + __get_user_size(*(u32 *)to, from, 4, ret); + break; + case 8: + barrier_nospec(); + __get_user_size(*(u64 *)to, from, 8, ret); + break; + } + if (ret == 0) + return 0; + } + + barrier_nospec(); + 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_allowed(void __user *to, const void *from, unsigned long n) +{ + if (__builtin_constant_p(n) && (n <= 8)) { + unsigned long ret = 1; + + switch (n) { + case 1: + __put_user_size_allowed(*(u8 *)from, (u8 __user *)to, 1, ret); + break; + case 2: + __put_user_size_allowed(*(u16 *)from, (u16 __user *)to, 2, ret); + break; + case 4: + __put_user_size_allowed(*(u32 *)from, (u32 __user *)to, 4, ret); + break; + case 8: + __put_user_size_allowed(*(u64 *)from, (u64 __user *)to, 8, ret); + break; + } + if (ret == 0) + return 0; + } + + return __copy_tofrom_user(to, (__force const void __user *)from, n); +} + +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 = raw_copy_to_user_allowed(to, 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 = size; + might_fault(); + if (likely(access_ok(VERIFY_WRITE, addr, size))) { + 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 clear_user(addr, 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); + +extern long __copy_from_user_flushcache(void *dst, const void __user *src, + unsigned size); +extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, + size_t len); + +#define user_access_begin(type, ptr, len) access_ok(type, ptr, len) +#define user_access_end() prevent_user_access(NULL, NULL, ~0ul) + +#define unsafe_op_wrap(op, err) do { if (unlikely(op)) goto err; } while (0) +#define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e) +#define unsafe_put_user(x, p, e) unsafe_op_wrap(__put_user_allowed(x, p), e) +#define unsafe_copy_to_user(d, s, l, e) \ + unsafe_op_wrap(raw_copy_to_user_allowed(d, s, l), e) + +#endif /* _ARCH_POWERPC_UACCESS_H */ |