diff options
Diffstat (limited to 'arch/riscv/include/asm/uaccess.h')
| -rw-r--r-- | arch/riscv/include/asm/uaccess.h | 426 |
1 files changed, 210 insertions, 216 deletions
diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h index f314ff44c48d..36bba6720c26 100644 --- a/arch/riscv/include/asm/uaccess.h +++ b/arch/riscv/include/asm/uaccess.h @@ -8,8 +8,42 @@ #ifndef _ASM_RISCV_UACCESS_H #define _ASM_RISCV_UACCESS_H +#include <asm/asm-extable.h> +#include <asm/cpufeature.h> #include <asm/pgtable.h> /* for TASK_SIZE */ +#ifdef CONFIG_RISCV_ISA_SUPM +static inline unsigned long __untagged_addr_remote(struct mm_struct *mm, unsigned long addr) +{ + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SUPM)) { + u8 pmlen = mm->context.pmlen; + + /* Virtual addresses are sign-extended; physical addresses are zero-extended. */ + if (IS_ENABLED(CONFIG_MMU)) + return (long)(addr << pmlen) >> pmlen; + else + return (addr << pmlen) >> pmlen; + } + + return addr; +} + +#define untagged_addr(addr) ({ \ + unsigned long __addr = (__force unsigned long)(addr); \ + (__force __typeof__(addr))__untagged_addr_remote(current->mm, __addr); \ +}) + +#define untagged_addr_remote(mm, addr) ({ \ + unsigned long __addr = (__force unsigned long)(addr); \ + mmap_assert_locked(mm); \ + (__force __typeof__(addr))__untagged_addr_remote(mm, __addr); \ +}) + +#define access_ok(addr, size) likely(__access_ok(untagged_addr(addr), size)) +#else +#define untagged_addr(addr) (addr) +#endif + /* * User space memory access functions */ @@ -20,41 +54,25 @@ #include <asm/byteorder.h> #include <asm/extable.h> #include <asm/asm.h> +#include <asm-generic/access_ok.h> #define __enable_user_access() \ __asm__ __volatile__ ("csrs sstatus, %0" : : "r" (SR_SUM) : "memory") #define __disable_user_access() \ __asm__ __volatile__ ("csrc sstatus, %0" : : "r" (SR_SUM) : "memory") -/** - * access_ok: - Checks if a user space pointer is valid - * @addr: User space pointer to start of block to check - * @size: Size of block to check - * - * Context: User context only. This function may sleep. - * - * Checks if a pointer to a block of memory in user space is valid. - * - * Returns true (nonzero) if the memory block may be valid, false (zero) - * if it is definitely invalid. - * - * Note that, depending on architecture, this function probably just - * checks that the pointer is in the user space range - after calling - * this function, memory access functions may still return -EFAULT. - */ -#define access_ok(addr, size) ({ \ - __chk_user_ptr(addr); \ - likely(__access_ok((unsigned long __force)(addr), (size))); \ -}) - /* - * Ensure that the range [addr, addr+size) is within the process's - * address space + * This is the smallest unsigned integer type that can fit a value + * (up to 'long long') */ -static inline int __access_ok(unsigned long addr, unsigned long size) -{ - return size <= TASK_SIZE && addr <= TASK_SIZE - size; -} +#define __inttype(x) __typeof__( \ + __typefits(x, char, \ + __typefits(x, short, \ + __typefits(x, int, \ + __typefits(x, long, 0ULL))))) + +#define __typefits(x, type, not) \ + __builtin_choose_expr(sizeof(x) <= sizeof(type), (unsigned type)0, not) /* * The exception table consists of pairs of addresses: the first is the @@ -78,87 +96,123 @@ static inline int __access_ok(unsigned long addr, unsigned long size) * call. */ -#define __get_user_asm(insn, x, ptr, err) \ +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT +#define __get_user_asm(insn, x, ptr, label) \ + asm_goto_output( \ + "1:\n" \ + " " insn " %0, %1\n" \ + _ASM_EXTABLE_UACCESS_ERR(1b, %l2, %0) \ + : "=&r" (x) \ + : "m" (*(ptr)) : : label) +#else /* !CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ +#define __get_user_asm(insn, x, ptr, label) \ do { \ - uintptr_t __tmp; \ - __typeof__(x) __x; \ + long __gua_err = 0; \ __asm__ __volatile__ ( \ "1:\n" \ - " " insn " %1, %3\n" \ + " " insn " %1, %2\n" \ "2:\n" \ - " .section .fixup,\"ax\"\n" \ - " .balign 4\n" \ - "3:\n" \ - " li %0, %4\n" \ - " li %1, 0\n" \ - " jump 2b, %2\n" \ - " .previous\n" \ - " .section __ex_table,\"a\"\n" \ - " .balign " RISCV_SZPTR "\n" \ - " " RISCV_PTR " 1b, 3b\n" \ - " .previous" \ - : "+r" (err), "=&r" (__x), "=r" (__tmp) \ - : "m" (*(ptr)), "i" (-EFAULT)); \ - (x) = __x; \ + _ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %0, %1) \ + : "+r" (__gua_err), "=&r" (x) \ + : "m" (*(ptr))); \ + if (__gua_err) \ + goto label; \ } while (0) +#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ #ifdef CONFIG_64BIT -#define __get_user_8(x, ptr, err) \ - __get_user_asm("ld", x, ptr, err) +#define __get_user_8(x, ptr, label) \ + __get_user_asm("ld", x, ptr, label) #else /* !CONFIG_64BIT */ -#define __get_user_8(x, ptr, err) \ + +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT +#define __get_user_8(x, ptr, label) \ +do { \ + u32 __user *__ptr = (u32 __user *)(ptr); \ + u32 __lo, __hi; \ + asm_goto_output( \ + "1:\n" \ + " lw %0, %2\n" \ + "2:\n" \ + " lw %1, %3\n" \ + _ASM_EXTABLE_UACCESS_ERR(1b, %l4, %0) \ + _ASM_EXTABLE_UACCESS_ERR(2b, %l4, %0) \ + : "=&r" (__lo), "=r" (__hi) \ + : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]) \ + : : label); \ + (x) = (__typeof__(x))((__typeof__((x) - (x)))( \ + (((u64)__hi << 32) | __lo))); \ +} while (0) +#else /* !CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ +#define __get_user_8(x, ptr, label) \ do { \ u32 __user *__ptr = (u32 __user *)(ptr); \ u32 __lo, __hi; \ - uintptr_t __tmp; \ + long __gu8_err = 0; \ __asm__ __volatile__ ( \ "1:\n" \ - " lw %1, %4\n" \ + " lw %1, %3\n" \ "2:\n" \ - " lw %2, %5\n" \ + " lw %2, %4\n" \ "3:\n" \ - " .section .fixup,\"ax\"\n" \ - " .balign 4\n" \ - "4:\n" \ - " li %0, %6\n" \ - " li %1, 0\n" \ - " li %2, 0\n" \ - " jump 3b, %3\n" \ - " .previous\n" \ - " .section __ex_table,\"a\"\n" \ - " .balign " RISCV_SZPTR "\n" \ - " " RISCV_PTR " 1b, 4b\n" \ - " " RISCV_PTR " 2b, 4b\n" \ - " .previous" \ - : "+r" (err), "=&r" (__lo), "=r" (__hi), \ - "=r" (__tmp) \ - : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]), \ - "i" (-EFAULT)); \ - (x) = (__typeof__(x))((__typeof__((x)-(x)))( \ + _ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 3b, %0, %1) \ + _ASM_EXTABLE_UACCESS_ERR_ZERO(2b, 3b, %0, %1) \ + : "+r" (__gu8_err), "=&r" (__lo), "=r" (__hi) \ + : "m" (__ptr[__LSW]), "m" (__ptr[__MSW])); \ + if (__gu8_err) { \ + __hi = 0; \ + goto label; \ + } \ + (x) = (__typeof__(x))((__typeof__((x) - (x)))( \ (((u64)__hi << 32) | __lo))); \ } while (0) +#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ + #endif /* CONFIG_64BIT */ -#define __get_user_nocheck(x, __gu_ptr, __gu_err) \ +unsigned long __must_check __asm_copy_to_user_sum_enabled(void __user *to, + const void *from, unsigned long n); +unsigned long __must_check __asm_copy_from_user_sum_enabled(void *to, + const void __user *from, unsigned long n); + +#define __get_user_nocheck(x, __gu_ptr, label) \ do { \ + if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \ + !IS_ALIGNED((uintptr_t)__gu_ptr, sizeof(*__gu_ptr))) { \ + if (__asm_copy_from_user_sum_enabled(&(x), __gu_ptr, sizeof(*__gu_ptr))) \ + goto label; \ + break; \ + } \ switch (sizeof(*__gu_ptr)) { \ case 1: \ - __get_user_asm("lb", (x), __gu_ptr, __gu_err); \ + __get_user_asm("lb", (x), __gu_ptr, label); \ break; \ case 2: \ - __get_user_asm("lh", (x), __gu_ptr, __gu_err); \ + __get_user_asm("lh", (x), __gu_ptr, label); \ break; \ case 4: \ - __get_user_asm("lw", (x), __gu_ptr, __gu_err); \ + __get_user_asm("lw", (x), __gu_ptr, label); \ break; \ case 8: \ - __get_user_8((x), __gu_ptr, __gu_err); \ + __get_user_8((x), __gu_ptr, label); \ break; \ default: \ BUILD_BUG(); \ } \ } while (0) +#define __get_user_error(x, ptr, err) \ +do { \ + __label__ __gu_failed; \ + \ + __get_user_nocheck(x, ptr, __gu_failed); \ + err = 0; \ + break; \ +__gu_failed: \ + x = (__typeof__(x))0; \ + err = -EFAULT; \ +} while (0) + /** * __get_user: - Get a simple variable from user space, with less checking. * @x: Variable to store result. @@ -181,15 +235,18 @@ do { \ */ #define __get_user(x, ptr) \ ({ \ - const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + const __typeof__(*(ptr)) __user *__gu_ptr = untagged_addr(ptr); \ long __gu_err = 0; \ + __typeof__(x) __gu_val; \ \ __chk_user_ptr(__gu_ptr); \ \ __enable_user_access(); \ - __get_user_nocheck(x, __gu_ptr, __gu_err); \ + __get_user_error(__gu_val, __gu_ptr, __gu_err); \ __disable_user_access(); \ \ + (x) = __gu_val; \ + \ __gu_err; \ }) @@ -216,84 +273,76 @@ do { \ might_fault(); \ access_ok(__p, sizeof(*__p)) ? \ __get_user((x), __p) : \ - ((x) = 0, -EFAULT); \ + ((x) = (__force __typeof__(x))0, -EFAULT); \ }) -#define __put_user_asm(insn, x, ptr, err) \ +#define __put_user_asm(insn, x, ptr, label) \ do { \ - uintptr_t __tmp; \ __typeof__(*(ptr)) __x = x; \ - __asm__ __volatile__ ( \ + asm goto( \ "1:\n" \ - " " insn " %z3, %2\n" \ - "2:\n" \ - " .section .fixup,\"ax\"\n" \ - " .balign 4\n" \ - "3:\n" \ - " li %0, %4\n" \ - " jump 2b, %1\n" \ - " .previous\n" \ - " .section __ex_table,\"a\"\n" \ - " .balign " RISCV_SZPTR "\n" \ - " " RISCV_PTR " 1b, 3b\n" \ - " .previous" \ - : "+r" (err), "=r" (__tmp), "=m" (*(ptr)) \ - : "rJ" (__x), "i" (-EFAULT)); \ + " " insn " %z0, %1\n" \ + _ASM_EXTABLE(1b, %l2) \ + : : "rJ" (__x), "m"(*(ptr)) : : label); \ } while (0) #ifdef CONFIG_64BIT -#define __put_user_8(x, ptr, err) \ - __put_user_asm("sd", x, ptr, err) +#define __put_user_8(x, ptr, label) \ + __put_user_asm("sd", x, ptr, label) #else /* !CONFIG_64BIT */ -#define __put_user_8(x, ptr, err) \ +#define __put_user_8(x, ptr, label) \ do { \ u32 __user *__ptr = (u32 __user *)(ptr); \ u64 __x = (__typeof__((x)-(x)))(x); \ - uintptr_t __tmp; \ - __asm__ __volatile__ ( \ + asm goto( \ "1:\n" \ - " sw %z4, %2\n" \ + " sw %z0, %2\n" \ "2:\n" \ - " sw %z5, %3\n" \ - "3:\n" \ - " .section .fixup,\"ax\"\n" \ - " .balign 4\n" \ - "4:\n" \ - " li %0, %6\n" \ - " jump 3b, %1\n" \ - " .previous\n" \ - " .section __ex_table,\"a\"\n" \ - " .balign " RISCV_SZPTR "\n" \ - " " RISCV_PTR " 1b, 4b\n" \ - " " RISCV_PTR " 2b, 4b\n" \ - " .previous" \ - : "+r" (err), "=r" (__tmp), \ - "=m" (__ptr[__LSW]), \ - "=m" (__ptr[__MSW]) \ - : "rJ" (__x), "rJ" (__x >> 32), "i" (-EFAULT)); \ + " sw %z1, %3\n" \ + _ASM_EXTABLE(1b, %l4) \ + _ASM_EXTABLE(2b, %l4) \ + : : "rJ" (__x), "rJ" (__x >> 32), \ + "m" (__ptr[__LSW]), \ + "m" (__ptr[__MSW]) : : label); \ } while (0) #endif /* CONFIG_64BIT */ -#define __put_user_nocheck(x, __gu_ptr, __pu_err) \ +#define __put_user_nocheck(x, __gu_ptr, label) \ do { \ + if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \ + !IS_ALIGNED((uintptr_t)__gu_ptr, sizeof(*__gu_ptr))) { \ + __typeof__(*(__gu_ptr)) ___val = (x); \ + if (__asm_copy_to_user_sum_enabled(__gu_ptr, &(___val), sizeof(*__gu_ptr))) \ + goto label; \ + break; \ + } \ switch (sizeof(*__gu_ptr)) { \ case 1: \ - __put_user_asm("sb", (x), __gu_ptr, __pu_err); \ + __put_user_asm("sb", (x), __gu_ptr, label); \ break; \ case 2: \ - __put_user_asm("sh", (x), __gu_ptr, __pu_err); \ + __put_user_asm("sh", (x), __gu_ptr, label); \ break; \ case 4: \ - __put_user_asm("sw", (x), __gu_ptr, __pu_err); \ + __put_user_asm("sw", (x), __gu_ptr, label); \ break; \ case 8: \ - __put_user_8((x), __gu_ptr, __pu_err); \ + __put_user_8((x), __gu_ptr, label); \ break; \ default: \ BUILD_BUG(); \ } \ } while (0) +#define __put_user_error(x, ptr, err) \ +do { \ + __label__ err_label; \ + __put_user_nocheck(x, ptr, err_label); \ + break; \ +err_label: \ + (err) = -EFAULT; \ +} while (0) + /** * __put_user: - Write a simple value into user space, with less checking. * @x: Value to copy to user space. @@ -317,14 +366,14 @@ do { \ */ #define __put_user(x, ptr) \ ({ \ - __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + __typeof__(*(ptr)) __user *__gu_ptr = untagged_addr(ptr); \ __typeof__(*__gu_ptr) __val = (x); \ long __pu_err = 0; \ \ __chk_user_ptr(__gu_ptr); \ \ __enable_user_access(); \ - __put_user_nocheck(__val, __gu_ptr, __pu_err); \ + __put_user_error(__val, __gu_ptr, __pu_err); \ __disable_user_access(); \ \ __pu_err; \ @@ -364,13 +413,13 @@ unsigned long __must_check __asm_copy_from_user(void *to, static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { - return __asm_copy_from_user(to, from, n); + return __asm_copy_from_user(to, untagged_addr(from), n); } static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) { - return __asm_copy_to_user(to, from, n); + return __asm_copy_to_user(untagged_addr(to), from, n); } extern long strncpy_from_user(char *dest, const char __user *src, long count); @@ -385,103 +434,48 @@ unsigned long __must_check clear_user(void __user *to, unsigned long n) { might_fault(); return access_ok(to, n) ? - __clear_user(to, n) : n; + __clear_user(untagged_addr(to), n) : n; +} + +#define arch_get_kernel_nofault(dst, src, type, err_label) \ + __get_user_nocheck(*((type *)(dst)), (__force __user type *)(src), err_label) + +#define arch_put_kernel_nofault(dst, src, type, err_label) \ + __put_user_nocheck(*((type *)(src)), (__force __user type *)(dst), err_label) + +static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len) +{ + if (unlikely(!access_ok(ptr, len))) + return 0; + __enable_user_access(); + return 1; } +#define user_access_begin user_access_begin +#define user_access_end __disable_user_access + +static inline unsigned long user_access_save(void) { return 0UL; } +static inline void user_access_restore(unsigned long enabled) { } /* - * Atomic compare-and-exchange, but with a fixup for userspace faults. Faults - * will set "err" to -EFAULT, while successful accesses return the previous - * value. + * We want the unsafe accessors to always be inlined and use + * the error labels - thus the macro games. */ -#define __cmpxchg_user(ptr, old, new, err, size, lrb, scb) \ -({ \ - __typeof__(ptr) __ptr = (ptr); \ - __typeof__(*(ptr)) __old = (old); \ - __typeof__(*(ptr)) __new = (new); \ - __typeof__(*(ptr)) __ret; \ - __typeof__(err) __err = 0; \ - register unsigned int __rc; \ - __enable_user_access(); \ - switch (size) { \ - case 4: \ - __asm__ __volatile__ ( \ - "0:\n" \ - " lr.w" #scb " %[ret], %[ptr]\n" \ - " bne %[ret], %z[old], 1f\n" \ - " sc.w" #lrb " %[rc], %z[new], %[ptr]\n" \ - " bnez %[rc], 0b\n" \ - "1:\n" \ - ".section .fixup,\"ax\"\n" \ - ".balign 4\n" \ - "2:\n" \ - " li %[err], %[efault]\n" \ - " jump 1b, %[rc]\n" \ - ".previous\n" \ - ".section __ex_table,\"a\"\n" \ - ".balign " RISCV_SZPTR "\n" \ - " " RISCV_PTR " 1b, 2b\n" \ - ".previous\n" \ - : [ret] "=&r" (__ret), \ - [rc] "=&r" (__rc), \ - [ptr] "+A" (*__ptr), \ - [err] "=&r" (__err) \ - : [old] "rJ" (__old), \ - [new] "rJ" (__new), \ - [efault] "i" (-EFAULT)); \ - break; \ - case 8: \ - __asm__ __volatile__ ( \ - "0:\n" \ - " lr.d" #scb " %[ret], %[ptr]\n" \ - " bne %[ret], %z[old], 1f\n" \ - " sc.d" #lrb " %[rc], %z[new], %[ptr]\n" \ - " bnez %[rc], 0b\n" \ - "1:\n" \ - ".section .fixup,\"ax\"\n" \ - ".balign 4\n" \ - "2:\n" \ - " li %[err], %[efault]\n" \ - " jump 1b, %[rc]\n" \ - ".previous\n" \ - ".section __ex_table,\"a\"\n" \ - ".balign " RISCV_SZPTR "\n" \ - " " RISCV_PTR " 1b, 2b\n" \ - ".previous\n" \ - : [ret] "=&r" (__ret), \ - [rc] "=&r" (__rc), \ - [ptr] "+A" (*__ptr), \ - [err] "=&r" (__err) \ - : [old] "rJ" (__old), \ - [new] "rJ" (__new), \ - [efault] "i" (-EFAULT)); \ - break; \ - default: \ - BUILD_BUG(); \ - } \ - __disable_user_access(); \ - (err) = __err; \ - __ret; \ -}) +#define arch_unsafe_put_user(x, ptr, label) \ + __put_user_nocheck(x, (ptr), label) -#define HAVE_GET_KERNEL_NOFAULT - -#define __get_kernel_nofault(dst, src, type, err_label) \ -do { \ - long __kr_err; \ - \ - __get_user_nocheck(*((type *)(dst)), (type *)(src), __kr_err); \ - if (unlikely(__kr_err)) \ - goto err_label; \ +#define arch_unsafe_get_user(x, ptr, label) do { \ + __inttype(*(ptr)) __gu_val; \ + __get_user_nocheck(__gu_val, (ptr), label); \ + (x) = (__force __typeof__(*(ptr)))__gu_val; \ } while (0) -#define __put_kernel_nofault(dst, src, type, err_label) \ -do { \ - long __kr_err; \ - \ - __put_user_nocheck(*((type *)(src)), (type *)(dst), __kr_err); \ - if (unlikely(__kr_err)) \ - goto err_label; \ -} while (0) +#define unsafe_copy_to_user(_dst, _src, _len, label) \ + if (__asm_copy_to_user_sum_enabled(_dst, _src, _len)) \ + goto label; + +#define unsafe_copy_from_user(_dst, _src, _len, label) \ + if (__asm_copy_from_user_sum_enabled(_dst, _src, _len)) \ + goto label; #else /* CONFIG_MMU */ #include <asm-generic/uaccess.h> |