diff options
Diffstat (limited to 'include/linux/uaccess.h')
| -rw-r--r-- | include/linux/uaccess.h | 197 |
1 files changed, 113 insertions, 84 deletions
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 67f016010aad..afb18f198843 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -2,11 +2,11 @@ #ifndef __LINUX_UACCESS_H__ #define __LINUX_UACCESS_H__ +#include <linux/fault-inject-usercopy.h> +#include <linux/instrumented.h> +#include <linux/minmax.h> #include <linux/sched.h> #include <linux/thread_info.h> -#include <linux/kasan-checks.h> - -#define uaccess_kernel() segment_eq(get_fs(), KERNEL_DS) #include <asm/uaccess.h> @@ -58,18 +58,28 @@ static __always_inline __must_check unsigned long __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) { - kasan_check_write(to, n); + unsigned long res; + + instrument_copy_from_user_before(to, from, n); check_object_size(to, n, false); - return raw_copy_from_user(to, from, n); + res = raw_copy_from_user(to, from, n); + instrument_copy_from_user_after(to, from, n, res); + return res; } static __always_inline __must_check unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) { + unsigned long res; + might_fault(); - kasan_check_write(to, n); + instrument_copy_from_user_before(to, from, n); + if (should_fail_usercopy()) + return n; check_object_size(to, n, false); - return raw_copy_from_user(to, from, n); + res = raw_copy_from_user(to, from, n); + instrument_copy_from_user_after(to, from, n, res); + return res; } /** @@ -88,7 +98,9 @@ __copy_from_user(void *to, const void __user *from, unsigned long n) static __always_inline __must_check unsigned long __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) { - kasan_check_read(from, n); + if (should_fail_usercopy()) + return n; + instrument_copy_to_user(to, from, n); check_object_size(from, n, true); return raw_copy_to_user(to, from, n); } @@ -97,7 +109,9 @@ static __always_inline __must_check unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n) { might_fault(); - kasan_check_read(from, n); + if (should_fail_usercopy()) + return n; + instrument_copy_to_user(to, from, n); check_object_size(from, n, true); return raw_copy_to_user(to, from, n); } @@ -108,9 +122,10 @@ _copy_from_user(void *to, const void __user *from, unsigned long n) { unsigned long res = n; might_fault(); - if (likely(access_ok(from, n))) { - kasan_check_write(to, n); + if (!should_fail_usercopy() && likely(access_ok(from, n))) { + instrument_copy_from_user_before(to, from, n); res = raw_copy_from_user(to, from, n); + instrument_copy_from_user_after(to, from, n, res); } if (unlikely(res)) memset(to + (n - res), 0, res); @@ -126,8 +141,10 @@ static inline __must_check unsigned long _copy_to_user(void __user *to, const void *from, unsigned long n) { might_fault(); + if (should_fail_usercopy()) + return n; if (access_ok(to, n)) { - kasan_check_read(from, n); + instrument_copy_to_user(to, from, n); n = raw_copy_to_user(to, from, n); } return n; @@ -140,7 +157,7 @@ _copy_to_user(void __user *, const void *, unsigned long); static __always_inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) { - if (likely(check_copy_size(to, n, false))) + if (check_copy_size(to, n, false)) n = _copy_from_user(to, from, n); return n; } @@ -148,18 +165,21 @@ copy_from_user(void *to, const void __user *from, unsigned long n) static __always_inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) { - if (likely(check_copy_size(from, n, true))) + if (check_copy_size(from, n, true)) n = _copy_to_user(to, from, n); return n; } -#ifdef CONFIG_COMPAT -static __always_inline unsigned long __must_check -copy_in_user(void __user *to, const void __user *from, unsigned long n) + +#ifndef copy_mc_to_kernel +/* + * Without arch opt-in this generic copy_mc_to_kernel() will not handle + * #MC (or arch equivalent) during source read. + */ +static inline unsigned long __must_check +copy_mc_to_kernel(void *dst, const void *src, size_t cnt) { - might_fault(); - if (access_ok(to, n) && access_ok(from, n)) - n = raw_copy_in_user(to, from, n); - return n; + memcpy(dst, src, cnt); + return 0; } #endif @@ -220,6 +240,28 @@ static inline bool pagefault_disabled(void) */ #define faulthandler_disabled() (pagefault_disabled() || in_atomic()) +#ifndef CONFIG_ARCH_HAS_SUBPAGE_FAULTS + +/** + * probe_subpage_writeable: probe the user range for write faults at sub-page + * granularity (e.g. arm64 MTE) + * @uaddr: start of address range + * @size: size of address range + * + * Returns 0 on success, the number of bytes not probed on fault. + * + * It is expected that the caller checked for the write permission of each + * page in the range either by put_user() or GUP. The architecture port can + * implement a more efficient get_user() probing if the same sub-page faults + * are triggered by either a read or a write. + */ +static inline size_t probe_subpage_writeable(char __user *uaddr, size_t size) +{ + return 0; +} + +#endif /* CONFIG_ARCH_HAS_SUBPAGE_FAULTS */ + #ifndef ARCH_HAS_NOCACHE_UACCESS static inline __must_check unsigned long @@ -301,72 +343,52 @@ copy_struct_from_user(void *dst, size_t ksize, const void __user *src, return 0; } -/* - * probe_kernel_read(): safely attempt to read from a location - * @dst: pointer to the buffer that shall take the data - * @src: address to read from - * @size: size of the data chunk - * - * Safely read from address @src to the buffer at @dst. If a kernel fault - * happens, handle that and return -EFAULT. - */ -extern long probe_kernel_read(void *dst, const void *src, size_t size); -extern long probe_kernel_read_strict(void *dst, const void *src, size_t size); -extern long __probe_kernel_read(void *dst, const void *src, size_t size); - -/* - * probe_user_read(): safely attempt to read from a location in user space - * @dst: pointer to the buffer that shall take the data - * @src: address to read from - * @size: size of the data chunk - * - * Safely read from address @src to the buffer at @dst. If a kernel fault - * happens, handle that and return -EFAULT. - */ -extern long probe_user_read(void *dst, const void __user *src, size_t size); -extern long __probe_user_read(void *dst, const void __user *src, size_t size); - -/* - * probe_kernel_write(): safely attempt to write to a location - * @dst: address to write to - * @src: pointer to the data that shall be written - * @size: size of the data chunk - * - * Safely write to address @dst from the buffer at @src. If a kernel fault - * happens, handle that and return -EFAULT. - */ -extern long notrace probe_kernel_write(void *dst, const void *src, size_t size); -extern long notrace __probe_kernel_write(void *dst, const void *src, size_t size); - -/* - * probe_user_write(): safely attempt to write to a location in user space - * @dst: address to write to - * @src: pointer to the data that shall be written - * @size: size of the data chunk - * - * Safely write to address @dst from the buffer at @src. If a kernel fault - * happens, handle that and return -EFAULT. - */ -extern long notrace probe_user_write(void __user *dst, const void *src, size_t size); -extern long notrace __probe_user_write(void __user *dst, const void *src, size_t size); - -extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count); -extern long strncpy_from_unsafe_strict(char *dst, const void *unsafe_addr, - long count); -extern long __strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count); -extern long strncpy_from_unsafe_user(char *dst, const void __user *unsafe_addr, - long count); -extern long strnlen_unsafe_user(const void __user *unsafe_addr, long count); +bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size); + +long copy_from_kernel_nofault(void *dst, const void *src, size_t size); +long notrace copy_to_kernel_nofault(void *dst, const void *src, size_t size); + +long copy_from_user_nofault(void *dst, const void __user *src, size_t size); +long notrace copy_to_user_nofault(void __user *dst, const void *src, + size_t size); + +long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, + long count); + +long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr, + long count); +long strnlen_user_nofault(const void __user *unsafe_addr, long count); + +#ifndef __get_kernel_nofault +#define __get_kernel_nofault(dst, src, type, label) \ +do { \ + type __user *p = (type __force __user *)(src); \ + type data; \ + if (__get_user(data, p)) \ + goto label; \ + *(type *)dst = data; \ +} while (0) + +#define __put_kernel_nofault(dst, src, type, label) \ +do { \ + type __user *p = (type __force __user *)(dst); \ + type data = *(type *)src; \ + if (__put_user(data, p)) \ + goto label; \ +} while (0) +#endif /** - * probe_kernel_address(): safely attempt to read from a location - * @addr: address to read from - * @retval: read into this variable + * get_kernel_nofault(): safely attempt to read from a location + * @val: read into this variable + * @ptr: address to read from * * Returns 0 on success, or -EFAULT. */ -#define probe_kernel_address(addr, retval) \ - probe_kernel_read(&retval, addr, sizeof(retval)) +#define get_kernel_nofault(val, ptr) ({ \ + const typeof(val) *__gk_ptr = (ptr); \ + copy_from_kernel_nofault(&(val), __gk_ptr, sizeof(val));\ +}) #ifndef user_access_begin #define user_access_begin(ptr,len) access_ok(ptr, len) @@ -375,13 +397,20 @@ extern long strnlen_unsafe_user(const void __user *unsafe_addr, long count); #define unsafe_get_user(x,p,e) unsafe_op_wrap(__get_user(x,p),e) #define unsafe_put_user(x,p,e) unsafe_op_wrap(__put_user(x,p),e) #define unsafe_copy_to_user(d,s,l,e) unsafe_op_wrap(__copy_to_user(d,s,l),e) +#define unsafe_copy_from_user(d,s,l,e) unsafe_op_wrap(__copy_from_user(d,s,l),e) static inline unsigned long user_access_save(void) { return 0UL; } static inline void user_access_restore(unsigned long flags) { } #endif +#ifndef user_write_access_begin +#define user_write_access_begin user_access_begin +#define user_write_access_end user_access_end +#endif +#ifndef user_read_access_begin +#define user_read_access_begin user_access_begin +#define user_read_access_end user_access_end +#endif #ifdef CONFIG_HARDENED_USERCOPY -void usercopy_warn(const char *name, const char *detail, bool to_user, - unsigned long offset, unsigned long len); void __noreturn usercopy_abort(const char *name, const char *detail, bool to_user, unsigned long offset, unsigned long len); |