diff options
Diffstat (limited to 'arch/arm64/include/asm/uaccess.h')
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index fad8c1b2ca3e..4ee8daa24d89 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -76,6 +76,15 @@ static inline unsigned long __range_ok(unsigned long addr, unsigned long size) { unsigned long limit = current_thread_info()->addr_limit; + /* + * Asynchronous I/O running in a kernel thread does not have the + * TIF_TAGGED_ADDR flag of the process owning the mm, so always untag + * the user address before checking. + */ + if (IS_ENABLED(CONFIG_ARM64_TAGGED_ADDR_ABI) && + (current->flags & PF_KTHREAD || test_thread_flag(TIF_TAGGED_ADDR))) + addr = untagged_addr(addr); + __chk_user_ptr(addr); asm volatile( // A + B <= C + 1 for all A,B,C, in four easy steps: @@ -97,13 +106,6 @@ static inline unsigned long __range_ok(unsigned long addr, unsigned long size) return addr; } -/* - * When dealing with data aborts, watchpoints, or instruction traps we may end - * up with a tagged userland pointer. Clear the tag to get a sane pointer to - * pass on to access_ok(), for instance. - */ -#define untagged_addr(addr) sign_extend64(addr, 55) - #define access_ok(type, addr, size) __range_ok((unsigned long)(addr), size) #define user_addr_max get_fs @@ -224,7 +226,8 @@ static inline void uaccess_enable_not_uao(void) /* * Sanitise a uaccess pointer such that it becomes NULL if above the - * current addr_limit. + * current addr_limit. In case the pointer is tagged (has the top byte set), + * untag the pointer before checking. */ #define uaccess_mask_ptr(ptr) (__typeof__(ptr))__uaccess_mask_ptr(ptr) static inline void __user *__uaccess_mask_ptr(const void __user *ptr) @@ -232,10 +235,11 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) void __user *safe_ptr; asm volatile( - " bics xzr, %1, %2\n" + " bics xzr, %3, %2\n" " csel %0, %1, xzr, eq\n" : "=&r" (safe_ptr) - : "r" (ptr), "r" (current_thread_info()->addr_limit) + : "r" (ptr), "r" (current_thread_info()->addr_limit), + "r" (untagged_addr(ptr)) : "cc"); csdb(); |