diff options
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 2 | ||||
| -rw-r--r-- | arch/x86/lib/usercopy_64.c | 15 |
2 files changed, 8 insertions, 9 deletions
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 12a26b979bf1..f2f9b39b274a 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -231,6 +231,6 @@ __copy_from_user_inatomic_nocache(void *dst, const void __user *src, } unsigned long -copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest); +copy_user_handle_tail(char *to, char *from, unsigned len); #endif /* _ASM_X86_UACCESS_64_H */ diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index c905e89e19fe..1f33b3d1fd68 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -69,21 +69,20 @@ EXPORT_SYMBOL(copy_in_user); * it is not necessary to optimize tail handling. */ __visible unsigned long -copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest) +copy_user_handle_tail(char *to, char *from, unsigned len) { - char c; - unsigned zero_len; - for (; len; --len, to++) { + char c; + if (__get_user_nocheck(c, from++, sizeof(char))) break; if (__put_user_nocheck(c, to, sizeof(char))) break; } - - for (c = 0, zero_len = len; zerorest && zero_len; --zero_len) - if (__put_user_nocheck(c, to++, sizeof(char))) - break; clac(); + + /* If the destination is a kernel buffer, we always clear the end */ + if ((unsigned long)to >= TASK_SIZE_MAX) + memset(to, 0, len); return len; } |