From 3a6fd752a50af92765853879f4a11cc0cfcd0320 Mon Sep 17 00:00:00 2001 From: Alexander Nyberg Date: Thu, 21 Apr 2005 07:59:51 -0700 Subject: [PATCH] [PATCH] x86_64: Bug in new out of line put_user() The new out of line put_user() assembly on x86_64 changes %rcx without telling GCC about it causing things like: http://bugme.osdl.org/show_bug.cgi?id=4515 See to it that %rcx is not changed (made it consistent with get_user()). Signed-off-by: Alexander Nyberg Signed-off-by: ak@suse.de Signed-off-by: Linus Torvalds --- arch/x86_64/lib/getuser.S | 4 ++-- arch/x86_64/lib/putuser.S | 27 ++++++++++++++++++--------- 2 files changed, 20 insertions(+), 11 deletions(-) diff --git a/arch/x86_64/lib/getuser.S b/arch/x86_64/lib/getuser.S index f94ea8a4405..f80bafee866 100644 --- a/arch/x86_64/lib/getuser.S +++ b/arch/x86_64/lib/getuser.S @@ -78,9 +78,9 @@ __get_user_4: __get_user_8: GET_THREAD_INFO(%r8) addq $7,%rcx - jc bad_get_user + jc 40f cmpq threadinfo_addr_limit(%r8),%rcx - jae bad_get_user + jae 40f subq $7,%rcx 4: movq (%rcx),%rdx xorl %eax,%eax diff --git a/arch/x86_64/lib/putuser.S b/arch/x86_64/lib/putuser.S index 0dee1fdcb16..d9d3e5ec9ad 100644 --- a/arch/x86_64/lib/putuser.S +++ b/arch/x86_64/lib/putuser.S @@ -46,36 +46,45 @@ __put_user_1: __put_user_2: GET_THREAD_INFO(%r8) addq $1,%rcx - jc bad_put_user + jc 20f cmpq threadinfo_addr_limit(%r8),%rcx - jae bad_put_user -2: movw %dx,-1(%rcx) + jae 20f +2: decq %rcx + movw %dx,(%rcx) xorl %eax,%eax ret +20: decq %rcx + jmp bad_put_user .p2align 4 .globl __put_user_4 __put_user_4: GET_THREAD_INFO(%r8) addq $3,%rcx - jc bad_put_user + jc 30f cmpq threadinfo_addr_limit(%r8),%rcx - jae bad_put_user -3: movl %edx,-3(%rcx) + jae 30f +3: subq $3,%rcx + movl %edx,(%rcx) xorl %eax,%eax ret +30: subq $3,%rcx + jmp bad_put_user .p2align 4 .globl __put_user_8 __put_user_8: GET_THREAD_INFO(%r8) addq $7,%rcx - jc bad_put_user + jc 40f cmpq threadinfo_addr_limit(%r8),%rcx - jae bad_put_user -4: movq %rdx,-7(%rcx) + jae 40f +4: subq $7,%rcx + movq %rdx,(%rcx) xorl %eax,%eax ret +40: subq $7,%rcx + jmp bad_put_user bad_put_user: movq $(-EFAULT),%rax -- 2.20.1