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[PATCH] x86_64: Bug in new out of line put_user()

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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 <alexn@telia.com>
Signed-off-by: ak@suse.de
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Alexander Nyberg 2005-04-21 07:59:51 -07:00 committed by Linus Torvalds
parent 6d9c5d94d3
commit 3a6fd752a5
2 changed files with 20 additions and 11 deletions
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4
arch/x86_64/lib/getuser.S
View File

@ -78,9 +78,9 @@ __get_user_4:
__get_user_8: __get_user_8:
GET_THREAD_INFO(%r8) GET_THREAD_INFO(%r8)
addq $7,%rcx addq $7,%rcx
jc bad_get_user jc 40f
cmpq threadinfo_addr_limit(%r8),%rcx cmpq threadinfo_addr_limit(%r8),%rcx
jae bad_get_user jae 40f
subq $7,%rcx subq $7,%rcx
4: movq (%rcx),%rdx 4: movq (%rcx),%rdx
xorl %eax,%eax xorl %eax,%eax

27
arch/x86_64/lib/putuser.S
View File

@ -46,36 +46,45 @@ __put_user_1:
__put_user_2: __put_user_2:
GET_THREAD_INFO(%r8) GET_THREAD_INFO(%r8)
addq $1,%rcx addq $1,%rcx
jc bad_put_user jc 20f
cmpq threadinfo_addr_limit(%r8),%rcx cmpq threadinfo_addr_limit(%r8),%rcx
jae bad_put_user jae 20f
2: movw %dx,-1(%rcx) 2: decq %rcx
movw %dx,(%rcx)
xorl %eax,%eax xorl %eax,%eax
ret ret
20: decq %rcx
jmp bad_put_user
.p2align 4 .p2align 4
.globl __put_user_4 .globl __put_user_4
__put_user_4: __put_user_4:
GET_THREAD_INFO(%r8) GET_THREAD_INFO(%r8)
addq $3,%rcx addq $3,%rcx
jc bad_put_user jc 30f
cmpq threadinfo_addr_limit(%r8),%rcx cmpq threadinfo_addr_limit(%r8),%rcx
jae bad_put_user jae 30f
3: movl %edx,-3(%rcx) 3: subq $3,%rcx
movl %edx,(%rcx)
xorl %eax,%eax xorl %eax,%eax
ret ret
30: subq $3,%rcx
jmp bad_put_user
.p2align 4 .p2align 4
.globl __put_user_8 .globl __put_user_8
__put_user_8: __put_user_8:
GET_THREAD_INFO(%r8) GET_THREAD_INFO(%r8)
addq $7,%rcx addq $7,%rcx
jc bad_put_user jc 40f
cmpq threadinfo_addr_limit(%r8),%rcx cmpq threadinfo_addr_limit(%r8),%rcx
jae bad_put_user jae 40f
4: movq %rdx,-7(%rcx) 4: subq $7,%rcx
movq %rdx,(%rcx)
xorl %eax,%eax xorl %eax,%eax
ret ret
40: subq $7,%rcx
jmp bad_put_user
bad_put_user: bad_put_user:
movq $(-EFAULT),%rax movq $(-EFAULT),%rax