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Subjectx86_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>

Index: test/arch/x86_64/lib/getuser.S
===================================================================
--- test.orig/arch/x86_64/lib/getuser.S 2005-04-20 23:55:35.000000000 +0200
+++ test/arch/x86_64/lib/getuser.S 2005-04-21 00:54:16.000000000 +0200
@@ -78,9 +78,9 @@
__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
Index: test/arch/x86_64/lib/putuser.S
===================================================================
--- test.orig/arch/x86_64/lib/putuser.S 2005-04-21 00:50:24.000000000 +0200
+++ test/arch/x86_64/lib/putuser.S 2005-04-21 01:02:15.000000000 +0200
@@ -46,36 +46,45 @@
__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

-
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