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authorDavid S. Miller <davem@davemloft.net>2009-02-08 22:32:31 -0800
committerDavid S. Miller <davem@davemloft.net>2009-02-08 22:32:31 -0800
commitaeb398768345c74a9e4c01aa3ebf839e858312ec (patch)
treec7755f40260ccf89e8f3b765a9b44dcbebcae896 /arch/sparc/lib
parent40bdac7dbc161639a498697f34fbd1ee800e51f4 (diff)
sparc64: Fix probe_kernel_{read,write}().
This is based upon a report from Chris Torek and his initial patch. From Chris's report: -------------------- This came up in testing kgdb, using the built-in tests -- turn on CONFIG_KGDB_TESTS, then echo V1 > /sys/module/kgdbts/parameters/kgdbts -- but it would affect using kgdb if you were debugging and looking at bad pointers. -------------------- When we get a copy_{from,to}_user() request and the %asi is set to something other than ASI_AIUS (which is userspace) then we branch off to a routine called memcpy_user_stub(). It just does a straight memcpy since we are copying from kernel to kernel in this case. The logic was that since source and destination are both kernel pointers we don't need to have exception checks. But for what probe_kernel_{read,write}() is trying to do, we have to have the checks, otherwise things like kgdb bad kernel pointer accesses don't do the right thing. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/lib')
-rw-r--r--arch/sparc/lib/GENcopy_from_user.S2
-rw-r--r--arch/sparc/lib/GENcopy_to_user.S2
-rw-r--r--arch/sparc/lib/NG2copy_from_user.S2
-rw-r--r--arch/sparc/lib/NG2copy_to_user.S2
-rw-r--r--arch/sparc/lib/NGcopy_from_user.S2
-rw-r--r--arch/sparc/lib/NGcopy_to_user.S2
-rw-r--r--arch/sparc/lib/U1copy_from_user.S2
-rw-r--r--arch/sparc/lib/U1copy_to_user.S2
-rw-r--r--arch/sparc/lib/U3copy_to_user.S2
-rw-r--r--arch/sparc/lib/copy_in_user.S55
10 files changed, 25 insertions, 48 deletions
diff --git a/arch/sparc/lib/GENcopy_from_user.S b/arch/sparc/lib/GENcopy_from_user.S
index 9b0e58f9f970..b7d0bd6b1406 100644
--- a/arch/sparc/lib/GENcopy_from_user.S
+++ b/arch/sparc/lib/GENcopy_from_user.S
@@ -23,7 +23,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop
#endif
diff --git a/arch/sparc/lib/GENcopy_to_user.S b/arch/sparc/lib/GENcopy_to_user.S
index ce79b495c65d..780550e1afc7 100644
--- a/arch/sparc/lib/GENcopy_to_user.S
+++ b/arch/sparc/lib/GENcopy_to_user.S
@@ -27,7 +27,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop
#endif
diff --git a/arch/sparc/lib/NG2copy_from_user.S b/arch/sparc/lib/NG2copy_from_user.S
index 01ac546a86f4..119ccb9a54f4 100644
--- a/arch/sparc/lib/NG2copy_from_user.S
+++ b/arch/sparc/lib/NG2copy_from_user.S
@@ -28,7 +28,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop
#endif
diff --git a/arch/sparc/lib/NG2copy_to_user.S b/arch/sparc/lib/NG2copy_to_user.S
index c477e1594a72..7fe1ccefd9d0 100644
--- a/arch/sparc/lib/NG2copy_to_user.S
+++ b/arch/sparc/lib/NG2copy_to_user.S
@@ -37,7 +37,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop
#endif
diff --git a/arch/sparc/lib/NGcopy_from_user.S b/arch/sparc/lib/NGcopy_from_user.S
index 39bb8912c6e7..5d1e4d1ac21e 100644
--- a/arch/sparc/lib/NGcopy_from_user.S
+++ b/arch/sparc/lib/NGcopy_from_user.S
@@ -25,7 +25,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop
#endif
diff --git a/arch/sparc/lib/NGcopy_to_user.S b/arch/sparc/lib/NGcopy_to_user.S
index bf62fc1a26c7..ff630dcb273c 100644
--- a/arch/sparc/lib/NGcopy_to_user.S
+++ b/arch/sparc/lib/NGcopy_to_user.S
@@ -28,7 +28,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop
#endif
diff --git a/arch/sparc/lib/U1copy_from_user.S b/arch/sparc/lib/U1copy_from_user.S
index f14efdd6d4a9..a6ae2ea04bf5 100644
--- a/arch/sparc/lib/U1copy_from_user.S
+++ b/arch/sparc/lib/U1copy_from_user.S
@@ -23,7 +23,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop; \
#include "U1memcpy.S"
diff --git a/arch/sparc/lib/U1copy_to_user.S b/arch/sparc/lib/U1copy_to_user.S
index 59d531b4a1a5..f4b970eeb485 100644
--- a/arch/sparc/lib/U1copy_to_user.S
+++ b/arch/sparc/lib/U1copy_to_user.S
@@ -23,7 +23,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop; \
#include "U1memcpy.S"
diff --git a/arch/sparc/lib/U3copy_to_user.S b/arch/sparc/lib/U3copy_to_user.S
index b4cbfe5a97ba..ef1e493afdfa 100644
--- a/arch/sparc/lib/U3copy_to_user.S
+++ b/arch/sparc/lib/U3copy_to_user.S
@@ -23,7 +23,7 @@
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
- bne,pn %icc, memcpy_user_stub; \
+ bne,pn %icc, ___copy_in_user; \
nop; \
#include "U3memcpy.S"
diff --git a/arch/sparc/lib/copy_in_user.S b/arch/sparc/lib/copy_in_user.S
index 884f46499d4e..302c0e60dc2c 100644
--- a/arch/sparc/lib/copy_in_user.S
+++ b/arch/sparc/lib/copy_in_user.S
@@ -3,6 +3,7 @@
* Copyright (C) 1999, 2000, 2004 David S. Miller (davem@redhat.com)
*/
+#include <linux/linkage.h>
#include <asm/asi.h>
#define XCC xcc
@@ -27,18 +28,7 @@
* to copy register windows around during thread cloning.
*/
- .globl ___copy_in_user
- .type ___copy_in_user,#function
-___copy_in_user: /* %o0=dst, %o1=src, %o2=len */
- /* Writing to %asi is _expensive_ so we hardcode it.
- * Reading %asi to check for KERNEL_DS is comparatively
- * cheap.
- */
- rd %asi, %g1
- cmp %g1, ASI_AIUS
- bne,pn %icc, memcpy_user_stub
- nop
-
+ENTRY(___copy_in_user) /* %o0=dst, %o1=src, %o2=len */
cmp %o2, 0
be,pn %XCC, 85f
or %o0, %o1, %o3
@@ -49,22 +39,24 @@ ___copy_in_user: /* %o0=dst, %o1=src, %o2=len */
/* 16 < len <= 64 */
andcc %o3, 0x7, %g0
bne,pn %XCC, 90f
- sub %o0, %o1, %o3
+ nop
andn %o2, 0x7, %o4
and %o2, 0x7, %o2
1: subcc %o4, 0x8, %o4
EX(ldxa [%o1] %asi, %o5)
- EX(stxa %o5, [%o1 + %o3] ASI_AIUS)
+ EX(stxa %o5, [%o0] %asi)
+ add %o1, 0x8, %o1
bgu,pt %XCC, 1b
- add %o1, 0x8, %o1
+ add %o0, 0x8, %o0
andcc %o2, 0x4, %g0
be,pt %XCC, 1f
nop
sub %o2, 0x4, %o2
EX(lduwa [%o1] %asi, %o5)
- EX(stwa %o5, [%o1 + %o3] ASI_AIUS)
+ EX(stwa %o5, [%o0] %asi)
add %o1, 0x4, %o1
+ add %o0, 0x4, %o0
1: cmp %o2, 0
be,pt %XCC, 85f
nop
@@ -74,14 +66,15 @@ ___copy_in_user: /* %o0=dst, %o1=src, %o2=len */
80: /* 0 < len <= 16 */
andcc %o3, 0x3, %g0
bne,pn %XCC, 90f
- sub %o0, %o1, %o3
+ nop
82:
subcc %o2, 4, %o2
EX(lduwa [%o1] %asi, %g1)
- EX(stwa %g1, [%o1 + %o3] ASI_AIUS)
+ EX(stwa %g1, [%o0] %asi)
+ add %o1, 4, %o1
bgu,pt %XCC, 82b
- add %o1, 4, %o1
+ add %o0, 4, %o0
85: retl
clr %o0
@@ -90,26 +83,10 @@ ___copy_in_user: /* %o0=dst, %o1=src, %o2=len */
90:
subcc %o2, 1, %o2
EX(lduba [%o1] %asi, %g1)
- EX(stba %g1, [%o1 + %o3] ASI_AIUS)
+ EX(stba %g1, [%o0] %asi)
+ add %o1, 1, %o1
bgu,pt %XCC, 90b
- add %o1, 1, %o1
+ add %o0, 1, %o0
retl
clr %o0
-
- .size ___copy_in_user, .-___copy_in_user
-
- /* Act like copy_{to,in}_user(), ie. return zero instead
- * of original destination pointer. This is invoked when
- * copy_{to,in}_user() finds that %asi is kernel space.
- */
- .globl memcpy_user_stub
- .type memcpy_user_stub,#function
-memcpy_user_stub:
- save %sp, -192, %sp
- mov %i0, %o0
- mov %i1, %o1
- call memcpy
- mov %i2, %o2
- ret
- restore %g0, %g0, %o0
- .size memcpy_user_stub, .-memcpy_user_stub
+ENDPROC(___copy_in_user)