The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from
the respective function and calculate the remaining bytes left to copy
using the current register contents. This commit fixes a couple of bad
calculations and a broken epilogue in the exception handlers. This will
prevent crashes and ensure correct return values of copy_from_user and
copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.
Fixes: 7ae3aaf53f16 ("sparc64: Convert NGcopy_{from,to}_user to accurate exception reporting.")
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # on SPARC T4 with modified kernel to use Niagara 1 code
Tested-by: Magnus Lindholm <linmag7@gmail.com> # on Sun Fire T2000
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
---
arch/sparc/lib/NGmemcpy.S | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/arch/sparc/lib/NGmemcpy.S b/arch/sparc/lib/NGmemcpy.S
index ee51c12306894eee4195887d2b28b2619f63c2b1..bbd3ea0a64822c7410278fcc3d101ce9cef96c89 100644
--- a/arch/sparc/lib/NGmemcpy.S
+++ b/arch/sparc/lib/NGmemcpy.S
@@ -79,8 +79,8 @@
#ifndef EX_RETVAL
#define EX_RETVAL(x) x
__restore_asi:
- ret
wr %g0, ASI_AIUS, %asi
+ ret
restore
ENTRY(NG_ret_i2_plus_i4_plus_1)
ba,pt %xcc, __restore_asi
@@ -125,15 +125,16 @@ ENTRY(NG_ret_i2_plus_g1_minus_56)
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_56)
-ENTRY(NG_ret_i2_plus_i4)
+ENTRY(NG_ret_i2_plus_i4_plus_16)
+ add %i4, 16, %i4
ba,pt %xcc, __restore_asi
add %i2, %i4, %i0
-ENDPROC(NG_ret_i2_plus_i4)
-ENTRY(NG_ret_i2_plus_i4_minus_8)
- sub %i4, 8, %i4
+ENDPROC(NG_ret_i2_plus_i4_plus_16)
+ENTRY(NG_ret_i2_plus_i4_plus_8)
+ add %i4, 8, %i4
ba,pt %xcc, __restore_asi
add %i2, %i4, %i0
-ENDPROC(NG_ret_i2_plus_i4_minus_8)
+ENDPROC(NG_ret_i2_plus_i4_plus_8)
ENTRY(NG_ret_i2_plus_8)
ba,pt %xcc, __restore_asi
add %i2, 8, %i0
@@ -160,6 +161,12 @@ ENTRY(NG_ret_i2_and_7_plus_i4)
ba,pt %xcc, __restore_asi
add %i2, %i4, %i0
ENDPROC(NG_ret_i2_and_7_plus_i4)
+ENTRY(NG_ret_i2_and_7_plus_i4_plus_8)
+ and %i2, 7, %i2
+ add %i4, 8, %i4
+ ba,pt %xcc, __restore_asi
+ add %i2, %i4, %i0
+ENDPROC(NG_ret_i2_and_7_plus_i4)
#endif
.align 64
@@ -405,13 +412,13 @@ FUNC_NAME: /* %i0=dst, %i1=src, %i2=len */
andn %i2, 0xf, %i4
and %i2, 0xf, %i2
1: subcc %i4, 0x10, %i4
- EX_LD(LOAD(ldx, %i1, %o4), NG_ret_i2_plus_i4)
+ EX_LD(LOAD(ldx, %i1, %o4), NG_ret_i2_plus_i4_plus_16)
add %i1, 0x08, %i1
- EX_LD(LOAD(ldx, %i1, %g1), NG_ret_i2_plus_i4)
+ EX_LD(LOAD(ldx, %i1, %g1), NG_ret_i2_plus_i4_plus_16)
sub %i1, 0x08, %i1
- EX_ST(STORE(stx, %o4, %i1 + %i3), NG_ret_i2_plus_i4)
+ EX_ST(STORE(stx, %o4, %i1 + %i3), NG_ret_i2_plus_i4_plus_16)
add %i1, 0x8, %i1
- EX_ST(STORE(stx, %g1, %i1 + %i3), NG_ret_i2_plus_i4_minus_8)
+ EX_ST(STORE(stx, %g1, %i1 + %i3), NG_ret_i2_plus_i4_plus_8)
bgu,pt %XCC, 1b
add %i1, 0x8, %i1
73: andcc %i2, 0x8, %g0
@@ -468,7 +475,7 @@ FUNC_NAME: /* %i0=dst, %i1=src, %i2=len */
subcc %i4, 0x8, %i4
srlx %g3, %i3, %i5
or %i5, %g2, %i5
- EX_ST(STORE(stx, %i5, %o0), NG_ret_i2_and_7_plus_i4)
+ EX_ST(STORE(stx, %i5, %o0), NG_ret_i2_and_7_plus_i4_plus_8)
add %o0, 0x8, %o0
bgu,pt %icc, 1b
sllx %g3, %g1, %g2
--
2.50.1