Gh0st
/
linux
mirror of https://github.com/torvalds/linux.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

sparc: fix accurate exception reporting in copy_{from_to}_user for Niagara 

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: 7ae3aaf53f ("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>
Tested-by: Ethan Hawke <ehawk@ember.systems> # on Sun Fire T2000
Tested-by: Ken Link <iissmart@numberzero.org> # on Sun Fire T1000
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-3-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
This commit is contained in:
Michael Karcher 2025-09-05 00:03:32 +02:00 committed by Andreas Larsson
parent 47b49c06eb
commit 0b67c8fc10
1 changed files with 18 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
arch/sparc/lib/NGmemcpy.S
View File

@ -79,8 +79,8 @@
#ifndef EX_RETVAL #ifndef EX_RETVAL
#define EX_RETVAL(x) x #define EX_RETVAL(x) x
__restore_asi: __restore_asi:
ret
wr %g0, ASI_AIUS, %asi wr %g0, ASI_AIUS, %asi
ret
restore restore
ENTRY(NG_ret_i2_plus_i4_plus_1) ENTRY(NG_ret_i2_plus_i4_plus_1)
ba,pt %xcc, __restore_asi ba,pt %xcc, __restore_asi
@ -125,15 +125,16 @@ ENTRY(NG_ret_i2_plus_g1_minus_56)
ba,pt %xcc, __restore_asi ba,pt %xcc, __restore_asi
add %i2, %g1, %i0 add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_56) 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 ba,pt %xcc, __restore_asi
add %i2, %i4, %i0 add %i2, %i4, %i0
ENDPROC(NG_ret_i2_plus_i4) ENDPROC(NG_ret_i2_plus_i4_plus_16)
ENTRY(NG_ret_i2_plus_i4_minus_8) ENTRY(NG_ret_i2_plus_i4_plus_8)
sub %i4, 8, %i4 add %i4, 8, %i4
ba,pt %xcc, __restore_asi ba,pt %xcc, __restore_asi
add %i2, %i4, %i0 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) ENTRY(NG_ret_i2_plus_8)
ba,pt %xcc, __restore_asi ba,pt %xcc, __restore_asi
add %i2, 8, %i0 add %i2, 8, %i0
@ -160,6 +161,12 @@ ENTRY(NG_ret_i2_and_7_plus_i4)
ba,pt %xcc, __restore_asi ba,pt %xcc, __restore_asi
add %i2, %i4, %i0 add %i2, %i4, %i0
ENDPROC(NG_ret_i2_and_7_plus_i4) 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 #endif
.align 64 .align 64
@ -405,13 +412,13 @@ FUNC_NAME: /* %i0=dst, %i1=src, %i2=len */
andn %i2, 0xf, %i4 andn %i2, 0xf, %i4
and %i2, 0xf, %i2 and %i2, 0xf, %i2
1: subcc %i4, 0x10, %i4 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 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 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 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 bgu,pt %XCC, 1b
add %i1, 0x8, %i1 add %i1, 0x8, %i1
73: andcc %i2, 0x8, %g0 73: andcc %i2, 0x8, %g0
@ -468,7 +475,7 @@ FUNC_NAME: /* %i0=dst, %i1=src, %i2=len */
subcc %i4, 0x8, %i4 subcc %i4, 0x8, %i4
srlx %g3, %i3, %i5 srlx %g3, %i3, %i5
or %i5, %g2, %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 add %o0, 0x8, %o0
bgu,pt %icc, 1b bgu,pt %icc, 1b
sllx %g3, %g1, %g2 sllx %g3, %g1, %g2