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

[ Upstream commit 4fba1713001195e59cfc001ff1f2837dab877efb ]

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. This will fix the return value of copy_from_user and
copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.

Fixes: cb736fdbb2 ("sparc64: Convert U1copy_{from,to}_user to accurate exception reporting.")
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # on QEMU 10.0.3
Tested-by: René Rebe <rene@exactcode.com> # on Ultra 5 UltraSparc IIi
Tested-by: Jonathan 'theJPster' Pallant <kernel@thejpster.org.uk> # on Sun Netra T1
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-1-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Michael Karcher
2025-09-05 00:03:30 +02:00
committed by Greg Kroah-Hartman
parent 77fe706ff0
commit 674ff59814

View File

@@ -164,17 +164,18 @@ ENTRY(U1_gs_40_fp)
retl
add %o0, %o2, %o0
ENDPROC(U1_gs_40_fp)
ENTRY(U1_g3_0_fp)
VISExitHalf
retl
add %g3, %o2, %o0
ENDPROC(U1_g3_0_fp)
ENTRY(U1_g3_8_fp)
VISExitHalf
add %g3, 8, %g3
retl
add %g3, %o2, %o0
ENDPROC(U1_g3_8_fp)
ENTRY(U1_g3_16_fp)
VISExitHalf
add %g3, 16, %g3
retl
add %g3, %o2, %o0
ENDPROC(U1_g3_16_fp)
ENTRY(U1_o2_0_fp)
VISExitHalf
retl
@@ -547,18 +548,18 @@ FUNC_NAME: /* %o0=dst, %o1=src, %o2=len */
62: FINISH_VISCHUNK(o0, f44, f46)
63: UNEVEN_VISCHUNK_LAST(o0, f46, f0)
93: EX_LD_FP(LOAD(ldd, %o1, %f2), U1_g3_0_fp)
93: EX_LD_FP(LOAD(ldd, %o1, %f2), U1_g3_8_fp)
add %o1, 8, %o1
subcc %g3, 8, %g3
faligndata %f0, %f2, %f8
EX_ST_FP(STORE(std, %f8, %o0), U1_g3_8_fp)
EX_ST_FP(STORE(std, %f8, %o0), U1_g3_16_fp)
bl,pn %xcc, 95f
add %o0, 8, %o0
EX_LD_FP(LOAD(ldd, %o1, %f0), U1_g3_0_fp)
EX_LD_FP(LOAD(ldd, %o1, %f0), U1_g3_8_fp)
add %o1, 8, %o1
subcc %g3, 8, %g3
faligndata %f2, %f0, %f8
EX_ST_FP(STORE(std, %f8, %o0), U1_g3_8_fp)
EX_ST_FP(STORE(std, %f8, %o0), U1_g3_16_fp)
bge,pt %xcc, 93b
add %o0, 8, %o0