5.4-stable review patch. If anyone has any objections, please let me know.
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From: Michael Karcher kernel@mkarcher.dialup.fu-berlin.de
[ 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: cb736fdbb208 ("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.... Signed-off-by: Andreas Larsson andreas@gaisler.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/sparc/lib/U1memcpy.S | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/arch/sparc/lib/U1memcpy.S b/arch/sparc/lib/U1memcpy.S index a6f4ee3918977..021b94a383d13 100644 --- a/arch/sparc/lib/U1memcpy.S +++ b/arch/sparc/lib/U1memcpy.S @@ -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