From: Michael Karcher Date: Thu, 4 Sep 2025 22:03:33 +0000 (+0200) Subject: sparc: fix accurate exception reporting in copy_to_user for Niagara 4 X-Git-Tag: v6.18-rc1~89^2~13 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5a746c1a2c7980de6c888b6373299f751ad7790b;p=thirdparty%2Fkernel%2Flinux.git sparc: fix accurate exception reporting in copy_to_user for Niagara 4 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 bad calculation. This will fix the return value of copy_to_user in a specific faulting case. The behaviour of memcpy stays unchanged. Fixes: 957077048009 ("sparc64: Convert NG4copy_{from,to}_user to accurate exception reporting.") Tested-by: John Paul Adrian Glaubitz # on Oracle SPARC T4-1 Signed-off-by: Michael Karcher Reviewed-by: Andreas Larsson Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-4-1ca72dda195b@mkarcher.dialup.fu-berlin.de Signed-off-by: Andreas Larsson --- diff --git a/arch/sparc/lib/NG4memcpy.S b/arch/sparc/lib/NG4memcpy.S index 7ad58ebe0d00..df0ec1bd1948 100644 --- a/arch/sparc/lib/NG4memcpy.S +++ b/arch/sparc/lib/NG4memcpy.S @@ -281,7 +281,7 @@ FUNC_NAME: /* %o0=dst, %o1=src, %o2=len */ subcc %o5, 0x20, %o5 EX_ST(STORE(stx, %g1, %o0 + 0x00), memcpy_retl_o2_plus_o5_plus_32) EX_ST(STORE(stx, %g2, %o0 + 0x08), memcpy_retl_o2_plus_o5_plus_24) - EX_ST(STORE(stx, GLOBAL_SPARE, %o0 + 0x10), memcpy_retl_o2_plus_o5_plus_24) + EX_ST(STORE(stx, GLOBAL_SPARE, %o0 + 0x10), memcpy_retl_o2_plus_o5_plus_16) EX_ST(STORE(stx, %o4, %o0 + 0x18), memcpy_retl_o2_plus_o5_plus_8) bne,pt %icc, 1b add %o0, 0x20, %o0