5.15-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 5a746c1a2c7980de6c888b6373299f751ad7790b ]
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 glaubitz@physik.fu-berlin.de # on Oracle SPARC T4-1 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-v4-4-1ca72dda195b@mkarcher.... Signed-off-by: Andreas Larsson andreas@gaisler.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/sparc/lib/NG4memcpy.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/sparc/lib/NG4memcpy.S b/arch/sparc/lib/NG4memcpy.S index 7ad58ebe0d009..df0ec1bd19489 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