From 1575fe06f6b1d156ed31fb22c8631d49d79751d8 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Wed, 20 Sep 2017 09:32:19 +1000 Subject: [PATCH] powerpc/sstep: mullw should calculate a 64 bit signed result mullw should do a 32 bit signed multiply and create a 64 bit signed result. It currently truncates the result to 32 bits. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman --- arch/powerpc/lib/sstep.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index c4cda1afb49d..5e8418c28bd8 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -1651,8 +1651,9 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, goto arith_done; case 235: /* mullw */ - op->val = (unsigned int) regs->gpr[ra] * - (unsigned int) regs->gpr[rb]; + op->val = (long)(int) regs->gpr[ra] * + (int) regs->gpr[rb]; + goto arith_done; case 266: /* add */ -- 2.20.1