[PATCH] powerpc/sstep: mullw should calculate a 64 bit signed result
From: Anton Blanchard <hidden>
Date: 2017-09-19 23:32:22
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
From: Anton Blanchard <redacted> 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 <redacted> --- 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 */
--
2.11.0