57 lines
2.2 KiB
Diff
57 lines
2.2 KiB
Diff
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From c65c24ba59c4a0442b81eaceec8bab1e5a0907cf Mon Sep 17 00:00:00 2001
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From: Ilya Leoshkevich <iii@linux.ibm.com>
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Date: Mon, 12 Aug 2024 10:53:08 +0200
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Subject: [PATCH] target/ppc: Set ctx->opcode for decode_insn32()
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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divdu (without a dot) sometimes updates cr0, even though it shouldn't.
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The reason is that gen_op_arith_divd() checks Rc(ctx->opcode), which is
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not initialized. This field is initialized only for instructions that
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go through decode_legacy(), and not decodetree.
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There already was a similar issue fixed in commit 86e6202a57b1
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("target/ppc: Make divw[u] handler method decodetree compatible.").
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It's not immediately clear what else may access the uninitialized
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ctx->opcode, so instead of playing whack-a-mole and changing the check
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to compute_rc0, simply initialize ctx->opcode.
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Cc: qemu-stable@nongnu.org
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Fixes: 99082815f17f ("target/ppc: Add infrastructure for prefixed insns")
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Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
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Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
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Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
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Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
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(cherry picked from commit c9b8a13a8841e0e23901e57e24ea98eeef16cf91)
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Signed-off-by: zhujun2 <zhujun2_yewu@cmss.chinamobile.com>
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---
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target/ppc/translate.c | 3 +--
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1 file changed, 1 insertion(+), 2 deletions(-)
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diff --git a/target/ppc/translate.c b/target/ppc/translate.c
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index 153552ab50..a03bafadbc 100644
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--- a/target/ppc/translate.c
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+++ b/target/ppc/translate.c
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@@ -8380,8 +8380,6 @@ static bool decode_legacy(PowerPCCPU *cpu, DisasContext *ctx, uint32_t insn)
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opc_handler_t **table, *handler;
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uint32_t inval;
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- ctx->opcode = insn;
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-
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LOG_DISAS("translate opcode %08x (%02x %02x %02x %02x) (%s)\n",
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insn, opc1(insn), opc2(insn), opc3(insn), opc4(insn),
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ctx->le_mode ? "little" : "big");
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@@ -8510,6 +8508,7 @@ static void ppc_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
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ctx->base.pc_next = pc += 4;
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if (!is_prefix_insn(ctx, insn)) {
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+ ctx->opcode = insn;
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ok = (decode_insn32(ctx, insn) ||
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decode_legacy(cpu, ctx, insn));
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} else if ((pc & 63) == 0) {
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--
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2.41.0.windows.1
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