From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DDE07C77B7F for ; Sat, 20 May 2023 18:24:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ClSyBa1yetGDzr6C9fGJy/3QB2AS9cu8WK3jR4l3lGE=; b=CjK0x9I15NeaXL w/IzRhh3E4LYT+w4MyMzG0952P839/4sND5BJuzVTVp4Is2yWMXv5xq9h393hkuGvLbvDbNk7ArsI t2Zfze2IOLkjJ+HR/EDwydmVjC+ATZ6jMO5RD41wPcxFL4QWMevEsbo7ChuxjB7vMKJAdmJjBdeyf q8wHAHYdLNYNhGBWiqL4ixxpZXtLe/XVsNvNCqtL/ZZtLCnKM0OoKmYUYYs5jc3IbGTzLgEEvpaWl Y0OGcOdbhIkk6068tyZe52xe/dATi3BlxFl6VMMRnGJY16oANbQsBEVhXDZvzPMZhHWNfrxUpXFLy pcBkvvYsBj9+nDOHIOoA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q0RFG-0022JX-2s; Sat, 20 May 2023 18:23:58 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q0RFE-0022Ir-2L; Sat, 20 May 2023 18:23:58 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1CE0360A73; Sat, 20 May 2023 18:23:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5095DC433D2; Sat, 20 May 2023 18:23:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684607035; bh=PrAnEKQM8ba/kaH3fVF6IzMwaMifVuJ1DuyslPXnVho=; h=From:To:Cc:Subject:Date:From; b=KnEP1p4LUskKk24nn0usqipva9lbzdeQTocs1FWDTDqr/PDy6MRKXCng1WIuf6Fg7 8zlmCxBGA8PUznB5GU3iefnyojMeQR76N3OaUuw2bqJBvpLQao1bj2cdxhXLcYu5yP MANsCGqRTHHwWDCFWoJa/zj7iZGcNhr5dVfhwp+/Cy05mtaVz/sAUSIvc751n1UqBY kfW/NCm8XAMPgLerkfY/NMBzqhETQACAd6fXp58+5ZrVCl4lpEdHyFJQbeBT8vi/5R uwPJ+EY47N+XLzypLp4RmrTKWSe+9s8nGYjvZrt5VezMR+kENiIl/ZDK2U+qxyuAYv b5Lby6EVeNtuA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Haibo Li , Linus Walleij , Alexandre Mergnat , AngeloGioacchino Del Regno , Russell King , Sasha Levin , linux@armlinux.org.uk, matthias.bgg@gmail.com, alexander.sverdlin@nokia.com, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 1/5] ARM: 9295/1: unwind:fix unwind abort for uleb128 case Date: Sat, 20 May 2023 14:23:43 -0400 Message-Id: <20230520182352.856378-1-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230520_112356_840103_65A4E78D X-CRM114-Status: GOOD ( 17.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Haibo Li [ Upstream commit fa3eeb638de0c1a9d2d860e5b48259facdd65176 ] When unwind instruction is 0xb2,the subsequent instructions are uleb128 bytes. For now,it uses only the first uleb128 byte in code. For vsp increments of 0x204~0x400,use one uleb128 byte like below: 0xc06a00e4 : 0x80b27fac Compact model index: 0 0xb2 0x7f vsp = vsp + 1024 0xac pop {r4, r5, r6, r7, r8, r14} For vsp increments larger than 0x400,use two uleb128 bytes like below: 0xc06a00e4 : @0xc0cc9e0c Compact model index: 1 0xb2 0x81 0x01 vsp = vsp + 1032 0xac pop {r4, r5, r6, r7, r8, r14} The unwind works well since the decoded uleb128 byte is also 0x81. For vsp increments larger than 0x600,use two uleb128 bytes like below: 0xc06a00e4 : @0xc0cc9e0c Compact model index: 1 0xb2 0x81 0x02 vsp = vsp + 1544 0xac pop {r4, r5, r6, r7, r8, r14} In this case,the decoded uleb128 result is 0x101(vsp=0x204+(0x101<<2)). While the uleb128 used in code is 0x81(vsp=0x204+(0x81<<2)). The unwind aborts at this frame since it gets incorrect vsp. To fix this,add uleb128 decode to cover all the above case. Signed-off-by: Haibo Li Reviewed-by: Linus Walleij Reviewed-by: Alexandre Mergnat Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin --- arch/arm/kernel/unwind.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index 4574e6aea0a52..f321c2aa94e1c 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -300,6 +300,29 @@ static int unwind_exec_pop_subset_r0_to_r3(struct unwind_ctrl_block *ctrl, return URC_OK; } +static unsigned long unwind_decode_uleb128(struct unwind_ctrl_block *ctrl) +{ + unsigned long bytes = 0; + unsigned long insn; + unsigned long result = 0; + + /* + * unwind_get_byte() will advance `ctrl` one instruction at a time, so + * loop until we get an instruction byte where bit 7 is not set. + * + * Note: This decodes a maximum of 4 bytes to output 28 bits data where + * max is 0xfffffff: that will cover a vsp increment of 1073742336, hence + * it is sufficient for unwinding the stack. + */ + do { + insn = unwind_get_byte(ctrl); + result |= (insn & 0x7f) << (bytes * 7); + bytes++; + } while (!!(insn & 0x80) && (bytes != sizeof(result))); + + return result; +} + /* * Execute the current unwind instruction. */ @@ -353,7 +376,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) if (ret) goto error; } else if (insn == 0xb2) { - unsigned long uleb128 = unwind_get_byte(ctrl); + unsigned long uleb128 = unwind_decode_uleb128(ctrl); ctrl->vrs[SP] += 0x204 + (uleb128 << 2); } else { -- 2.39.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel