From patchwork Mon Oct 14 16:36:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 13835315 Received: from mail-pf1-f175.google.com (mail-pf1-f175.google.com [209.85.210.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B2D2A175B1 for ; Mon, 14 Oct 2024 16:37:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728923856; cv=none; b=XHdeVBMbpolrKhyGvJONb8280qTds2Sa96AZcYzE9evSkdNjF1nLucR6sY7ehhsbGM/Saft6zP8gbvs2sioZMQL0e78LFwt34nxqLymAEb/PZYbpHMbR33mXPcnRVZQ1lXp6tBAQOlmyWnTHKdjVkZqnANIeWLibnUYR09kH3B4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728923856; c=relaxed/simple; bh=bTtG4MB3yjrdSPMsQ2e3jywBt+U40h9Vr1j3XOPrBNE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=UXQmhIU+2gFwESxgOkgXbS1hrL37peKEUAFvazjFzdX8HsIgS8qZx3FOMDb/M2c5kOkVilQXO+bikMX+Wohjb96RGfcDr3TjICKQC7YxJgWRGp9HdaTsrPaRwKfZZ/SfDrwLIqJiN54hz8tZ15Rmd97vR7BNqZZySKMO/+zcW/M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=cVhrqnpb; arc=none smtp.client-ip=209.85.210.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="cVhrqnpb" Received: by mail-pf1-f175.google.com with SMTP id d2e1a72fcca58-71e6f1a5a19so470792b3a.3 for ; Mon, 14 Oct 2024 09:37:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1728923854; x=1729528654; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Eq6RmtQgXylpaIuQSD/eFivfyV/YbUHAedXEkzzSSXc=; b=cVhrqnpbKclAuARyWtF73cvf6JxI6cb5Oal04gv5+1y3HofmxXUZ66xOdXJFwoaaL2 LurlygUEHq922C31Mw36x8UxXZShejvxwOFvD8F3MxMcrQTRhyaAcZYPHaZKsbtZ3DSc W/hsR8r/ElkhXQvAYnLSEE/MuPpaGpjarGESc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1728923854; x=1729528654; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Eq6RmtQgXylpaIuQSD/eFivfyV/YbUHAedXEkzzSSXc=; b=bJG0if06zL4PF0Vq158yMQq6KbnNvbDEeq0zip5dhUjN2Y3bsCjd6PiUaUwCvdNBmO qf4lLRvoGqssRo1GM5CaUTFZuHBtQzLXBkWx2K8kooe8EI7ufX64o6CoSaSEnHzTs7GN 9xDm6PTMQqZ4EHSzXty55qz0wykkbm/BNxCePTiYHnJp4LO7mCmAxSIKDQpxujhwYEyQ NvViWhFggbSOIjAkzGIrlDzJ3Qi+2369eriE4gc+mpKwQtTQk41+ndfBHyGbFjAt/67x Ra/rTOrH9Pb8L+DGbgJj39cZmuk/YOaoF1UHsPkKRMhtKNfAmbNZEc2/m5ZqKTTvGxEG BdYA== X-Forwarded-Encrypted: i=1; AJvYcCVoCvWOuKpYmiqICxiy3/dsV1k8itvq1M7/n2yPz55ixMfnkU7/mY7Ruwkriwn3cByK0TMUYs8w0mqklsRt@vger.kernel.org X-Gm-Message-State: AOJu0YzbozjJFRutddM7FoGNZ03pr4LQ+u/JHukT2rTsB+/vtQwOXgr6 K8rtyaHjNGc31NeDaXU7Y+psJpXKPeYiGBLxCpRGxHVhTCyWH1J1gtvV3LsH2A== X-Google-Smtp-Source: AGHT+IFrI6AyFlAD+rPt6sq8RJjzjcPvxnHIHU5bh4fmZllt0MuEFWzqp3sZJTWGMBx/myacl4Lxew== X-Received: by 2002:a05:6a00:9282:b0:717:9154:b5d6 with SMTP id d2e1a72fcca58-71e37f4ed89mr19746704b3a.22.1728923853741; Mon, 14 Oct 2024 09:37:33 -0700 (PDT) Received: from dianders.sjc.corp.google.com ([2620:15c:9d:2:1e71:8a09:a3b:1e00]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-71e51dc0617sm4383693b3a.165.2024.10.14.09.37.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Oct 2024 09:37:32 -0700 (PDT) From: Douglas Anderson To: Rob Clark , Abhinav Kumar , Dmitry Baryshkov Cc: Stephen Boyd , Douglas Anderson , David Airlie , Marijn Suijten , Sean Paul , Simona Vetter , dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/3] drm/msm: Avoid NULL dereference in msm_disp_state_print_regs() Date: Mon, 14 Oct 2024 09:36:08 -0700 Message-ID: <20241014093605.1.Ia1217cecec9ef09eb3c6d125360cc6c8574b0e73@changeid> X-Mailer: git-send-email 2.47.0.rc1.288.g06298d1525-goog Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 If the allocation in msm_disp_state_dump_regs() failed then `block->state` can be NULL. The msm_disp_state_print_regs() function _does_ have code to try to handle it with: if (*reg) dump_addr = *reg; ...but since "dump_addr" is initialized to NULL the above is actually a noop. The code then goes on to dereference `dump_addr`. Make the function print "Registers not stored" when it sees a NULL to solve this. Since we're touching the code, fix msm_disp_state_print_regs() not to pointlessly take a double-pointer and properly mark the pointer as `const`. Fixes: 98659487b845 ("drm/msm: add support to take dpu snapshot") Signed-off-by: Douglas Anderson Reviewed-by: Abhinav Kumar --- drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c index add72bbc28b1..bb149281d31f 100644 --- a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c +++ b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c @@ -48,20 +48,21 @@ static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *b } } -static void msm_disp_state_print_regs(u32 **reg, u32 len, void __iomem *base_addr, - struct drm_printer *p) +static void msm_disp_state_print_regs(const u32 *dump_addr, u32 len, + void __iomem *base_addr, struct drm_printer *p) { int i; - u32 *dump_addr = NULL; void __iomem *addr; u32 num_rows; + if (!dump_addr) { + drm_printf(p, "Registers not stored\n"); + return; + } + addr = base_addr; num_rows = len / REG_DUMP_ALIGN; - if (*reg) - dump_addr = *reg; - for (i = 0; i < num_rows; i++) { drm_printf(p, "0x%lx : %08x %08x %08x %08x\n", (unsigned long)(addr - base_addr), @@ -89,7 +90,7 @@ void msm_disp_state_print(struct msm_disp_state *state, struct drm_printer *p) list_for_each_entry_safe(block, tmp, &state->blocks, node) { drm_printf(p, "====================%s================\n", block->name); - msm_disp_state_print_regs(&block->state, block->size, block->base_addr, p); + msm_disp_state_print_regs(block->state, block->size, block->base_addr, p); } drm_printf(p, "===================dpu drm state================\n");