linux-kernel - [PATCH 5.10 074/306] dma-debug: fix debugfs initialization order

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210916155756.581873333@linuxfoundation.org>
Date:   Thu, 16 Sep 2021 17:56:59 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Anthony Iliopoulos <ailiop@...e.com>,
        Christoph Hellwig <hch@....de>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.10 074/306] dma-debug: fix debugfs initialization order

From: Anthony Iliopoulos <ailiop@...e.com>

[ Upstream commit 173735c346c412d9f084825ecb04f24ada0e2986 ]

Due to link order, dma_debug_init is called before debugfs has a chance
to initialize (via debugfs_init which also happens in the core initcall
stage), so the directories for dma-debug are never created.

Decouple dma_debug_fs_init from dma_debug_init and defer its init until
core_initcall_sync (after debugfs has been initialized) while letting
dma-debug initialization occur as soon as possible to catch any early
mappings, as suggested in [1].

[1] https://lore.kernel.org/linux-iommu/YIgGa6yF%2Fadg8OSN@kroah.com/

Fixes: 15b28bbcd567 ("dma-debug: move initialization to common code")
Signed-off-by: Anthony Iliopoulos <ailiop@...e.com>
Signed-off-by: Christoph Hellwig <hch@....de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 kernel/dma/debug.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 14de1271463f..445754529917 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -794,7 +794,7 @@ static int dump_show(struct seq_file *seq, void *v)
 }
 DEFINE_SHOW_ATTRIBUTE(dump);
 
-static void dma_debug_fs_init(void)
+static int __init dma_debug_fs_init(void)
 {
 	struct dentry *dentry = debugfs_create_dir("dma-api", NULL);
 
@@ -807,7 +807,10 @@ static void dma_debug_fs_init(void)
 	debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries);
 	debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops);
 	debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops);
+
+	return 0;
 }
+core_initcall_sync(dma_debug_fs_init);
 
 static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
 {
@@ -892,8 +895,6 @@ static int dma_debug_init(void)
 		spin_lock_init(&dma_entry_hash[i].lock);
 	}
 
-	dma_debug_fs_init();
-
 	nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES);
 	for (i = 0; i < nr_pages; ++i)
 		dma_debug_create_entries(GFP_KERNEL);
-- 
2.30.2