* [PATCH] swiotlb: Fix passing local variable to debugfs_create_ulong()
@ 2022-07-28 7:24 Tianyu Lan
2022-07-28 14:22 ` Christoph Hellwig
0 siblings, 1 reply; 2+ messages in thread
From: Tianyu Lan @ 2022-07-28 7:24 UTC (permalink / raw)
To: hch, m.szyprowski, robin.murphy; +Cc: Tianyu Lan, iommu, linux-kernel
From: Tianyu Lan <tiala@microsoft.com>
Debugfs node will be run-timely checked and so local variable
should be not passed to debugfs_create_ulong(). Fix it via
debugfs_create_file() to create io_tlb_used node and calculate
used io tlb number with fops_io_tlb_used attribute.
Fixes: 20347fca71a3 ("swiotlb: split up the global swiotlb lock")
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
---
kernel/dma/swiotlb.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index cc50f1fb127f..69986cffda5f 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -912,17 +912,24 @@ bool is_swiotlb_active(struct device *dev)
}
EXPORT_SYMBOL_GPL(is_swiotlb_active);
+static int io_tlb_used_get(void *data, u64 *val)
+{
+ *val = mem_used(&io_tlb_default_mem);
+
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(fops_io_tlb_used, io_tlb_used_get, NULL, "%llu\n");
+
static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem,
const char *dirname)
{
- unsigned long used = mem_used(mem);
-
mem->debugfs = debugfs_create_dir(dirname, io_tlb_default_mem.debugfs);
if (!mem->nslabs)
return;
debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs);
- debugfs_create_ulong("io_tlb_used", 0400, mem->debugfs, &used);
+ debugfs_create_file("io_tlb_used", 0400, mem->debugfs, NULL,
+ &fops_io_tlb_used);
}
static int __init __maybe_unused swiotlb_create_default_debugfs(void)
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] swiotlb: Fix passing local variable to debugfs_create_ulong()
2022-07-28 7:24 [PATCH] swiotlb: Fix passing local variable to debugfs_create_ulong() Tianyu Lan
@ 2022-07-28 14:22 ` Christoph Hellwig
0 siblings, 0 replies; 2+ messages in thread
From: Christoph Hellwig @ 2022-07-28 14:22 UTC (permalink / raw)
To: Tianyu Lan
Cc: hch, m.szyprowski, robin.murphy, Tianyu Lan, iommu, linux-kernel
Thanks, applied.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-07-28 14:22 ` Christoph Hellwig
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