Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
Merge tag 'dma-mapping-6.19-2026-02-06' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux
Pull dma-mapping fixes from Marek Szyprowski:
"Two minor fixes for the DMA-mapping subsystem:
- check for the rare case of the allocation failure of the global CMA
pool (Shanker Donthineni)
- avoid perf buffer overflow when tracing large scatter-gather lists
(Deepanshu Kartikey)"
* tag 'dma-mapping-6.19-2026-02-06' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
dma: contiguous: Check return value of dma_contiguous_reserve_area()
tracing/dma: Cap dma_map_sg tracepoint arrays to prevent buffer overflow
+19
-6
include/trace/events/dma.h
+19
-6
include/trace/events/dma.h
···
275
275
sizeof(u64), sizeof(u64)))
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);
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+
#define DMA_TRACE_MAX_ENTRIES 128
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+
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TRACE_EVENT(dma_map_sg,
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TP_PROTO(struct device *dev, struct scatterlist *sgl, int nents,
280
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int ents, enum dma_data_direction dir, unsigned long attrs),
···
284
282
285
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TP_STRUCT__entry(
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__string(device, dev_name(dev))
287
-
__dynamic_array(u64, phys_addrs, nents)
288
-
__dynamic_array(u64, dma_addrs, ents)
289
-
__dynamic_array(unsigned int, lengths, ents)
285
+
__field(int, full_nents)
286
+
__field(int, full_ents)
287
+
__field(bool, truncated)
288
+
__dynamic_array(u64, phys_addrs, min(nents, DMA_TRACE_MAX_ENTRIES))
289
+
__dynamic_array(u64, dma_addrs, min(ents, DMA_TRACE_MAX_ENTRIES))
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+
__dynamic_array(unsigned int, lengths, min(ents, DMA_TRACE_MAX_ENTRIES))
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__field(enum dma_data_direction, dir)
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__field(unsigned long, attrs)
292
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),
···
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292
TP_fast_assign(
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struct scatterlist *sg;
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int i;
295
+
int traced_nents = min_t(int, nents, DMA_TRACE_MAX_ENTRIES);
296
+
int traced_ents = min_t(int, ents, DMA_TRACE_MAX_ENTRIES);
300
297
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__assign_str(device);
302
-
for_each_sg(sgl, sg, nents, i)
299
+
__entry->full_nents = nents;
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+
__entry->full_ents = ents;
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+
__entry->truncated = (nents > DMA_TRACE_MAX_ENTRIES) || (ents > DMA_TRACE_MAX_ENTRIES);
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+
for_each_sg(sgl, sg, traced_nents, i)
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((u64 *)__get_dynamic_array(phys_addrs))[i] = sg_phys(sg);
304
-
for_each_sg(sgl, sg, ents, i) {
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+
for_each_sg(sgl, sg, traced_ents, i) {
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((u64 *)__get_dynamic_array(dma_addrs))[i] =
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sg_dma_address(sg);
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307
((unsigned int *)__get_dynamic_array(lengths))[i] =
···
316
306
__entry->attrs = attrs;
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307
),
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308
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-
TP_printk("%s dir=%s dma_addrs=%s sizes=%s phys_addrs=%s attrs=%s",
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+
TP_printk("%s dir=%s nents=%d/%d ents=%d/%d%s dma_addrs=%s sizes=%s phys_addrs=%s attrs=%s",
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__get_str(device),
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decode_dma_data_direction(__entry->dir),
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+
min_t(int, __entry->full_nents, DMA_TRACE_MAX_ENTRIES), __entry->full_nents,
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+
min_t(int, __entry->full_ents, DMA_TRACE_MAX_ENTRIES), __entry->full_ents,
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+
__entry->truncated ? " [TRUNCATED]" : "",
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__print_array(__get_dynamic_array(dma_addrs),
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__get_dynamic_array_len(dma_addrs) /
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317
sizeof(u64), sizeof(u64)),
+6
-4
kernel/dma/contiguous.c
+6
-4
kernel/dma/contiguous.c
···
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pr_debug("%s: reserving %ld MiB for global area\n", __func__,
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(unsigned long)selected_size / SZ_1M);
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-
dma_contiguous_reserve_area(selected_size, selected_base,
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-
selected_limit,
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-
&dma_contiguous_default_area,
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-
fixed);
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+
ret = dma_contiguous_reserve_area(selected_size, selected_base,
261
+
selected_limit,
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+
&dma_contiguous_default_area,
263
+
fixed);
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+
if (ret)
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+
return;
264
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ret = dma_heap_cma_register_heap(dma_contiguous_default_area);
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if (ret)