Messages in this thread | | | Date | Fri, 10 Feb 2023 11:16:29 +0530 | From | Vinod Koul <> | Subject | Re: [PATCH v1] dmaengine: sf-pdma: pdma_desc memory leak fix |
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On 20-01-23, 15:36, shravan kumar wrote: > From: Shravan Chippa <shravan.chippa@microchip.com> > > Commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a > DMA channel") changed sf_pdma_prep_dma_memcpy() to unconditionally > allocate a new sf_pdma_desc each time it is called. > > The driver previously recycled descs, by checking the in_use flag, only > allocating additional descs if the existing one was in use. This logic > was removed in commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread > support for a DMA channel"), but sf_pdma_free_desc() was not changed to > handle the new behaviour. > > As a result, each time sf_pdma_prep_dma_memcpy() is called, the previous > descriptor is leaked, over time leading to memory starvation: > > unreferenced object 0xffffffe008447300 (size 192): > comm "irq/39-mchp_dsc", pid 343, jiffies 4294906910 (age 981.200s) > hex dump (first 32 bytes): > 00 00 00 ff 00 00 00 00 b8 c1 00 00 00 00 00 00 ................ > 00 00 70 08 10 00 00 00 00 00 00 c0 00 00 00 00 ..p............. > backtrace: > [<00000000064a04f4>] kmemleak_alloc+0x1e/0x28 > [<00000000018927a7>] kmem_cache_alloc+0x11e/0x178 > [<000000002aea8d16>] sf_pdma_prep_dma_memcpy+0x40/0x112 > > Add the missing kfree() to sf_pdma_free_desc(), and remove the redundant > in_use flag.
Applied, thanks
-- ~Vinod
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