> -----Original Message----- > From: Jim Quinlan <jim2101...@gmail.com> > Sent: Monday, January 4, 2021 11:56 PM > To: Jim Quinlan <james.quin...@broadcom.com>; Li, Meng > <meng...@windriver.com>; open list <linux-kernel@vger.kernel.org> > Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>; raf...@kernel.org; > Hao, Kexin <kexin....@windriver.com>; Jim Quinlan > <jim2101...@gmail.com>; Christoph Hellwig <h...@lst.de> > Subject: Re: [PATCH] drivers core: Free dma_range_map when driver probe > failed > > > Subject: [PATCH] drivers core: Free dma_range_map when driver probe > > failed > > > > There will be memory leak if driver probe failed. Trace as below: > > backtrace: > > [<000000002415258f>] kmemleak_alloc+0x3c/0x50 > > [<00000000f447ebe4>] __kmalloc+0x208/0x530 > > [<0000000048bc7b3a>] of_dma_get_range+0xe4/0x1b0 > > [<0000000041e39065>] of_dma_configure_id+0x58/0x27c > > [<000000006356866a>] platform_dma_configure+0x2c/0x40 > > ...... > > [<000000000afcf9b5>] ret_from_fork+0x10/0x3c > > > > This issue is introduced by commit e0d072782c73("dma-mapping: > > introduce DMA range map, supplanting dma_pfn_offset "). It doesn't > > free dma_range_map when driver probe failed and cause above memory > > leak. So, add code to free it in error path. > > > > Fixes: e0d072782c73("dma-mapping: introduce DMA range map, > supplanting > > dma_pfn_offset ") > > Cc: sta...@vger.kernel.org > > Signed-off-by: Meng Li <meng...@windriver.com> > > --- > > drivers/base/dd.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c index > > 148e81969e04..8e4871aa34bc 100644 > > --- a/drivers/base/dd.c > > +++ b/drivers/base/dd.c > > @@ -612,6 +612,7 @@ static int really_probe(struct device *dev, struct > > device_driver *drv) > > else if (drv->remove) > > drv->remove(dev); > > probe_failed: > > + kfree(dev->dma_range_map); > > if (dev->bus) > > blocking_notifier_call_chain(&dev->bus->p->bus_notifier, > > > > BUS_NOTIFY_DRIVER_NOT_BOUND, dev); > > -- > > 2.17.1 > > > > -- > > Hi Meng, > > Sorry for the delay -- I was on vacation. I agree with you -- thanks. > However, note that in function device_release() in drivers/base/core.c > there is this line: > > kfree(dev->dma_range_map); > > Won't this also be called if all of the appropriate drivers' probes fail for > this > device, effecting a double kfree? Perhaps your patch could also set "dev- > >dma_range_map" to NULL after calling kfree()? >
Hi Jim, Please discard my previous reply, because I had a misunderstand about what you suggested. I agree with you total, and I will set dma_range_map as NULL in really_probe() function when driver probe failed. I will sent V2 patch. Thanks, Limeng > Thanks much, > Jim Quinlan > Broadcom STB