From: Stephen Boyd <swboyd@chromium.org> To: Brian Norris <briannorris@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-kernel@vger.kernel.org, Wei-Ning Huang <wnhuang@chromium.org>, Julius Werner <jwerner@chromium.org>, Samuel Holland <samuel@sholland.org> Subject: Re: [PATCH v3 2/7] firmware: coreboot: Unmap ioregion on failure Date: Thu, 09 Aug 2018 12:40:31 -0700 [thread overview] Message-ID: <153384363124.220756.3747855789935101539@swboyd.mtv.corp.google.com> (raw) In-Reply-To: <20180809174936.GC129285@ban.mtv.corp.google.com> Quoting Brian Norris (2018-08-09 10:49:38) > On Thu, Aug 09, 2018 at 10:17:17AM -0700, Stephen Boyd wrote: > > Both callers of coreboot_table_init() ioremap the pointer that comes in > > but they don't unmap the memory on failure. Both of them also fail probe > > immediately with the return value of coreboot_table_init(), leaking a > > mapping when it fails. Plug the leak so the mapping isn't left unused. > > > > Cc: Wei-Ning Huang <wnhuang@chromium.org> > > Cc: Julius Werner <jwerner@chromium.org> > > Cc: Brian Norris <briannorris@chromium.org> > > Cc: Samuel Holland <samuel@sholland.org> > > Fixes: 570d30c2823f ("firmware: coreboot: Expose the coreboot table as a bus") > > I suppose this is fair, since that commit introduced error paths and > didn't clean them up. But one warning below: > > > Signed-off-by: Stephen Boyd <swboyd@chromium.org> > > --- > > drivers/firmware/google/coreboot_table.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c > > index 19db5709ae28..0d3e140444ae 100644 > > --- a/drivers/firmware/google/coreboot_table.c > > +++ b/drivers/firmware/google/coreboot_table.c > > @@ -138,6 +138,9 @@ int coreboot_table_init(struct device *dev, void __iomem *ptr) > > ptr_entry += entry.size; > > } > > > > + if (ret) > > + iounmap(ptr); > > This works because no sub-driver is using this mapping any more (i.e., > because we killed coreboot_table_find()). Otherwise, we'd need to > explicitly kill all the sub-devices first. IOW, if this gets backported > to older kernels, it would need to go along with this and its other > dependencies: The memory is copied out of the table. So do the devices actually use the memory that we remap here? I don't see how it's a problem if we unmap the table after we populate devices. > > b616cf53aa7a firmware: coreboot: Remove unused coreboot_table_find > > But I guess that's a question for -stable. Or, we remove the 'Fixes' > tag? Or add another tag, to list other dependencies? Or just ignore it. > > But for this change as applied to mainline: > > Reviewed-by: Brian Norris <briannorris@chromium.org> > Thanks!
next prev parent reply other threads:[~2018-08-09 19:40 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-08-09 17:17 [PATCH v3 0/7] firmware: coreboot: Fix probe and simplify code Stephen Boyd 2018-08-09 17:17 ` [PATCH v3 1/7] firmware: coreboot: Let OF core populate platform device Stephen Boyd 2018-08-09 17:31 ` Brian Norris 2018-08-09 17:17 ` [PATCH v3 2/7] firmware: coreboot: Unmap ioregion on failure Stephen Boyd 2018-08-09 17:49 ` Brian Norris 2018-08-09 19:40 ` Stephen Boyd [this message] 2018-08-09 19:52 ` Brian Norris 2018-08-09 23:25 ` Stephen Boyd 2018-08-09 17:17 ` [PATCH v3 3/7] firmware: coreboot: Make bus registration symmetric Stephen Boyd 2018-08-09 18:10 ` Julius Werner 2018-08-09 23:30 ` Stephen Boyd 2018-08-09 17:17 ` [PATCH v3 4/7] firmware: coreboot: Collapse platform drivers into bus core Stephen Boyd 2018-08-09 17:17 ` [PATCH v3 5/7] firmware: coreboot: Remap RAM with memremap() instead of ioremap() Stephen Boyd 2018-08-09 18:24 ` Julius Werner 2018-08-09 22:07 ` Stephen Boyd 2018-08-09 17:17 ` [PATCH v3 6/7] firmware: coreboot: Only populate devices in coreboot_table_init() Stephen Boyd 2018-08-09 21:02 ` Julius Werner 2018-08-09 23:43 ` Stephen Boyd 2018-08-09 17:17 ` [PATCH v3 7/7] firmware: coreboot: Request table region for exclusive access Stephen Boyd 2018-08-09 21:07 ` Julius Werner 2018-08-09 23:03 ` Stephen Boyd 2018-08-09 23:37 ` Julius Werner 2018-08-09 23:44 ` Julius Werner 2018-08-10 2:54 ` Stephen Boyd 2018-08-10 23:24 ` Stephen Boyd 2018-08-09 18:03 ` [PATCH v3 0/7] firmware: coreboot: Fix probe and simplify code Brian Norris
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