* io-mapping: Indicate mapping failure @ 2020-07-21 14:16 Michael J. Ruhl 2020-07-21 14:16 ` Michael J. Ruhl 0 siblings, 1 reply; 9+ messages in thread From: Michael J. Ruhl @ 2020-07-21 14:16 UTC (permalink / raw) To: dri-devel I found this when my system crashed long after the mapping failure. The expected behavior should have been driver exit. Since this is almost exclusively used for drm, I am posting to the dri mailing list. Should this go to another list as well? Thanks, Mike _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] io-mapping: Indicate mapping failure 2020-07-21 14:16 io-mapping: Indicate mapping failure Michael J. Ruhl @ 2020-07-21 14:16 ` Michael J. Ruhl 0 siblings, 0 replies; 9+ messages in thread From: Michael J. Ruhl @ 2020-07-21 14:16 UTC (permalink / raw) To: dri-devel Cc: Mike Rapoport, stable, Chris Wilson, Michael J. Ruhl, Andrew Morton, Andy Shevchenko Sometimes it is good to know when your mapping failed. Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata about the io-mapping" Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: stable@vger.kernel.org Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com> --- include/linux/io-mapping.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index 0beaa3eba155..5641e06cbcf7 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -118,7 +118,7 @@ io_mapping_init_wc(struct io_mapping *iomap, iomap->prot = pgprot_noncached(PAGE_KERNEL); #endif - return iomap; + return iomap->iomem ? iomap : NULL; } static inline void -- 2.21.0 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH] io-mapping: Indicate mapping failure @ 2020-07-21 14:16 ` Michael J. Ruhl 0 siblings, 0 replies; 9+ messages in thread From: Michael J. Ruhl @ 2020-07-21 14:16 UTC (permalink / raw) To: dri-devel Cc: Michael J. Ruhl, Andrew Morton, Mike Rapoport, Andy Shevchenko, Chris Wilson, stable Sometimes it is good to know when your mapping failed. Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata about the io-mapping" Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: stable@vger.kernel.org Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com> --- include/linux/io-mapping.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index 0beaa3eba155..5641e06cbcf7 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -118,7 +118,7 @@ io_mapping_init_wc(struct io_mapping *iomap, iomap->prot = pgprot_noncached(PAGE_KERNEL); #endif - return iomap; + return iomap->iomem ? iomap : NULL; } static inline void -- 2.21.0 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] io-mapping: Indicate mapping failure 2020-07-21 14:16 ` Michael J. Ruhl @ 2020-07-21 14:47 ` Andy Shevchenko -1 siblings, 0 replies; 9+ messages in thread From: Andy Shevchenko @ 2020-07-21 14:47 UTC (permalink / raw) To: Michael J. Ruhl Cc: Andrew Morton, Chris Wilson, stable, dri-devel, Mike Rapoport On Tue, Jul 21, 2020 at 10:16:41AM -0400, Michael J. Ruhl wrote: > Sometimes it is good to know when your mapping failed. Can you elaborate... > Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata about the io-mapping" ...especially taking into account that Fixes implies regression / bug? -- With Best Regards, Andy Shevchenko _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] io-mapping: Indicate mapping failure @ 2020-07-21 14:47 ` Andy Shevchenko 0 siblings, 0 replies; 9+ messages in thread From: Andy Shevchenko @ 2020-07-21 14:47 UTC (permalink / raw) To: Michael J. Ruhl Cc: dri-devel, Andrew Morton, Mike Rapoport, Chris Wilson, stable On Tue, Jul 21, 2020 at 10:16:41AM -0400, Michael J. Ruhl wrote: > Sometimes it is good to know when your mapping failed. Can you elaborate... > Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata about the io-mapping" ...especially taking into account that Fixes implies regression / bug? -- With Best Regards, Andy Shevchenko ^ permalink raw reply [flat|nested] 9+ messages in thread
* RE: [PATCH] io-mapping: Indicate mapping failure 2020-07-21 14:47 ` Andy Shevchenko @ 2020-07-21 15:00 ` Ruhl, Michael J -1 siblings, 0 replies; 9+ messages in thread From: Ruhl, Michael J @ 2020-07-21 15:00 UTC (permalink / raw) To: Andy Shevchenko Cc: Andrew Morton, Chris Wilson, stable@vger.kernel.org, dri-devel@lists.freedesktop.org, Mike Rapoport >-----Original Message----- >From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> >Sent: Tuesday, July 21, 2020 10:47 AM >To: Ruhl, Michael J <michael.j.ruhl@intel.com> >Cc: dri-devel@lists.freedesktop.org; Andrew Morton <akpm@linux- >foundation.org>; Mike Rapoport <rppt@linux.ibm.com>; Chris Wilson ><chris@chris-wilson.co.uk>; stable@vger.kernel.org >Subject: Re: [PATCH] io-mapping: Indicate mapping failure > >On Tue, Jul 21, 2020 at 10:16:41AM -0400, Michael J. Ruhl wrote: >> Sometimes it is good to know when your mapping failed. > >Can you elaborate... Sure, guess I was too glib. 😊 Currently the io_mapping_init_wc (the !ATOMIC_IOMAP version), function will always return success. If the setting of the iomem (from ioremap_wc) fails, the only way for the caller to know is to check the value of iomap->iomem. Since all of the callers expect a NULL return on error, and check for a NULL, I felt this needed a fixes (i.e. unexpected behavior). >> Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata >about the io-mapping" > >...especially taking into account that Fixes implies regression / bug? The failure (in my case a crash) is not revealed until the address is accessed long after the init. I will update the commit. Mike >-- >With Best Regards, >Andy Shevchenko > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* RE: [PATCH] io-mapping: Indicate mapping failure @ 2020-07-21 15:00 ` Ruhl, Michael J 0 siblings, 0 replies; 9+ messages in thread From: Ruhl, Michael J @ 2020-07-21 15:00 UTC (permalink / raw) To: Andy Shevchenko Cc: dri-devel@lists.freedesktop.org, Andrew Morton, Mike Rapoport, Chris Wilson, stable@vger.kernel.org >-----Original Message----- >From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> >Sent: Tuesday, July 21, 2020 10:47 AM >To: Ruhl, Michael J <michael.j.ruhl@intel.com> >Cc: dri-devel@lists.freedesktop.org; Andrew Morton <akpm@linux- >foundation.org>; Mike Rapoport <rppt@linux.ibm.com>; Chris Wilson ><chris@chris-wilson.co.uk>; stable@vger.kernel.org >Subject: Re: [PATCH] io-mapping: Indicate mapping failure > >On Tue, Jul 21, 2020 at 10:16:41AM -0400, Michael J. Ruhl wrote: >> Sometimes it is good to know when your mapping failed. > >Can you elaborate... Sure, guess I was too glib. 😊 Currently the io_mapping_init_wc (the !ATOMIC_IOMAP version), function will always return success. If the setting of the iomem (from ioremap_wc) fails, the only way for the caller to know is to check the value of iomap->iomem. Since all of the callers expect a NULL return on error, and check for a NULL, I felt this needed a fixes (i.e. unexpected behavior). >> Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata >about the io-mapping" > >...especially taking into account that Fixes implies regression / bug? The failure (in my case a crash) is not revealed until the address is accessed long after the init. I will update the commit. Mike >-- >With Best Regards, >Andy Shevchenko > ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] io-mapping: Indicate mapping failure 2020-07-21 15:00 ` Ruhl, Michael J @ 2020-07-21 15:06 ` Mike Rapoport -1 siblings, 0 replies; 9+ messages in thread From: Mike Rapoport @ 2020-07-21 15:06 UTC (permalink / raw) To: Ruhl, Michael J Cc: Andrew Morton, Andy Shevchenko, stable@vger.kernel.org, dri-devel@lists.freedesktop.org, Chris Wilson On Tue, Jul 21, 2020 at 03:00:41PM +0000, Ruhl, Michael J wrote: > >-----Original Message----- > >From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > >Sent: Tuesday, July 21, 2020 10:47 AM > >To: Ruhl, Michael J <michael.j.ruhl@intel.com> > >Cc: dri-devel@lists.freedesktop.org; Andrew Morton <akpm@linux- > >foundation.org>; Mike Rapoport <rppt@linux.ibm.com>; Chris Wilson > ><chris@chris-wilson.co.uk>; stable@vger.kernel.org > >Subject: Re: [PATCH] io-mapping: Indicate mapping failure > > > >On Tue, Jul 21, 2020 at 10:16:41AM -0400, Michael J. Ruhl wrote: > >> Sometimes it is good to know when your mapping failed. I was going to say it's always a good idea ;-) > >Can you elaborate... > > Sure, guess I was too glib. 😊 > > Currently the io_mapping_init_wc (the !ATOMIC_IOMAP version), function will > always return success. > > If the setting of the iomem (from ioremap_wc) fails, the only way for the > caller to know is to check the value of iomap->iomem. > > Since all of the callers expect a NULL return on error, and check for a NULL, > I felt this needed a fixes (i.e. unexpected behavior). > > >> Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata > >about the io-mapping" > > > >...especially taking into account that Fixes implies regression / bug? > > The failure (in my case a crash) is not revealed until the address is accessed > long after the init. > > I will update the commit. > > Mike > > >-- > >With Best Regards, > >Andy Shevchenko > > > -- Sincerely yours, Mike. _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] io-mapping: Indicate mapping failure @ 2020-07-21 15:06 ` Mike Rapoport 0 siblings, 0 replies; 9+ messages in thread From: Mike Rapoport @ 2020-07-21 15:06 UTC (permalink / raw) To: Ruhl, Michael J Cc: Andy Shevchenko, dri-devel@lists.freedesktop.org, Andrew Morton, Chris Wilson, stable@vger.kernel.org On Tue, Jul 21, 2020 at 03:00:41PM +0000, Ruhl, Michael J wrote: > >-----Original Message----- > >From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > >Sent: Tuesday, July 21, 2020 10:47 AM > >To: Ruhl, Michael J <michael.j.ruhl@intel.com> > >Cc: dri-devel@lists.freedesktop.org; Andrew Morton <akpm@linux- > >foundation.org>; Mike Rapoport <rppt@linux.ibm.com>; Chris Wilson > ><chris@chris-wilson.co.uk>; stable@vger.kernel.org > >Subject: Re: [PATCH] io-mapping: Indicate mapping failure > > > >On Tue, Jul 21, 2020 at 10:16:41AM -0400, Michael J. Ruhl wrote: > >> Sometimes it is good to know when your mapping failed. I was going to say it's always a good idea ;-) > >Can you elaborate... > > Sure, guess I was too glib. 😊 > > Currently the io_mapping_init_wc (the !ATOMIC_IOMAP version), function will > always return success. > > If the setting of the iomem (from ioremap_wc) fails, the only way for the > caller to know is to check the value of iomap->iomem. > > Since all of the callers expect a NULL return on error, and check for a NULL, > I felt this needed a fixes (i.e. unexpected behavior). > > >> Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata > >about the io-mapping" > > > >...especially taking into account that Fixes implies regression / bug? > > The failure (in my case a crash) is not revealed until the address is accessed > long after the init. > > I will update the commit. > > Mike > > >-- > >With Best Regards, > >Andy Shevchenko > > > -- Sincerely yours, Mike. ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2020-07-22 7:03 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2020-07-21 14:16 io-mapping: Indicate mapping failure Michael J. Ruhl 2020-07-21 14:16 ` [PATCH] " Michael J. Ruhl 2020-07-21 14:16 ` Michael J. Ruhl 2020-07-21 14:47 ` Andy Shevchenko 2020-07-21 14:47 ` Andy Shevchenko 2020-07-21 15:00 ` Ruhl, Michael J 2020-07-21 15:00 ` Ruhl, Michael J 2020-07-21 15:06 ` Mike Rapoport 2020-07-21 15:06 ` Mike Rapoport
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