| Message ID | 20231202111430.18059-1-fancer.lancer@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | MIPS: mm: Fix some memory-related issues | expand |
On Sat, Dec 02, 2023 at 02:14:17PM +0300, Serge Semin wrote: > Just recently I've rebased my MIPS32-related work from kernel 6.5-rc4 onto > the latest kernel 6.7-rc1 and immediately got into a bootup-time > mm-related bug (see patches 3-4 in this series). After fixing it I decided > it was time to submit for review the generic MIPS code fixes which I have > been collecting in my local repo for the last year. I was going to submit > them a bit later after I finished working on a patchset with my SoC > arch-specific changes, but since it was getting bigger and bigger, it > turned to be reasonable to spill out the generic part of series right away > especially seeing it might get to be useful in the most recent kernel. > > So this series starts with the MIPS-specific dmi_early_remap() > implementation fix. It is utilized by the DMI driver in the framework of > the dmi_setup() method, which is called at the very early boot stage - in > setup_arch((). No VM and slab available at that stage which is required > for the ioremap_cache() to properly work. Thus it was a mistake to have > the dmi_early_remap() macro-function defined as ioremap_cache(). It should > have been ioremap() in first place. > > After that goes a fix for the high-memory zone PFNs calculation procedure > on MIPS. It turned out that after some not that recent commit the > IO-memory or just non-memory PFNs got to the high-memory even though they > were directly reachable, thus should have been left in the normal zone. > > Then a series of fixes for the recently discovered mm-bug is presented. > Any attempt to re-map the IO-memory with the cached attribute caused the > bootup procedure to crash with the "Unhandled kernel unaligned access" > message. After some digging I found out that the problem was in the > uninitialized IO-memory pages. Please see the patch "mips: Fix max_mapnr > being uninitialized on early stages" description for the detailed > explanation of the problem and suggested fix. > > After that goes a patch which adds the slab availability check into the > ioremap_prot() method. Indeed VM mapping performs the slab allocation in > the framework of the get_vm_area() method. Thus any other than uncached > IO-remappings must be proceeded only at the stages when slab is available. > A similar fix was just recently added to the generic version of > ioremap_prot() in the framework of commit a5f616483110 ("mm/ioremap: add > slab availability checking in ioremap_prot"). > > The patchset is closed with a small improvement which sets the MIPS > board/machine name to the dump-stack module in order to print > arch-personalized oopses in the same way as it's done on ARM, ARM64, > RISC-V, etc. > > That's it for today.) Thanks for review in advance. Any tests are very > welcome. > > Link: https://lore.kernel.org/linux-mips/20231122182419.30633-1-fancer.lancer@gmail.com/ > Changelog v2: > - Drop the patches: > [PATCH 5/7] mm/mm_init.c: Extend init unavailable range doc info > [PATCH 6/7] mm/mm_init.c: Append '\n' to the unavailable ranges log-message > since they have been picked up by Andrew. (@Andrew) > - Replace ioremap_uc() with using ioremap() due to having the former one > deprecated. (@Arnd) > - Add a new patch: > [PATCH v2 5/6] mips: mm: add slab availability checking in ioremap_prot > picked up from the generic ioremap_prot() implementation. > - Extend early DMI mem remapping patch log with a note regarding the unsynched > caches concern. (@Jiaxun) > > Signed-off-by: Serge Semin <fancer.lancer@gmail.com> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Aleksandar Rikalo <aleksandar.rikalo@syrmia.com> > Cc: Aleksandar Rikalo <arikalo@gmail.com> > Cc: Dragan Mladjenovic <dragan.mladjenovic@syrmia.com> > Cc: Christophe Leroy <christophe.leroy@csgroup.eu> > Cc: Baoquan He <bhe@redhat.com> > Cc: Chao-ying Fu <cfu@wavecomp.com> > Cc: Yinglu Yang <yangyinglu@loongson.cn> > Cc: Tiezhu Yang <yangtiezhu@loongson.cn> > Cc: Mike Rapoport <rppt@kernel.org> > Cc: Matthew Wilcox (Oracle) <willy@infradead.org> > Cc: Marc Zyngier <maz@kernel.org> > Cc: linux-mips@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > > Serge Semin (6): > mips: dmi: Fix early remap on MIPS32 > mips: Fix incorrect max_low_pfn adjustment > mips: Fix max_mapnr being uninitialized on early stages > mips: Optimize max_mapnr init procedure > mips: mm: add slab availability checking in ioremap_prot > mips: Set dump-stack arch description > > arch/mips/include/asm/dmi.h | 2 +- > arch/mips/kernel/prom.c | 2 ++ > arch/mips/kernel/setup.c | 4 ++-- > arch/mips/mm/init.c | 16 +++++++++------- > arch/mips/mm/ioremap.c | 4 ++++ > 5 files changed, 18 insertions(+), 10 deletions(-) series applied to mips-next. Thomas.
Just recently I've rebased my MIPS32-related work from kernel 6.5-rc4 onto the latest kernel 6.7-rc1 and immediately got into a bootup-time mm-related bug (see patches 3-4 in this series). After fixing it I decided it was time to submit for review the generic MIPS code fixes which I have been collecting in my local repo for the last year. I was going to submit them a bit later after I finished working on a patchset with my SoC arch-specific changes, but since it was getting bigger and bigger, it turned to be reasonable to spill out the generic part of series right away especially seeing it might get to be useful in the most recent kernel. So this series starts with the MIPS-specific dmi_early_remap() implementation fix. It is utilized by the DMI driver in the framework of the dmi_setup() method, which is called at the very early boot stage - in setup_arch((). No VM and slab available at that stage which is required for the ioremap_cache() to properly work. Thus it was a mistake to have the dmi_early_remap() macro-function defined as ioremap_cache(). It should have been ioremap() in first place. After that goes a fix for the high-memory zone PFNs calculation procedure on MIPS. It turned out that after some not that recent commit the IO-memory or just non-memory PFNs got to the high-memory even though they were directly reachable, thus should have been left in the normal zone. Then a series of fixes for the recently discovered mm-bug is presented. Any attempt to re-map the IO-memory with the cached attribute caused the bootup procedure to crash with the "Unhandled kernel unaligned access" message. After some digging I found out that the problem was in the uninitialized IO-memory pages. Please see the patch "mips: Fix max_mapnr being uninitialized on early stages" description for the detailed explanation of the problem and suggested fix. After that goes a patch which adds the slab availability check into the ioremap_prot() method. Indeed VM mapping performs the slab allocation in the framework of the get_vm_area() method. Thus any other than uncached IO-remappings must be proceeded only at the stages when slab is available. A similar fix was just recently added to the generic version of ioremap_prot() in the framework of commit a5f616483110 ("mm/ioremap: add slab availability checking in ioremap_prot"). The patchset is closed with a small improvement which sets the MIPS board/machine name to the dump-stack module in order to print arch-personalized oopses in the same way as it's done on ARM, ARM64, RISC-V, etc. That's it for today.) Thanks for review in advance. Any tests are very welcome. Link: https://lore.kernel.org/linux-mips/20231122182419.30633-1-fancer.lancer@gmail.com/ Changelog v2: - Drop the patches: [PATCH 5/7] mm/mm_init.c: Extend init unavailable range doc info [PATCH 6/7] mm/mm_init.c: Append '\n' to the unavailable ranges log-message since they have been picked up by Andrew. (@Andrew) - Replace ioremap_uc() with using ioremap() due to having the former one deprecated. (@Arnd) - Add a new patch: [PATCH v2 5/6] mips: mm: add slab availability checking in ioremap_prot picked up from the generic ioremap_prot() implementation. - Extend early DMI mem remapping patch log with a note regarding the unsynched caches concern. (@Jiaxun) Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Aleksandar Rikalo <aleksandar.rikalo@syrmia.com> Cc: Aleksandar Rikalo <arikalo@gmail.com> Cc: Dragan Mladjenovic <dragan.mladjenovic@syrmia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Baoquan He <bhe@redhat.com> Cc: Chao-ying Fu <cfu@wavecomp.com> Cc: Yinglu Yang <yangyinglu@loongson.cn> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Mike Rapoport <rppt@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Marc Zyngier <maz@kernel.org> Cc: linux-mips@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Serge Semin (6): mips: dmi: Fix early remap on MIPS32 mips: Fix incorrect max_low_pfn adjustment mips: Fix max_mapnr being uninitialized on early stages mips: Optimize max_mapnr init procedure mips: mm: add slab availability checking in ioremap_prot mips: Set dump-stack arch description arch/mips/include/asm/dmi.h | 2 +- arch/mips/kernel/prom.c | 2 ++ arch/mips/kernel/setup.c | 4 ++-- arch/mips/mm/init.c | 16 +++++++++------- arch/mips/mm/ioremap.c | 4 ++++ 5 files changed, 18 insertions(+), 10 deletions(-)