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2020-03-13powerpc/kasan: Fix shadow memory protection with CONFIG_KASAN_VMALLOCChristophe Leroy1-7/+2
With CONFIG_KASAN_VMALLOC, new page tables are created at the time shadow memory for vmalloc area is unmapped. If some parts of the page table still have entries to the zero page shadow memory, the entries are wrongly marked RW. With CONFIG_KASAN_VMALLOC, almost the entire kernel address space is managed by KASAN. To make it simple, just create KASAN page tables for the entire kernel space at kasan_init(). That doesn't use much more space, and that's anyway already done for hash platforms. Fixes: 3d4247fcc938 ("powerpc/32: Add support of KASAN_VMALLOC") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ef5248fc1f496c6b0dfdb59380f24968f25f75c5.1583513368.git.christophe.leroy@c-s.fr
2020-03-05powerpc/mm: Fix missing KUAP disable in flush_coherent_icache()Michael Ellerman1-0/+2
Stefan reported a strange kernel fault which turned out to be due to a missing KUAP disable in flush_coherent_icache() called from flush_icache_range(). The fault looks like: Kernel attempted to access user page (7fffc30d9c00) - exploit attempt? (uid: 1009) BUG: Unable to handle kernel data access on read at 0x7fffc30d9c00 Faulting instruction address: 0xc00000000007232c Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV CPU: 35 PID: 5886 Comm: sigtramp Not tainted 5.6.0-rc2-gcc-8.2.0-00003-gfc37a1632d40 #79 NIP: c00000000007232c LR: c00000000003b7fc CTR: 0000000000000000 REGS: c000001e11093940 TRAP: 0300 Not tainted (5.6.0-rc2-gcc-8.2.0-00003-gfc37a1632d40) MSR: 900000000280b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 28000884 XER: 00000000 CFAR: c0000000000722fc DAR: 00007fffc30d9c00 DSISR: 08000000 IRQMASK: 0 GPR00: c00000000003b7fc c000001e11093bd0 c0000000023ac200 00007fffc30d9c00 GPR04: 00007fffc30d9c18 0000000000000000 c000001e11093bd4 0000000000000000 GPR08: 0000000000000000 0000000000000001 0000000000000000 c000001e1104ed80 GPR12: 0000000000000000 c000001fff6ab380 c0000000016be2d0 4000000000000000 GPR16: c000000000000000 bfffffffffffffff 0000000000000000 0000000000000000 GPR20: 00007fffc30d9c00 00007fffc30d8f58 00007fffc30d9c18 00007fffc30d9c20 GPR24: 00007fffc30d9c18 0000000000000000 c000001e11093d90 c000001e1104ed80 GPR28: c000001e11093e90 0000000000000000 c0000000023d9d18 00007fffc30d9c00 NIP flush_icache_range+0x5c/0x80 LR handle_rt_signal64+0x95c/0xc2c Call Trace: 0xc000001e11093d90 (unreliable) handle_rt_signal64+0x93c/0xc2c do_notify_resume+0x310/0x430 ret_from_except_lite+0x70/0x74 Instruction dump: 409e002c 7c0802a6 3c62ff31 3863f6a0 f8010080 48195fed 60000000 48fe4c8d 60000000 e8010080 7c0803a6 7c0004ac <7c00ffac> 7c0004ac 4c00012c 38210070 This path through handle_rt_signal64() to setup_trampoline() and flush_icache_range() is only triggered by 64-bit processes that have unmapped their VDSO, which is rare. flush_icache_range() takes a range of addresses to flush. In flush_coherent_icache() we implement an optimisation for CPUs where we know we don't actually have to flush the whole range, we just need to do a single icbi. However we still execute the icbi on the user address of the start of the range we're flushing. On CPUs that also implement KUAP (Power9) that leads to the spurious fault above. We should be able to pass any address, including a kernel address, to the icbi on these CPUs, which would avoid any interaction with KUAP. But I don't want to make that change in a bug fix, just in case it surfaces some strange behaviour on some CPU. So for now just disable KUAP around the icbi. Note the icbi is treated as a load, so we allow read access, not write as you'd expect. Fixes: 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU") Cc: stable@vger.kernel.org # v5.2+ Reported-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200303235708.26004-1-mpe@ellerman.id.au
2020-02-18powerpc/32s: Fix DSI and ISI exceptions for CONFIG_VMAP_STACKChristophe Leroy3-39/+26
hash_page() needs to read page tables from kernel memory. When entire kernel memory is mapped by BATs, which is normally the case when CONFIG_STRICT_KERNEL_RWX is not set, it works even if the page hosting the page table is not referenced in the MMU hash table. However, if the page where the page table resides is not covered by a BAT, a DSI fault can be encountered from hash_page(), and it loops forever. This can happen when CONFIG_STRICT_KERNEL_RWX is selected and the alignment of the different regions is too small to allow covering the entire memory with BATs. This also happens when CONFIG_DEBUG_PAGEALLOC is selected or when booting with 'nobats' flag. Also, if the page containing the kernel stack is not present in the MMU hash table, registers cannot be saved and a recursive DSI fault is encountered. To allow hash_page() to properly do its job at all time and load the MMU hash table whenever needed, it must run with data MMU disabled. This means it must be called before re-enabling data MMU. To allow this, registers clobbered by hash_page() and create_hpte() have to be saved in the thread struct together with SRR0, SSR1, DAR and DSISR. It is also necessary to ensure that DSI prolog doesn't overwrite regs saved by prolog of the current running exception. That means: - DSI can only use SPRN_SPRG_SCRATCH0 - Exceptions must free SPRN_SPRG_SCRATCH0 before writing to the stack. This also fixes the Oops reported by Erhard when create_hpte() is called by add_hash_page(). Due to prolog size increase, a few more exceptions had to get split in two parts. Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Reported-by: Erhard F. <erhard_f@mailbox.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Tested-by: Erhard F. <erhard_f@mailbox.org> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206501 Link: https://lore.kernel.org/r/64a4aa44686e9fd4b01333401367029771d9b231.1581761633.git.christophe.leroy@c-s.fr
2020-02-17powerpc/hugetlb: Fix 512k hugepages on 8xx with 16k page sizeChristophe Leroy1-11/+18
Commit 55c8fc3f4930 ("powerpc/8xx: reintroduce 16K pages with HW assistance") redefined pte_t as a struct of 4 pte_basic_t, because in 16K pages mode there are four identical entries in the page table. But the size of hugepage tables is calculated based of the size of (void *). Therefore, we end up with page tables of size 1k instead of 4k for 512k pages. As 512k hugepage tables are the same size as standard page tables, ie 4k, use the standard page tables instead of PGT_CACHE tables. Fixes: 3fb69c6a1a13 ("powerpc/8xx: Enable 512k hugepage support with HW assistance") Cc: stable@vger.kernel.org # v5.0+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/90ec56a2315be602494619ed0223bba3b0b8d619.1580997007.git.christophe.leroy@c-s.fr
2020-02-04Merge tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds12-80/+125
Pull powerpc updates from Michael Ellerman: "A pretty small batch for us, and apologies for it being a bit late, I wanted to sneak Christophe's user_access_begin() series in. Summary: - Implement user_access_begin() and friends for our platforms that support controlling kernel access to userspace. - Enable CONFIG_VMAP_STACK on 32-bit Book3S and 8xx. - Some tweaks to our pseries IOMMU code to allow SVMs ("secure" virtual machines) to use the IOMMU. - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 32-bit VDSO, and some other improvements. - A series to use the PCI hotplug framework to control opencapi card's so that they can be reset and re-read after flashing a new FPGA image. As well as other minor fixes and improvements as usual. Thanks to: Alastair D'Silva, Alexandre Ghiti, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Bai Yingjie, Chen Zhou, Christophe Leroy, Frederic Barrat, Greg Kurz, Jason A. Donenfeld, Joel Stanley, Jordan Niethe, Julia Lawall, Krzysztof Kozlowski, Laurent Dufour, Laurentiu Tudor, Linus Walleij, Michael Bringmann, Nathan Chancellor, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Peter Ujfalusi, Pingfan Liu, Ram Pai, Randy Dunlap, Russell Currey, Sam Bobroff, Sebastian Andrzej Siewior, Shawn Anastasio, Stephen Rothwell, Steve Best, Sukadev Bhattiprolu, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain" * tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (131 commits) powerpc: configs: Cleanup old Kconfig options powerpc/configs/skiroot: Enable some more hardening options powerpc/configs/skiroot: Disable xmon default & enable reboot on panic powerpc/configs/skiroot: Enable security features powerpc/configs/skiroot: Update for symbol movement only powerpc/configs/skiroot: Drop default n CONFIG_CRYPTO_ECHAINIV powerpc/configs/skiroot: Drop HID_LOGITECH powerpc/configs: Drop NET_VENDOR_HP which moved to staging powerpc/configs: NET_CADENCE became NET_VENDOR_CADENCE powerpc/configs: Drop CONFIG_QLGE which moved to staging powerpc: Do not consider weak unresolved symbol relocations as bad powerpc/32s: Fix kasan_early_hash_table() for CONFIG_VMAP_STACK powerpc: indent to improve Kconfig readability powerpc: Provide initial documentation for PAPR hcalls powerpc: Implement user_access_save() and user_access_restore() powerpc: Implement user_access_begin and friends powerpc/32s: Prepare prevent_user_access() for user_access_end() powerpc/32s: Drop NULL addr verification powerpc/kuap: Fix set direction in allow/prevent_user_access() powerpc/32s: Fix bad_kuap_fault() ...
2020-02-04proc: convert everything to "struct proc_ops"Alexey Dobriyan1-6/+6
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-04powerpc/mmu_gather: enable RCU_TABLE_FREE even for !SMP caseAneesh Kumar K.V1-7/+0
Patch series "Fixup page directory freeing", v4. This is a repost of patch series from Peter with the arch specific changes except ppc64 dropped. ppc64 changes are added here because we are redoing the patch series on top of ppc64 changes. This makes it easy to backport these changes. Only the first 2 patches need to be backported to stable. The thing is, on anything SMP, freeing page directories should observe the exact same order as normal page freeing: 1) unhook page/directory 2) TLB invalidate 3) free page/directory Without this, any concurrent page-table walk could end up with a Use-after-Free. This is esp. trivial for anything that has software page-table walkers (HAVE_FAST_GUP / software TLB fill) or the hardware caches partial page-walks (ie. caches page directories). Even on UP this might give issues since mmu_gather is preemptible these days. An interrupt or preempted task accessing user pages might stumble into the free page if the hardware caches page directories. This patch series fixes ppc64 and add generic MMU_GATHER changes to support the conversion of other architectures. I haven't added patches w.r.t other architecture because they are yet to be acked. This patch (of 9): A followup patch is going to make sure we correctly invalidate page walk cache before we free page table pages. In order to keep things simple enable RCU_TABLE_FREE even for !SMP so that we don't have to fixup the !SMP case differently in the followup patch !SMP case is right now broken for radix translation w.r.t page walk cache flush. We can get interrupted in between page table free and that would imply we have page walk cache entries pointing to tables which got freed already. Michael said "both our platforms that run on Power9 force SMP on in Kconfig, so the !SMP case is unlikely to be a problem for anyone in practice, unless they've hacked their kernel to build it !SMP." Link: http://lkml.kernel.org/r/20200116064531.483522-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-01Merge branch 'topic/user-access-begin' into nextMichael Ellerman1-1/+1
Merge the user_access_begin() series from Christophe. This is based on a commit from Linus that went into v5.5-rc7.
2020-01-31mm, tree-wide: rename put_user_page*() to unpin_user_page*()John Hubbard1-2/+2
In order to provide a clearer, more symmetric API for pinning and unpinning DMA pages. This way, pin_user_pages*() calls match up with unpin_user_pages*() calls, and the API is a lot closer to being self-explanatory. Link: http://lkml.kernel.org/r/20200107224558.2362728-23-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-31powerpc: book3s64: convert to pin_user_pages() and put_user_page()John Hubbard1-5/+5
1. Convert from get_user_pages() to pin_user_pages(). 2. As required by pin_user_pages(), release these pages via put_user_page(). Link: http://lkml.kernel.org/r/20200107224558.2362728-21-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-30powerpc/32s: Fix kasan_early_hash_table() for CONFIG_VMAP_STACKChristophe Leroy1-2/+5
On book3s/32 CPUs that are handling MMU through a hash table, MMU_init_hw() function was adapted for VMAP_STACK in order to handle virtual addresses instead of physical addresses in the low level hash functions. When using KASAN, the same adaptations are required for the early hash table set up by kasan_early_hash_table() function. Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fc8390a33c2a470105f01abbcbdc7916c30c0a54.1580301269.git.christophe.leroy@c-s.fr
2020-01-28powerpc/32s: Fix bad_kuap_fault()Christophe Leroy1-1/+1
At the moment, bad_kuap_fault() reports a fault only if a bad access to userspace occurred while access to userspace was not granted. But if a fault occurs for a write outside the allowed userspace segment(s) that have been unlocked, bad_kuap_fault() fails to detect it and the kernel loops forever in do_page_fault(). Fix it by checking that the accessed address is within the allowed range. Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f48244e9485ada0a304ed33ccbb8da271180c80d.1579866752.git.christophe.leroy@c-s.fr
2020-01-27powerpc/32: Reuse orphaned memblocks in kasan_init_shadow_page_tables()Christophe Leroy1-3/+3
If concurrent PMD population has happened, re-use orphaned memblocks. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b29ffffb9206dc14541fa420c17604240728041b.1579024426.git.christophe.leroy@c-s.fr
2020-01-27powerpc/32: Simplify KASAN initChristophe Leroy1-21/+5
Since kasan_init_region() is not used anymore for modules, KASAN init is done while slab_is_available() is false. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/84b27bf08b41c8343efd88e10f2eccd8e9f85593.1579024426.git.christophe.leroy@c-s.fr
2020-01-27powerpc/32: Force KASAN_VMALLOC for modulesChristophe Leroy1-26/+5
Unloading/Reloading of modules seems to fail with KASAN_VMALLOC but works properly with it. Force selection of KASAN_VMALLOC when MODULES are selected, and drop module_alloc() which was dedicated to KASAN for modules. Reported-by: <erhard_f@mailbox.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://bugzilla.kernel.org/show_bug.cgi?id=205283 Link: https://lore.kernel.org/r/f909da11aecb59ab7f32ba01fae6f356eaa4d7bc.1579024426.git.christophe.leroy@c-s.fr
2020-01-27powerpc/32: Add support of KASAN_VMALLOCChristophe Leroy2-1/+36
Add support of KASAN_VMALLOC on PPC32. To allow this, the early shadow covering the VMALLOC space need to be removed once high_memory var is set and before freeing memblock. And the VMALLOC area need to be aligned such that boundaries are covered by a full shadow page. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/031dec5487bde9b2181c8b3c9800e1879cf98c1a.1579024426.git.christophe.leroy@c-s.fr
2020-01-27powerpc/mm: Don't log user reads to 0xffffffffChristophe Leroy1-0/+3
Running vdsotest leaves many times the following log: [ 79.629901] vdsotest[396]: User access of kernel address (ffffffff) - exploit attempt? (uid: 0) A pointer set to (-1) is likely a programming error similar to a NULL pointer and is not worth logging as an exploit attempt. Don't log user accesses to 0xffffffff. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0728849e826ba16f1fbd6fa7f5c6cc87bd64e097.1577087627.git.christophe.leroy@c-s.fr
2020-01-27powerpc/32s: Enable CONFIG_VMAP_STACKChristophe Leroy2-19/+36
A few changes to retrieve DAR and DSISR from struct regs instead of retrieving them directly, as they may have changed due to a TLB miss. Also modifies hash_page() and friends to work with virtual data addresses instead of physical ones. Same on load_up_fpu() and load_up_altivec(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Fix tovirt_vmstack call in head_32.S to fix CHRP build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2e2509a242fd5f3e23df4a06530c18060c4d321e.1576916812.git.christophe.leroy@c-s.fr
2020-01-26powerpc/mm: Remove kvm radix prefetch workaround for Power9 DD2.2Jordan Niethe2-1/+8
Commit a25bd72badfa ("powerpc/mm/radix: Workaround prefetch issue with KVM") introduced a number of workarounds as coming out of a guest with the mmu enabled would make the cpu would start running in hypervisor state with the PID value from the guest. The cpu will then start prefetching for the hypervisor with that PID value. In Power9 DD2.2 the cpu behaviour was modified to fix this. When accessing Quadrant 0 in hypervisor mode with LPID != 0 prefetching will not be performed. This means that we can get rid of the workarounds for Power9 DD2.2 and later revisions. Add a new cpu feature CPU_FTR_P9_RADIX_PREFETCH_BUG to indicate if the workarounds are needed. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191206031722.25781-1-jniethe5@gmail.com
2020-01-26powerpc: use probe_user_read() and probe_user_write()Christophe Leroy1-5/+1
Instead of opencoding, use probe_user_read() to failessly read a user location and probe_user_write() for writing to user. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e041f5eedb23f09ab553be8a91c3de2087147320.1579800517.git.christophe.leroy@c-s.fr
2020-01-23powerpc/8xx: Fix permanently mapped IMMR region.Christophe Leroy1-6/+7
When not using large TLBs, the IMMR region is still mapped as a whole block in the FIXMAP area. Properly report that the IMMR region is block-mapped even when not using large TLBs. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/45f4f414bcd7198b0755cf4287ff216fbfc24b9d.1574774187.git.christophe.leroy@c-s.fr
2020-01-23powerpc/ptdump: Fix W+X verificationChristophe Leroy1-1/+3
Verification cannot rely on simple bit checking because on some platforms PAGE_RW is 0, checking that a page is not W means checking that PAGE_RO is set instead of checking that PAGE_RW is not set. Use pte helpers instead of checking bits. Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0d894839fdbb19070f0e1e4140363be4f2bb62fc.1578989540.git.christophe.leroy@c-s.fr
2020-01-23powerpc/ptdump: Fix W+X verification call in mark_rodata_ro()Christophe Leroy1-0/+1
ptdump_check_wx() also have to be called when pages are mapped by blocks. Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/37517da8310f4457f28921a4edb88fb21d27b62a.1578989531.git.christophe.leroy@c-s.fr
2020-01-23powerpc/ptdump: don't entirely rebuild kernel when selecting CONFIG_PPC_DEBUG_WXChristophe Leroy2-0/+8
Selecting CONFIG_PPC_DEBUG_WX only impacts ptdump and pgtable_32/64 init calls. Declaring related functions in asm/pgtable.h implies rebuilding almost everything. Move ptdump_check_wx() declaration in mm/mmu_decl.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bf34fd9dca61eadf9a134a9f89ebbc162cfd5f86.1578986011.git.christophe.leroy@c-s.fr
2020-01-16powerpc/book3s64/hash: Disable 16M linear mapping size if not alignedRussell Currey1-1/+10
With STRICT_KERNEL_RWX on in a relocatable kernel under the hash MMU, if the position the kernel is loaded at is not 16M aligned things go horribly wrong. Specifically hash__mark_initmem_nx() will call hash__change_memory_range() which then aligns down the start address, and due to the text not being 16M aligned causes some of the kernel text to be marked non-executable. We can avoid this when selecting the linear mapping size, so do so and print a warning. I tested this for various alignments and as long as the position is 64K aligned it's fine (the base requirement for powerpc). Signed-off-by: Russell Currey <ruscur@russell.cc> [mpe: Add details of the failure mode] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191224064126.183670-1-ruscur@russell.cc
2020-01-04mm/memory_hotplug: shrink zones when offlining memoryDavid Hildenbrand1-2/+1
We currently try to shrink a single zone when removing memory. We use the zone of the first page of the memory we are removing. If that memmap was never initialized (e.g., memory was never onlined), we will read garbage and can trigger kernel BUGs (due to a stale pointer): BUG: unable to handle page fault for address: 000000000000353d #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP PTI CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:clear_zone_contiguous+0x5/0x10 Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840 RSP: 0018:ffffad2400043c98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000 RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40 RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000 R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680 FS: 0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __remove_pages+0x4b/0x640 arch_remove_memory+0x63/0x8d try_remove_memory+0xdb/0x130 __remove_memory+0xa/0x11 acpi_memory_device_remove+0x70/0x100 acpi_bus_trim+0x55/0x90 acpi_device_hotplug+0x227/0x3a0 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x221/0x550 worker_thread+0x50/0x3b0 kthread+0x105/0x140 ret_from_fork+0x3a/0x50 Modules linked in: CR2: 000000000000353d Instead, shrink the zones when offlining memory or when onlining failed. Introduce and use remove_pfn_range_from_zone(() for that. We now properly shrink the zones, even if we have DIMMs whereby - Some memory blocks fall into no zone (never onlined) - Some memory blocks fall into multiple zones (offlined+re-onlined) - Multiple memory blocks that fall into different zones Drop the zone parameter (with a potential dubious value) from __remove_pages() and __remove_section(). Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319] Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: <stable@vger.kernel.org> [5.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-23powerpc/mm: Mark get_slice_psize() & slice_addr_is_low() as notraceMichael Ellerman1-2/+2
These slice routines are called from the SLB miss handler, which can lead to warnings from the IRQ code, because we have not reconciled the IRQ state properly: WARNING: CPU: 72 PID: 30150 at arch/powerpc/kernel/irq.c:258 arch_local_irq_restore.part.0+0xcc/0x100 Modules linked in: CPU: 72 PID: 30150 Comm: ftracetest Not tainted 5.5.0-rc2-gcc9x-g7e0165b2f1a9 #1 NIP: c00000000001d83c LR: c00000000029ab90 CTR: c00000000026cf90 REGS: c0000007eee3b960 TRAP: 0700 Not tainted (5.5.0-rc2-gcc9x-g7e0165b2f1a9) MSR: 8000000000021033 <SF,ME,IR,DR,RI,LE> CR: 22242844 XER: 20000000 CFAR: c00000000001d780 IRQMASK: 0 ... NIP arch_local_irq_restore.part.0+0xcc/0x100 LR trace_graph_entry+0x270/0x340 Call Trace: trace_graph_entry+0x254/0x340 (unreliable) function_graph_enter+0xe4/0x1a0 prepare_ftrace_return+0xa0/0x130 ftrace_graph_caller+0x44/0x94 # (get_slice_psize()) slb_allocate_user+0x7c/0x100 do_slb_fault+0xf8/0x300 instruction_access_slb_common+0x140/0x180 Fixes: 48e7b7695745 ("powerpc/64s/hash: Convert SLB miss handlers to C") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191221121337.4894-1-mpe@ellerman.id.au
2019-12-16powerpc/8xx: fix bogus __init on mmu_mapin_ram_chunk()Christophe Leroy1-1/+1
Remove __init qualifier for mmu_mapin_ram_chunk() as it is called by mmu_mark_initmem_nx() and mmu_mark_rodata_ro() which are not __init functions. At the same time, mark it static as it is only used in this file. Reported-by: kbuild test robot <lkp@intel.com> Fixes: a2227a277743 ("powerpc/32: Don't populate page tables for block mapped pages except on the 8xx") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/56648921986a6b3e7315b1fbbf4684f21bd2dea8.1576310997.git.christophe.leroy@c-s.fr
2019-12-13powerpc: Ensure that swiotlb buffer is allocated from low memoryMike Rapoport1-0/+8
Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G. If a system has more physical memory than this limit, the swiotlb buffer is not addressable because it is allocated from memblock using top-down mode. Force memblock to bottom-up mode before calling swiotlb_init() to ensure that the swiotlb buffer is DMA-able. Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191204123524.22919-1-rppt@kernel.org
2019-12-05powerpc/pmem: Fix kernel crash due to wrong range value usage in flush_dcache_rangeAneesh Kumar K.V1-1/+1
This patch fix the below kernel crash. BUG: Unable to handle kernel data access on read at 0xc000000380000000 Faulting instruction address: 0xc00000000008b6f0 cpu 0x5: Vector: 300 (Data Access) at [c0000000d8587790] pc: c00000000008b6f0: arch_remove_memory+0x150/0x210 lr: c00000000008b720: arch_remove_memory+0x180/0x210 sp: c0000000d8587a20 msr: 800000000280b033 dar: c000000380000000 dsisr: 40000000 current = 0xc0000000d8558600 paca = 0xc00000000fff8f00 irqmask: 0x03 irq_happened: 0x01 pid = 1220, comm = ndctl enter ? for help memunmap_pages+0x33c/0x410 devm_action_release+0x30/0x50 release_nodes+0x30c/0x3a0 device_release_driver_internal+0x178/0x240 unbind_store+0x74/0x190 drv_attr_store+0x44/0x60 sysfs_kf_write+0x74/0xa0 kernfs_fop_write+0x1b0/0x260 __vfs_write+0x3c/0x70 vfs_write+0xe4/0x200 ksys_write+0x7c/0x140 system_call+0x5c/0x68 Fixes: 076265907cf9 ("powerpc: Chunk calls to flush_dcache_range in arch_*_memory") Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191204052909.59145-1-aneesh.kumar@linux.ibm.com
2019-12-01Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+1
Merge updates from Andrew Morton: "Incoming: - a small number of updates to scripts/, ocfs2 and fs/buffer.c - most of MM I still have quite a lot of material (mostly not MM) staged after linux-next due to -next dependencies. I'll send those across next week as the preprequisites get merged up" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (135 commits) mm/page_io.c: annotate refault stalls from swap_readpage mm/Kconfig: fix trivial help text punctuation mm/Kconfig: fix indentation mm/memory_hotplug.c: remove __online_page_set_limits() mm: fix typos in comments when calling __SetPageUptodate() mm: fix struct member name in function comments mm/shmem.c: cast the type of unmap_start to u64 mm: shmem: use proper gfp flags for shmem_writepage() mm/shmem.c: make array 'values' static const, makes object smaller userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register() userfaultfd: wrap the common dst_vma check into an inlined function userfaultfd: remove unnecessary WARN_ON() in __mcopy_atomic_hugetlb() userfaultfd: use vma_pagesize for all huge page size calculation mm/madvise.c: use PAGE_ALIGN[ED] for range checking mm/madvise.c: replace with page_size() in madvise_inject_error() mm/mmap.c: make vma_merge() comment more easy to understand mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops autonuma: reduce cache footprint when scanning page tables autonuma: fix watermark checking in migrate_balanced_pgdat() ...
2019-12-01powerpc/mm: remove pmd_huge/pud_huge stubs and include hugetlb.hMike Kravetz1-0/+1
Patch series "hugetlbfs: convert macros to static inline, fix sparse warning". The definition for huge_pte_offset() in <linux/hugetlb.h> causes a sparse warning in the !CONFIG_HUGETLB_PAGE. Fix this as well as converting all macros in this block of definitions to static inlines for better type checking. When making the above changes, build errors were found in powerpc due to duplicate definitions. A separate powerpc specific patch is included as a requisite to remove the definitions and get them from <linux/hugetlb.h>. This patch (of 2): This removes the power specific stubs created by commit aad71e3928be ("powerpc/mm: Fix build break with RADIX=y & HUGETLBFS=n") used when !CONFIG_HUGETLB_PAGE. Instead, it addresses the build break by getting the definitions from <linux/hugetlb.h>. This allows the macros in <linux/hugetlb.h> to be replaced with static inlines. Link: http://lkml.kernel.org/r/20191112194558.139389-2-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Jason Gunthorpe <jgg@ziepe.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-30Merge tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds18-135/+764
Pull powerpc updates from Michael Ellerman: "Highlights: - Infrastructure for secure boot on some bare metal Power9 machines. The firmware support is still in development, so the code here won't actually activate secure boot on any existing systems. - A change to xmon (our crash handler / pseudo-debugger) to restrict it to read-only mode when the kernel is lockdown'ed, otherwise it's trivial to drop into xmon and modify kernel data, such as the lockdown state. - Support for KASLR on 32-bit BookE machines (Freescale / NXP). - Fixes for our flush_icache_range() and __kernel_sync_dicache() (VDSO) to work with memory ranges >4GB. - Some reworks of the pseries CMM (Cooperative Memory Management) driver to make it behave more like other balloon drivers and enable some cleanups of generic mm code. - A series of fixes to our hardware breakpoint support to properly handle unaligned watchpoint addresses. Plus a bunch of other smaller improvements, fixes and cleanups. Thanks to: Alastair D'Silva, Andrew Donnellan, Aneesh Kumar K.V, Anthony Steinhauser, Cédric Le Goater, Chris Packham, Chris Smart, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens, David Hildenbrand, Deb McLemore, Diana Craciun, Eric Richter, Geert Uytterhoeven, Greg Kroah-Hartman, Greg Kurz, Gustavo L. F. Walbon, Hari Bathini, Harish, Jason Yan, Krzysztof Kozlowski, Leonardo Bras, Mathieu Malaterre, Mauro S. M. Rodrigues, Michal Suchanek, Mimi Zohar, Nathan Chancellor, Nathan Lynch, Nayna Jain, Nick Desaulniers, Oliver O'Halloran, Qian Cai, Rasmus Villemoes, Ravi Bangoria, Sam Bobroff, Santosh Sivaraj, Scott Wood, Thomas Huth, Tyrel Datwyler, Vaibhav Jain, Valentin Longchamp, YueHaibing" * tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (144 commits) powerpc/fixmap: fix crash with HIGHMEM x86/efi: remove unused variables powerpc: Define arch_is_kernel_initmem_freed() for lockdep powerpc/prom_init: Use -ffreestanding to avoid a reference to bcmp powerpc: Avoid clang warnings around setjmp and longjmp powerpc: Don't add -mabi= flags when building with Clang powerpc: Fix Kconfig indentation powerpc/fixmap: don't clear fixmap area in paging_init() selftests/powerpc: spectre_v2 test must be built 64-bit powerpc/powernv: Disable native PCIe port management powerpc/kexec: Move kexec files into a dedicated subdir. powerpc/32: Split kexec low level code out of misc_32.S powerpc/sysdev: drop simple gpio powerpc/83xx: map IMMR with a BAT. powerpc/32s: automatically allocate BAT in setbat() powerpc/ioremap: warn on early use of ioremap() powerpc: Add support for GENERIC_EARLY_IOREMAP powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt() powerpc/8xx: use the fixmapped IMMR in cpm_reset() powerpc/8xx: add __init to cpm1 init functions ...
2019-11-29powerpc/fixmap: fix crash with HIGHMEMChristophe Leroy1-0/+6
Commit f2bb86937d86 ("powerpc/fixmap: don't clear fixmap area in paging_init()") removed the clearing of fixmap area in order to avoid clearing fixmapped areas set earlier. However unlike all other users of fixmap which use __set_fixmap(), HIGHMEM functions directly use __set_pte_at(). This means the page table must pre-exist, otherwise the following crash can be encoutered due to the lack of entry in the PGD. Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.4.0+ #2528 NIP: c0144ce8 LR: c0144ccc CTR: 00000080 REGS: ef0b5aa0 TRAP: 0300 Not tainted (5.4.0+) MSR: 00009032 <EE,ME,IR,DR,RI> CR: 44282842 XER: 00000000 DAR: fffdf000 DSISR: 42000000 GPR00: c0144ccc ef0b5b58 ef0b0000 fffdf000 fffdf000 00000000 c0000f7c 00000000 GPR08: c0833000 fffdf000 00000000 ef1c53c9 24042842 00000000 00000000 00000000 GPR16: 00000000 00000000 ef7e7358 effe8160 00000000 c08a9660 c0851644 00000004 GPR24: c08c70a8 00002dc2 00000000 00000001 00000201 effe8160 effe8160 00000000 NIP [c0144ce8] prep_new_page+0x138/0x178 LR [c0144ccc] prep_new_page+0x11c/0x178 Call Trace: [ef0b5b58] [c0144ccc] prep_new_page+0x11c/0x178 (unreliable) [ef0b5b88] [c0147218] get_page_from_freelist+0x1fc/0xd88 [ef0b5c38] [c0148328] __alloc_pages_nodemask+0xd4/0xbb4 [ef0b5cf8] [c0142ba8] __vmalloc_node_range+0x1b4/0x2e0 [ef0b5d38] [c0142dd0] vzalloc+0x48/0x58 [ef0b5d58] [c0301c8c] check_partition+0x58/0x244 [ef0b5d78] [c02ffe80] blk_add_partitions+0x44/0x2cc [ef0b5db8] [c01a32d8] bdev_disk_changed+0x68/0xfc [ef0b5de8] [c01a4494] __blkdev_get+0x290/0x460 [ef0b5e28] [c02fdd40] __device_add_disk+0x480/0x4d8 [ef0b5e68] [c0810688] brd_init+0xc0/0x188 [ef0b5e88] [c0005194] do_one_initcall+0x40/0x19c [ef0b5ee8] [c07dd4dc] kernel_init_freeable+0x164/0x230 [ef0b5f28] [c0005408] kernel_init+0x18/0x10c [ef0b5f38] [c0014274] ret_from_kernel_thread+0x14/0x1c Partially revert that commit to still clear the fixmap area dedicated to HIGHMEM. Fixes: f2bb86937d86 ("powerpc/fixmap: don't clear fixmap area in paging_init()") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d42fa9747df5afa41e67b08e374c98d3b40529c9.1574927918.git.christophe.leroy@c-s.fr
2019-11-25powerpc/fixmap: don't clear fixmap area in paging_init()Christophe Leroy1-8/+0
fixmap is intended to map things permanently like the IMMR region on FSL SOC (8xx, 83xx, ...), so don't clear it when initialising paging() Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/41c99bc06394a6bc2888631cb98a3ed2ae281ddb.1568295907.git.christophe.leroy@c-s.fr
2019-11-21Merge branch 'for-next/zone-dma' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into dma-mapping-for-nextChristoph Hellwig1-5/+15
Pull in a stable branch from the arm64 tree that adds the zone_dma_bits variable to avoid creating hard to resolve conflicts with that addition.
2019-11-20dma-mapping: drop the dev argument to arch_sync_dma_for_*Christoph Hellwig1-4/+4
These are pure cache maintainance routines, so drop the unused struct device argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2019-11-19powerpc/32s: automatically allocate BAT in setbat()Christophe Leroy1-1/+10
If no BAT is given to setbat(), select an available BAT. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a212bd36fbd6179e0929b6c727febc35132ac25c.1568665466.git.christophe.leroy@c-s.fr
2019-11-19powerpc/ioremap: warn on early use of ioremap()Christophe Leroy2-0/+3
Powerpc now has EARLY_IOREMAP. Next step is to convert all early users of ioremap() to early_ioremap(). Add a warning to help locate those users. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b4f03a68ee8e68773c8973d74ec35f9c82c72871.1568295907.git.christophe.leroy@c-s.fr
2019-11-18powerpc/32: Don't populate page tables for block mapped pages except on the 8xx.Christophe Leroy2-7/+50
Commit d2f15e0979ee ("powerpc/32: always populate page tables for Abatron BDI.") wrongly sets page tables for any PPC32 for using BDI, and does't update them after init (remove RX on init section, set text and rodata read-only) Only the 8xx requires page tables to be populated for using the BDI. They also need to be populated in order to see the mappings in /sys/kernel/debug/kernel_page_tables On BOOK3S_32, pages that are not mapped by page tables are mapped by BATs. The BDI knows BATs and they can be viewed in /sys/kernel/debug/powerpc/block_address_translation Only set pagetables for RAM and IMMR on the 8xx and properly update them at the end of init. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c8610942203e0d93fcb02ad20c57edd3adb4c9d3.1566554029.git.christophe.leroy@c-s.fr
2019-11-18powerpc/mm: Show if a bad page fault on data is read or write.Christophe Leroy1-2/+4
DSISR (or ESR on some CPUs) has a bit to tell if the fault is due to a read or a write. Display it. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Santosh Sivaraj <santosh@fossix.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr
2019-11-14Merge branch 'topic/kaslr-book3e32' into nextMichael Ellerman7-12/+426
This is a slight rebase of Scott's next branch, which contained the KASLR support for book3e 32-bit, to squash in a couple of small fixes. See the original pull request: https://lore.kernel.org/r/20191022232155.GA26174@home.buserror.net
2019-11-13powerpc/fsl_booke/kaslr: support nokaslr cmdline parameterJason Yan1-0/+7
One may want to disable kaslr when boot, so provide a cmdline parameter 'nokaslr' to support this. Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13powerpc/fsl_booke/kaslr: clear the original kernel if randomizedJason Yan3-0/+14
The original kernel still exists in the memory, clear it now. Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13powerpc/fsl_booke/32: randomize the kernel image offsetJason Yan1-2/+323
After we have the basic support of relocate the kernel in some appropriate place, we can start to randomize the offset now. Entropy is derived from the banner and timer, which will change every build and boot. This not so much safe so additionally the bootloader may pass entropy via the /chosen/kaslr-seed node in device tree. We will use the first 512M of the low memory to randomize the kernel image. The memory will be split in 64M zones. We will use the lower 8 bit of the entropy to decide the index of the 64M zone. Then we chose a 16K aligned offset inside the 64M zone to put the kernel in. We also check if we will overlap with some areas like the dtb area, the initrd area or the crashkernel area. If we cannot find a proper area, kaslr will be disabled and boot from the original kernel. Some pieces of code are derived from arch/x86/boot/compressed/kaslr.c or arch/arm64/kernel/kaslr.c such as rotate_xor(). Credit goes to Kees and Ard. Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13powerpc/fsl_booke/32: implement KASLR infrastructureJason Yan4-2/+75
This patch add support to boot kernel from places other than KERNELBASE. Since CONFIG_RELOCATABLE has already supported, what we need to do is map or copy kernel to a proper place and relocate. Freescale Book-E parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1 entries are not suitable to map the kernel directly in a randomized region, so we chose to copy the kernel to a proper place and restart to relocate. The offset of the kernel was not randomized yet(a fixed 64M is set). We will randomize it in the next patch. Signed-off-by: Jason Yan <yanaijie@huawei.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net> [mpe: Use PTRRELOC() in early_init()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13powerpc/fsl_booke/32: introduce reloc_kernel_entry() helperJason Yan1-0/+1
Add a new helper reloc_kernel_entry() to jump back to the start of the new kernel. After we put the new kernel in a randomized place we can use this new helper to enter the kernel and begin to relocate again. Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13powerpc/fsl_booke/32: introduce create_kaslr_tlb_entry() helperJason Yan1-0/+1
Add a new helper create_kaslr_tlb_entry() to create a tlb entry by the virtual and physical address. This is a preparation to support boot kernel at a randomized address. Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13powerpc: introduce kernstart_virt_addr to store the kernel baseJason Yan1-0/+2
Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we need a variable to store the kernel base. Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13powerpc: move memstart_addr and kernstart_addr to init-common.cJason Yan3-10/+5
These two variables are both defined in init_32.c and init_64.c. Move them to init-common.c and make them __ro_after_init. Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>