- 21 Jul, 2020 13 commits
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Nicholas Piggin authored
The subpage_prot syscall was added for specialised system software (Lx86) that has been discontinued for about 7 years, and is not thought to be used elsewhere, so disable it by default. Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200703011958.1166620-4-npiggin@gmail.com
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Nicholas Piggin authored
ISA v3.1 does not support the SAO storage control attribute required to implement PROT_SAO. PROT_SAO was used by specialised system software (Lx86) that has been discontinued for about 7 years, and is not thought to be used elsewhere, so removal should not cause problems. We rather remove it than keep support for older processors, because live migrating guest partitions to newer processors may not be possible if SAO is in use (or worse allowed with silent races). - PROT_SAO stays in the uapi header so code using it would still build. - arch_validate_prot() is removed, the generic version rejects PROT_SAO so applications would get a failure at mmap() time. Signed-off-by:
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Nicholas Piggin authored
This comment is wrong, we wouldn't use calc_vm_prot_bits() here because we are being called by calc_vm_prot_bits() to modify its behaviour. Signed-off-by:
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YueHaibing authored
Both of those functions are only called from 64-bit only code, so the stubs should not be needed at all. Suggested-by:
YueHaibing <yuehaibing@huawei.com> Signed-off-by:
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Alexander A. Klimov authored
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by:Alexander A. Klimov <grandmaster@al2klimov.de> Signed-off-by:
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Alexander A. Klimov authored
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: -
Alexander A. Klimov authored
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: -
Michael Ellerman authored
Currently the spu coredump code triggers an RCU warning: ============================= WARNING: suspicious RCU usage 5.7.0-rc3-01755-g7cd49f0b7ec7 #1 Not tainted ----------------------------- include/linux/fdtable.h:95 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by spu-coredump/1343: #0: c0000007fa22f430 (sb_writers#2){.+.+}-{0:0}, at: .do_coredump+0x1010/0x13c8 stack backtrace: CPU: 0 PID: 1343 Comm: spu-coredump Not tainted 5.7.0-rc3-01755-g7cd49f0b7ec7 #1 Call Trace: .dump_stack+0xec/0x15c (unreliable) .lockdep_rcu_suspicious+0x120/0x144 .coredump_next_context+0x148/0x158 .spufs_coredump_extra_notes_size+0x54/0x190 .elf_coredump_extra_notes_size+0x34/0x50 .elf_core_dump+0xe48/0x19d0 .do_coredump+0xe50/0x13c8 .get_signal+0x864/0xd88 .do_notify_resume+0x158/0x3c8 .interrupt_exit_user_prepare+0x19c/0x208 interrupt_return+0x14/0x1c0 This comes from fcheck_files() via fcheck(). It's pretty clearly documented that fcheck() must be wrapped with rcu_read_lock(), adding that fixes the RCU warning. hch points out that once we've released the RCU read lock the file may be closed and freed, which would leave us with a pointer to a freed spu_context. To avoid that, take a reference to the spu_context while we hold the RCU read lock, and drop that reference later once we're done with the context. Signed-off-by: -
Michael Ellerman authored
The per_event_excludes test wants to run on Power8 or later. But currently it checks that AT_BASE_PLATFORM *equals* power8, which means it only runs on Power8. Fix it to check for the ISA 2.07 feature, which will be set on Power8 and later CPUs. Signed-off-by:
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Aneesh Kumar K.V authored
There is only one caller to this function and the function is wrongly named. Avoid further confusion w.r.t name and open code this at the only call site. Also remove read_uamor(). There are no users for the same after this. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
With commit 4a4a5e5d ("powerpc/pkeys: key allocation/deallocation must not change pkey registers") we are not updating UAMOR on key allocation. So don't update the expected uamor value in the test. Fixes: 4a4a5e5d ("powerpc/pkeys: key allocation/deallocation must not change pkey registers") Signed-off-by:
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Aneesh Kumar K.V authored
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Aneesh Kumar K.V authored
Rename variable to indicate that they are invalid values which we will use to test ptrace update of pkeys. Signed-off-by:
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- 20 Jul, 2020 26 commits
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Aneesh Kumar K.V authored
UAMOR values are not application-specific. The kernel initializes its value based on different reserved keys. Remove the thread-specific UAMOR value and don't switch the UAMOR on context switch. Move UAMOR initialization to key initialization code and remove thread_struct.uamor because it is not used anymore. Before commit: 4a4a5e5d ("powerpc/pkeys: key allocation/deallocation must not change pkey registers") we used to update uamor based on key allocation and free. Signed-off-by:
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Aneesh Kumar K.V authored
As we kexec across kernels that use AMR/IAMR for different purposes we need to ensure that new kernels get kexec'd with a reset value of AMR/IAMR. For ex: the new kernel can use key 0 for kernel mapping and the old AMR value prevents access to key 0. This patch also removes reset if IAMR and AMOR in kexec_sequence. Reset of AMOR is not needed and the IAMR reset is partial (it doesn't do the reset on secondary cpus) and is redundant with this patch. Signed-off-by:
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Aneesh Kumar K.V authored
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Aneesh Kumar K.V authored
Instead of pkey_disabled static key use mmu feature MMU_FTR_PKEY. Signed-off-by:
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Aneesh Kumar K.V authored
Use pkey_execute_disable_supported to check for execute key support instead of pkey_disabled. Signed-off-by:
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Aneesh Kumar K.V authored
This will be used to enable/disable Kernel Userspace Execution Prevention (KUEP). Signed-off-by:
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Aneesh Kumar K.V authored
Parse storage keys related device tree entry in early_init_devtree and enable MMU feature MMU_FTR_PKEY if pkeys are supported. MMU feature is used instead of CPU feature because this enables us to group MMU_FTR_KUAP and MMU_FTR_PKEY in asm feature fixup code. Signed-off-by:
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Aneesh Kumar K.V authored
The hypervisor can return less than max allowed pkey (for ex: 31) instead of 32. We should mark all the pkeys above max allowed as reserved so that we avoid the allocation of the wrong pkey(for ex: key 31 in the above case) by userspace. Signed-off-by:
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Aneesh Kumar K.V authored
initial_allocation_mask is not used outside this file. Also mark reserved_allocation_mask and initial_allocation_mask __ro_after_init; Signed-off-by:
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Aneesh Kumar K.V authored
num_pkey now represents max number of keys supported such that we return to userspace 0 - num_pkey - 1. Signed-off-by:
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Aneesh Kumar K.V authored
Make the default value FALSE (pkey enabled) and set to TRUE when we find the total number of keys supported to be zero. Signed-off-by:
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Aneesh Kumar K.V authored
We don't use CPU_FTR_PKEY anymore. Remove the feature bit and mark it free. Signed-off-by:
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Aneesh Kumar K.V authored
Key 1 is marked reserved by ISA. Setup uamor to prevent userspace modification of the same. Signed-off-by:
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Aneesh Kumar K.V authored
Add documentation explaining the execute_only_key. The reservation and initialization mask details are also explained in this patch. No functional change in this patch. Signed-off-by:
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Aneesh Kumar K.V authored
This explains the details w.r.t key 1. Signed-off-by:
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Aneesh Kumar K.V authored
To keep things simple, all the pkey related bits are kept together in linux page table for 64K config with hash translation. With hash-4k kernel requires 4 bits to store slots details. This is done by overloading some of the RPN bits for storing the slot details. Due to this PKEY_BIT0 on the 4K config is used for storing hash slot details. 64K before |....|RSV1| RSV2| RSV3 | RSV4 | RPN44| RPN43 |.... | RSV5| |....| P4 | P3 | P2 | P1 | Busy | HASHPTE |.... | P0 | after |....|RSV1| RSV2| RSV3 | RSV4 | RPN44 | RPN43 |.... | RSV5 | |....| P4 | P3 | P2 | P1 | P0 | HASHPTE |.... | Busy | 4k before |....| RSV1 | RSV2 | RSV3 | RSV4 | RPN44| RPN43.... | RSV5| |....| Busy | HASHPTE | P2 | P1 | F_SEC| F_GIX.... | P0 | after |....| RSV1 | RSV2| RSV3 | RSV4 | Free | RPN43.... | RSV5 | |....| HASHPTE | P2 | P1 | P0 | F_SEC| F_GIX.... | BUSY | Signed-off-by:
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Aneesh Kumar K.V authored
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Aneesh Kumar K.V authored
This number the pkey bit such that it is easy to follow. PKEY_BIT0 is the lower order bit. This makes further changes easy to follow. No functional change in this patch other than linux page table for hash translation now maps pkeys differently. Signed-off-by:
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Aneesh Kumar K.V authored
We are wrongly using CPU_FTRS_POWER8 to check for P8 support. Instead, we should use PVR value. Now considering we are using CPU_FTRS_POWER8, that implies we returned true for P9 with older firmware. Keep the same behavior by checking for P9 PVR value. Fixes: cf43d3b2 ("powerpc: Enable pkey subsystem") Signed-off-by:
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Santosh Sivaraj authored
Subscribe to the MCE notification and add the physical address which generated a memory error to nvdimm bad range. Signed-off-by:
Santosh Sivaraj <santosh@fossix.org> Reviewed-by:
Mahesh Salgaonkar <mahesh@linux.ibm.com> Reviewed-by:
Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:
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Santosh Sivaraj authored
Introduce notification chain which lets us know about uncorrected memory errors(UE). This would help prospective users in pmem or nvdimm subsystem to track bad blocks for better handling of persistent memory allocations. Signed-off-by:
Ganesh Goudar <ganeshgr@linux.ibm.com> Reviewed-by:
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Aneesh Kumar K.V authored
To enable memory unplug without splitting kernel page table mapping, we force the max mapping size to the LMB size. LMB size is the unit in which hypervisor will do memory add/remove operation. Pseries systems supports max LMB size of 256MB. Hence on pseries, we now end up mapping memory with 2M page size instead of 1G. To improve that we want hypervisor to hint the kernel about the hotplug memory range. That was added that as part of commit b6eca183 ("powerpc/kernel: Enables memory hot-remove after reboot on pseries guests") But PowerVM doesn't provide that hint yet. Once we get PowerVM updated, we can then force the 2M mapping only to hot-pluggable memory region using memblock_is_hotpluggable(). Till then let's depend on LMB size for finding the mapping page size for linear range. With this change KVM guest will also be doing linear mapping with 2M page size. The actual TLB benefit of mapping guest page table entries with hugepage size can only be materialized if the partition scoped entries are also using the same or higher page size. A guest using 1G hugetlbfs backing guest memory can have a performance impact with the above change. Signed-off-by:
Bharata B Rao <bharata@linux.ibm.com> Signed-off-by:
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Bharata B Rao authored
We split the page table mapping on memory unplug if the linear range was mapped with huge page mapping (for ex: 1G) The page table splitting code has a few issues: 1. Recursive locking -------------------- Memory unplug path takes cpu_hotplug_lock and calls stop_machine() for splitting the mappings. However stop_machine() takes cpu_hotplug_lock again causing deadlock. 2. BUG: sleeping function called from in_atomic() context --------------------------------------------------------- Memory unplug path (remove_pagetable) takes init_mm.page_table_lock spinlock and later calls stop_machine() which does wait_for_completion() 3. Bad unlock unbalance ----------------------- Memory unplug path takes init_mm.page_table_lock spinlock and calls stop_machine(). The stop_machine thread function runs in a different thread context (migration thread) which tries to release and reaquire ptl. Releasing ptl from a different thread than which acquired it causes bad unlock unbalance. These problems can be avoided if we avoid mapping hot-plugged memory with 1G mapping, thereby removing the need for splitting them during unplug. The kernel always make sure the minimum unplug request is SUBSECTION_SIZE for device memory and SECTION_SIZE for regular memory. In preparation for such a change remove page table splitting support. This essentially is a revert of commit 4dd5f8a9 ("powerpc/mm/radix: Split linear mapping on hot-unplug") Signed-off-by:
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Bharata B Rao authored
remove_pagetable() isn't freeing PUD table. This causes memory leak during memory unplug. Fix this. Fixes: 4b5d62ca ("powerpc/mm: add radix__remove_section_mapping()") Signed-off-by:
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Aneesh Kumar K.V authored
We can hit the following BUG_ON during memory unplug: kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:342! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries NIP [c000000000093308] pmd_fragment_free+0x48/0xc0 LR [c00000000147bfec] remove_pagetable+0x578/0x60c Call Trace: 0xc000008050000000 (unreliable) remove_pagetable+0x384/0x60c radix__remove_section_mapping+0x18/0x2c remove_section_mapping+0x1c/0x3c arch_remove_memory+0x11c/0x180 try_remove_memory+0x120/0x1b0 __remove_memory+0x20/0x40 dlpar_remove_lmb+0xc0/0x114 dlpar_memory+0x8b0/0xb20 handle_dlpar_errorlog+0xc0/0x190 pseries_hp_work_fn+0x2c/0x60 process_one_work+0x30c/0x810 worker_thread+0x98/0x540 kthread+0x1c4/0x1d0 ret_from_kernel_thread+0x5c/0x74 This occurs when unplug is attempted for such memory which has been mapped using memblock pages as part of early kernel page table setup. We wouldn't have initialized the PMD or PTE fragment count for those PMD or PTE pages. This can be fixed by allocating memory in PAGE_SIZE granularity during early page table allocation. This makes sure a specific page is not shared for another memblock allocation and we can free them correctly on removing page-table pages. Since we now do PAGE_SIZE allocations for both PUD table and PMD table (Note that PTE table allocation is already of PAGE_SIZE), we end up allocating more memory for the same amount of system RAM. Here is a comparision of how much more we need for a 64T and 2G system after this patch: 1. 64T system ------------- 64T RAM would need 64G for vmemmap with struct page size being 64B. 128 PUD tables for 64T memory (1G mappings) 1 PUD table and 64 PMD tables for 64G vmemmap (2M mappings) With default PUD[PMD]_TABLE_SIZE(4K), (128+1+64)*4K=772K With PAGE_SIZE(64K) table allocations, (128+1+64)*64K=12352K 2. 2G system ------------ 2G RAM would need 2M for vmemmap with struct page size being 64B. 1 PUD table for 2G memory (1G mapping) 1 PUD table and 1 PMD table for 2M vmemmap (2M mappings) With default PUD[PMD]_TABLE_SIZE(4K), (1+1+1)*4K=12K With new PAGE_SIZE(64K) table allocations, (1+1+1)*64K=192K Signed-off-by:
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Nicholas Piggin authored
When '029ab30b ("powerpc/mm: Enable radix GTSE only if supported.")' made GTSE an MMU feature, it was enabled by default in powerpc-cpu-features but was missed in pa-features. This causes random memory corruption during boot of PowerNV kernels where CONFIG_PPC_DT_CPU_FTRS isn't enabled. Fixes: 029ab30b ("powerpc/mm: Enable radix GTSE only if supported.") Reported-by:
Qian Cai <cai@lca.pw> Signed-off-by:
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- 18 Jul, 2020 1 commit
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Michael Ellerman authored
Merge our fixes branch, primarily to bring in the ebb selftests build fix and the pkey fix, which is a dependency for some future work.
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