- 17 Feb, 2018 1 commit
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Dan Williams authored
There are multiple problems with the dynamic sanity checking in array_index_nospec_mask_check(): * It causes unnecessary overhead in the 32-bit case since integer sized @index values will no longer cause the check to be compiled away like in the 64-bit case. * In the 32-bit case it may trigger with user controllable input when the expectation is that should only trigger during development of new kernel enabling. * The macro reuses the input parameter in multiple locations which is broken if someone passes an expression like 'index++' to array_index_nospec(). Reported-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Dan Williams <dan.j.williams@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/151881604278.17395.6605847763178076520.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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- 15 Feb, 2018 15 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar: "Here's the latest set of Spectre and PTI related fixes and updates: Spectre: - Add entry code register clearing to reduce the Spectre attack surface - Update the Spectre microcode blacklist - Inline the KVM Spectre helpers to get close to v4.14 performance again. - Fix indirect_branch_prediction_barrier() - Fix/improve Spectre related kernel messages - Fix array_index_nospec_mask() asm constraint - KVM: fix two MSR handling bugs PTI: - Fix a paranoid entry PTI CR3 handling bug - Fix comments objtool: - Fix paranoid_entry() frame pointer warning - Annotate WARN()-related UD2 as reachable - Various fixes - Add Add Peter Zijlstra as objtool co-maintainer Misc: - Various x86 entry code self-test fixes - Improve/simplify entry code stack frame generation and handling after recent heavy-handed PTI and Spectre changes. (There's two more WIP improvements expected here.) - Type fix for cache entries There's also some low risk non-fix changes I've included in this branch to reduce backporting conflicts: - rename a confusing x86_cpu field name - de-obfuscate the naming of single-TLB flushing primitives" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) x86/entry/64: Fix CR3 restore in paranoid_exit() x86/cpu: Change type of x86_cache_size variable to unsigned int x86/spectre: Fix an error message x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping selftests/x86/mpx: Fix incorrect bounds with old _sigfault x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]() x86/speculation: Add <asm/msr-index.h> dependency nospec: Move array_index_nospec() parameter checking into separate macro x86/speculation: Fix up array_index_nospec_mask() asm constraint x86/debug: Use UD2 for WARN() x86/debug, objtool: Annotate WARN()-related UD2 as reachable objtool: Fix segfault in ignore_unreachable_insn() selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory selftests/x86/pkeys: Remove unused functions selftests/x86: Clean up and document sscanf() usage selftests/x86: Fix vDSO selftest segfault for vsyscall=none x86/entry/64: Remove the unused 'icebp' macro ... -
Ingo Molnar authored
Josh Poimboeuf noticed the following bug: "The paranoid exit code only restores the saved CR3 when it switches back to the user GS. However, even in the kernel GS case, it's possible that it needs to restore a user CR3, if for example, the paranoid exception occurred in the syscall exit path between SWITCH_TO_USER_CR3_STACK and SWAPGS." Josh also confirmed via targeted testing that it's possible to hit this bug. Fix the bug by also restoring CR3 in the paranoid_exit_no_swapgs branch. The reason we haven't seen this bug reported by users yet is probably because "paranoid" entry points are limited to the following cases: idtentry double_fault do_double_fault has_error_code=1 paranoid=2 idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK idtentry machine_check do_mce has_error_code=0 paranoid=1 Amongst those entry points only machine_check is one that will interrupt an IRQS-off critical section asynchronously - and machine check events are rare. The other main asynchronous entries are NMI entries, which can be very high-freq with perf profiling, but they are special: they don't use the 'idtentry' macro but are open coded and restore user CR3 unconditionally so don't have this bug. Reported-and-tested-by:
Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by:
Andy Lutomirski <luto@kernel.org> Acked-by:
Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180214073910.boevmg65upbk3vqb@gmail.comSigned-off-by:
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Gustavo A. R. Silva authored
Currently, x86_cache_size is of type int, which makes no sense as we will never have a valid cache size equal or less than 0. So instead of initializing this variable to -1, it can perfectly be initialized to 0 and use it as an unsigned variable instead. Suggested-by:
Gustavo A. R. Silva <garsilva@embeddedor.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Addresses-Coverity-ID: 1464429 Link: http://lkml.kernel.org/r/20180213192208.GA26414@embeddedor.comSigned-off-by:
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Dan Carpenter authored
If i == ARRAY_SIZE(mitigation_options) then we accidentally print garbage from one space beyond the end of the mitigation_options[] array. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: KarimAllah Ahmed <karahmed@amazon.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-janitors@vger.kernel.org Fixes: 9005c683 ("x86/spectre: Simplify spectre_v2 command line parsing") Link: http://lkml.kernel.org/r/20180214071416.GA26677@mwandaSigned-off-by:
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Jia Zhang authored
x86_mask is a confusing name which is hard to associate with the processor's stepping. Additionally, correct an indent issue in lib/cpu.c. Signed-off-by:
Jia Zhang <qianyue.zj@alibaba-inc.com> [ Updated it to more recent kernels. ] Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: tony.luck@intel.com Link: http://lkml.kernel.org/r/1514771530-70829-1-git-send-email-qianyue.zj@alibaba-inc.comSigned-off-by:
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Rui Wang authored
For distributions with old userspace header files, the _sigfault structure is different. mpx-mini-test fails with the following error: [root@Purley]# mpx-mini-test_64 tabletest XSAVE is supported by HW & OS XSAVE processor supported state mask: 0x2ff XSAVE OS supported state mask: 0x2ff BNDREGS: size: 64 user: 1 supervisor: 0 aligned: 0 BNDCSR: size: 64 user: 1 supervisor: 0 aligned: 0 starting mpx bounds table test ERROR: siginfo bounds do not match shadow bounds for register 0 Fix it by using the correct offset of _lower/_upper in _sigfault. RHEL needs this patch to work. Signed-off-by:Rui Wang <rui.y.wang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave.hansen@linux.intel.com Fixes: e754aedc ("x86/mpx, selftests: Add MPX self test") Link: http://lkml.kernel.org/r/1513586050-1641-1-git-send-email-rui.y.wang@intel.comSigned-off-by:
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Andy Lutomirski authored
flush_tlb_single() and flush_tlb_one() sound almost identical, but they really mean "flush one user translation" and "flush one kernel translation". Rename them to flush_tlb_one_user() and flush_tlb_one_kernel() to make the semantics more obvious. [ I was looking at some PTI-related code, and the flush-one-address code is unnecessarily hard to understand because the names of the helpers are uninformative. This came up during PTI review, but no one got around to doing it. ] Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Hugh Dickins <hughd@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linux-MM <linux-mm@kvack.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/3303b02e3c3d049dc5235d5651e0ae6d29a34354.1517414378.git.luto@kernel.orgSigned-off-by:
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Peter Zijlstra authored
Joe Konno reported a compile failure resulting from using an MSR without inclusion of <asm/msr-index.h>, and while the current code builds fine (by accident) this needs fixing for future patches. Reported-by:
Joe Konno <joe.konno@linux.intel.com> Signed-off-by:
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Will Deacon authored
For architectures providing their own implementation of array_index_mask_nospec() in asm/barrier.h, attempting to use WARN_ONCE() to complain about out-of-range parameters using WARN_ON() results in a mess of mutually-dependent include files. Rather than unpick the dependencies, simply have the core code in nospec.h perform the checking for us. Signed-off-by:
Will Deacon <will.deacon@arm.com> Acked-by:
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Dan Williams authored
Allow the compiler to handle @size as an immediate value or memory directly rather than allocating a register. Reported-by:
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Peter Zijlstra authored
Since the Intel SDM added an ModR/M byte to UD0 and binutils followed that specification, we now cannot disassemble our kernel anymore. This now means Intel and AMD disagree on the encoding of UD0. And instead of playing games with additional bytes that are valid ModR/M and single byte instructions (0xd6 for instance), simply use UD2 for both WARN() and BUG(). Requested-by:
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Josh Poimboeuf authored
By default, objtool assumes that a UD2 is a dead end. This is mainly because GCC 7+ sometimes inserts a UD2 when it detects a divide-by-zero condition. Now that WARN() is moving back to UD2, annotate the code after it as reachable so objtool can follow the code flow. Reported-by:
Borislav Petkov <bp@alien8.de> Signed-off-by:
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Josh Poimboeuf authored
Peter Zijlstra's patch for converting WARN() to use UD2 triggered a bunch of false "unreachable instruction" warnings, which then triggered a seg fault in ignore_unreachable_insn(). The seg fault happened when it tried to dereference a NULL 'insn->func' pointer. Thanks to static_cpu_has(), some functions can jump to a non-function area in the .altinstr_aux section. That breaks ignore_unreachable_insn()'s assumption that it's always inside the original function. Make sure ignore_unreachable_insn() only follows jumps within the current function. Reported-by:
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Dominik Brodowski authored
The ldt_gdt and ptrace_syscall selftests, even in their 64-bit variant, use hard-coded 32-bit syscall numbers and call "int $0x80". This will fail on 64-bit systems with CONFIG_IA32_EMULATION=y disabled. Therefore, do not build these tests if we cannot build 32-bit binaries (which should be a good approximation for CONFIG_IA32_EMULATION=y being enabled). Signed-off-by:
Dominik Brodowski <linux@dominikbrodowski.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kselftest@vger.kernel.org Cc: shuah@kernel.org Link: http://lkml.kernel.org/r/20180211111013.16888-6-linux@dominikbrodowski.netSigned-off-by:
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Dominik Brodowski authored
On 64-bit builds, we should not rely on "int $0x80" working (it only does if CONFIG_IA32_EMULATION=y is enabled). To keep the "Set TF and check int80" test running on 64-bit installs with CONFIG_IA32_EMULATION=y enabled, build this test only if we can also build 32-bit binaries (which should be a good approximation for that). Signed-off-by:
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- 14 Feb, 2018 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2Linus Torvalds authored
Pull gfs2 fix from Bob Peterson: "Fix regressions in the gfs2 iomap for block_map implementation we recently discovered in commit 3974320c" * tag 'gfs2-4.16.rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: Fixes to "Implement iomap for block_map"
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc fixes from Michael Ellerman: "A larger batch of fixes than we'd like. Roughly 1/3 fixes for new code, 1/3 fixes for stable and 1/3 minor things. There's four commits fixing bugs when using 16GB huge pages on hash, caused by some of the preparatory changes for pkeys. Two fixes for bugs in the enhanced IRQ soft masking for local_t, one of which broke KVM in some circumstances. Four fixes for Power9. The most bizarre being a bug where futexes stopped working because a NULL pointer dereference didn't trap during early boot (it aliased the kernel mapping). A fix for memory hotplug when using the Radix MMU, and a fix for live migration of guests using the Radix MMU. Two fixes for hotplug on pseries machines. One where we weren't correctly updating NUMA info when CPUs are added and removed. And the other fixes crashes/hangs seen when doing memory hot remove during boot, which is apparently a thing people do. Finally a handful of build fixes for obscure configs and other minor fixes. Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Balbir Singh, Colin Ian King, Daniel Henrique Barboza, Florian Weimer, Guenter Roeck, Harish, Laurent Vivier, Madhavan Srinivasan, Mauricio Faria de Oliveira, Nathan Fontenot, Nicholas Piggin, Sam Bobroff" * tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: selftests/powerpc: Fix to use ucontext_t instead of struct ucontext powerpc/kdump: Fix powernv build break when KEXEC_CORE=n powerpc/pseries: Fix build break for SPLPAR=n and CPU hotplug powerpc/mm/hash64: Zero PGD pages on allocation powerpc/mm/hash64: Store the slot information at the right offset for hugetlb powerpc/mm/hash64: Allocate larger PMD table if hugetlb config is enabled powerpc/mm: Fix crashes with 16G huge pages powerpc/mm: Flush radix process translations when setting MMU type powerpc/vas: Don't set uses_vas for kernel windows powerpc/pseries: Enable RAS hotplug events later powerpc/mm/radix: Split linear mapping on hot-unplug powerpc/64s/radix: Boot-time NULL pointer protection using a guard-PID ocxl: fix signed comparison with less than zero powerpc/64s: Fix may_hard_irq_enable() for PMI soft masking powerpc/64s: Fix MASKABLE_RELON_EXCEPTION_HV_OOL macro powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove
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- 13 Feb, 2018 22 commits
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Andreas Gruenbacher authored
It turns out that commit 3974320c "Implement iomap for block_map" introduced a few bugs that trigger occasional failures with xfstest generic/476: In gfs2_iomap_begin, we jump to do_alloc when we determine that we are beyond the end of the allocated metadata (height > ip->i_height). There, we can end up calling hole_size with a metapath that doesn't match the current metadata tree, which doesn't make sense. After untangling the code at do_alloc, fix this by checking if the block we are looking for is within the range of allocated metadata. In addition, add a BUG() in case gfs2_iomap_begin is accidentally called for reading stuffed files: this is handled separately. Make sure we don't truncate iomap->length for reads beyond the end of the file; in that case, the entire range counts as a hole. Finally, revert to taking a bitmap write lock when doing allocations. It's unclear why that change didn't lead to any failures during testing. Signed-off-by:
Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by:
Bob Peterson <rpeterso@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mipsLinus Torvalds authored
Pull MIPS fix from James Hogan: "A single change (and associated DT binding update) to allow the address of the MIPS Cluster Power Controller (CPC) to be chosen by DT, which allows SMP to work on generic MIPS kernels where the bootloader hasn't configured the CPC address (i.e. the new Ranchu platform)" * tag 'mips_4.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips: MIPS: CPC: Map registers using DT in mips_cpc_default_phys_base() dt-bindings: Document mti,mips-cpc binding
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Harish authored
With glibc 2.26 'struct ucontext' is removed to improve POSIX compliance, which breaks powerpc/alignment_handler selftest. Fix the test by using ucontext_t. Tested on ppc, works with older glibc versions as well. Fixes the following: alignment_handler.c: In function ‘sighandler’: alignment_handler.c:68:5: error: dereferencing pointer to incomplete type ‘struct ucontext’ ucp->uc_mcontext.gp_regs[PT_NIP] += 4; Signed-off-by:Harish <harish@linux.vnet.ibm.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Guenter Roeck authored
If KEXEC_CORE is not enabled, powernv builds fail as follows. arch/powerpc/platforms/powernv/smp.c: In function 'pnv_smp_cpu_kill_self': arch/powerpc/platforms/powernv/smp.c:236:4: error: implicit declaration of function 'crash_ipi_callback' Add dummy function calls, similar to kdump_in_progress(), to solve the problem. Fixes: 4145f358 ("powernv/kdump: Fix cases where the kdump kernel can get HMI's") Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Acked-by:
Balbir Singh <bsingharora@gmail.com> Signed-off-by:
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Guenter Roeck authored
Commit e67e02a5 ("powerpc/pseries: Fix cpu hotplug crash with memoryless nodes") adds an unconditional call to find_and_online_cpu_nid(), which is only declared if CONFIG_PPC_SPLPAR is enabled. This results in the following build error if this is not the case. arch/powerpc/platforms/pseries/hotplug-cpu.o: In function `dlpar_online_cpu': arch/powerpc/platforms/pseries/hotplug-cpu.c:369: undefined reference to `.find_and_online_cpu_nid' Follow the guideline provided by similar functions and provide a dummy function if CONFIG_PPC_SPLPAR is not enabled. This also moves the external function declaration into an include file where it should be. Fixes: e67e02a5 ("powerpc/pseries: Fix cpu hotplug crash with memoryless nodes") Signed-off-by:
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Aneesh Kumar K.V authored
On powerpc we allocate page table pages from slab caches of different sizes. Currently we have a constructor that zeroes out the objects when we allocate them for the first time. We expect the objects to be zeroed out when we free the the object back to slab cache. This happens in the unmap path. For hugetlb pages we call huge_pte_get_and_clear() to do that. With the current configuration of page table size, both PUD and PGD level tables are allocated from the same slab cache. At the PUD level, we use the second half of the table to store the slot information. But we never clear that when unmapping. When such a freed object is then allocated for a PGD page, the second half of the page table page will not be zeroed as expected. This results in a kernel crash. Fix it by always clearing PGD pages when they're allocated. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Change log wording and formatting, add whitespace] Signed-off-by:
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Aneesh Kumar K.V authored
The hugetlb pte entries are at the PMD and PUD level, so we can't use PTRS_PER_PTE to find the second half of the page table. Use the right offset for PUD/PMD to get to the second half of the table. Fixes: bf9a95f9 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by:
Ram Pai <linuxram@us.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
We use the second half of the page table to store slot information, so we must allocate it always if hugetlb is possible. Fixes: bf9a95f9 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by:
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Aneesh Kumar K.V authored
To support memory keys, we moved the hash pte slot information to the second half of the page table. This was ok with PTE entries at level 4 (PTE page) and level 3 (PMD). We already allocate larger page table pages at those levels to accomodate extra details. For level 4 we already have the extra space which was used to track 4k hash page table entry details and at level 3 the extra space was allocated to track the THP details. With hugetlbfs PTE, we used this extra space at the PMD level to store the slot details. But we also support hugetlbfs PTE at PUD level for 16GB pages and PUD level page didn't allocate extra space. This resulted in memory corruption. Fix this by allocating extra space at PUD level when HUGETLB is enabled. Fixes: bf9a95f9 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by:
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Alexey Kardashevskiy authored
Radix guests do normally invalidate process-scoped translations when a new pid is allocated but migrated guests do not invalidate these so migrated guests crash sometime, especially easy to reproduce with migration happening within first 10 seconds after the guest boot start on the same machine. This adds the "Invalidate process-scoped translations" flush to fix radix guests migration. Fixes: 2ee13be3 ("KVM: PPC: Book3S HV: Update kvmppc_set_arch_compat() for ISA v3.00") Cc: stable@vger.kernel.org # v4.10+ Signed-off-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Tested-by:
Laurent Vivier <lvivier@redhat.com> Tested-by:
Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> Signed-off-by:
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Nicholas Piggin authored
cp_abort is only required for user windows, because kernel context must not be preempted between a copy/paste pair. Without this patch, the init task gets used_vas set when it runs the nx842_powernv_init initcall, which opens windows for kernel usage. used_vas is then never cleared anywhere, so it gets propagated into all other tasks. It's a property of the address space, so it should really be cleared when a new mm is created (or in dup_mmap if the mmaps are marked as VM_DONTCOPY). For now we seem to have no such driver, so leave that for another patch. Fixes: 6c8e6bb2 ("powerpc/vas: Add support for user receive window") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Reviewed-by:
Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by:
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Sam Bobroff authored
Currently if the kernel receives a memory hot-unplug event early enough, it may get stuck in an infinite loop in dissolve_free_huge_pages(). This appears as a stall just after: pseries-hotplug-mem: Attempting to hot-remove XX LMB(s) at YYYYYYYY It appears to be caused by "minimum_order" being uninitialized, due to init_ras_IRQ() executing before hugetlb_init(). To correct this, extract the part of init_ras_IRQ() that enables hotplug event processing and place it in the machine_late_initcall phase, which is guaranteed to be after hugetlb_init() is called. Signed-off-by:
Sam Bobroff <sam.bobroff@au1.ibm.com> Acked-by:
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Dominik Brodowski authored
On 64-bit builds, we should not rely on "int $0x80" working (it only does if CONFIG_IA32_EMULATION=y is enabled). Without this patch, the move test may succeed, but the "int $0x80" causes a segfault, resulting in a false negative output of this self-test. Signed-off-by:
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Dominik Brodowski authored
Signed-off-by:
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Ingo Molnar authored
This also gets rid of two build warnings: protection_keys.c: In function ‘dumpit’: protection_keys.c:419:3: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result] write(1, buf, nr_read); ^~~~~~~~~~~~~~~~~~~~~~ Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: -
Dominik Brodowski authored
Replace a couple of magically connected buffer length literal constants with a common definition that makes their relationship obvious. Also document why our sscanf() usage is safe. No intended functional changes. Suggested-by:
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Dominik Brodowski authored
The vDSO selftest tries to execute a vsyscall unconditionally, even if it is not present on the test system (e.g. if booted with vsyscall=none or with CONFIG_LEGACY_VSYSCALL_NONE=y set. Fix this by copying (and tweaking) the vsyscall check from test_vsyscall.c Signed-off-by:
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Borislav Petkov authored
That macro was touched around 2.5.8 times, judging by the full history linux repo, but it was unused even then. Get rid of it already. Signed-off-by:
Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux@dominikbrodowski.net Link: http://lkml.kernel.org/r/20180212201318.GD14640@pd.tnicSigned-off-by:
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Josh Poimboeuf authored
With the following commit: f09d160992d1 ("x86/entry/64: Get rid of the ALLOC_PT_GPREGS_ON_STACK and SAVE_AND_CLEAR_REGS macros") ... one of my suggested improvements triggered a frame pointer warning: arch/x86/entry/entry_64.o: warning: objtool: paranoid_entry()+0x11: call without frame pointer save/setup The warning is correct for the build-time code, but it's actually not relevant at runtime because of paravirt patching. The paravirt swapgs call gets replaced with either a SWAPGS instruction or NOPs at runtime. Go back to the previous behavior by removing the ELF function annotation for paranoid_entry() and adding an unwind hint, which effectively silences the warning. Reported-by:kbuild test robot <fengguang.wu@intel.com> Signed-off-by:
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Dominik Brodowski authored
... same as the other macros in arch/x86/entry/calling.h Signed-off-by:
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Dominik Brodowski authored
Previously, error_entry() and paranoid_entry() saved the GP registers onto stack space previously allocated by its callers. Combine these two steps in the callers, and use the generic PUSH_AND_CLEAR_REGS macro for that. This adds a significant amount ot text size. However, Ingo Molnar points out that: "these numbers also _very_ significantly over-represent the extra footprint. The assumptions that resulted in us compressing the IRQ entry code have changed very significantly with the new x86 IRQ allocation code we introduced in the last year: - IRQ vectors are usually populated in tightly clustered groups. With our new vector allocator code the typical per CPU allocation percentage on x86 systems is ~3 device vectors and ~10 fixed vectors out of ~220 vectors - i.e. a very low ~6% utilization (!). [...] The days where we allocated a lot of vectors on every CPU and the compression of the IRQ entry code text mattered are over. - Another issue is that only a small minority of vectors is frequent enough to actually matter to cache utilization in practice: 3-4 key IPIs and 1-2 device IRQs at most - and those vectors tend to be tightly clustered as well into about two groups, and are probably already on 2-3 cache lines in practice. For the common case of 'cache cold' IRQs it's the depth of the call chain and the fragmentation of the resulting I$ that should be the main performance limit - not the overall size of it. - The CPU side cost of IRQ delivery is still very expensive even in the best, most cached case, as in 'over a thousand cycles'. So much stuff is done that maybe contemporary x86 IRQ entry microcode already prefetches the IDT entry and its expected call target address."[*] [*] http://lkml.kernel.org/r/20180208094710.qnjixhm6hybebdv7@gmail.com The "testb $3, CS(%rsp)" instruction in the idtentry macro does not need modification. Previously, %rsp was manually decreased by 15*8; with this patch, %rsp is decreased by 15 pushq instructions. [jpoimboe@redhat.com: unwind hint improvements] Suggested-by:
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Dominik Brodowski authored
entry_SYSCALL_64_after_hwframe() and nmi() can be converted to use PUSH_AND_CLEAN_REGS instead of opencoded variants thereof. Due to the interleaving, the additional XOR-based clearing of R8 and R9 in entry_SYSCALL_64_after_hwframe() should not have any noticeable negative implications. Suggested-by:
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