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2017-06-19mm: larger stack guard gap, between vmasHugh Dickins
Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-19crypto: glue_helper - Delete some dead codeDan Carpenter
We checked (nbytes < bsize) inside the loops so it's not possible to hit the "goto done;" here. This code is cut and paste from other slightly different loops where we don't have the check inside the loop. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-06-15x86/PCI: Simplify Dell DMI B1 quirkJean Delvare
No need for such convoluted code, when all we need is to call one function in one specific case. Tested-by: Narendra K <Narendra.K@dell.com> # DellEMC PowerEdge 1950, R730XD Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-06-15x86, dax, libnvdimm: remove wb_cache_pmem() indirectionDan Williams
With all handling of the CONFIG_ARCH_HAS_PMEM_API case being moved to libnvdimm and the pmem driver directly we do not need to provide global wrappers and fallbacks in the CONFIG_ARCH_HAS_PMEM_API=n case. The pmem driver will simply not link to arch_wb_cache_pmem() in that case. Same as before, pmem flushing is only defined for x86_64, via clean_cache_range(), but it is straightforward to add other archs in the future. arch_wb_cache_pmem() is an exported function since the pmem module needs to find it, but it is privately declared in drivers/nvdimm/pmem.h because there are no consumers outside of the pmem driver. Cc: <x86@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Oliver O'Halloran <oohall@gmail.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-15x86, dax: replace clear_pmem() with open coded memset + dax_ops->flushDan Williams
The clear_pmem() helper simply combines a memset() plus a cache flush. Now that the flush routine is optionally provided by the dax device driver we can avoid unnecessary cache management on dax devices fronting volatile memory. With clear_pmem() gone we can follow on with a patch to make pmem cache management completely defined within the pmem driver. Cc: <x86@kernel.org> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-15filesystem-dax: convert to dax_copy_from_iter()Dan Williams
Now that all possible providers of the dax_operations copy_from_iter method are implemented, switch filesytem-dax to call the driver rather than copy_to_iter_pmem. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
The conflicts were two cases of overlapping changes in batman-adv and the qed driver. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15iommu/vt-d: Correctly disable Intel IOMMU force onShaohua Li
I made a mistake in commit bfd20f1. We should skip the force on with the option enabled instead of vice versa. Not sure why this passed our performance test, sorry. Fixes: bfd20f1cc850 ('x86, iommu/vt-d: Add an option to disable Intel IOMMU force on') Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-06-14x86/mce: Update bootlog description to reflect behavior on AMDYazen Ghannam
The bootlog option is only disabled by default on AMD Fam10h and older systems. Update bootlog description to say this. Change the family value to hex to avoid confusion. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/20170613162835.30750-9-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14x86/mce: Don't disable MCA banks when offlining a CPU on AMDYazen Ghannam
AMD systems have non-core, shared MCA banks within a die. These banks are controlled by a master CPU per die. If this CPU is offlined then all the shared banks are disabled in addition to the CPU's core banks. Also, Fam17h systems may have SMT enabled. The MCA_CTL register is shared between SMT thread siblings. If a CPU is offlined then all its sibling's MCA banks are also disabled. Extend the existing vendor check to AMD too. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> [ Fix up comment. ] Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/20170613162835.30750-8-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14x86/mce/mce-inject: Preset the MCE injection structBorislav Petkov
Populate the MCE injection struct before doing initial injection so that values which don't change have sane defaults. Tested-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Yazen Ghannam <yazen.ghannam@amd.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/20170613162835.30750-7-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14x86/mce: Clean up include filesBorislav Petkov
Not really needed. Tested-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Yazen Ghannam <yazen.ghannam@amd.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/20170613162835.30750-6-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14x86/mce: Get rid of register_mce_write_callback()Borislav Petkov
Make the mcelog call a notifier which lands in the injector module and does the injection. This allows for mce-inject to be a normal kernel module now. Tested-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Yazen Ghannam <yazen.ghannam@amd.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/20170613162835.30750-5-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14x86/mce: Merge mce_amd_inj into mce-injectBorislav Petkov
Reuse mce_amd_inj's debugfs interface so that mce-inject can benefit from it too. The old functionality is still preserved under CONFIG_X86_MCELOG_LEGACY. Tested-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Yazen Ghannam <yazen.ghannam@amd.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/20170613162835.30750-4-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14x86/mce/AMD: Use saved threshold block info in interrupt handlerYazen Ghannam
In the amd_threshold_interrupt() handler, we loop through every possible block in each bank and rediscover the block's address and if it's valid, e.g. valid, counter present and not locked. However, we already have the address saved in the threshold blocks list for each CPU and bank. The list only contains blocks that have passed all the valid checks. Besides the redundancy, there's also a smp_call_function* in get_block_address() which causes a warning when servicing the interrupt: WARNING: CPU: 0 PID: 0 at kernel/smp.c:281 smp_call_function_single+0xdd/0xf0 ... Call Trace: <IRQ> rdmsr_safe_on_cpu() get_block_address.isra.2() amd_threshold_interrupt() smp_threshold_interrupt() threshold_interrupt() because we do get called in an interrupt handler *with* interrupts disabled, which can result in a deadlock. Drop the redundant valid checks and move the overflow check, logging and block reset into a separate function. Check the first block then iterate over the rest. This procedure is needed since the first block is used as the head of the list. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/20170613162835.30750-3-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14x86/mce/AMD: Use msr_stat when clearing MCA_STATUSYazen Ghannam
The value of MCA_STATUS is used as the MSR when clearing MCA_STATUS. This may cause the following warning: unchecked MSR access error: WRMSR to 0x11b (tried to write 0x0000000000000000) Call Trace: <IRQ> smp_threshold_interrupt() threshold_interrupt() Use msr_stat instead which has the MSR address. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Fixes: 37d43acfd79f ("x86/mce/AMD: Redo error logging from APIC LVT interrupt handlers") Link: http://lkml.kernel.org/r/20170613162835.30750-2-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-14Merge tag 'v4.12-rc5' into ras/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/PCI: Fix whitespace in set_bios_x() printkVincent Legoll
Remove the space from "PCI :" to make the message consistent with other PCI messages. Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-06-13xen/vcpu: Handle xen_vcpu_setup() failure at bootAnkur Arora
On PVH, PVHVM, at failure in the VCPUOP_register_vcpu_info hypercall we limit the number of cpus to to MAX_VIRT_CPUS. However, if this failure had occurred for a cpu beyond MAX_VIRT_CPUS, we continue to function with > MAX_VIRT_CPUS. This leads to problems at the next save/restore cycle when there are > MAX_VIRT_CPUS threads going into stop_machine() but coming back up there's valid state for only the first MAX_VIRT_CPUS. This patch pulls the excess CPUs down via cpu_down(). Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-13xen/vcpu: Handle xen_vcpu_setup() failure in hotplugAnkur Arora
The hypercall VCPUOP_register_vcpu_info can fail. This failure is handled by making per_cpu(xen_vcpu, cpu) point to its shared_info slot and those without one (cpu >= MAX_VIRT_CPUS) be NULL. For PVH/PVHVM, this is not enough, because we also need to pull these VCPUs out of circulation. Fix for PVH/PVHVM: on registration failure in the cpuhp prepare callback (xen_cpu_up_prepare_hvm()), return an error to the cpuhp state-machine so it can fail the CPU init. Fix for PV: the registration happens before smp_init(), so, in the failure case we clamp setup_max_cpus and limit the number of VCPUs that smp_init() will bring-up to MAX_VIRT_CPUS. This is functionally correct but it makes the code a bit simpler if we get rid of this explicit clamping: for VCPUs that don't have valid xen_vcpu, fail the CPU init in the cpuhp prepare callback (xen_cpu_up_prepare_pv()). Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-13xen/pv: Fix OOPS on restore for a PV, !SMP domainAnkur Arora
If CONFIG_SMP is disabled, xen_setup_vcpu_info_placement() is called from xen_setup_shared_info(). This is fine as far as boot goes, but it means that we also call it in the restore path. This results in an OOPS because we assign to pv_mmu_ops.read_cr2 which is __ro_after_init. Also, though less problematically, this means we call xen_vcpu_setup() twice at restore -- once from the vcpu info placement call and the second time from xen_vcpu_restore(). Fix by calling xen_setup_vcpu_info_placement() at boot only. Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-13xen/pvh*: Support > 32 VCPUs at domain restoreAnkur Arora
When Xen restores a PVHVM or PVH guest, its shared_info only holds up to 32 CPUs. The hypercall VCPUOP_register_vcpu_info allows us to setup per-page areas for VCPUs. This means we can boot PVH* guests with more than 32 VCPUs. During restore the per-cpu structure is allocated freshly by the hypervisor (vcpu_info_mfn is set to INVALID_MFN) so that the newly restored guest can make a VCPUOP_register_vcpu_info hypercall. However, we end up triggering this condition in Xen: /* Run this command on yourself or on other offline VCPUS. */ if ( (v != current) && !test_bit(_VPF_down, &v->pause_flags) ) which means we are unable to setup the per-cpu VCPU structures for running VCPUS. The Linux PV code paths makes this work by iterating over cpu_possible in xen_vcpu_restore() with: 1) is target CPU up (VCPUOP_is_up hypercall?) 2) if yes, then VCPUOP_down to pause it 3) VCPUOP_register_vcpu_info 4) if it was down, then VCPUOP_up to bring it back up With Xen commit 192df6f9122d ("xen/x86: allow HVM guests to use hypercalls to bring up vCPUs") this is available for non-PV guests. As such first check if VCPUOP_is_up is actually possible before trying this dance. As most of this dance code is done already in xen_vcpu_restore() let's make it callable on PV, PVH and PVHVM. Based-on-patch-by: Konrad Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-13xen/vcpu: Simplify xen_vcpu related codeAnkur Arora
Largely mechanical changes to aid unification of xen_vcpu_restore() logic for PV, PVH and PVHVM. xen_vcpu_setup(): the only change in logic is that clamp_max_cpus() is now handled inside the "if (!xen_have_vcpu_info_placement)" block. xen_vcpu_restore(): code movement from enlighten_pv.c to enlighten.c. xen_vcpu_info_reset(): pulls together all the code where xen_vcpu is set to default. Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-13x86/mm: Add support for 5-level paging for KASLRKirill A. Shutemov
With 5-level paging randomization happens on P4D level instead of PUD. Maximum amount of physical memory also bumped to 52-bits for 5-level paging. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-13-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/mm: Make kernel_physical_mapping_init() support 5-level pagingKirill A. Shutemov
Populate additional page table level if CONFIG_X86_5LEVEL is enabled. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-12-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/mm: Add sync_global_pgds() for configuration with 5-level pagingKirill A. Shutemov
This basically restores slightly modified version of original sync_global_pgds() which we had before folded p4d was introduced. The only modification is protection against 'addr' overflow. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-11-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/boot/64: Add support of additional page table level during early bootKirill A. Shutemov
This patch adds support for 5-level paging during early boot. It generalizes boot for 4- and 5-level paging on 64-bit systems with compile-time switch between them. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-10-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/boot/64: Rename init_level4_pgt and early_level4_pgtKirill A. Shutemov
With CONFIG_X86_5LEVEL=y, level 4 is no longer top level of page tables. Let's give these variable more generic names: init_top_pgt and early_top_pgt. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-9-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/boot/64: Rewrite startup_64() in CKirill A. Shutemov
The patch write most of startup_64 logic in C. This is preparation for 5-level paging enabling. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-8-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/boot/compressed: Enable 5-level paging during decompression stageKirill A. Shutemov
We need to cover two basic cases: when bootloader left us in 32-bit mode and when bootloader enabled long mode. The patch implements unified codepath to enabled 5-level paging for both cases. It means case when we start in 32-bit mode, we first enable long mode with 4-level and then switch over to 5-level paging. Switching from 4-level to 5-level paging is not trivial. We cannot do it directly. Setting LA57 in long mode would trigger #GP. So we need to switch off long mode first and the then re-enable with 5-level paging. NOTE: The need of switching off long mode means we are in trouble if bootloader put us above 4G boundary. If bootloader wants to boot 5-level paging kernel, it has to put kernel below 4G or enable 5-level paging on it's own, so we could avoid the step. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-7-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/boot/efi: Define __KERNEL32_CS GDT on 64-bit configurationsKirill A. Shutemov
We would need to switch temporarily to compatibility mode during booting with 5-level paging enabled. It would require 32-bit code segment descriptor. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-6-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/boot/efi: Fix __KERNEL_CS definition of GDT entry on 64-bit configurationsKirill A. Shutemov
Define __KERNEL_CS GDT entry as long mode (.L=1, .D=0) on 64-bit configurations. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-5-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/boot/efi: Cleanup initialization of GDT entriesKirill A. Shutemov
This is preparation for following patches without changing semantics of the code. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-4-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/asm: Fix comment in return_from_SYSCALL_64()Kirill A. Shutemov
On x86-64 __VIRTUAL_MASK_SHIFT depends on paging mode now. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementationKirill A. Shutemov
This patch provides all required callbacks required by the generic get_user_pages_fast() code and switches x86 over - and removes the platform specific implementation. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.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-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170606113133.22974-2-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3()Andy Lutomirski
The kernel has several code paths that read CR3. Most of them assume that CR3 contains the PGD's physical address, whereas some of them awkwardly use PHYSICAL_PAGE_MASK to mask off low bits. Add explicit mask macros for CR3 and convert all of the CR3 readers. This will keep them from breaking when PCID is enabled. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> 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: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13Merge branch 'sched/urgent' into x86/mm, to pick up dependent fixIngo Molnar
Andy will need the following scheduler fix for the PCID series: 252d2a4117bc: sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off() So do a cross-merge. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/time: Make setup_default_timer_irq() staticDou Liyang
This function isn't used outside of time.c, so let's mark it static. Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1497321029-29049-1-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-13x86/mm: Disable 1GB direct mappings when disabling 2MB mappingsVlastimil Babka
The kmemleak and debug_pagealloc features both disable using huge pages for direct mappings so they can do cpa() on page level granularity in any context. However they only do that for 2MB pages, which means 1GB pages can still be used if the CPU supports it, unless disabled by a boot param, which is non-obvious. Disable also 1GB pages when disabling 2MB pages. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vegard Nossum <vegardno@ifi.uio.no> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/2be70c78-6130-855d-3dfa-d87bd1dd4fda@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-12x86/debug: Handle early WARN_ONs properPeter Zijlstra
Hans managed to trigger a WARN very early in the boot which killed his (Virtual) box. The reason is that the recent rework of WARN() to use UD0 forgot to add the fixup_bug() call to early_fixup_exception(). As a result the kernel does not handle the WARN_ON injected UD0 exception and panics. Add the missing fixup call, so early UD's injected by WARN() get handled. Fixes: 9a93848fe787 ("x86/debug: Implement __WARN() using UD0") Reported-and-tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frank Mehnert <frank.mehnert@oracle.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Michael Thayer <michael.thayer@oracle.com> Link: http://lkml.kernel.org/r/20170612180108.w4vgu2ckucmllf3a@hirez.programming.kicks-ass.net
2017-06-12Merge 4.12-rc5 into char-misc-nextGreg Kroah-Hartman
We want the char/misc driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull key subsystem fixes from James Morris: "Here are a bunch of fixes for Linux keyrings, including: - Fix up the refcount handling now that key structs use the refcount_t type and the refcount_t ops don't allow a 0->1 transition. - Fix a potential NULL deref after error in x509_cert_parse(). - Don't put data for the crypto algorithms to use on the stack. - Fix the handling of a null payload being passed to add_key(). - Fix incorrect cleanup an uninitialised key_preparsed_payload in key_update(). - Explicit sanitisation of potentially secure data before freeing. - Fixes for the Diffie-Helman code" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits) KEYS: fix refcount_inc() on zero KEYS: Convert KEYCTL_DH_COMPUTE to use the crypto KPP API crypto : asymmetric_keys : verify_pefile:zero memory content before freeing KEYS: DH: add __user annotations to keyctl_kdf_params KEYS: DH: ensure the KDF counter is properly aligned KEYS: DH: don't feed uninitialized "otherinfo" into KDF KEYS: DH: forbid using digest_null as the KDF hash KEYS: sanitize key structs before freeing KEYS: trusted: sanitize all key material KEYS: encrypted: sanitize all key material KEYS: user_defined: sanitize key payloads KEYS: sanitize add_key() and keyctl() key payloads KEYS: fix freeing uninitialized memory in key_update() KEYS: fix dereferencing NULL payload with nonzero length KEYS: encrypted: use constant-time HMAC comparison KEYS: encrypted: fix race causing incorrect HMAC calculations KEYS: encrypted: fix buffer overread in valid_master_desc() KEYS: encrypted: avoid encrypting/decrypting stack buffers KEYS: put keyring if install_session_keyring_to_cred() fails KEYS: Delete an error message for a failed memory allocation in get_derived_key() ...
2017-06-11Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "Bug fixes (ARM, s390, x86)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: async_pf: avoid async pf injection when in guest mode KVM: cpuid: Fix read/write out-of-bounds vulnerability in cpuid emulation arm: KVM: Allow unaligned accesses at HYP arm64: KVM: Allow unaligned accesses at EL2 arm64: KVM: Preserve RES1 bits in SCTLR_EL2 KVM: arm/arm64: Handle possible NULL stage2 pud when ageing pages KVM: nVMX: Fix exception injection kvm: async_pf: fix rcu_irq_enter() with irqs enabled KVM: arm/arm64: vgic-v3: Fix nr_pre_bits bitfield extraction KVM: s390: fix ais handling vs cpu model KVM: arm/arm64: Fix isues with GICv2 on GICv3 migration
2017-06-11KVM: async_pf: avoid async pf injection when in guest modeWanpeng Li
INFO: task gnome-terminal-:1734 blocked for more than 120 seconds. Not tainted 4.12.0-rc4+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. gnome-terminal- D 0 1734 1015 0x00000000 Call Trace: __schedule+0x3cd/0xb30 schedule+0x40/0x90 kvm_async_pf_task_wait+0x1cc/0x270 ? __vfs_read+0x37/0x150 ? prepare_to_swait+0x22/0x70 do_async_page_fault+0x77/0xb0 ? do_async_page_fault+0x77/0xb0 async_page_fault+0x28/0x30 This is triggered by running both win7 and win2016 on L1 KVM simultaneously, and then gives stress to memory on L1, I can observed this hang on L1 when at least ~70% swap area is occupied on L0. This is due to async pf was injected to L2 which should be injected to L1, L2 guest starts receiving pagefault w/ bogus %cr2(apf token from the host actually), and L1 guest starts accumulating tasks stuck in D state in kvm_async_pf_task_wait() since missing PAGE_READY async_pfs. This patch fixes the hang by doing async pf when executing L1 guest. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-09x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass ↵Dan Williams
operations The pmem driver has a need to transfer data with a persistent memory destination and be able to rely on the fact that the destination writes are not cached. It is sufficient for the writes to be flushed to a cpu-store-buffer (non-temporal / "movnt" in x86 terms), as we expect userspace to call fsync() to ensure data-writes have reached a power-fail-safe zone in the platform. The fsync() triggers a REQ_FUA or REQ_FLUSH to the pmem driver which will turn around and fence previous writes with an "sfence". Implement a __copy_from_user_inatomic_flushcache, memcpy_page_flushcache, and memcpy_flushcache, that guarantee that the destination buffer is not dirty in the cpu cache on completion. The new copy_from_iter_flushcache and sub-routines will be used to replace the "pmem api" (include/linux/pmem.h + arch/x86/include/asm/pmem.h). The availability of copy_from_iter_flushcache() and memcpy_flushcache() are gated by the CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE config symbol, and fallback to copy_from_iter_nocache() and plain memcpy() otherwise. This is meant to satisfy the concern from Linus that if a driver wants to do something beyond the normal nocache semantics it should be something private to that driver [1], and Al's concern that anything uaccess related belongs with the rest of the uaccess code [2]. The first consumer of this interface is a new 'copy_from_iter' dax operation so that pmem can inject cache maintenance operations without imposing this overhead on other dax-capable drivers. [1]: https://lists.01.org/pipermail/linux-nvdimm/2017-January/008364.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2017-April/009942.html Cc: <x86@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-09security/keys: add CONFIG_KEYS_COMPAT to KconfigBilal Amarni
CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for several 64-bit architectures : mips, parisc, tile. At the moment and for those architectures, calling in 32-bit userspace the keyctl syscall would return an ENOSYS error. This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to make sure the compatibility wrapper is registered by default for any 64-bit architecture as long as it is configured with CONFIG_COMPAT. [DH: Modified to remove arm64 compat enablement also as requested by Eric Biggers] Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> cc: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-08xen: fix HYPERVISOR_dm_op() prototypeSergey Dyasli
Change the third parameter to be the required struct xen_dm_op_buf * instead of a generic void * (which blindly accepts any pointer). Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-08KVM: cpuid: Fix read/write out-of-bounds vulnerability in cpuid emulationWanpeng Li
If "i" is the last element in the vcpu->arch.cpuid_entries[] array, it potentially can be exploited the vulnerability. this will out-of-bounds read and write. Luckily, the effect is small: /* when no next entry is found, the current entry[i] is reselected */ for (j = i + 1; ; j = (j + 1) % nent) { struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; if (ej->function == e->function) { It reads ej->maxphyaddr, which is user controlled. However... ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; After cpuid_entries there is int maxphyaddr; struct x86_emulate_ctxt emulate_ctxt; /* 16-byte aligned */ So we have: - cpuid_entries at offset 1B50 (6992) - maxphyaddr at offset 27D0 (6992 + 3200 = 10192) - padding at 27D4...27DF - emulate_ctxt at 27E0 And it writes in the padding. Pfew, writing the ops field of emulate_ctxt would have been much worse. This patch fixes it by modding the index to avoid the out-of-bounds access. Worst case, i == j and ej->function == e->function, the loop can bail out. Reported-by: Moguofang <moguofang@huawei.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Guofang Mo <moguofang@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-08locking/x86: Remove the unused atomic_inc_short() methdDmitry Vyukov
It is completely unused and implemented only on x86. Remove it. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170526172900.91058-1-dvyukov@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>