kernel.git/arch/x86/include, branch linux-4.20.y

x86: Add TSX Force Abort CPUID/MSR

2019-03-13T21:04:20Z

commit 52f64909409c17adf54fcf5f9751e0544ca3a6b4 upstream Skylake systems will receive a microcode update to address a TSX errata. This microcode will (by default) clobber PMC3 when TSX instructions are (speculatively or not) executed. It also provides an MSR to cause all TSX transaction to abort and preserve PMC3. Add the CPUID enumeration and MSR definition. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

x86_64: increase stack size for KASAN_EXTRA

2019-03-13T21:04:08Z

[ Upstream commit a8e911d13540487942d53137c156bd7707f66e5d ] If the kernel is configured with KASAN_EXTRA, the stack size is increasted significantly because this option sets "-fstack-reuse" to "none" in GCC [1]. As a result, it triggers stack overrun quite often with 32k stack size compiled using GCC 8. For example, this reproducer https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/madvise/madvise06.c triggers a "corrupted stack end detected inside scheduler" very reliably with CONFIG_SCHED_STACK_END_CHECK enabled. There are just too many functions that could have a large stack with KASAN_EXTRA due to large local variables that have been called over and over again without being able to reuse the stacks. Some noticiable ones are size 7648 shrink_page_list 3584 xfs_rmap_convert 3312 migrate_page_move_mapping 3312 dev_ethtool 3200 migrate_misplaced_transhuge_page 3168 copy_process There are other 49 functions are over 2k in size while compiling kernel with "-Wframe-larger-than=" even with a related minimal config on this machine. Hence, it is too much work to change Makefiles for each object to compile without "-fsanitize-address-use-after-scope" individually. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715#c23 Although there is a patch in GCC 9 to help the situation, GCC 9 probably won't be released in a few months and then it probably take another 6-month to 1-year for all major distros to include it as a default. Hence, the stack usage with KASAN_EXTRA can be revisited again in 2020 when GCC 9 is everywhere. Until then, this patch will help users avoid stack overrun. This has already been fixed for arm64 for the same reason via 6e8830674ea ("arm64: kasan: Increase stack size for KASAN_EXTRA"). Link: http://lkml.kernel.org/r/20190109215209.2903-1-cai@lca.pw Signed-off-by: Qian Cai Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

x86/cpu: Add Atom Tremont (Jacobsville)

2019-03-13T21:04:07Z

[ Upstream commit 00ae831dfe4474ef6029558f5eb3ef0332d80043 ] Add the Atom Tremont model number to the Intel family list. [ Tony: Also update comment at head of file to say "_X" suffix is also used for microserver parts. ] Signed-off-by: Kan Liang Signed-off-by: Qiuxu Zhuo Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov Cc: Andy Shevchenko Cc: Aristeu Rozanski Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: linux-edac Cc: Mauro Carvalho Chehab Cc: Megha Dey Cc: Peter Zijlstra Cc: Qiuxu Zhuo Cc: Rajneesh Bhardwaj Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20190125195902.17109-4-tony.luck@intel.com Signed-off-by: Sasha Levin

x86/uaccess: Don't leak the AC flag into __put_user() value evaluation

2019-03-05T16:59:45Z

commit 2a418cf3f5f1caf911af288e978d61c9844b0695 upstream. When calling __put_user(foo(), ptr), the __put_user() macro would call foo() in between __uaccess_begin() and __uaccess_end(). If that code were buggy, then those bugs would be run without SMAP protection. Fortunately, there seem to be few instances of the problem in the kernel. Nevertheless, __put_user() should be fixed to avoid doing this. Therefore, evaluate __put_user()'s argument before setting AC. This issue was noticed when an objtool hack by Peter Zijlstra complained about genregs_get() and I compared the assembly output to the C source. [ bp: Massage commit message and fixed up whitespace. ] Fixes: 11f1a4b9755f ("x86: reorganize SMAP handling in user space accesses") Signed-off-by: Andy Lutomirski Signed-off-by: Borislav Petkov Acked-by: Linus Torvalds Cc: Peter Zijlstra Cc: Brian Gerst Cc: Josh Poimboeuf Cc: Denys Vlasenko Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20190225125231.845656645@infradead.org Signed-off-by: Greg Kroah-Hartman

x86/kvm/mmu: fix switch between root and guest MMUs

2019-02-27T09:09:56Z

commit ad7dc69aeb23138cc23c406cac25003b97e8ee17 upstream. Commit 14c07ad89f4d ("x86/kvm/mmu: introduce guest_mmu") brought one subtle change: previously, when switching back from L2 to L1, we were resetting MMU hooks (like mmu->get_cr3()) in kvm_init_mmu() called from nested_vmx_load_cr3() and now we do that in nested_ept_uninit_mmu_context() when we re-target vcpu->arch.mmu pointer. The change itself looks logical: if nested_ept_init_mmu_context() changes something than nested_ept_uninit_mmu_context() restores it back. There is, however, one thing: the following call chain: nested_vmx_load_cr3() kvm_mmu_new_cr3() __kvm_mmu_new_cr3() fast_cr3_switch() cached_root_available() now happens with MMU hooks pointing to the new MMU (root MMU in our case) while previously it was happening with the old one. cached_root_available() tries to stash current root but it is incorrect to read current CR3 with mmu->get_cr3(), we need to use old_mmu->get_cr3() which in case we're switching from L2 to L1 is guest_mmu. (BTW, in shadow page tables case this is a non-issue because we don't switch MMU). While we could've tried to guess that we're switching between MMUs and call the right ->get_cr3() from cached_root_available() this seems to be overly complicated. Instead, just stash the corresponding CR3 when setting root_hpa and make cached_root_available() use the stashed value. Fixes: 14c07ad89f4d ("x86/kvm/mmu: introduce guest_mmu") Signed-off-by: Vitaly Kuznetsov Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

KVM: MMU: record maximum physical address width in kvm_mmu_extended_role

2019-02-27T09:09:56Z

commit de3ccd26fafc707b09792d9b633c8b5b48865315 upstream. Previously, commit 7dcd57552008 ("x86/kvm/mmu: check if tdp/shadow MMU reconfiguration is needed") offered some optimization to avoid the unnecessary reconfiguration. Yet one scenario is broken - when cpuid changes VM's maximum physical address width, reconfiguration is needed to reset the reserved bits. Also, the TDP may need to reset its shadow_root_level when this value is changed. To fix this, a new field, maxphyaddr, is introduced in the extended role structure to keep track of the configured guest physical address width. Signed-off-by: Yu Zhang Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls

2019-02-20T09:29:14Z

commit f331e766c4be33f4338574f3c9f7f77e98ab4571 upstream. Calls into UV firmware must be protected against concurrency, expose the efi_runtime_lock to the UV platform, and use it to serialise UV BIOS calls. Signed-off-by: Hedi Berriche Signed-off-by: Borislav Petkov Reviewed-by: Ard Biesheuvel Reviewed-by: Russ Anderson Reviewed-by: Dimitri Sivanich Reviewed-by: Mike Travis Cc: Andy Shevchenko Cc: Bhupesh Sharma Cc: Darren Hart Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: linux-efi Cc: platform-driver-x86@vger.kernel.org Cc: stable@vger.kernel.org # v4.9+ Cc: Steve Wahl Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20190213193413.25560-5-hedi.berriche@hpe.com Signed-off-by: Greg Kroah-Hartman

x86/fpu: Add might_fault() to user_insn()

2019-02-12T19:02:13Z

[ Upstream commit 6637401c35b2f327a35d27f44bda05e327f2f017 ] Every user of user_insn() passes an user memory pointer to this macro. Add might_fault() to user_insn() so we can spot users which are using this macro in sections where page faulting is not allowed. [ bp: Space it out to make it more visible. ] Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Borislav Petkov Reviewed-by: Rik van Riel Cc: "H. Peter Anvin" Cc: "Jason A. Donenfeld" Cc: Andy Lutomirski Cc: Dave Hansen Cc: Ingo Molnar Cc: Jann Horn Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Thomas Gleixner Cc: kvm ML Cc: x86-ml Link: https://lkml.kernel.org/r/20181128222035.2996-6-bigeasy@linutronix.de Signed-off-by: Sasha Levin

x86/pkeys: Properly copy pkey state at fork()

2019-01-31T07:15:42Z

commit a31e184e4f69965c99c04cc5eb8a4920e0c63737 upstream. Memory protection key behavior should be the same in a child as it was in the parent before a fork. But, there is a bug that resets the state in the child at fork instead of preserving it. The creation of new mm's is a bit convoluted. At fork(), the code does: 1. memcpy() the parent mm to initialize child 2. mm_init() to initalize some select stuff stuff 3. dup_mmap() to create true copies that memcpy() did not do right For pkeys two bits of state need to be preserved across a fork: 'execute_only_pkey' and 'pkey_allocation_map'. Those are preserved by the memcpy(), but mm_init() invokes init_new_context() which overwrites 'execute_only_pkey' and 'pkey_allocation_map' with "new" values. The author of the code erroneously believed that init_new_context is *only* called at execve()-time. But, alas, init_new_context() is used at execve() and fork(). The result is that, after a fork(), the child's pkey state ends up looking like it does after an execve(), which is totally wrong. pkeys that are already allocated can be allocated again, for instance. To fix this, add code called by dup_mmap() to copy the pkey state from parent to child explicitly. Also add a comment above init_new_context() to make it more clear to the next poor sod what this code is used for. Fixes: e8c24d3a23a ("x86/pkeys: Allocation/free syscalls") Signed-off-by: Dave Hansen Signed-off-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Cc: bp@alien8.de Cc: hpa@zytor.com Cc: peterz@infradead.org Cc: mpe@ellerman.id.au Cc: will.deacon@arm.com Cc: luto@kernel.org Cc: jroedel@suse.de Cc: stable@vger.kernel.org Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Peter Zijlstra Cc: Michael Ellerman Cc: Will Deacon Cc: Andy Lutomirski Cc: Joerg Roedel Link: https://lkml.kernel.org/r/20190102215655.7A69518C@viggo.jf.intel.com Signed-off-by: Greg Kroah-Hartman

x86/mce: Fix -Wmissing-prototypes warnings

2019-01-26T08:20:41Z

[ Upstream commit 68b5e4326e4b8ac9080835005d8254fed0fb3c56 ] Add the proper includes and make smca_get_name() static. Fix an actual bug too which the warning triggered: arch/x86/kernel/cpu/mcheck/therm_throt.c:395:39: error: conflicting \ types for ‘smp_thermal_interrupt’ asmlinkage __visible void __irq_entry smp_thermal_interrupt(struct pt_regs *r) ^~~~~~~~~~~~~~~~~~~~~ In file included from arch/x86/kernel/cpu/mcheck/therm_throt.c:29: ./arch/x86/include/asm/traps.h:107:17: note: previous declaration of \ ‘smp_thermal_interrupt’ was here asmlinkage void smp_thermal_interrupt(void); Signed-off-by: Borislav Petkov Cc: Yi Wang Cc: Michael Matz Cc: x86@kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1811081633160.1549@nanos.tec.linutronix.de Signed-off-by: Sasha Levin