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2014-09-09Merge tag 'v3.17-rc4' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-09percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fixMel Gorman
A commit in linux-next was causing boot to fail and bisection identified the patch 4ba2968420fa ("percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_"). One of the changes in that patch looks very suspicious. Reverting the full patch fixes boot as does this fixlet. Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com>
2014-09-08x86_64, entry: Use split-phase syscall_trace_enter for 64-bit syscallsAndy Lutomirski
On KVM on my box, this reduces the overhead from an always-accept seccomp filter from ~130ns to ~17ns. Most of that comes from avoiding IRET on every syscall when seccomp is enabled. In extremely approximate hacked-up benchmarking, just bypassing IRET saves about 80ns, so there's another 43ns of savings here from simplifying the seccomp path. The diffstat is also rather nice :) Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/a3dbd267ee990110478d349f78cccfdac5497a84.1409954077.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-08x86_64, entry: Treat regs->ax the same in fastpath and slowpath syscallsAndy Lutomirski
For slowpath syscalls, we initialize regs->ax to -ENOSYS and stick the syscall number into regs->orig_ax prior to any possible tracing and syscall execution. This is user-visible ABI used by ptrace syscall emulation and seccomp. For fastpath syscalls, there's no good reason not to do the same thing. It's even slightly simpler than what we're currently doing. It probably has no measureable performance impact. It should have no user-visible effect. The purpose of this patch is to prepare for two-phase syscall tracing, in which the first phase might modify the saved RAX without leaving the fast path. This change is just subtle enough that I'm keeping it separate. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/01218b493f12ae2f98034b78c9ae085e38e94350.1409954077.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-08x86: Split syscall_trace_enter into two phasesAndy Lutomirski
This splits syscall_trace_enter into syscall_trace_enter_phase1 and syscall_trace_enter_phase2. Only phase 2 has full pt_regs, and only phase 2 is permitted to modify any of pt_regs except for orig_ax. The intent is that phase 1 can be called from the syscall fast path. In this implementation, phase1 can handle any combination of TIF_NOHZ (RCU context tracking), TIF_SECCOMP, and TIF_SYSCALL_AUDIT, unless seccomp requests a ptrace event, in which case phase2 is forced. In principle, this could yield a big speedup for TIF_NOHZ as well as for TIF_SECCOMP if syscall exit work were similarly split up. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/2df320a600020fda055fccf2b668145729dd0c04.1409954077.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-08x86, entry: Only call user_exit if TIF_NOHZAndy Lutomirski
The RCU context tracking code requires that arch code call user_exit() on any entry into kernel code if TIF_NOHZ is set. This patch adds a check for TIF_NOHZ and a comment to the syscall entry tracing code. The main purpose of this patch is to make the code easier to follow: one can read the body of user_exit and of every function it calls without finding any explanation of why it's called for traced syscalls but not for untraced syscalls. This makes it clear when user_exit() is necessary. Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/0b13e0e24ec0307d67ab7a23b58764f6b1270116.1409954077.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-08x86, x32, audit: Fix x32's AUDIT_ARCH wrt auditAndy Lutomirski
is_compat_task() is the wrong check for audit arch; the check should be is_ia32_task(): x32 syscalls should be AUDIT_ARCH_X86_64, not AUDIT_ARCH_I386. CONFIG_AUDITSYSCALL is currently incompatible with x32, so this has no visible effect. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/a0138ed8c709882aec06e4acc30bfa9b623b8717.1409954077.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-08x86/efi: Fixup GOT in all boot code pathsMatt Fleming
Maarten reported that his Macbook pro 8.2 stopped booting after commit f23cf8bd5c1f49 ("efi/x86: efistub: Move shared dependencies to <asm/efi.h>"), the main feature of which is changing the visibility of symbol 'efi_early' from local to global. By making 'efi_early' global we end up requiring an entry in the Global Offset Table. Unfortunately, while we do include code to fixup GOT entries in the early boot code, it's only called after we've executed the EFI boot stub. What this amounts to is that references to 'efi_early' in the EFI boot stub don't point to the correct place. Since we've got multiple boot entry points we need to be prepared to fixup the GOT in multiple places, while ensuring that we never do it more than once, otherwise the GOT entries will still point to the wrong place. Reported-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Tested-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-09-08x86/efi: Only load initrd above 4g on second tryYinghai Lu
Mantas found that after commit 4bf7111f5016 ("x86/efi: Support initrd loaded above 4G"), the kernel freezes at the earliest possible moment when trying to boot via UEFI on Asus laptop. Revert to old way to load initrd under 4G on first try, second try will use above 4G buffer when initrd is too big and does not fit under 4G. [ The cause of the freeze appears to be a firmware bug when reading file data into buffers above 4GB, though the exact reason is unknown. Mantas reports that the hang can be avoid if the file size is a multiple of 512 bytes, but I've seen some ASUS firmware simply corrupting the file data rather than freezing. Laszlo fixed an issue in the upstream EDK2 DiskIO code in Aug 2013 which may possibly be related, commit 4e39b75e ("MdeModulePkg/DiskIoDxe: fix source/destination pointer of overrun transfer"). Whatever the cause, it's unlikely that a fix will be forthcoming from the vendor, hence the workaround - Matt ] Cc: Laszlo Ersek <lersek@redhat.com> Reported-by: Mantas Mikulėnas <grawity@gmail.com> Reported-by: Harald Hoyer <harald@redhat.com> Tested-by: Anders Darander <anders@chargestorm.se> Tested-by: Calvin Walton <calvin.walton@kepstin.ca> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-09-08x86-64, ptdump: Mark espfix area only if existentMathias Krause
We should classify the espfix area as such only if we actually have enabled the corresponding option. Otherwise the page table dump might look confusing. Signed-off-by: Mathias Krause <minipli@googlemail.com> Link: http://lkml.kernel.org/r/1410114629-24523-1-git-send-email-minipli@googlemail.com Cc: Arjan van de Ven <arjan.van.de.ven@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-09-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2014-09-08percpu_counter: add @gfp to percpu_counter_init()Tejun Heo
Percpu allocator now supports allocation mask. Add @gfp to percpu_counter_init() so that !GFP_KERNEL allocation masks can be used with percpu_counters too. We could have left percpu_counter_init() alone and added percpu_counter_init_gfp(); however, the number of users isn't that high and introducing _gfp variants to all percpu data structures would be quite ugly, so let's just do the conversion. This is the one with the most users. Other percpu data structures are a lot easier to convert. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jan Kara <jack@suse.cz> Acked-by: "David S. Miller" <davem@davemloft.net> Cc: x86@kernel.org Cc: Jens Axboe <axboe@kernel.dk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org>
2014-09-06x86/tty/serial/8250: Clean up the asm/serial.h include file a bitIngo Molnar
- correct spelling - align fields vertically to make things more readable - make the layout of magic defines more obvious Cc: Mark Rustad <mark.d.rustad@intel.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Link: http://lkml.kernel.org/r/1409972149-26272-1-git-send-email-jeffrey.t.kirsher@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-06x86/tty/serial/8250: Resolve missing-field-initializers warningsMark Rustad
Resolve some missing-field-initializers warnings by using designated initialization in the expansion of the SERIAL_PORT_DFNS macro. Signed-off-by: Mark Rustad <mark.d.rustad@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Link: http://lkml.kernel.org/r/1409972149-26272-1-git-send-email-jeffrey.t.kirsher@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-05net: bpf: make eBPF interpreter images read-onlyDaniel Borkmann
With eBPF getting more extended and exposure to user space is on it's way, hardening the memory range the interpreter uses to steer its command flow seems appropriate. This patch moves the to be interpreted bytecode to read-only pages. In case we execute a corrupted BPF interpreter image for some reason e.g. caused by an attacker which got past a verifier stage, it would not only provide arbitrary read/write memory access but arbitrary function calls as well. After setting up the BPF interpreter image, its contents do not change until destruction time, thus we can setup the image on immutable made pages in order to mitigate modifications to that code. The idea is derived from commit 314beb9bcabf ("x86: bpf_jit_comp: secure bpf jit against spraying attacks"). This is possible because bpf_prog is not part of sk_filter anymore. After setup bpf_prog cannot be altered during its life-time. This prevents any modifications to the entire bpf_prog structure (incl. function/JIT image pointer). Every eBPF program (including classic BPF that are migrated) have to call bpf_prog_select_runtime() to select either interpreter or a JIT image as a last setup step, and they all are being freed via bpf_prog_free(), including non-JIT. Therefore, we can easily integrate this into the eBPF life-time, plus since we directly allocate a bpf_prog, we have no performance penalty. Tested with seccomp and test_bpf testsuite in JIT/non-JIT mode and manual inspection of kernel_page_tables. Brad Spengler proposed the same idea via Twitter during development of this patch. Joint work with Hannes Frederic Sowa. Suggested-by: Brad Spengler <spender@grsecurity.net> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Kees Cook <keescook@chromium.org> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05KVM: x86: propagate exception from permission checks on the nested page faultPaolo Bonzini
Currently, if a permission error happens during the translation of the final GPA to HPA, walk_addr_generic returns 0 but does not fill in walker->fault. To avoid this, add an x86_exception* argument to the translate_gpa function, and let it fill in walker->fault. The nested_page_fault field will be true, since the walk_mmu is the nested_mmu and translate_gpu instead operates on the "outer" (NPT) instance. Reported-by: Valentine Sinitsyn <valentine.sinitsyn@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-05KVM: x86: skip writeback on injection of nested exceptionPaolo Bonzini
If a nested page fault happens during emulation, we will inject a vmexit, not a page fault. However because writeback happens after the injection, we will write ctxt->eip from L2 into the L1 EIP. We do not write back if an instruction caused an interception vmexit---do the same for page faults. Suggested-by: Gleb Natapov <gleb@kernel.org> Reviewed-by: Gleb Natapov <gleb@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03seccomp,x86,arm,mips,s390: Remove nr parameter from secure_computingAndy Lutomirski
The secure_computing function took a syscall number parameter, but it only paid any attention to that parameter if seccomp mode 1 was enabled. Rather than coming up with a kludge to get the parameter to work in mode 2, just remove the parameter. To avoid churn in arches that don't have seccomp filters (and may not even support syscall_get_nr right now), this leaves the parameter in secure_computing_strict, which is now a real function. For ARM, this is a bit ugly due to the fact that ARM conditionally supports seccomp filters. Fixing that would probably only be a couple of lines of code, but it should be coordinated with the audit maintainers. This will be a slight slowdown on some arches. The right fix is to pass in all of seccomp_data instead of trying to make just the syscall nr part be fast. This is a prerequisite for making two-phase seccomp work cleanly. Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-09-03KVM: nSVM: propagate the NPF EXITINFO to the guestPaolo Bonzini
This is similar to what the EPT code does with the exit qualification. This allows the guest to see a valid value for bits 33:32. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMDPaolo Bonzini
Bit 8 would be the "global" bit, which does not quite make sense for non-leaf page table entries. Intel ignores it; AMD ignores it in PDEs, but reserves it in PDPEs and PML4Es. The SVM test is relying on this behavior, so enforce it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03KVM: mmio: cleanup kvm_set_mmio_spte_maskTiejun Chen
Just reuse rsvd_bits() inside kvm_set_mmio_spte_mask() for slightly better code. Signed-off-by: Tiejun Chen <tiejun.chen@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03kvm: x86: fix stale mmio cache bugDavid Matlack
The following events can lead to an incorrect KVM_EXIT_MMIO bubbling up to userspace: (1) Guest accesses gpa X without a memory slot. The gfn is cached in struct kvm_vcpu_arch (mmio_gfn). On Intel EPT-enabled hosts, KVM sets the SPTE write-execute-noread so that future accesses cause EPT_MISCONFIGs. (2) Host userspace creates a memory slot via KVM_SET_USER_MEMORY_REGION covering the page just accessed. (3) Guest attempts to read or write to gpa X again. On Intel, this generates an EPT_MISCONFIG. The memory slot generation number that was incremented in (2) would normally take care of this but we fast path mmio faults through quickly_check_mmio_pf(), which only checks the per-vcpu mmio cache. Since we hit the cache, KVM passes a KVM_EXIT_MMIO up to userspace. This patch fixes the issue by using the memslot generation number to validate the mmio cache. Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> [xiaoguangrong: adjust the code to make it simpler for stable-tree fix.] Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Tested-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03kvm: fix potentially corrupt mmio cacheDavid Matlack
vcpu exits and memslot mutations can run concurrently as long as the vcpu does not aquire the slots mutex. Thus it is theoretically possible for memslots to change underneath a vcpu that is handling an exit. If we increment the memslot generation number again after synchronize_srcu_expedited(), vcpus can safely cache memslot generation without maintaining a single rcu_dereference through an entire vm exit. And much of the x86/kvm code does not maintain a single rcu_dereference of the current memslots during each exit. We can prevent the following case: vcpu (CPU 0) | thread (CPU 1) --------------------------------------------+-------------------------- 1 vm exit | 2 srcu_read_unlock(&kvm->srcu) | 3 decide to cache something based on | old memslots | 4 | change memslots | (increments generation) 5 | synchronize_srcu(&kvm->srcu); 6 retrieve generation # from new memslots | 7 tag cache with new memslot generation | 8 srcu_read_unlock(&kvm->srcu) | ... | <action based on cache occurs even | though the caching decision was based | on the old memslots> | ... | <action *continues* to occur until next | memslot generation change, which may | be never> | | By incrementing the generation after synchronizing with kvm->srcu readers, we ensure that the generation retrieved in (6) will become invalid soon after (8). Keeping the existing increment is not strictly necessary, but we do keep it and just move it for consistency from update_memslots to install_new_memslots. It invalidates old cached MMIOs immediately, instead of having to wait for the end of synchronize_srcu_expedited, which makes the code more clearly correct in case CPU 1 is preempted right after synchronize_srcu() returns. To avoid halving the generation space in SPTEs, always presume that the low bit of the generation is zero when reconstructing a generation number out of an SPTE. This effectively disables MMIO caching in SPTEs during the call to synchronize_srcu_expedited. Using the low bit this way is somewhat like a seqcount---where the protected thing is a cache, and instead of retrying we can simply punt if we observe the low bit to be 1. Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03KVM: do not bias the generation number in kvm_current_mmio_generationPaolo Bonzini
The next patch will give a meaning (a la seqcount) to the low bit of the generation number. Ensure that it matches between kvm->memslots->generation and kvm_current_mmio_generation(). Cc: stable@vger.kernel.org Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-02x86: copy_thread: Don't nullify ->ptrace_bps twiceOleg Nesterov
Both 32bit and 64bit versions of copy_thread() do memset(ptrace_bps) twice for no reason, kill the 2nd memset(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175733.GA21676@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-02x86, fpu: Shift "fpu_counter = 0" from copy_thread() to arch_dup_task_struct()Oleg Nesterov
Cosmetic, but I think thread.fpu_counter should be initialized in arch_dup_task_struct() too, along with other "fpu" variables. And probably it make sense to turn it into thread.fpu->counter. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175730.GA21669@redhat.com Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-02x86, fpu: copy_process: Sanitize fpu->last_cpu initializationOleg Nesterov
Cosmetic, but imho memset(&dst->thread.fpu, 0) is not good simply because it hides the (important) usage of ->has_fpu/etc from grep. Change this code to initialize the members explicitly. And note that ->last_cpu = 0 looks simply wrong, this can confuse fpu_lazy_restore() if per_cpu(fpu_owner_task, 0) has already exited and copy_process() re-allocated the same task_struct. Fortunately this is not actually possible because child->fpu_counter == 0 and thus fpu_lazy_restore() will not be called, but still this is not clean/robust. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175727.GA21666@redhat.com Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-02x86, fpu: copy_process: Avoid fpu_alloc/copy if !used_math()Oleg Nesterov
arch_dup_task_struct() copies thread.fpu if fpu_allocated(), this looks suboptimal and misleading. Say, a forking process could use FPU only once in a signal handler but now tsk_used_math(src) == F, in this case the child gets a copy of fpu->state for no reason. The child won't use the saved registers anyway even if it starts to use FPU, this can only avoid fpu_alloc() in do_device_not_available(). Change this code to check tsk_used_math(current) instead. We still need to clear fpu->has_fpu/state, we could do this memset(0) under fpu_allocated() check but I think this doesn't make sense. See also the next change. use_eager_fpu() assumes that fpu_allocated() is always true, but a forking task (and thus its child) must always have PF_USED_MATH set, otherwise the child can either use FPU without used_math() (note that switch_fpu_prepare() doesn't do stts() in this case), or it will be killed by do_device_not_available()->BUG_ON(use_eager_fpu). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175723.GA21659@redhat.com Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-02x86, fpu: Change __thread_fpu_begin() to use use_eager_fpu()Oleg Nesterov
__thread_fpu_begin() checks X86_FEATURE_EAGER_FPU by hand, we have a helper for that. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175720.GA21656@redhat.com Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-02x86, fpu: __restore_xstate_sig()->math_state_restore() needs preempt_disable()Oleg Nesterov
Add preempt_disable() + preempt_enable() around math_state_restore() in __restore_xstate_sig(). Otherwise __switch_to() after __thread_fpu_begin() can overwrite fpu->state we are going to restore. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175717.GA21649@redhat.com Cc: <stable@vger.kernel.org> # v3.7+ Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-02x86, fpu: shift drop_init_fpu() from save_xstate_sig() to handle_signal()Oleg Nesterov
save_xstate_sig()->drop_init_fpu() doesn't look right. setup_rt_frame() can fail after that, in this case the next setup_rt_frame() triggered by SIGSEGV won't save fpu simply because the old state was lost. This obviously mean that fpu won't be restored after sys_rt_sigreturn() from SIGSEGV handler. Shift drop_init_fpu() into !failed branch in handle_signal(). Test-case (needs -O2): #include <stdio.h> #include <signal.h> #include <unistd.h> #include <sys/syscall.h> #include <sys/mman.h> #include <pthread.h> #include <assert.h> volatile double D; void test(double d) { int pid = getpid(); for (D = d; D == d; ) { /* sys_tkill(pid, SIGHUP); asm to avoid save/reload * fp regs around "C" call */ asm ("" : : "a"(200), "D"(pid), "S"(1)); asm ("syscall" : : : "ax"); } printf("ERR!!\n"); } void sigh(int sig) { } char altstack[4096 * 10] __attribute__((aligned(4096))); void *tfunc(void *arg) { for (;;) { mprotect(altstack, sizeof(altstack), PROT_READ); mprotect(altstack, sizeof(altstack), PROT_READ|PROT_WRITE); } } int main(void) { stack_t st = { .ss_sp = altstack, .ss_size = sizeof(altstack), .ss_flags = SS_ONSTACK, }; struct sigaction sa = { .sa_handler = sigh, }; pthread_t pt; sigaction(SIGSEGV, &sa, NULL); sigaltstack(&st, NULL); sa.sa_flags = SA_ONSTACK; sigaction(SIGHUP, &sa, NULL); pthread_create(&pt, NULL, tfunc, NULL); test(123.456); return 0; } Reported-by: Bean Anderson <bean@azulsystems.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175713.GA21646@redhat.com Cc: <stable@kernel.org> # v3.7+ Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-01x86 / PM: Set IRQCHIP_SKIP_SET_WAKE for IOAPIC IRQ chip objectsRafael J. Wysocki
Set the IRQCHIP_SKIP_SET_WAKE for IOAPIC IRQ chip objects so that interrupts from them can work as wakeup interrupts for suspend-to-idle. After this change, running enable_irq_wake() on one of the IRQs in question will succeed and IRQD_WAKEUP_STATE will be set for it, so all of the suspend-to-idle wakeup mechanics introduced previously will work for it automatically. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01x86: Remove set_pmd_pfnMatthew Wilcox
The last user of set_pmd_pfn() went away in commit f03574f2d5b2, so this has been dead code for over a year. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> arch/x86/include/asm/pgtable_32.h | 3 --- arch/x86/mm/pgtable_32.c | 35 ----------------------------------- 2 files changed, 38 deletions(-)
2014-09-01x86, irq: Fix build error caused by 9eabc99a635a77cbf09Jiang Liu
Commit 9eabc99a635a77cbf09 causes following build error when IOAPIC is disabled. arch/x86/pci/irq.c: In function 'pirq_disable_irq': >> arch/x86/pci/irq.c:1259:2: error: implicit declaration of function 'mp_should_keep_irq' [-Werror=implicit-function-declaration] if (io_apic_assign_pci_irqs && !mp_should_keep_irq(&dev->dev) && ^ cc1: some warnings being treated as errors Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Grant Likely <grant.likely@linaro.org> Link: http://lkml.kernel.org/r/1409382916-10649-1-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-08-29Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "One patch to avoid assigning interrupts we don't actually have on non-PC platforms, and two patches that addresses bugs in the new IOAPIC assignment code" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, irq, PCI: Keep IRQ assignment for runtime power management x86: irq: Fix bug in setting IOAPIC pin attributes x86: Fix non-PC platform kernel crash on boot due to NULL dereference
2014-08-29kexec: purgatory: add clean-up for purgatory directoryMichael Welling
Without this patch the kexec-purgatory.c and purgatory.ro files are not removed after make mrproper. Signed-off-by: Michael Welling <mwelling@ieee.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-29x86/purgatory: use approprate -m64/-32 build flag for arch/x86/purgatoryVivek Goyal
Thomas reported that build of x86_64 kernel was failing for him. He is using 32bit tool chain. Problem is that while compiling purgatory, I have not specified -m64 flag. And 32bit tool chain must be assuming -m32 by default. Following is error message. (mini) [~/work/linux-2.6] make scripts/kconfig/conf --silentoldconfig Kconfig CHK include/config/kernel.release UPD include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h UPD include/generated/utsrelease.h CC arch/x86/purgatory/purgatory.o arch/x86/purgatory/purgatory.c:1:0: error: code model 'large' not supported in the 32 bit mode Fix it by explicitly passing appropriate -m64/-m32 build flag for purgatory. Reported-by: Thomas Glanzmann <thomas@glanzmann.de> Tested-by: Thomas Glanzmann <thomas@glanzmann.de> Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-29kexec: create a new config option CONFIG_KEXEC_FILE for new syscallVivek Goyal
Currently new system call kexec_file_load() and all the associated code compiles if CONFIG_KEXEC=y. But new syscall also compiles purgatory code which currently uses gcc option -mcmodel=large. This option seems to be available only gcc 4.4 onwards. Hiding new functionality behind a new config option will not break existing users of old gcc. Those who wish to enable new functionality will require new gcc. Having said that, I am trying to figure out how can I move away from using -mcmodel=large but that can take a while. I think there are other advantages of introducing this new config option. As this option will be enabled only on x86_64, other arches don't have to compile generic kexec code which will never be used. This new code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches had to do this for CONFIG_KEXEC. Now with introduction of new config option, we can remove crypto dependency from other arches. Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I had CONFIG_X86_64 defined, I got rid of that. For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to "depends on CRYPTO=y". This should be safer as "select" is not recursive. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-29x86,mm: fix pte_special versus pte_numaHugh Dickins
Sasha Levin has shown oopses on ffffea0003480048 and ffffea0003480008 at mm/memory.c:1132, running Trinity on different 3.16-rc-next kernels: where zap_pte_range() checks page->mapping to see if PageAnon(page). Those addresses fit struct pages for pfns d2001 and d2000, and in each dump a register or a stack slot showed d2001730 or d2000730: pte flags 0x730 are PCD ACCESSED PROTNONE SPECIAL IOMAP; and Sasha's e820 map has a hole between cfffffff and 100000000, which would need special access. Commit c46a7c817e66 ("x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels") has broken vm_normal_page(): a PROTNONE SPECIAL pte no longer passes the pte_special() test, so zap_pte_range() goes on to try to access a non-existent struct page. Fix this by refining pte_special() (SPECIAL with PRESENT or PROTNONE) to complement pte_numa() (SPECIAL with neither PRESENT nor PROTNONE). A hint that this was a problem was that c46a7c817e66 added pte_numa() test to vm_normal_page(), and moved its is_zero_pfn() test from slow to fast path: This was papering over a pte_special() snag when the zero page was encountered during zap. This patch reverts vm_normal_page() to how it was before, relying on pte_special(). It still appears that this patch may be incomplete: aren't there other places which need to be handling PROTNONE along with PRESENT? For example, pte_mknuma() clears _PAGE_PRESENT and sets _PAGE_NUMA, but on a PROT_NONE area, that would make it pte_special(). This is side-stepped by the fact that NUMA hinting faults skipped PROT_NONE VMAs and there are no grounds where a NUMA hinting fault on a PROT_NONE VMA would be interesting. Fixes: c46a7c817e66 ("x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels") Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: <stable@vger.kernel.org> [3.16] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-29KVM: x86: use guest maxphyaddr to check MTRR valuesPaolo Bonzini
The check introduced in commit d7a2a246a1b5 (KVM: x86: #GP when attempts to write reserved bits of Variable Range MTRRs, 2014-08-19) will break if the guest maxphyaddr is higher than the host's (which sometimes happens depending on your hardware and how QEMU is configured). To fix this, use cpuid_maxphyaddr similar to how the APIC_BASE MSR does already. Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Tested-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29KVM: remove garbage arg to *hardware_{en,dis}ableRadim Krčmář
In the beggining was on_each_cpu(), which required an unused argument to kvm_arch_ops.hardware_{en,dis}able, but this was soon forgotten. Remove unnecessary arguments that stem from this. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29KVM: forward declare structs in kvm_types.hPaolo Bonzini
Opaque KVM structs are useful for prototypes in asm/kvm_host.h, to avoid "'struct foo' declared inside parameter list" warnings (and consequent breakage due to conflicting types). Move them from individual files to a generic place in linux/kvm_types.h. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29KVM: x86: remove Aligned bit from movntps/movntpdPaolo Bonzini
These are not explicitly aligned, and do not require alignment on AVX. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29KVM: x86 emulator: emulate MOVNTDQAlex Williamson
Windows 8.1 guest with NVIDIA driver and GPU fails to boot with an emulation failure. The KVM spew suggests the fault is with lack of movntdq emulation (courtesy of Paolo): Code=02 00 00 b8 08 00 00 00 f3 0f 6f 44 0a f0 f3 0f 6f 4c 0a e0 <66> 0f e7 41 f0 66 0f e7 49 e0 48 83 e9 40 f3 0f 6f 44 0a 10 f3 0f 6f 0c 0a 66 0f e7 41 10 $ as -o a.out .section .text .byte 0x66, 0x0f, 0xe7, 0x41, 0xf0 .byte 0x66, 0x0f, 0xe7, 0x49, 0xe0 $ objdump -d a.out 0: 66 0f e7 41 f0 movntdq %xmm0,-0x10(%rcx) 5: 66 0f e7 49 e0 movntdq %xmm1,-0x20(%rcx) Add the necessary emulation. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29KVM: vmx: VMXOFF emulation in vm86 should cause #UDNadav Amit
Unlike VMCALL, the instructions VMXOFF, VMLAUNCH and VMRESUME should cause a UD exception in real-mode or vm86. However, the emulator considers all these instructions the same for the matter of mode checks, and emulation upon exit due to #UD exception. As a result, the hypervisor behaves incorrectly on vm86 mode. VMXOFF, VMLAUNCH or VMRESUME cause on vm86 exit due to #UD. The hypervisor then emulates these instruction and inject #GP to the guest instead of #UD. This patch creates a new group for these instructions and mark only VMCALL as an instruction which can be emulated. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29KVM: x86: fix some sparse warningsPaolo Bonzini
Sparse reports the following easily fixed warnings: arch/x86/kvm/vmx.c:8795:48: sparse: Using plain integer as NULL pointer arch/x86/kvm/vmx.c:2138:5: sparse: symbol vmx_read_l1_tsc was not declared. Should it be static? arch/x86/kvm/vmx.c:6151:48: sparse: Using plain integer as NULL pointer arch/x86/kvm/vmx.c:8851:6: sparse: symbol vmx_sched_in was not declared. Should it be static? arch/x86/kvm/svm.c:2162:5: sparse: symbol svm_read_l1_tsc was not declared. Should it be static? Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29KVM: nVMX: nested TPR shadow/threshold emulationWanpeng Li
This patch fix bug https://bugzilla.kernel.org/show_bug.cgi?id=61411 TPR shadow/threshold feature is important to speed up the Windows guest. Besides, it is a must feature for certain VMM. We map virtual APIC page address and TPR threshold from L1 VMCS. If TPR_BELOW_THRESHOLD VM exit is triggered by L2 guest and L1 interested in, we inject it into L1 VMM for handling. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> [Add PAGE_ALIGNED check, do not write useless virtual APIC page address if TPR shadowing is disabled. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29KVM: nVMX: introduce nested_get_vmcs12_pagesWanpeng Li
Introduce function nested_get_vmcs12_pages() to check the valid of nested apic access page and virtual apic page earlier. Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29x86, irq, PCI: Keep IRQ assignment for runtime power managementJiang Liu
Now IOAPIC driver dynamically allocates IRQ numbers for IOAPIC pins. We need to keep IRQ assignment for PCI devices during runtime power management, otherwise it may cause failure of device wakeups. Commit 3eec595235c17a7 "x86, irq, PCI: Keep IRQ assignment for PCI devices during suspend/hibernation" has fixed the issue for suspend/ hibernation, we also need the same fix for runtime device sleep too. Fix: https://bugzilla.kernel.org/show_bug.cgi?id=83271 Reported-and-Tested-by: EmanueL Czirai <amanual@openmailbox.org> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: EmanueL Czirai <amanual@openmailbox.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Grant Likely <grant.likely@linaro.org> Link: http://lkml.kernel.org/r/1409304383-18806-1-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-08-28percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_tChristoph Lameter
__get_cpu_var can paper over differences in the definitions of cpumask_var_t and either use the address of the cpumask variable directly or perform a fetch of the address of the struct cpumask allocated elsewhere. This is important particularly when using per cpu cpumask_var_t declarations because in one case we have an offset into a per cpu area to handle and in the other case we need to fetch a pointer from the offset. This patch introduces a new macro this_cpu_cpumask_var_ptr() that is defined where cpumask_var_t is defined and performs the proper actions. All use cases where __get_cpu_var is used with cpumask_var_t are converted to the use of this_cpu_cpumask_var_ptr(). Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>