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2020-07-22s390/mm: fix huge pte soft dirty copyingJanosch Frank1-1/+1
commit 528a9539348a0234375dfaa1ca5dbbb2f8f8e8d2 upstream. If the pmd is soft dirty we must mark the pte as soft dirty (and not dirty). This fixes some cases for guest migration with huge page backings. Cc: <stable@vger.kernel.org> # 4.8 Fixes: bc29b7ac1d9f ("s390/mm: clean up pte/pmd encoding") Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22s390/kasan: fix early pgm check handler executionVasily Gorbik1-0/+2
[ Upstream commit 998f5bbe3dbdab81c1cfb1aef7c3892f5d24f6c7 ] Currently if early_pgm_check_handler is called it ends up in pgm check loop. The problem is that early_pgm_check_handler is instrumented by KASAN but executed without DAT flag enabled which leads to addressing exception when KASAN checks try to access shadow memory. Fix that by executing early handlers with DAT flag on under KASAN as expected. Reported-and-tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-22KVM: s390: reduce number of IO pins to 1Christian Borntraeger1-4/+4
[ Upstream commit 774911290c589e98e3638e73b24b0a4d4530e97c ] The current number of KVM_IRQCHIP_NUM_PINS results in an order 3 allocation (32kb) for each guest start/restart. This can result in OOM killer activity even with free swap when the memory is fragmented enough: kernel: qemu-system-s39 invoked oom-killer: gfp_mask=0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_COMP|__GFP_ZERO), order=3, oom_score_adj=0 kernel: CPU: 1 PID: 357274 Comm: qemu-system-s39 Kdump: loaded Not tainted 5.4.0-29-generic #33-Ubuntu kernel: Hardware name: IBM 8562 T02 Z06 (LPAR) kernel: Call Trace: kernel: ([<00000001f848fe2a>] show_stack+0x7a/0xc0) kernel: [<00000001f8d3437a>] dump_stack+0x8a/0xc0 kernel: [<00000001f8687032>] dump_header+0x62/0x258 kernel: [<00000001f8686122>] oom_kill_process+0x172/0x180 kernel: [<00000001f8686abe>] out_of_memory+0xee/0x580 kernel: [<00000001f86e66b8>] __alloc_pages_slowpath+0xd18/0xe90 kernel: [<00000001f86e6ad4>] __alloc_pages_nodemask+0x2a4/0x320 kernel: [<00000001f86b1ab4>] kmalloc_order+0x34/0xb0 kernel: [<00000001f86b1b62>] kmalloc_order_trace+0x32/0xe0 kernel: [<00000001f84bb806>] kvm_set_irq_routing+0xa6/0x2e0 kernel: [<00000001f84c99a4>] kvm_arch_vm_ioctl+0x544/0x9e0 kernel: [<00000001f84b8936>] kvm_vm_ioctl+0x396/0x760 kernel: [<00000001f875df66>] do_vfs_ioctl+0x376/0x690 kernel: [<00000001f875e304>] ksys_ioctl+0x84/0xb0 kernel: [<00000001f875e39a>] __s390x_sys_ioctl+0x2a/0x40 kernel: [<00000001f8d55424>] system_call+0xd8/0x2c8 As far as I can tell s390x does not use the iopins as we bail our for anything other than KVM_IRQ_ROUTING_S390_ADAPTER and the chip/pin is only used for KVM_IRQ_ROUTING_IRQCHIP. So let us use a small number to reduce the memory footprint. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200617083620.5409-1-borntraeger@de.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30s390/ptrace: fix setting syscall numberSven Schnelle1-1/+30
[ Upstream commit 873e5a763d604c32988c4a78913a8dab3862d2f9 ] When strace wants to update the syscall number, it sets GPR2 to the desired number and updates the GPR via PTRACE_SETREGSET. It doesn't update regs->int_code which would cause the old syscall executed on syscall restart. As we cannot change the ptrace ABI and don't have a field for the interruption code, check whether the tracee is in a syscall and the last instruction was svc. In that case assume that the tracer wants to update the syscall number and copy the GPR2 value to regs->int_code. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25s390: fix syscall_get_error for compat processesDmitry V. Levin1-1/+11
commit b3583fca5fb654af2cfc1c08259abb9728272538 upstream. If both the tracer and the tracee are compat processes, and gprs[2] is assigned a value by __poke_user_compat, then the higher 32 bits of gprs[2] are cleared, IS_ERR_VALUE() always returns false, and syscall_get_error() always returns 0. Fix the implementation by sign-extending the value for compat processes the same way as x86 implementation does. The bug was exposed to user space by commit 201766a20e30f ("ptrace: add PTRACE_GET_SYSCALL_INFO request") and detected by strace test suite. This change fixes strace syscall tampering on s390. Link: https://lkml.kernel.org/r/20200602180051.GA2427@altlinux.org Fixes: 753c4dd6a2fa2 ("[S390] ptrace changes") Cc: Elvira Khabirova <lineprinter@altlinux.org> Cc: stable@vger.kernel.org # v2.6.28+ Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-11s390/ftrace: save traced function callerVasily Gorbik1-0/+1
[ Upstream commit b4adfe55915d8363e244e42386d69567db1719b9 ] A typical backtrace acquired from ftraced function currently looks like the following (e.g. for "path_openat"): arch_stack_walk+0x15c/0x2d8 stack_trace_save+0x50/0x68 stack_trace_call+0x15a/0x3b8 ftrace_graph_caller+0x0/0x1c 0x3e0007e3c98 <- ftraced function caller (should be do_filp_open+0x7c/0xe8) do_open_execat+0x70/0x1b8 __do_execve_file.isra.0+0x7d8/0x860 __s390x_sys_execve+0x56/0x68 system_call+0xdc/0x2d8 Note random "0x3e0007e3c98" stack value as ftraced function caller. This value causes either imprecise unwinder result or unwinding failure. That "0x3e0007e3c98" comes from r14 of ftraced function stack frame, which it haven't had a chance to initialize since the very first instruction calls ftrace code ("ftrace_caller"). (ftraced function might never save r14 as well). Nevertheless according to s390 ABI any function is called with stack frame allocated for it and r14 contains return address. "ftrace_caller" itself is called with "brasl %r0,ftrace_caller". So, to fix this issue simply always save traced function caller onto ftraced function stack frame. Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-10s390/ftrace: fix potential crashes when switching tracersPhilipp Rudo3-4/+4
[ Upstream commit 8ebf6da9db1b2a20bb86cc1bee2552e894d03308 ] Switching tracers include instruction patching. To prevent that a instruction is patched while it's read the instruction patching is done in stop_machine 'context'. This also means that any function called during stop_machine must not be traced. Thus add 'notrace' to all functions called within stop_machine. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Fixes: 38f2c691a4b3 ("s390: improve wait logic of stop_machine") Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield") Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24KVM: s390: vsie: Fix possible race when shadowing region 3 tablesDavid Hildenbrand1-0/+1
[ Upstream commit 1493e0f944f3c319d11e067c185c904d01c17ae5 ] We have to properly retry again by returning -EINVAL immediately in case somebody else instantiated the table concurrently. We missed to add the goto in this function only. The code now matches the other, similar shadowing functions. We are overwriting an existing region 2 table entry. All allocated pages are added to the crst_list to be freed later, so they are not lost forever. However, when unshadowing the region 2 table, we wouldn't trigger unshadowing of the original shadowed region 3 table that we replaced. It would get unshadowed when the original region 3 table is modified. As it's not connected to the page table hierarchy anymore, it's not going to get used anymore. However, for a limited time, this page table will stick around, so it's in some sense a temporary memory leak. Identified by manual code inspection. I don't think this classifies as stable material. Fixes: 998f637cc4b9 ("s390/mm: avoid races on region/segment/page table shadowing") Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200403153050.20569-4-david@redhat.com Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24s390/cpuinfo: fix wrong output when CPU0 is offlineAlexander Gordeev1-1/+4
[ Upstream commit 872f27103874a73783aeff2aac2b41a489f67d7c ] /proc/cpuinfo should not print information about CPU 0 when it is offline. Fixes: 281eaa8cb67c ("s390/cpuinfo: simplify locking and skip offline cpus early") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> [heiko.carstens@de.ibm.com: shortened commit message] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24s390/diag: fix display of diagnose call statisticsMichael Mueller1-1/+1
commit 6c7c851f1b666a8a455678a0b480b9162de86052 upstream. Show the full diag statistic table and not just parts of it. The issue surfaced in a KVM guest with a number of vcpus defined smaller than NR_DIAG_STAT. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Cc: stable@vger.kernel.org Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24KVM: s390: vsie: Fix delivery of addressing exceptionsDavid Hildenbrand1-0/+1
commit 4d4cee96fb7a3cc53702a9be8299bf525be4ee98 upstream. Whenever we get an -EFAULT, we failed to read in guest 2 physical address space. Such addressing exceptions are reported via a program intercept to the nested hypervisor. We faked the intercept, we have to return to guest 2. Instead, right now we would be returning -EFAULT from the intercept handler, eventually crashing the VM. the correct thing to do is to return 1 as rc == 1 is the internal representation of "we have to go back into g2". Addressing exceptions can only happen if the g2->g3 page tables reference invalid g2 addresses (say, either a table or the final page is not accessible - so something that basically never happens in sane environments. Identified by manual code inspection. Fixes: a3508fbe9dc6 ("KVM: s390: vsie: initial support for nested virtualization") Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200403153050.20569-3-david@redhat.com Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [borntraeger@de.ibm.com: fix patch description] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checksDavid Hildenbrand1-1/+5
commit a1d032a49522cb5368e5dfb945a85899b4c74f65 upstream. In case we have a region 1 the following calculation (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11) results in 64. As shifts beyond the size are undefined the compiler is free to use instructions like sllg. sllg will only use 6 bits of the shift value (here 64) resulting in no shift at all. That means that ALL addresses will be rejected. The can result in endless loops, e.g. when prefix cannot get mapped. Fixes: 4be130a08420 ("s390/mm: add shadow gmap support") Tested-by: Janosch Frank <frankja@linux.ibm.com> Reported-by: Janosch Frank <frankja@linux.ibm.com> Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200403153050.20569-2-david@redhat.com Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [borntraeger@de.ibm.com: fix patch description, remove WARN_ON_ONCE] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28s390/mm: Explicitly compare PAGE_DEFAULT_KEY against zero in ↵Nathan Chancellor1-1/+1
storage_key_init_range commit 380324734956c64cd060e1db4304f3117ac15809 upstream. Clang warns: In file included from ../arch/s390/purgatory/purgatory.c:10: In file included from ../include/linux/kexec.h:18: In file included from ../include/linux/crash_core.h:6: In file included from ../include/linux/elfcore.h:5: In file included from ../include/linux/user.h:1: In file included from ../arch/s390/include/asm/user.h:11: ../arch/s390/include/asm/page.h:45:6: warning: converting the result of '<<' to a boolean always evaluates to false [-Wtautological-constant-compare] if (PAGE_DEFAULT_KEY) ^ ../arch/s390/include/asm/page.h:23:44: note: expanded from macro 'PAGE_DEFAULT_KEY' #define PAGE_DEFAULT_KEY (PAGE_DEFAULT_ACC << 4) ^ 1 warning generated. Explicitly compare this against zero to silence the warning as it is intended to be used in a boolean context. Fixes: de3fa841e429 ("s390/mm: fix compile for PAGE_DEFAULT_KEY != 0") Link: https://github.com/ClangBuiltLinux/linux/issues/860 Link: https://lkml.kernel.org/r/20200214064207.10381-1-natechancellor@gmail.com Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28s390/ftrace: generate traced function stack frameVasily Gorbik1-1/+14
[ Upstream commit 45f7a0da600d3c409b5ad8d5ddddacd98ddc8840 ] Currently backtrace from ftraced function does not contain ftraced function itself. e.g. for "path_openat": arch_stack_walk+0x15c/0x2d8 stack_trace_save+0x50/0x68 stack_trace_call+0x15e/0x3d8 ftrace_graph_caller+0x0/0x1c <-- ftrace code do_filp_open+0x7c/0xe8 <-- ftraced function caller do_open_execat+0x76/0x1b8 open_exec+0x52/0x78 load_elf_binary+0x180/0x1160 search_binary_handler+0x8e/0x288 load_script+0x2a8/0x2b8 search_binary_handler+0x8e/0x288 __do_execve_file.isra.39+0x6fa/0xb40 __s390x_sys_execve+0x56/0x68 system_call+0xdc/0x2d8 Ftraced function is expected in the backtrace by ftrace kselftests, which are now failing. It would also be nice to have it for clarity reasons. "ftrace_caller" itself is called without stack frame allocated for it and does not store its caller (ftraced function). Instead it simply allocates a stack frame for "ftrace_trace_function" and sets backchain to point to ftraced function stack frame (which contains ftraced function caller in saved r14). To fix this issue make "ftrace_caller" allocate a stack frame for itself just to store ftraced function for the stack unwinder. As a result backtrace looks like the following: arch_stack_walk+0x15c/0x2d8 stack_trace_save+0x50/0x68 stack_trace_call+0x15e/0x3d8 ftrace_graph_caller+0x0/0x1c <-- ftrace code path_openat+0x6/0xd60 <-- ftraced function do_filp_open+0x7c/0xe8 <-- ftraced function caller do_open_execat+0x76/0x1b8 open_exec+0x52/0x78 load_elf_binary+0x180/0x1160 search_binary_handler+0x8e/0x288 load_script+0x2a8/0x2b8 search_binary_handler+0x8e/0x288 __do_execve_file.isra.39+0x6fa/0xb40 __s390x_sys_execve+0x56/0x68 system_call+0xdc/0x2d8 Reported-by: Sven Schnelle <sven.schnelle@ibm.com> Tested-by: Sven Schnelle <sven.schnelle@ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-28KVM: s390: ENOTSUPP -> EOPNOTSUPP fixupsChristian Borntraeger1-3/+3
[ Upstream commit c611990844c28c61ca4b35ff69d3a2ae95ccd486 ] There is no ENOTSUPP for userspace. Reported-by: Julian Wiedmann <jwi@linux.ibm.com> Fixes: 519783935451 ("KVM: s390: introduce ais mode modify function") Fixes: 2c1a48f2e5ed ("KVM: S390: add new group for flic") Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-28s390/time: Fix clk type in get_tod_clockNathan Chancellor1-1/+1
commit 0f8a206df7c920150d2aa45574fba0ab7ff6be4f upstream. Clang warns: In file included from ../arch/s390/boot/startup.c:3: In file included from ../include/linux/elf.h:5: In file included from ../arch/s390/include/asm/elf.h:132: In file included from ../include/linux/compat.h:10: In file included from ../include/linux/time.h:74: In file included from ../include/linux/time32.h:13: In file included from ../include/linux/timex.h:65: ../arch/s390/include/asm/timex.h:160:20: warning: passing 'unsigned char [16]' to parameter of type 'char *' converts between pointers to integer types with different sign [-Wpointer-sign] get_tod_clock_ext(clk); ^~~ ../arch/s390/include/asm/timex.h:149:44: note: passing argument to parameter 'clk' here static inline void get_tod_clock_ext(char *clk) ^ Change clk's type to just be char so that it matches what happens in get_tod_clock_ext. Fixes: 57b28f66316d ("[S390] s390_hypfs: Add new attributes") Link: https://github.com/ClangBuiltLinux/linux/issues/861 Link: http://lkml.kernel.org/r/20200208140858.47970-1-natechancellor@gmail.com Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-15KVM: s390: do not clobber registers during guest reset/store statusChristian Borntraeger1-4/+2
[ Upstream commit 55680890ea78be0df5e1384989f1be835043c084 ] The initial CPU reset clobbers the userspace fpc and the store status ioctl clobbers the guest acrs + fpr. As these calls are only done via ioctl (and not via vcpu_run), no CPU context is loaded, so we can (and must) act directly on the sync regs, not on the thread context. Cc: stable@kernel.org Fixes: e1788bb995be ("KVM: s390: handle floating point registers in the run ioctl not in vcpu_put/load") Fixes: 31d8b8d41a7e ("KVM: s390: handle access registers in the run ioctl not in vcpu_put/load") Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20200131100205.74720-2-frankja@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-15s390/mm: fix dynamic pagetable upgrade for hugetlbfsGerald Schaefer2-1/+101
commit 5f490a520bcb393389a4d44bec90afcb332eb112 upstream. Commit ee71d16d22bb ("s390/mm: make TASK_SIZE independent from the number of page table levels") changed the logic of TASK_SIZE and also removed the arch_mmap_check() implementation for s390. This combination has a subtle effect on how get_unmapped_area() for hugetlbfs pages works. It is now possible that a user process establishes a hugetlbfs mapping at an address above 4 TB, without triggering a dynamic pagetable upgrade from 3 to 4 levels. This is because hugetlbfs mappings will not use mm->get_unmapped_area, but rather file->f_op->get_unmapped_area, which currently is the generic implementation of hugetlb_get_unmapped_area() that does not know about s390 dynamic pagetable upgrades, but with the new definition of TASK_SIZE, it will now allow mappings above 4 TB. Subsequent access to such a mapped address above 4 TB will result in a page fault loop, because the CPU cannot translate such a large address with 3 pagetable levels. The fault handler will try to map in a hugepage at the address, but due to the folded pagetable logic it will end up with creating entries in the 3 level pagetable, possibly overwriting existing mappings, and then it all repeats when the access is retried. Apart from the page fault loop, this can have various nasty effects, e.g. kernel panic from one of the BUG_ON() checks in memory management code, or even data loss if an existing mapping gets overwritten. Fix this by implementing HAVE_ARCH_HUGETLB_UNMAPPED_AREA support for s390, providing an s390 version for hugetlb_get_unmapped_area() with pagetable upgrade support similar to arch_get_unmapped_area(), which will then be used instead of the generic version. Fixes: ee71d16d22bb ("s390/mm: make TASK_SIZE independent from the number of page table levels") Cc: <stable@vger.kernel.org> # 4.12+ Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09s390/smp: fix physical to logical CPU map for SMTHeiko Carstens1-26/+54
[ Upstream commit 72a81ad9d6d62dcb79f7e8ad66ffd1c768b72026 ] If an SMT capable system is not IPL'ed from the first CPU the setup of the physical to logical CPU mapping is broken: the IPL core gets CPU number 0, but then the next core gets CPU number 1. Correct would be that all SMT threads of CPU 0 get the subsequent logical CPU numbers. This is important since a lot of code (like e.g. the CPU topology code) assumes that CPU maps are setup like this. If the mapping is broken the system will not IPL due to broken topology masks: [ 1.716341] BUG: arch topology broken [ 1.716342] the SMT domain not a subset of the MC domain [ 1.716343] BUG: arch topology broken [ 1.716344] the MC domain not a subset of the BOOK domain This scenario can usually not happen since LPARs are always IPL'ed from CPU 0 and also re-IPL is intiated from CPU 0. However older kernels did initiate re-IPL on an arbitrary CPU. If therefore a re-IPL from an old kernel into a new kernel is initiated this may lead to crash. Fix this by setting up the physical to logical CPU mapping correctly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09s390/cpum_sf: Avoid SBD overflow condition in irq handlerThomas Richter1-6/+0
[ Upstream commit 0539ad0b22877225095d8adef0c376f52cc23834 ] The s390 CPU Measurement sampling facility has an overflow condition which fires when all entries in a SBD are used. The measurement alert interrupt is triggered and reads out all samples in this SDB. It then tests the successor SDB, if this SBD is not full, the interrupt handler does not read any samples at all from this SDB The design waits for the hardware to fill this SBD and then trigger another meassurement alert interrupt. This scheme works nicely until an perf_event_overflow() function call discards the sample due to a too high sampling rate. The interrupt handler has logic to read out a partially filled SDB when the perf event overflow condition in linux common code is met. This causes the CPUM sampling measurement hardware and the PMU device driver to operate on the same SBD's trailer entry. This should not happen. This can be seen here using this trace: cpumsf_pmu_add: tear:0xb5286000 hw_perf_event_update: sdbt 0xb5286000 full 1 over 0 flush_all:0 hw_perf_event_update: sdbt 0xb5286008 full 0 over 0 flush_all:0 above shows 1. interrupt hw_perf_event_update: sdbt 0xb5286008 full 1 over 0 flush_all:0 hw_perf_event_update: sdbt 0xb5286008 full 0 over 0 flush_all:0 above shows 2. interrupt ... this goes on fine until... hw_perf_event_update: sdbt 0xb5286068 full 1 over 0 flush_all:0 perf_push_sample1: overflow one or more samples read from the IRQ handler are rejected by perf_event_overflow() and the IRQ handler advances to the next SDB and modifies the trailer entry of a partially filled SDB. hw_perf_event_update: sdbt 0xb5286070 full 0 over 0 flush_all:1 timestamp: 14:32:52.519953 Next time the IRQ handler is called for this SDB the trailer entry shows an overflow count of 19 missed entries. hw_perf_event_update: sdbt 0xb5286070 full 1 over 19 flush_all:1 timestamp: 14:32:52.970058 Remove access to a follow on SDB when event overflow happened. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09s390/cpum_sf: Adjust sampling interval to avoid hitting sample limitsThomas Richter1-0/+16
[ Upstream commit 39d4a501a9ef55c57b51e3ef07fc2aeed7f30b3b ] Function perf_event_ever_overflow() and perf_event_account_interrupt() are called every time samples are processed by the interrupt handler. However function perf_event_account_interrupt() has checks to avoid being flooded with interrupts (more then 1000 samples are received per task_tick). Samples are then dropped and a PERF_RECORD_THROTTLED is added to the perf data. The perf subsystem limit calculation is: maximum sample frequency := 100000 --> 1 samples per 10 us task_tick = 10ms = 10000us --> 1000 samples per task_tick The work flow is measurement_alert() uses SDBT head and each SBDT points to 511 SDB pages, each with 126 sample entries. After processing 8 SBDs and for each valid sample calling: perf_event_overflow() perf_event_account_interrupts() there is a considerable amount of samples being dropped, especially when the sample frequency is very high and near the 100000 limit. To avoid the high amount of samples being dropped near the end of a task_tick time frame, increment the sampling interval in case of dropped events. The CPU Measurement sampling facility on the s390 supports only intervals, specifiing how many CPU cycles have to be executed before a sample is generated. Increase the interval when the samples being generated hit the task_tick limit. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-04s390/cpum_sf: Check for SDBT and SDB consistencyThomas Richter1-2/+15
[ Upstream commit 247f265fa502e7b17a0cb0cc330e055a36aafce4 ] Each SBDT is located at a 4KB page and contains 512 entries. Each entry of a SDBT points to a SDB, a 4KB page containing sampled data. The last entry is a link to another SDBT page. When an event is created the function sequence executed is: __hw_perf_event_init() +--> allocate_buffers() +--> realloc_sampling_buffers() +---> alloc_sample_data_block() Both functions realloc_sampling_buffers() and alloc_sample_data_block() allocate pages and the allocation can fail. This is handled correctly and all allocated pages are freed and error -ENOMEM is returned to the top calling function. Finally the event is not created. Once the event has been created, the amount of initially allocated SDBT and SDB can be too low. This is detected during measurement interrupt handling, where the amount of lost samples is calculated. If the number of lost samples is too high considering sampling frequency and already allocated SBDs, the number of SDBs is enlarged during the next execution of cpumsf_pmu_enable(). If more SBDs need to be allocated, functions realloc_sampling_buffers() +---> alloc-sample_data_block() are called to allocate more pages. Page allocation may fail and the returned error is ignored. A SDBT and SDB setup already exists. However the modified SDBTs and SDBs might end up in a situation where the first entry of an SDBT does not point to an SDB, but another SDBT, basicly an SBDT without payload. This can not be handled by the interrupt handler, where an SDBT must have at least one entry pointing to an SBD. Add a check to avoid SDBTs with out payload (SDBs) when enlarging the buffer setup. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31s390/ftrace: fix endless recursion in function_graph tracerSven Schnelle1-2/+2
[ Upstream commit 6feeee8efc53035c3195b02068b58ae947538aa4 ] The following sequence triggers a kernel stack overflow on s390x: mount -t tracefs tracefs /sys/kernel/tracing cd /sys/kernel/tracing echo function_graph > current_tracer [crash] This is because preempt_count_{add,sub} are in the list of traced functions, which can be demonstrated by: echo preempt_count_add >set_ftrace_filter echo function_graph > current_tracer [crash] The stack overflow happens because get_tod_clock_monotonic() gets called by ftrace but itself calls preempt_{disable,enable}(), which leads to a endless recursion. Fix this by using preempt_{disable,enable}_notrace(). Fixes: 011620688a71 ("s390/time: ensure get_clock_monotonic() returns monotonic values") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31s390/disassembler: don't hide instruction addressesIlya Leoshkevich1-6/+7
[ Upstream commit 544f1d62e3e6c6e6d17a5e56f6139208acb5ff46 ] Due to kptr_restrict, JITted BPF code is now displayed like this: 000000000b6ed1b2: ebdff0800024 stmg %r13,%r15,128(%r15) 000000004cde2ba0: 41d0f040 la %r13,64(%r15) 00000000fbad41b0: a7fbffa0 aghi %r15,-96 Leaking kernel addresses to dmesg is not a concern in this case, because this happens only when JIT debugging is explicitly activated, which only root can do. Use %px in this particular instance, and also to print an instruction address in show_code and PCREL (e.g. brasl) arguments in print_insn. While at present functionally equivalent to %016lx, %px is recommended by Documentation/core-api/printk-formats.rst for such cases. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31s390/mm: add mm_pxd_folded() checks to pxd_free()Gerald Schaefer1-2/+14
[ Upstream commit 2416cefc504ba8ae9b17e3e6b40afc72708f96be ] Unlike pxd_free_tlb(), the pxd_free() functions do not check for folded page tables. This is not an issue so far, as those functions will actually never be called, since no code will reach them when page tables are folded. In order to avoid future issues, and to make the s390 code more similar to other architectures, add mm_pxd_folded() checks, similar to how it is done in pxd_free_tlb(). This was found by testing a patch from from Anshuman Khandual, which is currently discussed on LKML ("mm/debug: Add tests validating architecture page table helpers"). Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31s390/time: ensure get_clock_monotonic() returns monotonic valuesHeiko Carstens1-6/+10
[ Upstream commit 011620688a71f2f1fe9901dbc2479a7c01053196 ] The current implementation of get_clock_monotonic() leaves it up to the caller to call the function with preemption disabled. The only core kernel caller (sched_clock) however does not disable preemption. In order to make sure that all callers of this function see monotonic values handle disabling preemption within the function itself. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-17s390/mm: properly clear _PAGE_NOEXEC bit when it is not supportedGerald Schaefer1-2/+2
commit ab874f22d35a8058d8fdee5f13eb69d8867efeae upstream. On older HW or under a hypervisor, w/o the instruction-execution- protection (IEP) facility, and also w/o EDAT-1, a translation-specification exception may be recognized when bit 55 of a pte is one (_PAGE_NOEXEC). The current code tries to prevent setting _PAGE_NOEXEC in such cases, by removing it within set_pte_at(). However, ptep_set_access_flags() will modify a pte directly, w/o using set_pte_at(). There is at least one scenario where this can result in an active pte with _PAGE_NOEXEC set, which would then lead to a panic due to a translation-specification exception (write to swapped out page): do_swap_page pte = mk_pte (with _PAGE_NOEXEC bit) set_pte_at (will remove _PAGE_NOEXEC bit in page table, but keep it in local variable pte) vmf->orig_pte = pte (pte still contains _PAGE_NOEXEC bit) do_wp_page wp_page_reuse entry = vmf->orig_pte (still with _PAGE_NOEXEC bit) ptep_set_access_flags (writes entry with _PAGE_NOEXEC bit) Fix this by clearing _PAGE_NOEXEC already in mk_pte_phys(), where the pgprot value is applied, so that no pte with _PAGE_NOEXEC will ever be visible, if it is not supported. The check in set_pte_at() can then also be removed. Cc: <stable@vger.kernel.org> # 4.11+ Fixes: 57d7f939e7bd ("s390: add no-execute support") Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-05mm, gup: add missing refcount overflow checks on s390Vlastimil Babka1-3/+6
The mainline commit 8fde12ca79af ("mm: prevent get_user_pages() from overflowing page refcount") was backported to 4.14.y stable as commit 04198de24771. The backport however missed that in 4.14, there are several arch-specific gup.c versions with fast gup implementations, so these do not prevent refcount overflow. This stable-only commit fixes the s390 version, and is based on the backport in SUSE SLES/openSUSE 4.12-based kernels. The remaining architectures with own gup.c are sparc, mips, sh. It's unlikely the known overflow scenario based on FUSE, which needs 140GB of RAM, is a problem for those architectures, and I don't feel confident enough to patch them. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05KVM: s390: unregister debug feature on failing arch initMichael Mueller1-3/+14
[ Upstream commit 308c3e6673b012beecb96ef04cc65f4a0e7cdd99 ] Make sure the debug feature and its allocated resources get released upon unsuccessful architecture initialization. A related indication of the issue will be reported as kernel message. Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Message-Id: <20181130143215.69496-2-mimu@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01s390/perf: Return error when debug_register failsThomas Richter1-1/+5
[ Upstream commit ec0c0bb489727de0d4dca6a00be6970ab8a3b30a ] Return an error when the function debug_register() fails allocating the debug handle. Also remove the registered debug handle when the initialization fails later on. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24s390/kasan: avoid vdso instrumentationVasily Gorbik2-2/+4
[ Upstream commit 348498458505e202df41b6b9a78da448d39298b7 ] vdso is mapped into user space processes, which won't have kasan shodow mapped. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-12kvm: Convert kvm_lock to a mutexJunaid Shahid1-2/+2
commit 0d9ce162cf46c99628cc5da9510b959c7976735b upstream. It doesn't seem as if there is any particular need for kvm_lock to be a spinlock, so convert the lock to a mutex so that sleepable functions (in particular cond_resched()) can be called while holding it. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06s390/idle: fix cpu idle time calculationHeiko Carstens1-7/+22
commit 3d7efa4edd07be5c5c3ffa95ba63e97e070e1f3f upstream. The idle time reported in /proc/stat sometimes incorrectly contains huge values on s390. This is caused by a bug in arch_cpu_idle_time(). The kernel tries to figure out when a different cpu entered idle by accessing its per-cpu data structure. There is an ordering problem: if the remote cpu has an idle_enter value which is not zero, and an idle_exit value which is zero, it is assumed it is idle since "now". The "now" timestamp however is taken before the idle_enter value is read. Which in turn means that "now" can be smaller than idle_enter of the remote cpu. Unconditionally subtracting idle_enter from "now" can thus lead to a negative value (aka large unsigned value). Fix this by moving the get_tod_clock() invocation out of the loop. While at it also make the code a bit more readable. A similar bug also exists for show_idle_time(). Fix this is as well. Cc: <stable@vger.kernel.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06s390/cmm: fix information leak in cmm_timeout_handler()Yihui ZENG1-6/+6
commit b8e51a6a9db94bc1fb18ae831b3dab106b5a4b5f upstream. The problem is that we were putting the NUL terminator too far: buf[sizeof(buf) - 1] = '\0'; If the user input isn't NUL terminated and they haven't initialized the whole buffer then it leads to an info leak. The NUL terminator should be: buf[len - 1] = '\0'; Signed-off-by: Yihui Zeng <yzeng56@asu.edu> Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> [heiko.carstens@de.ibm.com: keep semantics of how *lenp and *ppos are handled] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06s390/uaccess: avoid (false positive) compiler warningsChristian Borntraeger1-2/+2
[ Upstream commit 062795fcdcb2d22822fb42644b1d76a8ad8439b3 ] Depending on inlining decisions by the compiler, __get/put_user_fn might become out of line. Then the compiler is no longer able to tell that size can only be 1,2,4 or 8 due to the check in __get/put_user resulting in false positives like ./arch/s390/include/asm/uaccess.h: In function ‘__put_user_fn’: ./arch/s390/include/asm/uaccess.h:113:9: warning: ‘rc’ may be used uninitialized in this function [-Wmaybe-uninitialized] 113 | return rc; | ^~ ./arch/s390/include/asm/uaccess.h: In function ‘__get_user_fn’: ./arch/s390/include/asm/uaccess.h:143:9: warning: ‘rc’ may be used uninitialized in this function [-Wmaybe-uninitialized] 143 | return rc; | ^~ These functions are supposed to be always inlined. Mark it as such. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11s390/topology: avoid firing events before kobjs are createdVasily Gorbik1-1/+2
commit f3122a79a1b0a113d3aea748e0ec26f2cb2889de upstream. arch_update_cpu_topology is first called from: kernel_init_freeable->sched_init_smp->sched_init_domains even before cpus has been registered in: kernel_init_freeable->do_one_initcall->s390_smp_init Do not trigger kobject_uevent change events until cpu devices are actually created. Fixes the following kasan findings: BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb40/0xee0 Read of size 8 at addr 0000000000000020 by task swapper/0/1 BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb36/0xee0 Read of size 8 at addr 0000000000000018 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B Hardware name: IBM 3906 M04 704 (LPAR) Call Trace: ([<0000000143c6db7e>] show_stack+0x14e/0x1a8) [<0000000145956498>] dump_stack+0x1d0/0x218 [<000000014429fb4c>] print_address_description+0x64/0x380 [<000000014429f630>] __kasan_report+0x138/0x168 [<0000000145960b96>] kobject_uevent_env+0xb36/0xee0 [<0000000143c7c47c>] arch_update_cpu_topology+0x104/0x108 [<0000000143df9e22>] sched_init_domains+0x62/0xe8 [<000000014644c94a>] sched_init_smp+0x3a/0xc0 [<0000000146433a20>] kernel_init_freeable+0x558/0x958 [<000000014599002a>] kernel_init+0x22/0x160 [<00000001459a71d4>] ret_from_fork+0x28/0x30 [<00000001459a71dc>] kernel_thread_starter+0x0/0x10 Cc: stable@vger.kernel.org Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-11KVM: s390: Test for bad access register and size at the start of S390_MEM_OPThomas Huth1-1/+1
commit a13b03bbb4575b350b46090af4dfd30e735aaed1 upstream. If the KVM_S390_MEM_OP ioctl is called with an access register >= 16, then there is certainly a bug in the calling userspace application. We check for wrong access registers, but only if the vCPU was already in the access register mode before (i.e. the SIE block has recorded it). The check is also buried somewhere deep in the calling chain (in the function ar_translation()), so this is somewhat hard to find. It's better to always report an error to the userspace in case this field is set wrong, and it's safer in the KVM code if we block wrong values here early instead of relying on a check somewhere deep down the calling chain, so let's add another check to kvm_s390_guest_mem_op() directly. We also should check that the "size" is non-zero here (thanks to Janosch Frank for the hint!). If we do not check the size, we could call vmalloc() with this 0 value, and this will cause a kernel warning. Signed-off-by: Thomas Huth <thuth@redhat.com> Link: https://lkml.kernel.org/r/20190829122517.31042-1-thuth@redhat.com Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-11s390/process: avoid potential reading of freed stackVasily Gorbik1-6/+16
commit 8769f610fe6d473e5e8e221709c3ac402037da6c upstream. With THREAD_INFO_IN_TASK (which is selected on s390) task's stack usage is refcounted and should always be protected by get/put when touching other task's stack to avoid race conditions with task's destruction code. Fixes: d5c352cdd022 ("s390: move thread_info into task_struct") Cc: stable@vger.kernel.org # v4.10+ Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-07hypfs: Fix error number left in struct pointer memberDavid Howells1-4/+5
[ Upstream commit b54c64f7adeb241423cd46598f458b5486b0375e ] In hypfs_fill_super(), if hypfs_create_update_file() fails, sbi->update_file is left holding an error number. This is passed to hypfs_kill_super() which doesn't check for this. Fix this by not setting sbi->update_value until after we've checked for error. Fixes: 24bbb1faf3f0 ("[PATCH] s390_hypfs filesystem") Signed-off-by: David Howells <dhowells@redhat.com> cc: Martin Schwidefsky <schwidefsky@de.ibm.com> cc: Heiko Carstens <heiko.carstens@de.ibm.com> cc: linux-s390@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05s390/crypto: xts-aes-s390 fix extra run-time crypto self tests findingHarald Freudenberger1-0/+6
[ Upstream commit 9e323d45ba94262620a073a3f9945ca927c07c71 ] With 'extra run-time crypto self tests' enabled, the selftest for s390-xts fails with alg: skcipher: xts-aes-s390 encryption unexpectedly succeeded on test vector "random: len=0 klen=64"; expected_error=-22, cfg="random: inplace use_digest nosimd src_divs=[2.61%@+4006, 84.44%@+21, 1.55%@+13, 4.50%@+344, 4.26%@+21, 2.64%@+27]" This special case with nbytes=0 is not handled correctly and this fix now makes sure that -EINVAL is returned when there is en/decrypt called with 0 bytes to en/decrypt. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-21s390/bpf: use 32-bit index for tail callsIlya Leoshkevich1-4/+6
[ Upstream commit 91b4db5313a2c793aabc2143efb8ed0cf0fdd097 ] "p runtime/jit: pass > 32bit index to tail_call" fails when bpf_jit_enable=1, because the tail call is not executed. This in turn is because the generated code assumes index is 64-bit, while it must be 32-bit, and as a result prog array bounds check fails, while it should pass. Even if bounds check would have passed, the code that follows uses 64-bit index to compute prog array offset. Fix by using clrj instead of clgrj for comparing index with array size, and also by using llgfr for truncating index to 32 bits before using it to compute prog array offset. Fixes: 6651ee070b31 ("s390/bpf: implement bpf_tail_call() helper") Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-21s390/bpf: fix lcgr instruction encodingIlya Leoshkevich1-1/+1
[ Upstream commit bb2d267c448f4bc3a3389d97c56391cb779178ae ] "masking, test in bounds 3" fails on s390, because BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0) ignores the top 32 bits of BPF_REG_2. The reason is that JIT emits lcgfr instead of lcgr. The associated comment indicates that the code was intended to emit lcgr in the first place, it's just that the wrong opcode was used. Fix by using the correct opcode. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-19KVM: s390: Do not leak kernel stack data in the KVM_S390_INTERRUPT ioctlThomas Huth2-1/+11
commit 53936b5bf35e140ae27e4bbf0447a61063f400da upstream. When the userspace program runs the KVM_S390_INTERRUPT ioctl to inject an interrupt, we convert them from the legacy struct kvm_s390_interrupt to the new struct kvm_s390_irq via the s390int_to_s390irq() function. However, this function does not take care of all types of interrupts that we can inject into the guest later (see do_inject_vcpu()). Since we do not clear out the s390irq values before calling s390int_to_s390irq(), there is a chance that we copy random data from the kernel stack which could be leaked to the userspace later. Specifically, the problem exists with the KVM_S390_INT_PFAULT_INIT interrupt: s390int_to_s390irq() does not handle it, and the function __inject_pfault_init() later copies irq->u.ext which contains the random kernel stack data. This data can then be leaked either to the guest memory in __deliver_pfault_init(), or the userspace might retrieve it directly with the KVM_S390_GET_IRQ_STATE ioctl. Fix it by handling that interrupt type in s390int_to_s390irq(), too, and by making sure that the s390irq struct is properly pre-initialized. And while we're at it, make sure that s390int_to_s390irq() now directly returns -EINVAL for unknown interrupt types, so that we immediately get a proper error code in case we add more interrupt types to do_inject_vcpu() without updating s390int_to_s390irq() sometime in the future. Cc: stable@vger.kernel.org Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/kvm/20190912115438.25761-1-thuth@redhat.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25bpf: get rid of pure_initcall dependency to enable jitsDaniel Borkmann1-2/+0
commit fa9dd599b4dae841924b022768354cfde9affecb upstream. Having a pure_initcall() callback just to permanently enable BPF JITs under CONFIG_BPF_JIT_ALWAYS_ON is unnecessary and could leave a small race window in future where JIT is still disabled on boot. Since we know about the setting at compilation time anyway, just initialize it properly there. Also consolidate all the individual bpf_jit_enable variables into a single one and move them under one location. Moreover, don't allow for setting unspecified garbage values on them. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> [bwh: Backported to 4.14 as dependency of commit 2e4a30983b0f "bpf: restrict access to core bpf sysctls": - Adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-21s390: fix stfle zero paddingHeiko Carstens1-7/+14
commit 4f18d869ffd056c7858f3d617c71345cf19be008 upstream. The stfle inline assembly returns the number of double words written (condition code 0) or the double words it would have written (condition code 3), if the memory array it got as parameter would have been large enough. The current stfle implementation assumes that the array is always large enough and clears those parts of the array that have not been written to with a subsequent memset call. If however the array is not large enough memset will get a negative length parameter, which means that memset clears memory until it gets an exception and the kernel crashes. To fix this simply limit the maximum length. Move also the inline assembly to an extra function to avoid clobbering of register 0, which might happen because of the added min_t invocation together with code instrumentation. The bug was introduced with commit 14375bc4eb8d ("[S390] cleanup facility list handling") but was rather harmless, since it would only write to a rather large array. It became a potential problem with commit 3ab121ab1866 ("[S390] kernel: Add z/VM LGR detection"). Since then it writes to an array with only four double words, while some machines already deliver three double words. As soon as machines have a facility bit within the fifth double a crash on IPL would happen. Fixes: 14375bc4eb8d ("[S390] cleanup facility list handling") Cc: <stable@vger.kernel.org> # v2.6.37+ Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19KVM: s390: fix memory slot handling for KVM_SET_USER_MEMORY_REGIONChristian Borntraeger1-14/+21
[ Upstream commit 19ec166c3f39fe1d3789888a74cc95544ac266d4 ] kselftests exposed a problem in the s390 handling for memory slots. Right now we only do proper memory slot handling for creation of new memory slots. Neither MOVE, nor DELETION are handled properly. Let us implement those. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-19s390/kasan: fix strncpy_from_user kasan checksVasily Gorbik1-0/+2
[ Upstream commit 01eb42afb45719cb41bb32c278e068073738899d ] arch/s390/lib/uaccess.c is built without kasan instrumentation. Kasan checks are performed explicitly in copy_from_user/copy_to_user functions. But since those functions could be inlined, calls from files like uaccess.c with instrumentation disabled won't generate kasan reports. This is currently the case with strncpy_from_user function which was revealed by newly added kasan test. Avoid inlining of copy_from_user/copy_to_user when the kernel is built with kasan support to make sure kasan checks are fully functional. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-09KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_IDThomas Huth1-0/+1
commit a86cb413f4bf273a9d341a3ab2c2ca44e12eb317 upstream. KVM_CAP_MAX_VCPU_ID is currently always reporting KVM_MAX_VCPU_ID on all architectures. However, on s390x, the amount of usable CPUs is determined during runtime - it is depending on the features of the machine the code is running on. Since we are using the vcpu_id as an index into the SCA structures that are defined by the hardware (see e.g. the sca_add_vcpu() function), it is not only the amount of CPUs that is limited by the hard- ware, but also the range of IDs that we can use. Thus KVM_CAP_MAX_VCPU_ID must be determined during runtime on s390x, too. So the handling of KVM_CAP_MAX_VCPU_ID has to be moved from the common code into the architecture specific code, and on s390x we have to return the same value here as for KVM_CAP_MAX_VCPUS. This problem has been discovered with the kvm_create_max_vcpus selftest. With this change applied, the selftest now passes on s390x, too. Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20190523164309.13345-9-thuth@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-16s390/speculation: Fix build error caused by bad backportGuenter Roeck1-0/+1
The backport of commit 0336e04a6520 ("s390/speculation: Support 'mitigations=' cmdline option") introduces a build error. Fix it up. Fixes: 91788fcb21d0 ("s390/speculation: Support 'mitigations=' cmdline option") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14s390/speculation: Support 'mitigations=' cmdline optionJosh Poimboeuf1-0/+9
commit 0336e04a6520bdaefdb0769d2a70084fa52e81ed upstream Configure s390 runtime CPU speculation bug mitigations in accordance with the 'mitigations=' cmdline option. This affects Spectre v1 and Spectre v2. The default behavior is unchanged. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86) Reviewed-by: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jon Masters <jcm@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Price <steven.price@arm.com> Cc: Phil Auld <pauld@redhat.com> Link: https://lkml.kernel.org/r/e4a161805458a5ec88812aac0307ae3908a030fc.1555085500.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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