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2021-05-14KVM: s390: extend kvm_s390_shadow_fault to return entry pointerClaudio Imbrenda3-10/+34
commit 5ac14bac08ae827b619f21bcceaaac3b8c497e31 upstream. Extend kvm_s390_shadow_fault to return the pointer to the valid leaf DAT table entry, or to the invalid entry. Also return some flags in the lower bits of the address: PEI_DAT_PROT: indicates that DAT protection applies because of the protection bit in the segment (or, if EDAT, region) tables. PEI_NOT_PTE: indicates that the address of the DAT table entry returned does not refer to a PTE, but to a segment or region table. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: stable@vger.kernel.org Reviewed-by: Janosch Frank <frankja@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Link: https://lore.kernel.org/r/20210302174443.514363-3-imbrenda@linux.ibm.com [borntraeger@de.ibm.com: fold in a fix from Claudio] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14KVM: s390: split kvm_s390_real_to_absClaudio Imbrenda1-6/+17
commit c5d1f6b531e68888cbe6718b3f77a60115d58b9c upstream. A new function _kvm_s390_real_to_abs will apply prefixing to a real address with a given prefix value. The old kvm_s390_real_to_abs becomes now a wrapper around the new function. This is needed to avoid code duplication in vSIE. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210322140559.500716-2-imbrenda@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14KVM: s390: VSIE: fix MVPG handling for prefixing and MSOClaudio Imbrenda1-1/+4
commit c3171e94cc1cdcc3229565244112e869f052b8d9 upstream. Prefixing needs to be applied to the guest real address to translate it into a guest absolute address. The value of MSO needs to be added to a guest-absolute address in order to obtain the host-virtual. Fixes: bdf7509bbefa ("s390/kvm: VSIE: correctly handle MVPG when in VSIE") Reported-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210322140559.500716-3-imbrenda@linux.ibm.com [borntraeger@de.ibm.com simplify mso] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14s390: fix detection of vector enhancements facility 1 vs. vector packed ↵David Hildenbrand1-2/+2
decimal facility commit b208108638c4bd3215792415944467c36f5dfd97 upstream. The PoP documents: 134: The vector packed decimal facility is installed in the z/Architecture architectural mode. When bit 134 is one, bit 129 is also one. 135: The vector enhancements facility 1 is installed in the z/Architecture architectural mode. When bit 135 is one, bit 129 is also one. Looks like we confuse the vector enhancements facility 1 ("EXT") with the Vector packed decimal facility ("BCD"). Let's fix the facility checks. Detected while working on QEMU/tcg z14 support and only unlocking the vector enhancements facility 1, but not the vector packed decimal facility. Fixes: 2583b848cad0 ("s390: report new vector facilities") Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20210503121244.25232-1-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14KVM: s390: fix guarded storage control register handlingHeiko Carstens1-2/+2
commit 44bada28219031f9e8e86b84460606efa57b871e upstream. store_regs_fmt2() has an ordering problem: first the guarded storage facility is enabled on the local cpu, then preemption disabled, and then the STGSC (store guarded storage controls) instruction is executed. If the process gets scheduled away between enabling the guarded storage facility and before preemption is disabled, this might lead to a special operation exception and therefore kernel crash as soon as the process is scheduled back and the STGSC instruction is executed. Fixes: 4e0b1ab72b8a ("KVM: s390: gs support for kvm guests") Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Cc: <stable@vger.kernel.org> # 4.12 Link: https://lore.kernel.org/r/20210415080127.1061275-1-hca@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14KVM: s390: split kvm_s390_logical_to_effectiveClaudio Imbrenda1-7/+24
commit f85f1baaa18932a041fd2b1c2ca6cfd9898c7d2b upstream. Split kvm_s390_logical_to_effective to a generic function called _kvm_s390_logical_to_effective. The new function takes a PSW and an address and returns the address with the appropriate bits masked off. The old function now calls the new function with the appropriate PSW from the vCPU. This is needed to avoid code duplication for vSIE. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: stable@vger.kernel.org # for VSIE: correctly handle MVPG when in VSIE Link: https://lore.kernel.org/r/20210302174443.514363-2-imbrenda@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14KVM: s390: VSIE: correctly handle MVPG when in VSIEClaudio Imbrenda1-5/+93
commit bdf7509bbefa20855d5f6bacdc5b62a8489477c9 upstream. Correctly handle the MVPG instruction when issued by a VSIE guest. Fixes: a3508fbe9dc6d ("KVM: s390: vsie: initial support for nested virtualization") Cc: stable@vger.kernel.org # f85f1baaa189: KVM: s390: split kvm_s390_logical_to_effective Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Link: https://lore.kernel.org/r/20210302174443.514363-4-imbrenda@linux.ibm.com [borntraeger@de.ibm.com: apply fixup from Claudio] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11s390/archrandom: add parameter check for s390_arch_random_generateHarald Freudenberger1-0/+4
[ Upstream commit 28096067686c5a5cbd4c35b079749bd805df5010 ] A review of the code showed, that this function which is exposed within the whole kernel should do a parameter check for the amount of bytes requested. If this requested bytes is too high an unsigned int overflow could happen causing this function to try to memcpy a really big memory chunk. This is not a security issue as there are only two invocations of this function from arch/s390/include/asm/archrandom.h and both are not exposed to userland. Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-11s390/disassembler: increase ebpf disasm buffer sizeVasily Gorbik1-1/+1
commit 6f3353c2d2b3eb4de52e9704cb962712033db181 upstream. Current ebpf disassembly buffer size of 64 is too small. E.g. this line takes 65 bytes: 01fffff8005822e: ec8100ed8065\tclgrj\t%r8,%r1,8,001fffff80058408\n\0 Double the buffer size like it is done for the kernel disassembly buffer. Fixes the following KASAN finding: UG: KASAN: stack-out-of-bounds in print_fn_code+0x34c/0x380 Write of size 1 at addr 001fff800ad5f970 by task test_progs/853 CPU: 53 PID: 853 Comm: test_progs Not tainted 5.12.0-rc7-23786-g23457d86b1f0-dirty #19 Hardware name: IBM 3906 M04 704 (LPAR) Call Trace: [<0000000cd8e0538a>] show_stack+0x17a/0x1668 [<0000000cd8e2a5d8>] dump_stack+0x140/0x1b8 [<0000000cd8e16e74>] print_address_description.constprop.0+0x54/0x260 [<0000000cd75a8698>] kasan_report+0xc8/0x130 [<0000000cd6e26da4>] print_fn_code+0x34c/0x380 [<0000000cd6ea0f4e>] bpf_int_jit_compile+0xe3e/0xe58 [<0000000cd72c4c88>] bpf_prog_select_runtime+0x5b8/0x9c0 [<0000000cd72d1bf8>] bpf_prog_load+0xa78/0x19c0 [<0000000cd72d7ad6>] __do_sys_bpf.part.0+0x18e/0x768 [<0000000cd6e0f392>] do_syscall+0x12a/0x220 [<0000000cd8e333f8>] __do_syscall+0x98/0xc8 [<0000000cd8e54834>] system_call+0x6c/0x94 1 lock held by test_progs/853: #0: 0000000cd9bf7460 (report_lock){....}-{2:2}, at: kasan_report+0x96/0x130 addr 001fff800ad5f970 is located in stack of task test_progs/853 at offset 96 in frame: print_fn_code+0x0/0x380 this frame has 1 object: [32, 96) 'buffer' Memory state around the buggy address: 001fff800ad5f800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 001fff800ad5f880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >001fff800ad5f900: 00 00 f1 f1 f1 f1 00 00 00 00 00 00 00 00 f3 f3 ^ 001fff800ad5f980: f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 001fff800ad5fa00: 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 Cc: <stable@vger.kernel.org> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-28s390/entry: save the caller of psw_idleVasily Gorbik1-0/+1
[ Upstream commit a994eddb947ea9ebb7b14d9a1267001699f0a136 ] Currently psw_idle does not allocate a stack frame and does not save its r14 and r15 into the save area. Even though this is valid from call ABI point of view, because psw_idle does not make any calls explicitly, in reality psw_idle is an entry point for controlled transition into serving interrupts. So, in practice, psw_idle stack frame is analyzed during stack unwinding. Depending on build options that r14 slot in the save area of psw_idle might either contain a value saved by previous sibling call or complete garbage. [task 0000038000003c28] do_ext_irq+0xd6/0x160 [task 0000038000003c78] ext_int_handler+0xba/0xe8 [task *0000038000003dd8] psw_idle_exit+0x0/0x8 <-- pt_regs ([task 0000038000003dd8] 0x0) [task 0000038000003e10] default_idle_call+0x42/0x148 [task 0000038000003e30] do_idle+0xce/0x160 [task 0000038000003e70] cpu_startup_entry+0x36/0x40 [task 0000038000003ea0] arch_call_rest_init+0x76/0x80 So, to make a stacktrace nicer and actually point for the real caller of psw_idle in this frequently occurring case, make psw_idle save its r14. [task 0000038000003c28] do_ext_irq+0xd6/0x160 [task 0000038000003c78] ext_int_handler+0xba/0xe8 [task *0000038000003dd8] psw_idle_exit+0x0/0x6 <-- pt_regs ([task 0000038000003dd8] arch_cpu_idle+0x3c/0xd0) [task 0000038000003e10] default_idle_call+0x42/0x148 [task 0000038000003e30] do_idle+0xce/0x160 [task 0000038000003e70] cpu_startup_entry+0x36/0x40 [task 0000038000003ea0] arch_call_rest_init+0x76/0x80 Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14s390/cpcmd: fix inline assembly register clobberingAlexander Gordeev1-2/+4
[ Upstream commit 7a2f91441b2c1d81b77c1cd816a4659f4abc9cbe ] Register variables initialized using arithmetic. That leads to kasan instrumentaton code corrupting the registers contents. Follow GCC guidlines and use temporary variables for assigning init values to register variables. Fixes: 94c12cc7d196 ("[S390] Inline assembly cleanup.") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://gcc.gnu.org/onlinedocs/gcc-10.2.0/gcc/Local-Register-Variables.html Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07s390/vdso: fix tod_steering_delta typeHeiko Carstens1-1/+1
commit b24bacd67ffddd9192c4745500fd6f73dbfe565e upstream. The s390 specific vdso function __arch_get_hw_counter() is supposed to consider tod clock steering. If a tod clock steering event happens and the tod clock is set to a new value __arch_get_hw_counter() will not return the real tod clock value but slowly drift it from the old delta until the returned value finally matches the real tod clock value again. Unfortunately the type of tod_steering_delta unsigned while it is supposed to be signed. It depends on if tod_steering_delta is negative or positive in which direction the vdso code drifts the clock value. Worst case is now that instead of drifting the clock slowly it will jump into the opposite direction by a factor of two. Fix this by simply making tod_steering_delta signed. Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO") Cc: <stable@vger.kernel.org> # 5.10 Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-07s390/vdso: copy tod_steering_delta value to vdso_data pageHeiko Carstens1-0/+1
commit 72bbc226ed2ef0a46c165a482861fff00dd6d4e1 upstream. When converting the vdso assembler code to C it was forgotten to actually copy the tod_steering_delta value to vdso_data page. Which in turn means that tod clock steering will not work correctly. Fix this by simply copying the value whenever it is updated. Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO") Cc: <stable@vger.kernel.org> # 5.10 Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25s390/pci: fix leak of PCI device structureNiklas Schnelle3-17/+31
commit 0b13525c20febcfecccf6fc1db5969727401317d upstream. In commit 05bc1be6db4b2 ("s390/pci: create zPCI bus") we removed the pci_dev_put() call matching the earlier pci_get_slot() done as part of __zpci_event_availability(). This was based on the wrong understanding that the device_put() done as part of pci_destroy_device() would counter the pci_get_slot() when it only counters the initial reference. This same understanding and existing bad example also lead to not doing a pci_dev_put() in zpci_remove_device(). Since releasing the PCI devices, unlike releasing the PCI slot, does not print any debug message for testing I added one in pci_release_dev(). This revealed that we are indeed leaking the PCI device on PCI hotunplug. Further testing also revealed another missing pci_dev_put() in disable_slot(). Fix this by adding the missing pci_dev_put() in disable_slot() and fix zpci_remove_device() with the correct pci_dev_put() calls. Also instead of calling pci_get_slot() in __zpci_event_availability() to determine if a PCI device is registered and then doing the same again in zpci_remove_device() do this once in zpci_remove_device() which makes sure that the pdev in __zpci_event_availability() is only used for the result of pci_scan_single_device() which does not need a reference count decremnt as its ownership goes to the PCI bus. Also move the check if zdev->zbus->bus is set into zpci_remove_device() since it may be that we're removing a device with devfn != 0 which never had a PCI bus. So we can still set the pdev->error_state to indicate that the device is not usable anymore, add a flag to set the error state. Fixes: 05bc1be6db4b2 ("s390/pci: create zPCI bus") Cc: <stable@vger.kernel.org> # 5.8+: e1bff843cde6 s390/pci: remove superfluous zdev->zbus check Cc: <stable@vger.kernel.org> # 5.8+: ba764dd703fe s390/pci: refactor zpci_create_device() Cc: <stable@vger.kernel.org> # 5.8+ Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25s390/pci: remove superfluous zdev->zbus checkNiklas Schnelle1-1/+1
commit e1bff843cde62a45a287b7f9b4cd5e824e8e49e2 upstream. Checking zdev->zbus for NULL in __zpci_event_availability() is superfluous as it can never be NULL at this point. While harmless this check causes smatch warnings because we later access zdev->zbus with only having checked zdev != NULL which is sufficient. The reason zdev->zbus can never be NULL is since with zdev != NULL given we know the zdev came from get_zdev_by_fid() and thus the zpci_list. Now on first glance at zpci_create_device() one may assume that there is a window where the zdev is in the list without a zdev, however this window can't overlap with __zpci_event_availability() as zpci_create_device() either runs on the same kthread as part of availability events, or during the initial CLP List PCI at which point the __zpci_event_availability() is not yet called as zPCI is not yet initialized. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25s390/pci: refactor zpci_create_device()Niklas Schnelle4-57/+48
commit ba764dd703feacb5a9c410d191af1b6cfbe96845 upstream. Currently zpci_create_device() is only called in clp_add_pci_device() which allocates the memory for the struct zpci_dev being created. There is little separation of concerns as only both functions together can create a zpci_dev and the only CLP specific code in clp_add_pci_device() is a call to clp_query_pci_fn(). Improve this by removing clp_add_pci_device() and refactor zpci_create_device() such that it alone creates and initializes the zpci_dev given the FID and Function Handle. For this we need to make clp_query_pci_fn() non-static. While at it remove the function handle parameter since we can just take that from the zpci_dev. Also move adding to the zpci_list to after the zdev has been fully created which eliminates a window where a partially initialized zdev can be found by get_zdev_by_fid(). Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25s390/vtime: fix increased steal time accountingGerald Schaefer1-1/+1
commit d54cb7d54877d529bc1e0e1f47a3dd082f73add3 upstream. Commit 152e9b8676c6e ("s390/vtime: steal time exponential moving average") inadvertently changed the input value for account_steal_time() from "cputime_to_nsecs(steal)" to just "steal", resulting in broken increased steal time accounting. Fix this by changing it back to "cputime_to_nsecs(steal)". Fixes: 152e9b8676c6e ("s390/vtime: steal time exponential moving average") Cc: <stable@vger.kernel.org> # 5.1 Reported-by: Sabine Forkel <sabine.forkel@de.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17s390/smp: __smp_rescan_cpus() - move cpumask away from stackHeiko Carstens1-1/+1
[ Upstream commit 62c8dca9e194326802b43c60763f856d782b225c ] Avoid a potentially large stack frame and overflow by making "cpumask_t avail" a static variable. There is no concurrent access due to the existing locking. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04s390/vtime: fix inline assembly clobber listHeiko Carstens1-1/+2
commit b29c5093820d333eef22f58cd04ec0d089059c39 upstream. The stck/stckf instruction used within the inline assembly within do_account_vtime() changes the condition code. This is not reflected with the clobber list, and therefore might result in incorrect code generation. It seems unlikely that the compiler could generate incorrect code considering the surrounding C code, but it must still be fixed. Cc: <stable@vger.kernel.org> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-03s390: uv: Fix sysfs max number of VCPUs reportingJanosch Frank3-4/+4
commit e82080e1f456467cc185fe65ee69fe9f9bd0b576 upstream. The number reported by the query is N-1 and I think people reading the sysfs file would expect N instead. For users creating VMs there's no actual difference because KVM's limit is currently below the UV's limit. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Fixes: a0f60f8431999 ("s390/protvirt: Add sysfs firmware interface for Ultravisor information") Cc: stable@vger.kernel.org Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-12local64.h: make <asm/local64.h> mandatoryRandy Dunlap1-1/+0
[ Upstream commit 87dbc209ea04645fd2351981f09eff5d23f8e2e9 ] Make <asm-generic/local64.h> mandatory in include/asm-generic/Kbuild and remove all arch/*/include/asm/local64.h arch-specific files since they only #include <asm-generic/local64.h>. This fixes build errors on arch/c6x/ and arch/nios2/ for block/blk-iocost.c. Build-tested on 21 of 25 arch-es. (tools problems on the others) Yes, we could even rename <asm-generic/local64.h> to <linux/local64.h> and change all #includes to use <linux/local64.h> instead. Link: https://lkml.kernel.org/r/20201227024446.17018-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Suggested-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Masahiro Yamada <masahiroy@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06s390: always clear kernel stack backchain before calling functionsHeiko Carstens1-6/+6
[ Upstream commit 9365965db0c7ca7fc81eee27c21d8522d7102c32 ] Clear the kernel stack backchain before potentially calling the lockdep trace_hardirqs_off/on functions. Without this walking the kernel backchain, e.g. during a panic, might stop too early. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30s390/idle: fix accounting with machine checksSven Schnelle1-6/+6
commit 454efcf82ea17d7efeb86ebaa20775a21ec87d27 upstream. When a machine check interrupt is triggered during idle, the code is using the async timer/clock for idle time calculation. It should use the machine check enter timer/clock which is passed to the macro. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Cc: <stable@vger.kernel.org> # 5.8 Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30s390/idle: add missing mt_cycles calculationSven Schnelle1-9/+25
commit e259b3fafa7de362b04ecd86e7fa9a9e9273e5fb upstream. During removal of the critical section cleanup the calculation of mt_cycles during idle was removed. This causes invalid accounting on systems with SMT enabled. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Cc: <stable@vger.kernel.org> # 5.8 Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30s390/kexec_file: fix diag308 subcode when loading crash kernelPhilipp Rudo1-4/+5
commit 613775d62ec60202f98d2c5f520e6e9ba6dd4ac4 upstream. diag308 subcode 0 performes a clear reset which inlcudes the reset of all registers in the system. While this is the preferred behavior when loading a normal kernel via kexec it prevents the crash kernel to store the register values in the dump. To prevent this use subcode 1 when loading a crash kernel instead. Fixes: ee337f5469fd ("s390/kexec_file: Add crash support to image loader") Cc: <stable@vger.kernel.org> # 4.17 Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Reported-by: Xiaoying Yan <yiyan@redhat.com> Tested-by: Lianbo Jiang <lijiang@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30s390/smp: perform initial CPU reset also for SMT siblingsSven Schnelle1-15/+3
commit b5e438ebd7e808d1d2435159ac4742e01a94b8da upstream. Not resetting the SMT siblings might leave them in unpredictable state. One of the observed problems was that the CPU timer wasn't reset and therefore large system time values where accounted during CPU bringup. Cc: <stable@kernel.org> # 4.0 Fixes: 10ad34bc76dfb ("s390: add SMT support") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30s390/test_unwind: fix CALL_ON_STACK testsHeiko Carstens1-2/+5
[ Upstream commit f22b9c219a798e1bf11110a3d2733d883e6da059 ] The CALL_ON_STACK tests use the no_dat stack to switch to a different stack for unwinding tests. If an interrupt or machine check happens while using that stack, and previously being on the async stack, the interrupt / machine check entry code (SWITCH_ASYNC) will assume that the previous context did not use the async stack and happily use the async stack again. This will lead to stack corruption of the previous context. To solve this disable both interrupts and machine checks before switching to the no_dat stack. Fixes: 7868249fbbc8 ("s390/test_unwind: add CALL_ON_STACK tests") Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-02s390: fix irq state tracingHeiko Carstens2-18/+2
With commit 58c644ba512c ("sched/idle: Fix arch_cpu_idle() vs tracing") common code calls arch_cpu_idle() with a lockdep state that tells irqs are on. This doesn't work very well for s390: psw_idle() will enable interrupts to wait for an interrupt. As soon as an interrupt occurs the interrupt handler will verify if the old context was psw_idle(). If that is the case the interrupt enablement bits in the old program status word will be cleared. A subsequent test in both the external as well as the io interrupt handler checks if in the old context interrupts were enabled. Due to the above patching of the old program status word it is assumed the old context had interrupts disabled, and therefore a call to TRACE_IRQS_OFF (aka trace_hardirqs_off_caller) is skipped. Which in turn makes lockdep incorrectly "think" that interrupts are enabled within the interrupt handler. Fix this by unconditionally calling TRACE_IRQS_OFF when entering interrupt handlers. Also call unconditionally TRACE_IRQS_ON when leaving interrupts handlers. This leaves the special psw_idle() case, which now returns with interrupts disabled, but has an "irqs on" lockdep state. So callers of psw_idle() must adjust the state on their own, if required. This is currently only __udelay_disabled(). Fixes: 58c644ba512c ("sched/idle: Fix arch_cpu_idle() vs tracing") Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02s390/pci: fix CPU address in MSI for directed IRQAlexander Gordeev1-3/+11
The directed MSIs are delivered to CPUs whose address is written to the MSI message address. The current code assumes that a CPU logical number (as it is seen by the kernel) is also the CPU address. The above assumption is not correct, as the CPU address is rather the value returned by STAP instruction. That value does not necessarily match the kernel logical CPU number. Fixes: e979ce7bced2 ("s390/pci: provide support for CPU directed interrupts") Cc: <stable@vger.kernel.org> # v5.2+ Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-29Merge tag 'locking-urgent-2020-11-29' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "Two more places which invoke tracing from RCU disabled regions in the idle path. Similar to the entry path the low level idle functions have to be non-instrumentable" * tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: intel_idle: Fix intel_idle() vs tracing sched/idle: Fix arch_cpu_idle() vs tracing
2020-11-27Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds4-5/+13
Pull kvm fixes from Paolo Bonzini: "ARM: - Fix alignment of the new HYP sections - Fix GICR_TYPER access from userspace S390: - do not reset the global diag318 data for per-cpu reset - do not mark memory as protected too early - fix for destroy page ultravisor call x86: - fix for SEV debugging - fix incorrect return code - fix for 'noapic' with PIC in userspace and LAPIC in kernel - fix for 5-level paging" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: x86/mmu: Fix get_mmio_spte() on CPUs supporting 5-level PT KVM: x86: Fix split-irqchip vs interrupt injection window request KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extint MAINTAINERS: Update email address for Sean Christopherson MAINTAINERS: add uv.c also to KVM/s390 s390/uv: handle destroy page legacy interface KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace KVM: SVM: fix error return code in svm_create_vcpu() KVM: SVM: Fix offset computation bug in __sev_dbg_decrypt(). KVM: arm64: Correctly align nVHE percpu data KVM: s390: remove diag318 reset code KVM: s390: pv: Mark mm as protected after the set secure parameters and improve cleanup
2020-11-24Merge tag 's390-5.10-5' of ↵Linus Torvalds2-5/+7
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fix from Heiko Carstens: "Disable interrupts when restoring fpu and vector registers, otherwise KVM guests might see corrupted register contents" * tag 's390-5.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390: fix fpu restore in entry.S
2020-11-24sched/idle: Fix arch_cpu_idle() vs tracingPeter Zijlstra1-3/+3
We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry. (XXX: we really should change arch_cpu_idle() to not return with interrupts enabled) Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
2020-11-23s390: fix fpu restore in entry.SSven Schnelle2-5/+7
We need to disable interrupts in load_fpu_regs(). Otherwise an interrupt might come in after the registers are loaded, but before CIF_FPU is cleared in load_fpu_regs(). When the interrupt returns, CIF_FPU will be cleared and the registers will never be restored. The entry.S code usually saves the interrupt state in __SF_EMPTY on the stack when disabling/restoring interrupts. sie64a however saves the pointer to the sie control block in __SF_SIE_CONTROL, which references the same location. This is non-obvious to the reader. To avoid thrashing the sie control block pointer in load_fpu_regs(), move the __SIE_* offsets eight bytes after __SF_EMPTY on the stack. Cc: <stable@vger.kernel.org> # 5.8 Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Reported-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-18Merge tag 'kvm-s390-master-5.10-2' of ↵Paolo Bonzini1-1/+8
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master KVM: s390: Fix for destroy page ultravisor call - handle response code from older firmware - add uv.c to KVM: s390/s390 maintainer list
2020-11-18s390/uv: handle destroy page legacy interfaceChristian Borntraeger1-1/+8
Older firmware can return rc=0x107 rrc=0xd for destroy page if the page is already non-secure. This should be handled like a success as already done by newer firmware. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Fixes: 1a80b54d1ce1 ("s390/uv: add destroy page call") Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
2020-11-17Merge tag 's390-5.10-4' of ↵Linus Torvalds3-1/+4
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Heiko Carstens: - fix system call exit path; avoid return to user space with any TIF/CIF/PIF set - fix file permission for cpum_sfb_size parameter - another small defconfig update * tag 's390-5.10-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/cpum_sf.c: fix file permission for cpum_sfb_size s390: update defconfigs s390: fix system call exit path
2020-11-16Merge tag 'kvm-s390-master-5.10-1' of ↵Paolo Bonzini3-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master KVM: s390: Fixes for 5.10 - do not reset the global diag318 data for per-cpu reset - do not mark memory as protected too early
2020-11-12s390/cpum_sf.c: fix file permission for cpum_sfb_sizeThomas Richter1-1/+1
This file is installed by the s390 CPU Measurement sampling facility device driver to export supported minimum and maximum sample buffer sizes. This file is read by lscpumf tool to display the details of the device driver capabilities. The lscpumf tool might be invoked by a non-root user. In this case it does not print anything because the file contents can not be read. Fix this by allowing read access for all users. Reading the file contents is ok, changing the file contents is left to the root user only. For further reference and details see: [1] https://github.com/ibm-s390-tools/s390-tools/issues/97 Fixes: 69f239ed335a ("s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur") Cc: <stable@vger.kernel.org> # 3.14 Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-12s390: update defconfigsHeiko Carstens1-0/+1
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-11KVM: s390: remove diag318 reset codeCollin Walling1-2/+0
The diag318 data must be set to 0 by VM-wide reset events triggered by diag308. As such, KVM should not handle resetting this data via the VCPU ioctls. Fixes: 23a60f834406 ("s390/kvm: diagnose 0x318 sync and reset") Signed-off-by: Collin Walling <walling@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Link: https://lore.kernel.org/r/20201104181032.109800-1-walling@linux.ibm.com
2020-11-11KVM: s390: pv: Mark mm as protected after the set secure parameters and ↵Janosch Frank3-2/+5
improve cleanup We can only have protected guest pages after a successful set secure parameters call as only then the UV allows imports and unpacks. By moving the test we can now also check for it in s390_reset_acc() and do an early return if it is 0. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Fixes: 29b40f105ec8 ("KVM: s390: protvirt: Add initial vm and cpu lifecycle handling") Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-11-09perf/arch: Remove perf_sample_data::regs_user_copyPeter Zijlstra1-2/+1
struct perf_sample_data lives on-stack, we should be careful about it's size. Furthermore, the pt_regs copy in there is only because x86_64 is a trainwreck, solve it differently. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Steven Rostedt <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
2020-11-09perf: Reduce stack usage of perf_output_begin()Peter Zijlstra1-1/+1
__perf_output_begin() has an on-stack struct perf_sample_data in the unlikely case it needs to generate a LOST record. However, every call to perf_output_begin() must already have a perf_sample_data on-stack. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201030151954.985416146@infradead.org
2020-11-09s390: fix system call exit pathHeiko Carstens1-0/+2
The system call exit path is running with interrupts enabled while checking for TIF/PIF/CIF bits which require special handling. If all bits have been checked interrupts are disabled and the kernel exits to user space. The problem is that after checking all bits and before interrupts are disabled bits can be set already again, due to interrupt handling. This means that the kernel can exit to user space with some TIF/PIF/CIF bits set, which should never happen. E.g. TIF_NEED_RESCHED might be set, which might lead to additional latencies, since that bit will only be recognized with next exit to user space. Fix this by checking the corresponding bits only when interrupts are disabled. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Cc: <stable@vger.kernel.org> # 5.8 Acked-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-03s390/pci: fix hot-plug of PCI function missing busNiklas Schnelle1-0/+4
Under some circumstances in particular with "Reconfigure I/O Path" a zPCI function may first appear in Standby through a PCI event with PEC 0x0302 which initially makes it visible to the zPCI subsystem, Only after that is it configured with a zPCI event with PEC 0x0301. If the zbus is still missing a PCI function zero (devfn == 0) when the PCI event 0x0301 is handled zdev->zbus->bus is still NULL and gets dereferenced in common code. Check for this case and enable but don't scan the zPCI function. This matches what would happen if we immediately got the 0x0301 configuration request or the function was included in CLP List PCI. In all cases the PCI functions with devfn != 0 will be scanned once function 0 appears. Fixes: 3047766bc6ec ("s390/pci: fix enabling a reserved PCI function") Cc: <stable@vger.kernel.org> # 5.8 Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-03s390/smp: move rcu_cpu_starting() earlierQian Cai1-1/+2
The call to rcu_cpu_starting() in smp_init_secondary() is not early enough in the CPU-hotplug onlining process, which results in lockdep splats as follows: WARNING: suspicious RCU usage ----------------------------- kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/1/0. Call Trace: show_stack+0x158/0x1f0 dump_stack+0x1f2/0x238 __lock_acquire+0x2640/0x4dd0 lock_acquire+0x3a8/0xd08 _raw_spin_lock_irqsave+0xc0/0xf0 clockevents_register_device+0xa8/0x528 init_cpu_timer+0x33e/0x468 smp_init_secondary+0x11a/0x328 smp_start_secondary+0x82/0x88 This is avoided by moving the call to rcu_cpu_starting up near the beginning of the smp_init_secondary() function. Note that the raw_smp_processor_id() is required in order to avoid calling into lockdep before RCU has declared the CPU to be watched for readers. Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/ Signed-off-by: Qian Cai <cai@redhat.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-03s390: update defconfigsHeiko Carstens3-9/+12
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-03s390/vdso: remove unused constantsHeiko Carstens1-8/+0