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2022-07-07s390: remove unneeded 'select BUILD_BIN2C'Masahiro Yamada1-1/+0
commit 25deecb21c18ee29e3be8ac6177b2a9504c33d2d upstream. Since commit 4c0f032d4963 ("s390/purgatory: Omit use of bin2c"), s390 builds the purgatory without using bin2c. Remove 'select BUILD_BIN2C' to avoid the unneeded build of bin2c. Fixes: 4c0f032d4963 ("s390/purgatory: Omit use of bin2c") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20220613170902.1775211-1-masahiroy@kernel.org Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-07s390/archrandom: simplify back to earlier design and initialize earlierJason A. Donenfeld3-224/+12
commit e4f74400308cb8abde5fdc9cad609c2aba32110c upstream. s390x appears to present two RNG interfaces: - a "TRNG" that gathers entropy using some hardware function; and - a "DRBG" that takes in a seed and expands it. Previously, the TRNG was wired up to arch_get_random_{long,int}(), but it was observed that this was being called really frequently, resulting in high overhead. So it was changed to be wired up to arch_get_random_ seed_{long,int}(), which was a reasonable decision. Later on, the DRBG was then wired up to arch_get_random_{long,int}(), with a complicated buffer filling thread, to control overhead and rate. Fortunately, none of the performance issues matter much now. The RNG always attempts to use arch_get_random_seed_{long,int}() first, which means a complicated implementation of arch_get_random_{long,int}() isn't really valuable or useful to have around. And it's only used when reseeding, which means it won't hit the high throughput complications that were faced before. So this commit returns to an earlier design of just calling the TRNG in arch_get_random_seed_{long,int}(), and returning false in arch_get_ random_{long,int}(). Part of what makes the simplification possible is that the RNG now seeds itself using the TRNG at bootup. But this only works if the TRNG is detected early in boot, before random_init() is called. So this commit also causes that check to happen in setup_arch(). Cc: stable@vger.kernel.org Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Ingo Franzki <ifranzki@linux.ibm.com> Cc: Juergen Christ <jchrist@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20220610222023.378448-1-Jason@zx2c4.com Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29s390/crash: make copy_oldmem_page() return number of bytes copiedAlexander Gordeev1-3/+4
[ Upstream commit af2debd58bd769e38f538143f0d332e15d753396 ] Callback copy_oldmem_page() returns either error code or zero. Instead, it should return the error code or number of bytes copied. Fixes: df9694c7975f ("s390/dump: streamline oldmem copy functions") Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29s390/crash: add missing iterator advance in copy_oldmem_page()Alexander Gordeev1-0/+7
[ Upstream commit cc02e6e21aa5f2ac0defe8c15e5a9d024da6e73d ] In case old memory was successfully copied the passed iterator should be advanced as well. Currently copy_oldmem_page() is always called with single-segment iterator. Should that ever change - copy_oldmem_user and copy_oldmem_kernel() functions would need a rework to deal with multi-segment iterators. Fixes: 5d8de293c224 ("vmcore: convert copy_oldmem_page() to take an iov_iter") Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-29vmcore: convert copy_oldmem_page() to take an iov_iterMatthew Wilcox (Oracle)1-5/+8
[ Upstream commit 5d8de293c224896a4da99763fce4f9794308caf4 ] Patch series "Convert vmcore to use an iov_iter", v5. For some reason several people have been sending bad patches to fix compiler warnings in vmcore recently. Here's how it should be done. Compile-tested only on x86. As noted in the first patch, s390 should take this conversion a bit further, but I'm not inclined to do that work myself. This patch (of 3): Instead of passing in a 'buf' and 'userbuf' argument, pass in an iov_iter. s390 needs more work to pass the iov_iter down further, or refactor, but I'd be more comfortable if someone who can test on s390 did that work. It's more convenient to convert the whole of read_from_oldmem() to take an iov_iter at the same time, so rename it to read_from_oldmem_iter() and add a temporary read_from_oldmem() wrapper that creates an iov_iter. Link: https://lkml.kernel.org/r/20220408090636.560886-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20220408090636.560886-2-bhe@redhat.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-29s390/cpumf: Handle events cycles and instructions identicalThomas Richter1-1/+21
[ Upstream commit be857b7f77d130dbbd47c91fc35198b040f35865 ] Events CPU_CYCLES and INSTRUCTIONS can be submitted with two different perf_event attribute::type values: - PERF_TYPE_HARDWARE: when invoked via perf tool predefined events name cycles or cpu-cycles or instructions. - pmu->type: when invoked via perf tool event name cpu_cf/CPU_CYLCES/ or cpu_cf/INSTRUCTIONS/. This invocation also selects the PMU to which the event belongs. Handle both type of invocations identical for events CPU_CYLCES and INSTRUCTIONS. They address the same hardware. The result is different when event modifier exclude_kernel is also set. Invocation with event modifier for user space event counting fails. Output before: # perf stat -e cpum_cf/cpu_cycles/u -- true Performance counter stats for 'true': <not supported> cpum_cf/cpu_cycles/u 0.000761033 seconds time elapsed 0.000076000 seconds user 0.000725000 seconds sys # Output after: # perf stat -e cpum_cf/cpu_cycles/u -- true Performance counter stats for 'true': 349,613 cpum_cf/cpu_cycles/u 0.000844143 seconds time elapsed 0.000079000 seconds user 0.000800000 seconds sys # Fixes: 6a82e23f45fe ("s390/cpumf: Adjust registration of s390 PMU device drivers") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> [agordeev@linux.ibm.com corrected commit ID of Fixes commit] Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-25s390/mm: use non-quiescing sske for KVM switch to keyed guestChristian Borntraeger1-1/+1
commit 3ae11dbcfac906a8c3a480e98660a823130dc16a upstream. The switch to a keyed guest does not require a classic sske as the other guest CPUs are not accessing the key before the switch is complete. By using the NQ SSKE things are faster especially with multiple guests. Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Suggested-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220530092706.11637-3-borntraeger@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-22gcc-12: disable '-Warray-bounds' universally for nowLinus Torvalds2-9/+2
[ Upstream commit f0be87c42cbd341d436d06da4792e6b0c83c3aeb ] In commit 8b202ee21839 ("s390: disable -Warray-bounds") the s390 people disabled the '-Warray-bounds' warning for gcc-12, because the new logic in gcc would cause warnings for their use of the S390_lowcore macro, which accesses absolute pointers. It turns out gcc-12 has many other issues in this area, so this takes that s390 warning disable logic, and turns it into a kernel build config entry instead. Part of the intent is that we can make this all much more targeted, and use this conflig flag to disable it in only particular configurations that cause problems, with the s390 case as an example: select GCC12_NO_ARRAY_BOUNDS and we could do that for other configuration cases that cause issues. Or we could possibly use the CONFIG_CC_NO_ARRAY_BOUNDS thing in a more targeted way, and disable the warning only for particular uses: again the s390 case as an example: KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_CC_NO_ARRAY_BOUNDS),-Wno-array-bounds) but this ends up just doing it globally in the top-level Makefile, since the current issues are spread fairly widely all over: KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds We'll try to limit this later, since the gcc-12 problems are rare enough that *much* of the kernel can be built with it without disabling this warning. Cc: Kees Cook <keescook@chromium.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14s390/gmap: voluntarily schedule during key settingChristian Borntraeger1-0/+14
[ Upstream commit 6d5946274df1fff539a7eece458a43be733d1db8 ] With large and many guest with storage keys it is possible to create large latencies or stalls during initial key setting: rcu: INFO: rcu_sched self-detected stall on CPU rcu: 18-....: (2099 ticks this GP) idle=54e/1/0x4000000000000002 softirq=35598716/35598716 fqs=998 (t=2100 jiffies g=155867385 q=20879) Task dump for CPU 18: CPU 1/KVM R running task 0 1030947 256019 0x06000004 Call Trace: sched_show_task rcu_dump_cpu_stacks rcu_sched_clock_irq update_process_times tick_sched_handle tick_sched_timer __hrtimer_run_queues hrtimer_interrupt do_IRQ ext_int_handler ptep_zap_key The mmap lock is held during the page walking but since this is a semaphore scheduling is still possible. Same for the kvm srcu. To minimize overhead do this on every segment table entry or large page. Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220530092706.11637-2-borntraeger@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14s390/mcck: isolate SIE instruction when setting CIF_MCCK_GUEST flagAlexander Gordeev1-1/+5
[ Upstream commit 29ccaa4b35ea874ddd50518e5c2c746b9238a792 ] Commit d768bd892fc8 ("s390: add options to change branch prediction behaviour for the kernel") introduced .Lsie_exit label - supposedly to fence off SIE instruction. However, the corresponding address range length .Lsie_crit_mcck_length was not updated, which led to BPON code potentionally marked with CIF_MCCK_GUEST flag. Both .Lsie_exit and .Lsie_crit_mcck_length were removed with commit 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S"), but the issue persisted - currently BPOFF and BPENTER macros might get wrongly considered by the machine check handler as a guest. Fixes: d768bd892fc8 ("s390: add options to change branch prediction behaviour for the kernel") Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14s390/crypto: fix scatterwalk_unmap() callers in AES-GCMJann Horn1-2/+2
[ Upstream commit bd52cd5e23f134019b23f0c389db0f9a436e4576 ] The argument of scatterwalk_unmap() is supposed to be the void* that was returned by the previous scatterwalk_map() call. The s390 AES-GCM implementation was instead passing the pointer to the struct scatter_walk. This doesn't actually break anything because scatterwalk_unmap() only uses its argument under CONFIG_HIGHMEM and ARCH_HAS_FLUSH_ON_KUNMAP. Fixes: bf7fa038707c ("s390/crypto: add s390 platform specific aes gcm support.") Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Harald Freudenberger <freude@linux.ibm.com> Link: https://lore.kernel.org/r/20220517143047.3054498-1-jannh@google.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]Naveen N. Rao1-0/+10
commit 3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc upstream. Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") [1], binutils (v2.36+) started dropping section symbols that it thought were unused. This isn't an issue in general, but with kexec_file.c, gcc is placing kexec_arch_apply_relocations[_add] into a separate .text.unlikely section and the section symbol ".text.unlikely" is being dropped. Due to this, recordmcount is unable to find a non-weak symbol in .text.unlikely to generate a relocation record against. Address this by dropping the weak attribute from these functions. Instead, follow the existing pattern of having architectures #define the name of the function they want to override in their headers. [1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1 [akpm@linux-foundation.org: arch/s390/include/asm/kexec.h needs linux/module.h] Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09s390/stp: clock_delta should be signedSven Schnelle2-5/+5
commit 5ace65ebb5ce9fe1cc8fdbdd97079fb566ef0ea4 upstream. clock_delta is declared as unsigned long in various places. However, the clock sync delta can be negative. This would add a huge positive offset in clock_sync_global where clock_delta is added to clk.eitod which is a 72 bit integer. Declare it as signed long to fix this. Cc: stable@vger.kernel.org Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09s390/perf: obtain sie_block from the right addressNico Boehr1-1/+1
commit c9bfb460c3e4da2462e16b0f0b200990b36b1dd2 upstream. Since commit 1179f170b6f0 ("s390: fix fpu restore in entry.S"), the sie_block pointer is located at empty1[1], but in sie_block() it was taken from empty1[0]. This leads to a random pointer being dereferenced, possibly causing system crash. This problem can be observed when running a simple guest with an endless loop and recording the cpu-clock event: sudo perf kvm --guestvmlinux=<guestkernel> --guest top -e cpu-clock With this fix, the correct guest address is shown. Fixes: 1179f170b6f0 ("s390: fix fpu restore in entry.S") Cc: stable@vger.kernel.org Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09s390/preempt: disable __preempt_count_add() optimization for ↵Heiko Carstens1-4/+11
PROFILE_ALL_BRANCHES [ Upstream commit 63678eecec57fc51b778be3da35a397931287170 ] gcc 12 does not (always) optimize away code that should only be generated if parameters are constant and within in a certain range. This depends on various obscure kernel config options, however in particular PROFILE_ALL_BRANCHES can trigger this compile error: In function ‘__atomic_add_const’, inlined from ‘__preempt_count_add.part.0’ at ./arch/s390/include/asm/preempt.h:50:3: ./arch/s390/include/asm/atomic_ops.h:80:9: error: impossible constraint in ‘asm’ 80 | asm volatile( \ | ^~~ Workaround this by simply disabling the optimization for PROFILE_ALL_BRANCHES, since the kernel will be so slow, that this optimization won't matter at all. Reported-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-30s390: define get_cycles macro for arch-overrideJason A. Donenfeld1-0/+1
commit 2e3df523256cb9836de8441e9c791a796759bb3c upstream. S390x defines a get_cycles() function, but it does not do the usual `#define get_cycles get_cycles` dance, making it impossible for generic code to see if an arch-specific function was defined. While the get_cycles() ifdef is not currently used, the following timekeeping patch in this series will depend on the macro existing (or not existing) when defining random_get_entropy(). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-03KVM: s390: vsie/gmap: reduce gmap_rmap overheadChristian Borntraeger1-0/+7
there are cases that trigger a 2nd shadow event for the same vmaddr/raddr combination. (prefix changes, reboots, some known races) This will increase memory usages and it will result in long latencies when cleaning up, e.g. on shutdown. To avoid cases with a list that has hundreds of identical raddrs we check existing entries at insert time. As this measurably reduces the list length this will be faster than traversing the list at shutdown time. In the long run several places will be optimized to create less entries and a shrinker might be necessary. Fixes: 4be130a08420 ("s390/mm: add shadow gmap support") Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20220429151526.1560-1-borntraeger@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-02KVM: s390: Fix lockdep issue in vm memopJanis Schoetterl-Glausch1-1/+10
Issuing a memop on a protected vm does not make sense, neither is the memory readable/writable, nor does it make sense to check storage keys. This is why the ioctl will return -EINVAL when it detects the vm to be protected. However, in order to ensure that the vm cannot become protected during the memop, the kvm->lock would need to be taken for the duration of the ioctl. This is also required because kvm_s390_pv_is_protected asserts that the lock must be held. Instead, don't try to prevent this. If user space enables secure execution concurrently with a memop it must accecpt the possibility of the memop failing. Still check if the vm is currently protected, but without locking and consider it a heuristic. Fixes: ef11c9463ae0 ("KVM: s390: Add vm IOCTL for key checked guest absolute memory access") Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220322153204.2637400-1-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-27s390: disable -Warray-boundsSven Schnelle1-0/+10
gcc-12 shows a lot of array bound warnings on s390. This is caused by the S390_lowcore macro which uses a hardcoded address of 0. Wrapping that with absolute_pointer() works, but gcc no longer knows that a 12 bit displacement is sufficient to access lowcore. So it emits instructions like 'lghi %r1,0; l %rx,xxx(%r1)' instead of a single load/store instruction. As s390 stores variables often read/written in lowcore, this is considered problematic. Therefore disable -Warray-bounds on s390 for gcc-12 for the time being, until there is a better solution. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Link: https://lore.kernel.org/r/yt9dzgkelelc.fsf@linux.ibm.com Link: https://lore.kernel.org/r/20220422134308.1613610-1-svens@linux.ibm.com Link: https://lore.kernel.org/r/20220425121742.3222133-1-svens@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-23Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds3-8/+8
Pull kvm fixes from Paolo Bonzini: "The main and larger change here is a workaround for AMD's lack of cache coherency for encrypted-memory guests. I have another patch pending, but it's waiting for review from the architecture maintainers. RISC-V: - Remove 's' & 'u' as valid ISA extension - Do not allow disabling the base extensions 'i'/'m'/'a'/'c' x86: - Fix NMI watchdog in guests on AMD - Fix for SEV cache incoherency issues - Don't re-acquire SRCU lock in complete_emulated_io() - Avoid NULL pointer deref if VM creation fails - Fix race conditions between APICv disabling and vCPU creation - Bugfixes for disabling of APICv - Preserve BSP MSR_KVM_POLL_CONTROL across suspend/resume selftests: - Do not use bitfields larger than 32-bits, they differ between GCC and clang" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: selftests: introduce and use more page size-related constants kvm: selftests: do not use bitfields larger than 32-bits for PTEs KVM: SEV: add cache flush to solve SEV cache incoherency issues KVM: SVM: Flush when freeing encrypted pages even on SME_COHERENT CPUs KVM: SVM: Simplify and harden helper to flush SEV guest page(s) KVM: selftests: Silence compiler warning in the kvm_page_table_test KVM: x86/pmu: Update AMD PMC sample period to fix guest NMI-watchdog x86/kvm: Preserve BSP MSR_KVM_POLL_CONTROL across suspend/resume KVM: SPDX style and spelling fixes KVM: x86: Skip KVM_GUESTDBG_BLOCKIRQ APICv update if APICv is disabled KVM: x86: Pend KVM_REQ_APICV_UPDATE during vCPU creation to fix a race KVM: nVMX: Defer APICv updates while L2 is active until L1 is active KVM: x86: Tag APICv DISABLE inhibit, not ABSENT, if APICv is disabled KVM: Initialize debugfs_dentry when a VM is created to avoid NULL deref KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abused KVM: RISC-V: Use kvm_vcpu.srcu_idx, drop RISC-V's unnecessary copy KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io() RISC-V: KVM: Restrict the extensions that can be disabled RISC-V: KVM: Remove 's' & 'u' as valid ISA extension
2022-04-21KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abusedSean Christopherson3-8/+8
Add wrappers to acquire/release KVM's SRCU lock when stashing the index in vcpu->src_idx, along with rudimentary detection of illegal usage, e.g. re-acquiring SRCU and thus overwriting vcpu->src_idx. Because the SRCU index is (currently) either 0 or 1, illegal nesting bugs can go unnoticed for quite some time and only cause problems when the nested lock happens to get a different index. Wrap the WARNs in PROVE_RCU=y, and make them ONCE, otherwise KVM will likely yell so loudly that it will bring the kernel to its knees. Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Fabiano Rosas <farosas@linux.ibm.com> Message-Id: <20220415004343.2203171-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-19vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLOW_HUGE_VMAPSong Liu1-6/+1
Huge page backed vmalloc memory could benefit performance in many cases. However, some users of vmalloc may not be ready to handle huge pages for various reasons: hardware constraints, potential pages split, etc. VM_NO_HUGE_VMAP was introduced to allow vmalloc users to opt-out huge pages. However, it is not easy to track down all the users that require the opt-out, as the allocation are passed different stacks and may cause issues in different layers. To address this issue, replace VM_NO_HUGE_VMAP with an opt-in flag, VM_ALLOW_HUGE_VMAP, so that users that benefit from huge pages could ask specificially. Also, remove vmalloc_no_huge() and add opt-in helper vmalloc_huge(). Fixes: fac54e2bfb5b ("x86/Kconfig: Select HAVE_ARCH_HUGE_VMALLOC with HAVE_ARCH_HUGE_VMAP") Link: https://lore.kernel.org/netdev/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/" Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-12s390: enable CONFIG_HARDENED_USERCOPY in debug_defconfigSven Schnelle1-0/+1
Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-12s390: current_stack_pointer shouldn't be a functionSven Schnelle4-10/+4
s390 defines current_stack_pointer as function while all other architectures use 'register unsigned long asm("<stackptr reg>"). This make codes like the following from check_stack_object() fail: if (IS_ENABLED(CONFIG_STACK_GROWSUP)) { if ((void *)current_stack_pointer < obj + len) return BAD_STACK; } else { if (obj < (void *)current_stack_pointer) return BAD_STACK; } because this would compare the address of current_stack_pointer() and not the stackpointer value. Reported-by: Karsten Graul <kgraul@linux.ibm.com> Fixes: 2792d84e6da5 ("usercopy: Check valid lifetime via stack depth") Cc: Kees Cook <keescook@chromium.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-10s390: update defconfigsHeiko Carstens3-7/+12
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-07s390/kexec: silence -Warray-bounds warningHeiko Carstens1-1/+1
Just use absolute_pointer() like e.g. in commit 545c272232ca ("alpha: Silence -Warray-bounds warnings") to get rid of this warning: arch/s390/kernel/machine_kexec.c:59:9: warning: ‘memcpy’ offset [0, 511] is out of the bounds [0, 0] [-Warray-bounds] Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-06s390: allow to compile with z16 optimizationsHeiko Carstens2-0/+21
Add config and compile options which allow to compile with z16 optimizations if the compiler supports it. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-06s390: add z16 elf platformHeiko Carstens1-0/+4
Add detection for machine types 0x3931 and 0x3932 and set ELF platform name to z16. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-1/+1
Pull kvm fixes from Paolo Bonzini: - Only do MSR filtering for MSRs accessed by rdmsr/wrmsr - Documentation improvements - Prevent module exit until all VMs are freed - PMU Virtualization fixes - Fix for kvm_irq_delivery_to_apic_fast() NULL-pointer dereferences - Other miscellaneous bugfixes * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits) KVM: x86: fix sending PV IPI KVM: x86/mmu: do compare-and-exchange of gPTE via the user address KVM: x86: Remove redundant vm_entry_controls_clearbit() call KVM: x86: cleanup enter_rmode() KVM: x86: SVM: fix tsc scaling when the host doesn't support it kvm: x86: SVM: remove unused defines KVM: x86: SVM: move tsc ratio definitions to svm.h KVM: x86: SVM: fix avic spec based definitions again KVM: MIPS: remove reference to trap&emulate virtualization KVM: x86: document limitations of MSR filtering KVM: x86: Only do MSR filtering when access MSR by rdmsr/wrmsr KVM: x86/emulator: Emulate RDPID only if it is enabled in guest KVM: x86/pmu: Fix and isolate TSX-specific performance event logic KVM: x86: mmu: trace kvm_mmu_set_spte after the new SPTE was set KVM: x86/svm: Clear reserved bits written to PerfEvtSeln MSRs KVM: x86: Trace all APICv inhibit changes and capture overall status KVM: x86: Add wrappers for setting/clearing APICv inhibits KVM: x86: Make APICv inhibit reasons an enum and cleanup naming KVM: X86: Handle implicit supervisor access with SMAP KVM: X86: Rename variable smap to not_smap in permission_fault() ...
2022-04-02KVM: Don't actually set a request when evicting vCPUs for GFN cache invdSean Christopherson1-1/+1
Don't actually set a request bit in vcpu->requests when making a request purely to force a vCPU to exit the guest. Logging a request but not actually consuming it would cause the vCPU to get stuck in an infinite loop during KVM_RUN because KVM would see the pending request and bail from VM-Enter to service the request. Note, it's currently impossible for KVM to set KVM_REQ_GPC_INVALIDATE as nothing in KVM is wired up to set guest_uses_pa=true. But, it'd be all too easy for arch code to introduce use of kvm_gfn_to_pfn_cache_init() without implementing handling of the request, especially since getting test coverage of MMU notifier interaction with specific KVM features usually requires a directed test. Opportunistically rename gfn_to_pfn_cache_invalidate_start()'s wake_vcpus to evict_vcpus. The purpose of the request is to get vCPUs out of guest mode, it's supposed to _avoid_ waking vCPUs that are blocking. Opportunistically rename KVM_REQ_GPC_INVALIDATE to be more specific as to what it wants to accomplish, and to genericize the name so that it can used for similar but unrelated scenarios, should they arise in the future. Add a comment and documentation to explain why the "no action" request exists. Add compile-time assertions to help detect improper usage. Use the inner assertless helper in the one s390 path that makes requests without a hardcoded request. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220223165302.3205276-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-02Merge branch 'work.misc' of ↵Linus Torvalds1-4/+0
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "Assorted bits and pieces" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: aio: drop needless assignment in aio_read() clean overflow checks in count_mounts() a bit seq_file: fix NULL pointer arithmetic warning uml/x86: use x86 load_unaligned_zeropad() asm/user.h: killed unused macros constify struct path argument of finish_automount()/do_add_mount() fs: Remove FIXME comment in generic_write_checks()
2022-04-01Merge tag 's390-5.18-2' of ↵Linus Torvalds24-140/+208
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Vasily Gorbik: - Add kretprobes framepointer verification and return address recovery in stacktrace. - Support control domain masks on custom zcrypt devices and filter admin requests. - Cleanup timer API usage. - Rework absolute lowcore access helpers. - Other various small improvements and fixes. * tag 's390-5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (26 commits) s390/alternatives: avoid using jgnop mnemonic s390/pci: rename get_zdev_by_bus() to zdev_from_bus() s390/pci: improve zpci_dev reference counting s390/smp: use physical address for SIGP_SET_PREFIX command s390: cleanup timer API use s390/zcrypt: fix using the correct variable for sizeof() s390/vfio-ap: fix kernel doc and signature of group notifier functions s390/maccess: rework absolute lowcore accessors s390/smp: cleanup control register update routines s390/smp: cleanup target CPU callback starting s390/test_unwind: verify __kretprobe_trampoline is replaced s390/unwind: avoid duplicated unwinding entries for kretprobes s390/unwind: recover kretprobe modified return address in stacktrace s390/kprobes: enable kretprobes framepointer verification s390/test_unwind: extend kretprobe test s390/ap: adjust whitespace s390/ap: use insn format for new instructions s390/alternatives: use insn format for new instructions s390/alternatives: use instructions instead of byte patterns s390/traps: improve panic message for translation-specification exception ...
2022-03-31Merge tag 'kbuild-v5.18-v2' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add new environment variables, USERCFLAGS and USERLDFLAGS to allow additional flags to be passed to user-space programs. - Fix missing fflush() bugs in Kconfig and fixdep - Fix a minor bug in the comment format of the .config file - Make kallsyms ignore llvm's local labels, .L* - Fix UAPI compile-test for cross-compiling with Clang - Extend the LLVM= syntax to support LLVM=<suffix> form for using a particular version of LLVm, and LLVM=<prefix> form for using custom LLVM in a particular directory path. - Clean up Makefiles * tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: Make $(LLVM) more flexible kbuild: add --target to correctly cross-compile UAPI headers with Clang fixdep: use fflush() and ferror() to ensure successful write to files arch: syscalls: simplify uapi/kapi directory creation usr/include: replace extra-y with always-y certs: simplify empty certs creation in certs/Makefile certs: include certs/signing_key.x509 unconditionally kallsyms: ignore all local labels prefixed by '.L' kconfig: fix missing '# end of' for empty menu kconfig: add fflush() before ferror() check kbuild: replace $(if A,A,B) with $(or A,B) kbuild: Add environment variables for userprogs flags kbuild: unify cmd_copy and cmd_shipped
2022-03-31arch: syscalls: simplify uapi/kapi directory creationMasahiro Yamada1-2/+1
$(shell ...) expands to empty. There is no need to assign it to _dummy. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2022-03-29Merge tag 'ptrace-cleanups-for-v5.18' of ↵Linus Torvalds3-5/+2
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ptrace cleanups from Eric Biederman: "This set of changes removes tracehook.h, moves modification of all of the ptrace fields inside of siglock to remove races, adds a missing permission check to ptrace.c The removal of tracehook.h is quite significant as it has been a major source of confusion in recent years. Much of that confusion was around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the semantics clearer). For people who don't know tracehook.h is a vestiage of an attempt to implement uprobes like functionality that was never fully merged, and was later superseeded by uprobes when uprobes was merged. For many years now we have been removing what tracehook functionaly a little bit at a time. To the point where anything left in tracehook.h was some weird strange thing that was difficult to understand" * tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ptrace: Remove duplicated include in ptrace.c ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE ptrace: Return the signal to continue with from ptrace_stop ptrace: Move setting/clearing ptrace_message into ptrace_stop tracehook: Remove tracehook.h resume_user_mode: Move to resume_user_mode.h resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume signal: Move set_notify_signal and clear_notify_signal into sched/signal.h task_work: Decouple TIF_NOTIFY_SIGNAL and task_work task_work: Call tracehook_notify_signal from get_signal on all architectures task_work: Introduce task_work_pending task_work: Remove unnecessary include from posix_timers.h ptrace: Remove tracehook_signal_handler ptrace: Remove arch_syscall_{enter,exit}_tracehook ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h ptrace/arm: Rename tracehook_report_syscall report_syscall ptrace: Move ptrace_report_syscall into ptrace.h
2022-03-29s390/alternatives: avoid using jgnop mnemonicVasily Gorbik2-2/+2
jgnop mnemonic is only available since binutils 2.36, kernel minimal required version is 2.23. Stick to brcl to avoid build errors. Reported-by: Nathan Chancellor <nathan@kernel.org> Fixes: 4afeb670710e ("s390/alternatives: use instructions instead of byte patterns") Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/pci: rename get_zdev_by_bus() to zdev_from_bus()Niklas Schnelle2-4/+4
Getting a zpci_dev via get_zdev_by_bus() uses the long lived reference held in zbus->function[devfn]. This is accounted for in pcibios_add_device() and pcibios_release_device(). Therefore there is no need to increment the reference count in get_zdev_by_bus() as is done for get_zdev_by_fid(). Instead callers must not access the device after pcibios_release_device() was called which is necessary for common PCI code anyway. With this though the very similar naming may be misleading so rename get_zdev_by_bus() to zdev_from_bus() emphasizing that we are directly referencing the zdev via the bus. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/pci: improve zpci_dev reference countingNiklas Schnelle4-4/+16
Currently zpci_dev uses kref based reference counting but only accounts for one original reference plus one reference from an added pci_dev to its underlying zpci_dev. Counting just the original reference worked until the pci_dev reference was added in commit 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") because once a zpci_dev goes away, i.e. enters the reserved state, it would immediately get released. However with the pci_dev reference this is no longer the case and the zpci_dev may still appear in multiple availability events indicating that it was reserved. This was solved by detecting when the zpci_dev is already on its way out but still hanging around. This has however shown some light on how unusual our zpci_dev reference counting is. Improve upon this by modelling zpci_dev reference counting on pci_dev. Analogous to pci_get_slot() increment the reference count in get_zdev_by_fid(). Thus all users of get_zdev_by_fid() must drop the reference once they are done with the zpci_dev. Similar to pci_scan_single_device(), zpci_create_device() returns the device with an initial count of 1 and the device added to the zpci_list (analogous to the PCI bus' device_list). In turn users of zpci_create_device() must only drop the reference once the device is gone from the point of view of the zPCI subsystem, it might still be referenced by the common PCI subsystem though. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/smp: use physical address for SIGP_SET_PREFIX commandAlexander Gordeev1-1/+1
Signal processor SIGP_SET_PREFIX command expects physical address of the lowcore to be installed, but instead the virtual address is provided. Note: this does not fix a bug currently, since virtual and physical addresses are identical. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/maccess: rework absolute lowcore accessorsAlexander Gordeev6-24/+32
Macro mem_assign_absolute() is able to access the whole memory, but is only used and makes sense when updating the absolute lowcore. Instead, introduce get_abs_lowcore() and put_abs_lowcore() macros that limit access to absolute lowcore addresses only. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/smp: cleanup control register update routinesAlexander Gordeev2-29/+23
Get rid of duplicate code and redundant data. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/smp: cleanup target CPU callback startingAlexander Gordeev1-4/+11
Macro mem_assign_absolute() is used to initialize a target CPU lowcore callback parameters. But despite the macro name it writes to the absolute lowcore only if the target CPU is offline. In case the CPU is online the macro does implicitly write to the normal memory. That behaviour is correct, but extremely subtle. Sacrifice few program bits in favour of clarity and distinguish between online vs offline CPUs and normal vs absolute lowcore pointer. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/test_unwind: verify __kretprobe_trampoline is replacedVasily Gorbik1-1/+8
Reviewed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/unwind: avoid duplicated unwinding entries for kretprobesVasily Gorbik2-2/+3
Currently when unwinding starts from pt_regs or encounters pt_regs along the way unwinder tries to yield 2 unwinding entries: 1. (reliable) ip1: pt_regs->psw.addr, sp1: regs->gprs[15] 2. (non-reliable) ip2: sp1->gprs[8] (r14), sp2: regs->gprs[15] In case of kretprobes those are identical and serves no other purpose than causing confusion over duplicated entries and cause kprobes tests to fail. So, skip a duplicate non-reliable entry in this case. With that kretprobes and unwinder implementation now comply with ARCH_CORRECT_STACKTRACE_ON_KRETPROBE. Reviewed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/unwind: recover kretprobe modified return address in stacktraceVasily Gorbik2-6/+15
Based on commit cd9bc2c92588 ("arm64: Recover kretprobe modified return address in stacktrace"). """ Since the kretprobe replaces the function return address with the __kretprobe_trampoline on the stack, stack unwinder shows it instead of the correct return address. This checks whether the next return address is the __kretprobe_trampoline(), and if so, try to find the correct return address from the kretprobe instance list. """ Original patch series: https://lore.kernel.org/all/163163030719.489837.2236069935502195491.stgit@devnote2/ Reviewed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/kprobes: enable kretprobes framepointer verificationVasily Gorbik1-4/+4
Use regs->gprs[15] for framepointer verification. This enables additional sanity checks for nested kretprobes. Reviewed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/test_unwind: extend kretprobe testVasily Gorbik1-16/+33
Verify unwinding from kretprobed function. Reviewed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/ap: adjust whitespaceHeiko Carstens1-23/+23
Adjust indentation of inline assemblies, so all comments start at the same position. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/ap: use insn format for new instructionsHeiko Carstens1-7/+7
Use insn format with instruction format specifier instead of plain longs. This way it is also more obvious that code instead of data is generated. The generated code is identical. Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-27s390/alternatives: use insn format for new instructionsHeiko Carstens3-8/+8
Use insn format with instruction format specifier instead of plain longs. This way it is also more obvious that code instead of data is generated. The generated code is identical. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>