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2022-08-21kexec, KEYS, s390: Make use of built-in and secondary keyring for signature ↵Michal Suchanek1-5/+13
verification [ Upstream commit 0828c4a39be57768b8788e8cbd0d84683ea757e5 ] commit e23a8020ce4e ("s390/kexec_file: Signature verification prototype") adds support for KEXEC_SIG verification with keys from platform keyring but the built-in keys and secondary keyring are not used. Add support for the built-in keys and secondary keyring as x86 does. Fixes: e23a8020ce4e ("s390/kexec_file: Signature verification prototype") Cc: stable@vger.kernel.org Cc: Philipp Rudo <prudo@linux.ibm.com> Cc: kexec@lists.infradead.org Cc: keyrings@vger.kernel.org Cc: linux-security-module@vger.kernel.org Signed-off-by: Michal Suchanek <msuchanek@suse.de> Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com> Acked-by: Baoquan He <bhe@redhat.com> Signed-off-by: Coiby Xu <coxu@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21s390/dump: fix old lowcore virtual vs physical address confusionAlexander Gordeev3-2/+5
[ Upstream commit dc306186a130c6d9feb0aabc1c71b8ed1674a3bf ] Virtual addresses of vmcore_info and os_info members are wrongly passed to copy_oldmem_kernel(), while the function expects physical address of the source. Instead, __pa() macro should have been applied. Yet, use of __pa() macro could be somehow confusing, since copy_oldmem_kernel() may treat the source as an offset, not as a direct physical address (that depens from the oldmem availability and location). Fix the virtual vs physical address confusion and make the way the old lowcore is read consistent across all sources. 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21KVM: s390: pv: leak the topmost page table when destroy failsClaudio Imbrenda3-3/+94
[ Upstream commit faa2f72cb3569256480c5540d242c84e99965160 ] Each secure guest must have a unique ASCE (address space control element); we must avoid that new guests use the same page for their ASCE, to avoid errors. Since the ASCE mostly consists of the address of the topmost page table (plus some flags), we must not return that memory to the pool unless the ASCE is no longer in use. Only a successful Destroy Secure Configuration UVC will make the ASCE reusable again. If the Destroy Configuration UVC fails, the ASCE cannot be reused for a secure guest (either for the ASCE or for other memory areas). To avoid a collision, it must not be used again. This is a permanent error and the page becomes in practice unusable, so we set it aside and leak it. On failure we already leak other memory that belongs to the ultravisor (i.e. the variable and base storage for a guest) and not leaking the topmost page table was an oversight. This error (and thus the leakage) should not happen unless the hardware is broken or KVM has some unknown serious bug. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Fixes: 29b40f105ec8d55 ("KVM: s390: protvirt: Add initial vm and cpu lifecycle handling") Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20220628135619.32410-2-imbrenda@linux.ibm.com Message-Id: <20220628135619.32410-2-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21KVM: s390: pv: don't present the ecall interrupt twiceNico Boehr2-2/+17
commit c3f0e5fd2d33d80c5a5a8b5e5d2bab2841709cc8 upstream. When the SIGP interpretation facility is present and a VCPU sends an ecall to another VCPU in enabled wait, the sending VCPU receives a 56 intercept (partial execution), so KVM can wake up the receiving CPU. Note that the SIGP interpretation facility will take care of the interrupt delivery and KVM's only job is to wake the receiving VCPU. For PV, the sending VCPU will receive a 108 intercept (pv notify) and should continue like in the non-PV case, i.e. wake the receiving VCPU. For PV and non-PV guests the interrupt delivery will occur through the SIGP interpretation facility on SIE entry when SIE finds the X bit in the status field set. However, in handle_pv_notification(), there was no special handling for SIGP, which leads to interrupt injection being requested by KVM for the next SIE entry. This results in the interrupt being delivered twice: once by the SIGP interpretation facility and once by KVM through the IICTL. Add the necessary special handling in handle_pv_notification(), similar to handle_partial_execution(), which simply wakes the receiving VCPU and leave interrupt delivery to the SIGP interpretation facility. In contrast to external calls, emergency calls are not interpreted but also cause a 108 intercept, which is why we still need to call handle_instruction() for SIGP orders other than ecall. Since kvm_s390_handle_sigp_pei() is now called for all SIGP orders which cause a 108 intercept - even if they are actually handled by handle_instruction() - move the tracepoint in kvm_s390_handle_sigp_pei() to avoid possibly confusing trace messages. Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Cc: <stable@vger.kernel.org> # 5.7 Fixes: da24a0cc58ed ("KVM: s390: protvirt: Instruction emulation") Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220718130434.73302-1-nrb@linux.ibm.com Message-Id: <20220718130434.73302-1-nrb@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-03s390/archrandom: prevent CPACF trng invocations in interrupt contextHarald Freudenberger1-3/+6
commit 918e75f77af7d2e049bb70469ec0a2c12782d96a upstream. This patch slightly reworks the s390 arch_get_random_seed_{int,long} implementation: Make sure the CPACF trng instruction is never called in any interrupt context. This is done by adding an additional condition in_task(). Justification: There are some constrains to satisfy for the invocation of the arch_get_random_seed_{int,long}() functions: - They should provide good random data during kernel initialization. - They should not be called in interrupt context as the TRNG instruction is relatively heavy weight and may for example make some network loads cause to timeout and buck. However, it was not clear what kind of interrupt context is exactly encountered during kernel init or network traffic eventually calling arch_get_random_seed_long(). After some days of investigations it is clear that the s390 start_kernel function is not running in any interrupt context and so the trng is called: Jul 11 18:33:39 t35lp54 kernel: [<00000001064e90ca>] arch_get_random_seed_long.part.0+0x32/0x70 Jul 11 18:33:39 t35lp54 kernel: [<000000010715f246>] random_init+0xf6/0x238 Jul 11 18:33:39 t35lp54 kernel: [<000000010712545c>] start_kernel+0x4a4/0x628 Jul 11 18:33:39 t35lp54 kernel: [<000000010590402a>] startup_continue+0x2a/0x40 The condition in_task() is true and the CPACF trng provides random data during kernel startup. The network traffic however, is more difficult. A typical call stack looks like this: Jul 06 17:37:07 t35lp54 kernel: [<000000008b5600fc>] extract_entropy.constprop.0+0x23c/0x240 Jul 06 17:37:07 t35lp54 kernel: [<000000008b560136>] crng_reseed+0x36/0xd8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b5604b8>] crng_make_state+0x78/0x340 Jul 06 17:37:07 t35lp54 kernel: [<000000008b5607e0>] _get_random_bytes+0x60/0xf8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b56108a>] get_random_u32+0xda/0x248 Jul 06 17:37:07 t35lp54 kernel: [<000000008aefe7a8>] kfence_guarded_alloc+0x48/0x4b8 Jul 06 17:37:07 t35lp54 kernel: [<000000008aeff35e>] __kfence_alloc+0x18e/0x1b8 Jul 06 17:37:07 t35lp54 kernel: [<000000008aef7f10>] __kmalloc_node_track_caller+0x368/0x4d8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b611eac>] kmalloc_reserve+0x44/0xa0 Jul 06 17:37:07 t35lp54 kernel: [<000000008b611f98>] __alloc_skb+0x90/0x178 Jul 06 17:37:07 t35lp54 kernel: [<000000008b6120dc>] __napi_alloc_skb+0x5c/0x118 Jul 06 17:37:07 t35lp54 kernel: [<000000008b8f06b4>] qeth_extract_skb+0x13c/0x680 Jul 06 17:37:07 t35lp54 kernel: [<000000008b8f6526>] qeth_poll+0x256/0x3f8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b63d76e>] __napi_poll.constprop.0+0x46/0x2f8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b63dbec>] net_rx_action+0x1cc/0x408 Jul 06 17:37:07 t35lp54 kernel: [<000000008b937302>] __do_softirq+0x132/0x6b0 Jul 06 17:37:07 t35lp54 kernel: [<000000008abf46ce>] __irq_exit_rcu+0x13e/0x170 Jul 06 17:37:07 t35lp54 kernel: [<000000008abf531a>] irq_exit_rcu+0x22/0x50 Jul 06 17:37:07 t35lp54 kernel: [<000000008b922506>] do_io_irq+0xe6/0x198 Jul 06 17:37:07 t35lp54 kernel: [<000000008b935826>] io_int_handler+0xd6/0x110 Jul 06 17:37:07 t35lp54 kernel: [<000000008b9358a6>] psw_idle_exit+0x0/0xa Jul 06 17:37:07 t35lp54 kernel: ([<000000008ab9c59a>] arch_cpu_idle+0x52/0xe0) Jul 06 17:37:07 t35lp54 kernel: [<000000008b933cfe>] default_idle_call+0x6e/0xd0 Jul 06 17:37:07 t35lp54 kernel: [<000000008ac59f4e>] do_idle+0xf6/0x1b0 Jul 06 17:37:07 t35lp54 kernel: [<000000008ac5a28e>] cpu_startup_entry+0x36/0x40 Jul 06 17:37:07 t35lp54 kernel: [<000000008abb0d90>] smp_start_secondary+0x148/0x158 Jul 06 17:37:07 t35lp54 kernel: [<000000008b935b9e>] restart_int_handler+0x6e/0x90 which confirms that the call is in softirq context. So in_task() covers exactly the cases where we want to have CPACF trng called: not in nmi, not in hard irq, not in soft irq but in normal task context and during kernel init. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Link: https://lore.kernel.org/r/20220713131721.257907-1-freude@linux.ibm.com Fixes: e4f74400308c ("s390/archrandom: simplify back to earlier design and initialize earlier") [agordeev@linux.ibm.com changed desc, added Fixes and Link, removed -stable] Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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. Donenfeld3-115/+14
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: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>
2022-06-14s390/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/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/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>
2022-05-25s390/pci: improve zpci_dev reference countingNiklas Schnelle4-4/+16
[ Upstream commit c122383d221dfa2f41cfe5e672540595de986fde ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-18s390: disable -Warray-boundsSven Schnelle1-0/+10
[ Upstream commit 8b202ee218395319aec1ef44f72043e1fbaccdd6 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08s390/extable: fix exception table sortingHeiko Carstens1-2/+7
commit c194dad21025dfd043210912653baab823bdff67 upstream. s390 has a swap_ex_entry_fixup function, however it is not being used since common code expects a swap_ex_entry_fixup define. If it is not defined the default implementation will be used. So fix this by adding a proper define. However also the implementation of the function must be fixed, since a NULL value for handler has a special meaning and must not be adjusted. Luckily all of this doesn't fix a real bug currently: the main extable is correctly sorted during build time, and for runtime sorting there is currently no case where the handler field is not NULL. Fixes: 05a68e892e89 ("s390/kernel: expand exception table logic to allow new handling options") Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.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>
2022-02-11KVM: s390: Return error on SIDA memop on normal guestJanis Schoetterl-Glausch1-0/+2
commit 2c212e1baedcd782b2535a3f86bc491977677c0e upstream. Refuse SIDA memops on guests which are not protected. For normal guests, the secure instruction data address designation, which determines the location we access, is not under control of KVM. Fixes: 19e122776886 (KVM: S390: protvirt: Introduce instruction data area bounce buffer) Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01s390/hypfs: include z/VM guests with access control group setVasily Gorbik1-2/+4
commit 663d34c8df98740f1e90241e78e456d00b3c6cad upstream. Currently if z/VM guest is allowed to retrieve hypervisor performance data globally for all guests (privilege class B) the query is formed in a way to include all guests but the group name is left empty. This leads to that z/VM guests which have access control group set not being included in the results (even local vm). Change the query group identifier from empty to "any" to retrieve information about all guests from any groups (or without a group set). Cc: stable@vger.kernel.org Fixes: 31cb4bd31a48 ("[S390] Hypervisor filesystem (s390_hypfs) for z/VM") Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01s390/module: fix loading modules with a lot of relocationsIlya Leoshkevich1-19/+18
commit f3b7e73b2c6619884351a3a0a7468642f852b8a2 upstream. If the size of the PLT entries generated by apply_rela() exceeds 64KiB, the first ones can no longer reach __jump_r1 with brc. Fix by using brcl. An alternative solution is to add a __jump_r1 copy after every 64KiB, however, the space savings are quite small and do not justify the additional complexity. Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches") Cc: stable@vger.kernel.org Reported-by: Andrea Righi <andrea.righi@canonical.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27s390/mm: fix 2KB pgtable release raceAlexander Gordeev1-1/+3
commit c2c224932fd0ee6854d6ebfc8d059c2bcad86606 upstream. There is a race on concurrent 2KB-pgtables release paths when both upper and lower halves of the containing parent page are freed, one via page_table_free_rcu() + __tlb_remove_table(), and the other via page_table_free(). The race might lead to a corruption as result of remove of list item in page_table_free() concurrently with __free_page() in __tlb_remove_table(). Let's assume first the lower and next the upper 2KB-pgtables are freed from a page. Since both halves of the page are allocated the tracking byte (bits 24-31 of the page _refcount) has value of 0x03 initially: CPU0 CPU1 ---- ---- page_table_free_rcu() // lower half { // _refcount[31..24] == 0x03 ... atomic_xor_bits(&page->_refcount, 0x11U << (0 + 24)); // _refcount[31..24] <= 0x12 ... table = table | (1U << 0); tlb_remove_table(tlb, table); } ... __tlb_remove_table() { // _refcount[31..24] == 0x12 mask = _table & 3; // mask <= 0x01 ... page_table_free() // upper half { // _refcount[31..24] == 0x12 ... atomic_xor_bits( &page->_refcount, 1U << (1 + 24)); // _refcount[31..24] <= 0x10 // mask <= 0x10 ... atomic_xor_bits(&page->_refcount, mask << (4 + 24)); // _refcount[31..24] <= 0x00 // mask <= 0x00 ... if (mask != 0) // == false break; fallthrough; ... if (mask & 3) // == false ... else __free_page(page); list_del(&page->lru); ^^^^^^^^^^^^^^^^^^ RACE! ^^^^^^^^^^^^^^^^^^^^^ } ... } The problem is page_table_free() releases the page as result of lower nibble unset and __tlb_remove_table() observing zero too early. With this update page_table_free() will use the similar logic as page_table_free_rcu() + __tlb_remove_table(), and mark the fragment as pending for removal in the upper nibble until after the list_del(). In other words, the parent page is considered as unreferenced and safe to release only when the lower nibble is cleared already and unsetting a bit in upper nibble results in that nibble turned zero. Cc: stable@vger.kernel.org Suggested-by: Vlastimil Babka <vbabka@suse.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-20KVM: s390: Clarify SIGP orders versus STOP/RESTARTEric Farman4-2/+43
commit 812de04661c4daa7ac385c0dfd62594540538034 upstream. With KVM_CAP_S390_USER_SIGP, there are only five Signal Processor orders (CONDITIONAL EMERGENCY SIGNAL, EMERGENCY SIGNAL, EXTERNAL CALL, SENSE, and SENSE RUNNING STATUS) which are intended for frequent use and thus are processed in-kernel. The remainder are sent to userspace with the KVM_CAP_S390_USER_SIGP capability. Of those, three orders (RESTART, STOP, and STOP AND STORE STATUS) have the potential to inject work back into the kernel, and thus are asynchronous. Let's look for those pending IRQs when processing one of the in-kernel SIGP orders, and return BUSY (CC2) if one is in process. This is in agreement with the Principles of Operation, which states that only one order can be "active" on a CPU at a time. Cc: stable@vger.kernel.org Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20211213210550.856213-2-farman@linux.ibm.com [borntraeger@linux.ibm.com: add stable tag] Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22s390/kexec_file: fix error handling when applying relocationsPhilipp Rudo1-1/+6
[ Upstream commit 41967a37b8eedfee15b81406a9f3015be90d3980 ] arch_kexec_apply_relocations_add currently ignores all errors returned by arch_kexec_do_relocs. This means that every unknown relocation is silently skipped causing unpredictable behavior while the relocated code runs. Fix this by checking for errors and fail kexec_file_load if an unknown relocation type is encountered. The problem was found after gcc changed its behavior and used R_390_PLT32DBL relocations for brasl instruction and relied on ld to resolve the relocations in the final link in case direct calls are possible. As the purgatory code is only linked partially (option -r) ld didn't resolve the relocations leaving them for arch_kexec_do_relocs. But arch_kexec_do_relocs doesn't know how to handle R_390_PLT32DBL relocations so they were silently skipped. This ultimately caused an endless loop in the purgatory as the brasl instructions kept branching to itself. Fixes: 71406883fd35 ("s390/kexec_file: Add kexec_file_load system call") Reported-by: Tao Liu <ltao@redhat.com> Signed-off-by: Philipp Rudo <prudo@redhat.com> Link: https://lore.kernel.org/r/20211208130741.5821-3-prudo@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-17s390/test_unwind: use raw opcode instead of invalid instructionIlie Halip1-2/+3
[ Upstream commit 53ae7230918154d1f4281d7aa3aae9650436eadf ] Building with clang & LLVM_IAS=1 leads to an error: arch/s390/lib/test_unwind.c:179:4: error: invalid register pair " mvcl %%r1,%%r1\n" ^ The test creates an invalid instruction that would trap at runtime, but the LLVM inline assembler tries to validate it at compile time too. Use the raw instruction opcode instead. Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Ilie Halip <ilie.halip@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Suggested-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1421 Link: https://lore.kernel.org/r/20211117174822.3632412-1-ilie.halip@gmail.com Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> [hca@linux.ibm.com: use illegal opcode, and update comment] Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08s390/pci: move pseudo-MMIO to prevent MIO overlapNiklas Schnelle1-3/+4
commit 52d04d408185b7aa47628d2339c28ec70074e0ae upstream. When running without MIO support, with pci=nomio or for devices which are not MIO-capable the zPCI subsystem generates pseudo-MMIO addresses to allow access to PCI BARs via MMIO based Linux APIs even though the platform uses function handles and BAR numbers. This is done by stashing an index into our global IOMAP array which contains the function handle in the 16 most significant bits of the addresses returned by ioremap() always setting the most significant bit. On the other hand the MIO addresses assigned by the platform for use, while requiring special instructions, allow PCI access with virtually mapped physical addresses. Now the problem is that these MIO addresses and our own pseudo-MMIO addresses may overlap, while functionally this would not be a problem by itself this overlap is detected by common code as both address types are added as resources in the iomem_resource tree. This leads to the overlapping resource claim of either the MIO capable or non-MIO capable devices with being rejected. Since PCI is tightly coupled to the use of the iomem_resource tree, see for example the code for request_mem_region(), we can't reasonably get rid of the overlap being detected by keeping our pseudo-MMIO addresses out of the iomem_resource tree. Instead let's move the range used by our own pseudo-MMIO addresses by starting at (1UL << 62) and only using addresses below (1UL << 63) thus avoiding the range currently used for MIO addresses. Fixes: c7ff0e918a7c ("s390/pci: deal with devices that have no support for MIO instructions") Cc: stable@vger.kernel.org # 5.3+ Reviewed-by: Pierre Morel <pmorel@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>
2021-12-08s390/setup: avoid using memblock_enforce_memory_limitVasily Gorbik1-3/+0
[ Upstream commit 5dbc4cb4667457b0c53bcd7bff11500b3c362975 ] There is a difference in how architectures treat "mem=" option. For some that is an amount of online memory, for s390 and x86 this is the limiting max address. Some memblock api like memblock_enforce_memory_limit() take limit argument and explicitly treat it as the size of online memory, and use __find_max_addr to convert it to an actual max address. Current s390 usage: memblock_enforce_memory_limit(memblock_end_of_DRAM()); yields different results depending on presence of memory holes (offline memory blocks in between online memory). If there are no memory holes limit == max_addr in memblock_enforce_memory_limit() and it does trim online memory and reserved memory regions. With memory holes present it actually does nothing. Since we already use memblock_remove() explicitly to trim online memory regions to potential limit (think mem=, kdump, addressing limits, etc.) drop the usage of memblock_enforce_memory_limit() altogether. Trimming reserved regions should not be required, since we now use memblock_set_current_limit() to limit allocations and any explicit memory reservations above the limit is an actual problem we should not hide. 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: Sasha Levin <sashal@kernel.org>
2021-12-01s390/mm: validate VMA in PGSTE manipulation functionsDavid Hildenbrand1-0/+13
commit fe3d10024073f06f04c74b9674bd71ccc1d787cf upstream. We should not walk/touch page tables outside of VMA boundaries when holding only the mmap sem in read mode. Evil user space can modify the VMA layout just before this function runs and e.g., trigger races with page table removal code since commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"). gfn_to_hva() will only translate using KVM memory regions, but won't validate the VMA. Further, we should not allocate page tables outside of VMA boundaries: if evil user space decides to map hugetlbfs to these ranges, bad things will happen because we suddenly have PTE or PMD page tables where we shouldn't have them. Similarly, we have to check if we suddenly find a hugetlbfs VMA, before calling get_locked_pte(). Fixes: 2d42f9477320 ("s390/kvm: Add PGSTE manipulation functions") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20210909162248.14969-4-david@redhat.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26s390/kexec: fix memory leak of ipl report bufferBaoquan He2-0/+16
commit 4aa9340584e37debef06fa99b56d064beb723891 upstream. unreferenced object 0x38000195000 (size 4096): comm "kexec", pid 8548, jiffies 4294953647 (age 32443.270s) hex dump (first 32 bytes): 00 00 00 c8 20 00 00 00 00 00 00 c0 02 80 00 00 .... ........... 40 40 40 40 40 40 40 40 00 00 00 00 00 00 00 00 @@@@@@@@........ backtrace: [<0000000011a2f199>] __vmalloc_node_range+0xc0/0x140 [<0000000081fa2752>] vzalloc+0x5a/0x70 [<0000000063a4c92d>] ipl_report_finish+0x2c/0x180 [<00000000553304da>] kexec_file_add_ipl_report+0xf4/0x150 [<00000000862d033f>] kexec_file_add_components+0x124/0x160 [<000000000d2717bb>] arch_kexec_kernel_image_load+0x62/0x90 [<000000002e0373b6>] kimage_file_alloc_init+0x1aa/0x2e0 [<0000000060f2d14f>] __do_sys_kexec_file_load+0x17c/0x2c0 [<000000008c86fe5a>] __s390x_sys_kexec_file_load+0x40/0x50 [<000000001fdb9dac>] __do_syscall+0x1bc/0x1f0 [<000000003ee4258d>] system_call+0x78/0xa0 Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Philipp Rudo <prudo@redhat.com> Fixes: 99feaa717e55 ("s390/kexec_file: Create ipl report and pass to next kernel") Cc: <stable@vger.kernel.org> # v5.2: 20c76e242e70: s390/kexec: fix return code handling Cc: <stable@vger.kernel.org> # v5.2 Link: https://lore.kernel.org/r/20211116033101.GD21646@MiWiFi-R3L-srv Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26s390/kexec: fix return code handlingHeiko Carstens2-2/+9
[ Upstream commit 20c76e242e7025bd355619ba67beb243ba1a1e95 ] kexec_file_add_ipl_report ignores that ipl_report_finish may fail and can return an error pointer instead of a valid pointer. Fix this and simplify by returning NULL in case of an error and let the only caller handle this case. Fixes: 99feaa717e55 ("s390/kexec_file: Create ipl report and pass to next kernel") Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18KVM: s390: Fix handle_sske page fault handlingJanis Schoetterl-Glausch1-0/+2
[ Upstream commit 85f517b29418158d3e6e90c3f0fc01b306d2f1a1 ] If handle_sske cannot set the storage key, because there is no page table entry or no present large page entry, it calls fixup_user_fault. However, currently, if the call succeeds, handle_sske returns -EAGAIN, without having set the storage key. Instead, retry by continue'ing the loop without incrementing the address. The same issue in handle_pfmf was fixed by a11bdb1a6b78 ("KVM: s390: Fix pfmf and conditional skey emulation"). Fixes: bd096f644319 ("KVM: s390: Add skey emulation fault handling") Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20211022152648.26536-1-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vmClaudio Imbrenda1-1/+1
[ Upstream commit 1e2aa46de526a5adafe580bca4c25856bb06f09e ] When the system is heavily overcommitted, kvm_s390_pv_init_vm might generate stall notifications. Fix this by using uv_call_sched instead of just uv_call. This is ok because we are not holding spinlocks. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Fixes: 214d9bbcd3a672 ("s390/mm: provide memory management functions for protected KVM guests") Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Message-Id: <20210920132502.36111-4-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18KVM: s390: pv: avoid double free of sida pageClaudio Imbrenda1-10/+9
[ Upstream commit d4074324b07a94a1fca476d452dfbb3a4e7bf656 ] If kvm_s390_pv_destroy_cpu is called more than once, we risk calling free_page on a random page, since the sidad field is aliased with the gbea, which is not guaranteed to be zero. This can happen, for example, if userspace calls the KVM_PV_DISABLE IOCTL, and it fails, and then userspace calls the same IOCTL again. This scenario is only possible if KVM has some serious bug or if the hardware is broken. The solution is to simply return successfully immediately if the vCPU was already non secure. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Fixes: 19e1227768863a1469797c13ef8fea1af7beac2c ("KVM: S390: protvirt: Introduce instruction data area bounce buffer") Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Message-Id: <20210920132502.36111-3-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18s390/gmap: don't unconditionally call pte_unmap_unlock() in __gmap_zap()David Hildenbrand1-2/+3
[ Upstream commit b159f94c86b43cf7e73e654bc527255b1f4eafc4 ] ... otherwise we will try unlocking a spinlock that was never locked via a garbage pointer. At the time we reach this code path, we usually successfully looked up a PGSTE already; however, evil user space could have manipulated the VMA layout in the meantime and triggered removal of the page table. Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20210909162248.14969-3-david@redhat.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02KVM: s390: preserve deliverable_mask in __airqs_kick_single_vcpuHalil Pasic1-2/+3
[ Upstream commit 0e9ff65f455dfd0a8aea5e7843678ab6fe097e21 ] Changing the deliverable mask in __airqs_kick_single_vcpu() is a bug. If one idle vcpu can't take the interrupts we want to deliver, we should look for another vcpu that can, instead of saying that we don't want to deliver these interrupts by clearing the bits from the deliverable_mask. Fixes: 9f30f6216378 ("KVM: s390: add gib_alert_irq_handler()") Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20211019175401.3757927-3-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02KVM: s390: clear kicked_mask before sleeping againHalil Pasic1-0/+1
[ Upstream commit 9b57e9d5010bbed7c0d9d445085840f7025e6f9a ] The idea behind kicked mask is that we should not re-kick a vcpu that is already in the "kick" process, i.e. that was kicked and is is about to be dispatched if certain conditions are met. The problem with the current implementation is, that it assumes the kicked vcpu is going to enter SIE shortly. But under certain circumstances, the vcpu we just kicked will be deemed non-runnable and will remain in wait state. This can happen, if the interrupt(s) this vcpu got kicked to deal with got already cleared (because the interrupts got delivered to another vcpu). In this case kvm_arch_vcpu_runnable() would return false, and the vcpu would remain in kvm_vcpu_block(), but this time with its kicked_mask bit set. So next time around we wouldn't kick the vcpu form __airqs_kick_single_vcpu(), but would assume that we just kicked it. Let us make sure the kicked_mask is cleared before we give up on re-dispatching the vcpu. Fixes: 9f30f6216378 ("KVM: s390: add gib_alert_irq_handler()") Reported-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20211019175401.3757927-2-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-27s390/pci: fix zpci_zdev_put() on reserveNiklas Schnelle3-7/+45
commit a46044a92add6a400f4dada7b943b30221f7cc80 upstream. Since commit 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") the reference count of a zpci_dev is incremented between pcibios_add_device() and pcibios_release_device() which was supposed to prevent the zpci_dev from being freed while the common PCI code has access to it. It was missed however that the handling of zPCI availability events assumed that once zpci_zdev_put() was called no later availability event would still see the device. With the previously mentioned commit however this assumption no longer holds and we must make sure that we only drop the initial long-lived reference the zPCI subsystem holds exactly once. Do so by introducing a zpci_device_reserved() function that handles when a device is reserved. Here we make sure the zpci_dev will not be considered for further events by removing it from the zpci_list. This also means that the device actually stays in the ZPCI_FN_STATE_RESERVED state between the time we know it has been reserved and the final reference going away. We thus need to consider it a real state instead of just a conceptual state after the removal. The final cleanup of PCI resources, removal from zbus, and destruction of the IOMMU stays in zpci_release_device() to make sure holders of the reference do see valid data until the release. Fixes: 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") Cc: stable@vger.kernel.org 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>
2021-10-20s390: fix strrchr() implementationRoberto Sassu1-8/+7
commit 8e0ab8e26b72a80e991c66a8abc16e6c856abe3d upstream. Fix two problems found in the strrchr() implementation for s390 architectures: evaluate empty strings (return the string address instead of NULL, if '\0' is passed as second argument); evaluate the first character of non-empty strings (the current implementation stops at the second). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Heiko Carstens <hca@linux.ibm.com> (incorrect behavior with empty strings) Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Link: https://lore.kernel.org/r/20211005120836.60630-1-roberto.sassu@huawei.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>
2021-10-13bpf, s390: Fix potential memory leak about jit_dataTiezhu Yang1-1/+1
[ Upstream commit 686cb8b9f6b46787f035afe8fbd132a74e6b1bdd ] Make sure to free jit_data through kfree() in the error path. Fixes: 1c8f9b91c456 ("bpf: s390: add JIT support for multi-function programs") Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> 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>
2021-09-26s390/pci_mmio: fully validate the VMA before calling follow_pte()David Hildenbrand1-1/+1
commit a8b92b8c1eac8d655a97b1e90f4d83c25d9b9a18 upstream. We should not walk/touch page tables outside of VMA boundaries when holding only the mmap sem in read mode. Evil user space can modify the VMA layout just before this function runs and e.g., trigger races with page table removal code since commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"). find_vma() does not check if the address is >= the VMA start address; use vma_lookup() instead. Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22s390/bpf: Fix branch shortening during codegen passIlya Leoshkevich1-2/+1
commit 1511df6f5e9ef32826f20db2ee81f8527154dc14 upstream. EMIT6_PCREL() macro assumes that the previous pass generated 6 bytes of code, which is not the case if branch shortening took place. Fix by using jit->prg, like all the other EMIT6_PCREL_*() macros. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches") Signed-off-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>
2021-09-22s390/bpf: Fix 64-bit subtraction of the -0x80000000 constantIlya Leoshkevich1-2/+7
commit 6e61dc9da0b7a0d91d57c2e20b5ea4fd2d4e7e53 upstream. The JIT uses agfi for subtracting constants, but -(-0x80000000) cannot be represented as a 32-bit signed binary integer. Fix by using algfi in this particular case. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-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>
2021-09-22s390/bpf: Fix optimizing out zero-extensionsIlya Leoshkevich1-28/+30
commit db7bee653859ef7179be933e7d1384644f795f26 upstream. Currently the JIT completely removes things like `reg32 += 0`, however, the BPF_ALU semantics requires the target register to be zero-extended in such cases. Fix by optimizing out only the arithmetic operation, but not the subsequent zero-extension. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-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>
2021-09-18s390/pv: fix the forcing of the swiotlbHalil Pasic1-1/+1
commit 93ebb6828723b8aef114415c4dc3518342f7dcad upstream. Since commit 903cd0f315fe ("swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing") if code sets swiotlb_force it needs to do so before the swiotlb is initialised. Otherwise io_tlb_default_mem->force_bounce will not get set to true, and devices that use (the default) swiotlb will not bounce despite switolb_force having the value of SWIOTLB_FORCE. Let us restore swiotlb functionality for PV by fulfilling this new requirement. This change addresses what turned out to be a fragility in commit 64e1f0c531d1 ("s390/mm: force swiotlb for protected virtualization"), which ain't exactly broken in its original context, but could give us some more headache if people backport the broken change and forget this fix. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Fixes: 903cd0f315fe ("swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing") Fixes: 64e1f0c531d1 ("s390/mm: force swiotlb for protected virtualization") Cc: stable@vger.kernel.org #5.3+ Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18s390: make PCI mio support a machine flagNiklas Schnelle3-3/+8
[ Upstream commit 3322ba0d7bea1e24ae464418626f6a15b69533ab ] Kernel support for the newer PCI mio instructions can be toggled off with the pci=nomio command line option which needs to integrate with common code PCI option parsing. However this option then toggles static branches which can't be toggled yet in an early_param() call. Thus commit 9964f396f1d0 ("s390: fix setting of mio addressing control") moved toggling the static branches to the PCI init routine. With this setup however we can't check for mio support outside the PCI code during early boot, i.e. before switching the static branches, which we need to be able to export this as an ELF HWCAP. Improve on this by turning mio availability into a machine flag that gets initially set based on CONFIG_PCI and the facility bit and gets toggled off if pci=nomio is found during PCI option parsing allowing simple access to this machine flag after early init. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18s390/jump_label: print real address in a case of a jump label bugHeiko Carstens1-1/+1
[ Upstream commit 5492886c14744d239e87f1b0b774b5a341e755cc ] In case of a jump label print the real address of the piece of code where a mismatch was detected. This is right before the system panics, so there is nothing revealed. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15KVM: s390: index kvm->arch.idle_mask by vcpu_idxHalil Pasic4-8/+9
commit a3e03bc1368c1bc16e19b001fc96dc7430573cc8 upstream. While in practice vcpu->vcpu_idx == vcpu->vcp_id is often true, it may not always be, and we must not rely on this. Reason is that KVM decides the vcpu_idx, userspace decides the vcpu_id, thus the two might not match. Currently kvm->arch.idle_mask is indexed by vcpu_id, which implies that code like for_each_set_bit(vcpu_id, kvm->arch.idle_mask, online_vcpus) { vcpu = kvm_get_vcpu(kvm, vcpu_id); do_stuff(vcpu); } is not legit. Reason is that kvm_get_vcpu expects an vcpu_idx, not an vcpu_id. The trouble is, we do actually use kvm->arch.idle_mask like this. To fix this problem we have two options. Either use kvm_get_vcpu_by_id(vcpu_id), which would loop to find the right vcpu_id, or switch to indexing via vcpu_idx. The latter is preferable for obvious reasons. Let us make switch from indexing kvm->arch.idle_mask by vcpu_id to indexing it by vcpu_idx. To keep gisa_int.kicked_mask indexed by the same index as idle_mask lets make the same change for it as well. Fixes: 1ee0bc559dc3 ("KVM: s390: get rid of local_int array") Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Christian Bornträger <borntraeger@de.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: <stable@vger.kernel.org> # 3.15+ Link: https://lore.kernel.org/r/20210827125429.1912577-1-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-15s390/debug: fix debug area life cyclePeter Oberparleiter1-46/+56
[ Upstream commit 9372a82892c2caa6bccab9a4081166fa769699f8 ] Currently allocation and registration of s390dbf debug areas are tied together. As a result, a debug area cannot be unregistered and re-registered while any process has an associated debugfs file open. Fix this by splitting alloc/release from register/unregister. Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15s390/debug: keep debug data on resizePeter Oberparleiter1-21/+53
[ Upstream commit 1204777867e8486a88dbb4793fe256b31ea05eeb ] Any previously recorded s390dbf debug data is reset when a debug area is resized using the 'pages' sysfs attribute. This can make live-debugging unnecessarily complex. Fix this by copying existing debug data to the newly allocated debug area when resizing. Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15s390/pci: fix misleading rc in clp_set_pci_fn()Niklas Schnelle2-20/+20
[ Upstream commit f7addcdd527a6dddfebe20c358b87bdb95624612 ] Currently clp_set_pci_fn() always returns 0 as long as the CLP request itself succeeds even if the operation itself returns a response code other than CLP_RC_OK or CLP_RC_SETPCIFN_ALRDY. This is highly misleading because calling code assumes that a zero rc means that the operation was successful. Fix this by returning the response code or cc on failure with the exception of the special handling for CLP_RC_SETPCIFN_ALRDY. Also let's not assume that the returned function handle for CLP_RC_SETPCIFN_ALRDY is 0, we don't need it anyway. 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: Sasha Levin <sashal@kernel.org>