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2020-07-22KVM: s390: reduce number of IO pins to 1Christian Borntraeger
[ Upstream commit 774911290c589e98e3638e73b24b0a4d4530e97c ] The current number of KVM_IRQCHIP_NUM_PINS results in an order 3 allocation (32kb) for each guest start/restart. This can result in OOM killer activity even with free swap when the memory is fragmented enough: kernel: qemu-system-s39 invoked oom-killer: gfp_mask=0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_COMP|__GFP_ZERO), order=3, oom_score_adj=0 kernel: CPU: 1 PID: 357274 Comm: qemu-system-s39 Kdump: loaded Not tainted 5.4.0-29-generic #33-Ubuntu kernel: Hardware name: IBM 8562 T02 Z06 (LPAR) kernel: Call Trace: kernel: ([<00000001f848fe2a>] show_stack+0x7a/0xc0) kernel: [<00000001f8d3437a>] dump_stack+0x8a/0xc0 kernel: [<00000001f8687032>] dump_header+0x62/0x258 kernel: [<00000001f8686122>] oom_kill_process+0x172/0x180 kernel: [<00000001f8686abe>] out_of_memory+0xee/0x580 kernel: [<00000001f86e66b8>] __alloc_pages_slowpath+0xd18/0xe90 kernel: [<00000001f86e6ad4>] __alloc_pages_nodemask+0x2a4/0x320 kernel: [<00000001f86b1ab4>] kmalloc_order+0x34/0xb0 kernel: [<00000001f86b1b62>] kmalloc_order_trace+0x32/0xe0 kernel: [<00000001f84bb806>] kvm_set_irq_routing+0xa6/0x2e0 kernel: [<00000001f84c99a4>] kvm_arch_vm_ioctl+0x544/0x9e0 kernel: [<00000001f84b8936>] kvm_vm_ioctl+0x396/0x760 kernel: [<00000001f875df66>] do_vfs_ioctl+0x376/0x690 kernel: [<00000001f875e304>] ksys_ioctl+0x84/0xb0 kernel: [<00000001f875e39a>] __s390x_sys_ioctl+0x2a/0x40 kernel: [<00000001f8d55424>] system_call+0xd8/0x2c8 As far as I can tell s390x does not use the iopins as we bail our for anything other than KVM_IRQ_ROUTING_S390_ADAPTER and the chip/pin is only used for KVM_IRQ_ROUTING_IRQCHIP. So let us use a small number to reduce the memory footprint. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200617083620.5409-1-borntraeger@de.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-29s390: fix syscall_get_error for compat processesDmitry V. Levin
commit b3583fca5fb654af2cfc1c08259abb9728272538 upstream. If both the tracer and the tracee are compat processes, and gprs[2] is assigned a value by __poke_user_compat, then the higher 32 bits of gprs[2] are cleared, IS_ERR_VALUE() always returns false, and syscall_get_error() always returns 0. Fix the implementation by sign-extending the value for compat processes the same way as x86 implementation does. The bug was exposed to user space by commit 201766a20e30f ("ptrace: add PTRACE_GET_SYSCALL_INFO request") and detected by strace test suite. This change fixes strace syscall tampering on s390. Link: https://lkml.kernel.org/r/20200602180051.GA2427@altlinux.org Fixes: 753c4dd6a2fa2 ("[S390] ptrace changes") Cc: Elvira Khabirova <lineprinter@altlinux.org> Cc: stable@vger.kernel.org # v2.6.28+ Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-11s390/ftrace: save traced function callerVasily Gorbik
[ Upstream commit b4adfe55915d8363e244e42386d69567db1719b9 ] A typical backtrace acquired from ftraced function currently looks like the following (e.g. for "path_openat"): arch_stack_walk+0x15c/0x2d8 stack_trace_save+0x50/0x68 stack_trace_call+0x15a/0x3b8 ftrace_graph_caller+0x0/0x1c 0x3e0007e3c98 <- ftraced function caller (should be do_filp_open+0x7c/0xe8) do_open_execat+0x70/0x1b8 __do_execve_file.isra.0+0x7d8/0x860 __s390x_sys_execve+0x56/0x68 system_call+0xdc/0x2d8 Note random "0x3e0007e3c98" stack value as ftraced function caller. This value causes either imprecise unwinder result or unwinding failure. That "0x3e0007e3c98" comes from r14 of ftraced function stack frame, which it haven't had a chance to initialize since the very first instruction calls ftrace code ("ftrace_caller"). (ftraced function might never save r14 as well). Nevertheless according to s390 ABI any function is called with stack frame allocated for it and r14 contains return address. "ftrace_caller" itself is called with "brasl %r0,ftrace_caller". So, to fix this issue simply always save traced function caller onto ftraced function stack frame. Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24s390/diag: fix display of diagnose call statisticsMichael Mueller
commit 6c7c851f1b666a8a455678a0b480b9162de86052 upstream. Show the full diag statistic table and not just parts of it. The issue surfaced in a KVM guest with a number of vcpus defined smaller than NR_DIAG_STAT. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Cc: stable@vger.kernel.org Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11mm: prevent get_user_pages() from overflowing page refcountLinus Torvalds
commit 8fde12ca79aff9b5ba951fce1a2641901b8d8e64 upstream. If the page refcount wraps around past zero, it will be freed while there are still four billion references to it. One of the possible avenues for an attacker to try to make this happen is by doing direct IO on a page multiple times. This patch makes get_user_pages() refuse to take a new page reference if there are already more than two billion references to the page. Reported-by: Jann Horn <jannh@google.com> Acked-by: Matthew Wilcox <willy@infradead.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [ 4.4.y backport notes: Ajay: - Added local variable 'err' with-in follow_hugetlb_page() from 2be7cfed995e, to resolve compilation error - Added page_ref_count() - Added missing refcount overflow checks on x86 and s390 (Vlastimil, thanks for this change) Srivatsa: - Replaced call to get_page_foll() with try_get_page_foll() ] Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu> Signed-off-by: Ajay Kaher <akaher@vmware.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28s390/ftrace: generate traced function stack frameVasily Gorbik
[ Upstream commit 45f7a0da600d3c409b5ad8d5ddddacd98ddc8840 ] Currently backtrace from ftraced function does not contain ftraced function itself. e.g. for "path_openat": arch_stack_walk+0x15c/0x2d8 stack_trace_save+0x50/0x68 stack_trace_call+0x15e/0x3d8 ftrace_graph_caller+0x0/0x1c <-- ftrace code do_filp_open+0x7c/0xe8 <-- ftraced function caller do_open_execat+0x76/0x1b8 open_exec+0x52/0x78 load_elf_binary+0x180/0x1160 search_binary_handler+0x8e/0x288 load_script+0x2a8/0x2b8 search_binary_handler+0x8e/0x288 __do_execve_file.isra.39+0x6fa/0xb40 __s390x_sys_execve+0x56/0x68 system_call+0xdc/0x2d8 Ftraced function is expected in the backtrace by ftrace kselftests, which are now failing. It would also be nice to have it for clarity reasons. "ftrace_caller" itself is called without stack frame allocated for it and does not store its caller (ftraced function). Instead it simply allocates a stack frame for "ftrace_trace_function" and sets backchain to point to ftraced function stack frame (which contains ftraced function caller in saved r14). To fix this issue make "ftrace_caller" allocate a stack frame for itself just to store ftraced function for the stack unwinder. As a result backtrace looks like the following: arch_stack_walk+0x15c/0x2d8 stack_trace_save+0x50/0x68 stack_trace_call+0x15e/0x3d8 ftrace_graph_caller+0x0/0x1c <-- ftrace code path_openat+0x6/0xd60 <-- ftraced function do_filp_open+0x7c/0xe8 <-- ftraced function caller do_open_execat+0x76/0x1b8 open_exec+0x52/0x78 load_elf_binary+0x180/0x1160 search_binary_handler+0x8e/0x288 load_script+0x2a8/0x2b8 search_binary_handler+0x8e/0x288 __do_execve_file.isra.39+0x6fa/0xb40 __s390x_sys_execve+0x56/0x68 system_call+0xdc/0x2d8 Reported-by: Sven Schnelle <sven.schnelle@ibm.com> Tested-by: Sven Schnelle <sven.schnelle@ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-28s390/time: Fix clk type in get_tod_clockNathan Chancellor
commit 0f8a206df7c920150d2aa45574fba0ab7ff6be4f upstream. Clang warns: In file included from ../arch/s390/boot/startup.c:3: In file included from ../include/linux/elf.h:5: In file included from ../arch/s390/include/asm/elf.h:132: In file included from ../include/linux/compat.h:10: In file included from ../include/linux/time.h:74: In file included from ../include/linux/time32.h:13: In file included from ../include/linux/timex.h:65: ../arch/s390/include/asm/timex.h:160:20: warning: passing 'unsigned char [16]' to parameter of type 'char *' converts between pointers to integer types with different sign [-Wpointer-sign] get_tod_clock_ext(clk); ^~~ ../arch/s390/include/asm/timex.h:149:44: note: passing argument to parameter 'clk' here static inline void get_tod_clock_ext(char *clk) ^ Change clk's type to just be char so that it matches what happens in get_tod_clock_ext. Fixes: 57b28f66316d ("[S390] s390_hypfs: Add new attributes") Link: https://github.com/ClangBuiltLinux/linux/issues/861 Link: http://lkml.kernel.org/r/20200208140858.47970-1-natechancellor@gmail.com Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-12s390/smp: fix physical to logical CPU map for SMTHeiko Carstens
[ Upstream commit 72a81ad9d6d62dcb79f7e8ad66ffd1c768b72026 ] If an SMT capable system is not IPL'ed from the first CPU the setup of the physical to logical CPU mapping is broken: the IPL core gets CPU number 0, but then the next core gets CPU number 1. Correct would be that all SMT threads of CPU 0 get the subsequent logical CPU numbers. This is important since a lot of code (like e.g. the CPU topology code) assumes that CPU maps are setup like this. If the mapping is broken the system will not IPL due to broken topology masks: [ 1.716341] BUG: arch topology broken [ 1.716342] the SMT domain not a subset of the MC domain [ 1.716343] BUG: arch topology broken [ 1.716344] the MC domain not a subset of the BOOK domain This scenario can usually not happen since LPARs are always IPL'ed from CPU 0 and also re-IPL is intiated from CPU 0. However older kernels did initiate re-IPL on an arbitrary CPU. If therefore a re-IPL from an old kernel into a new kernel is initiated this may lead to crash. Fix this by setting up the physical to logical CPU mapping correctly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12s390/cpum_sf: Avoid SBD overflow condition in irq handlerThomas Richter
[ Upstream commit 0539ad0b22877225095d8adef0c376f52cc23834 ] The s390 CPU Measurement sampling facility has an overflow condition which fires when all entries in a SBD are used. The measurement alert interrupt is triggered and reads out all samples in this SDB. It then tests the successor SDB, if this SBD is not full, the interrupt handler does not read any samples at all from this SDB The design waits for the hardware to fill this SBD and then trigger another meassurement alert interrupt. This scheme works nicely until an perf_event_overflow() function call discards the sample due to a too high sampling rate. The interrupt handler has logic to read out a partially filled SDB when the perf event overflow condition in linux common code is met. This causes the CPUM sampling measurement hardware and the PMU device driver to operate on the same SBD's trailer entry. This should not happen. This can be seen here using this trace: cpumsf_pmu_add: tear:0xb5286000 hw_perf_event_update: sdbt 0xb5286000 full 1 over 0 flush_all:0 hw_perf_event_update: sdbt 0xb5286008 full 0 over 0 flush_all:0 above shows 1. interrupt hw_perf_event_update: sdbt 0xb5286008 full 1 over 0 flush_all:0 hw_perf_event_update: sdbt 0xb5286008 full 0 over 0 flush_all:0 above shows 2. interrupt ... this goes on fine until... hw_perf_event_update: sdbt 0xb5286068 full 1 over 0 flush_all:0 perf_push_sample1: overflow one or more samples read from the IRQ handler are rejected by perf_event_overflow() and the IRQ handler advances to the next SDB and modifies the trailer entry of a partially filled SDB. hw_perf_event_update: sdbt 0xb5286070 full 0 over 0 flush_all:1 timestamp: 14:32:52.519953 Next time the IRQ handler is called for this SDB the trailer entry shows an overflow count of 19 missed entries. hw_perf_event_update: sdbt 0xb5286070 full 1 over 19 flush_all:1 timestamp: 14:32:52.970058 Remove access to a follow on SDB when event overflow happened. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12s390/cpum_sf: Adjust sampling interval to avoid hitting sample limitsThomas Richter
[ Upstream commit 39d4a501a9ef55c57b51e3ef07fc2aeed7f30b3b ] Function perf_event_ever_overflow() and perf_event_account_interrupt() are called every time samples are processed by the interrupt handler. However function perf_event_account_interrupt() has checks to avoid being flooded with interrupts (more then 1000 samples are received per task_tick). Samples are then dropped and a PERF_RECORD_THROTTLED is added to the perf data. The perf subsystem limit calculation is: maximum sample frequency := 100000 --> 1 samples per 10 us task_tick = 10ms = 10000us --> 1000 samples per task_tick The work flow is measurement_alert() uses SDBT head and each SBDT points to 511 SDB pages, each with 126 sample entries. After processing 8 SBDs and for each valid sample calling: perf_event_overflow() perf_event_account_interrupts() there is a considerable amount of samples being dropped, especially when the sample frequency is very high and near the 100000 limit. To avoid the high amount of samples being dropped near the end of a task_tick time frame, increment the sampling interval in case of dropped events. The CPU Measurement sampling facility on the s390 supports only intervals, specifiing how many CPU cycles have to be executed before a sample is generated. Increase the interval when the samples being generated hit the task_tick limit. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-04s390/cpum_sf: Check for SDBT and SDB consistencyThomas Richter
[ Upstream commit 247f265fa502e7b17a0cb0cc330e055a36aafce4 ] Each SBDT is located at a 4KB page and contains 512 entries. Each entry of a SDBT points to a SDB, a 4KB page containing sampled data. The last entry is a link to another SDBT page. When an event is created the function sequence executed is: __hw_perf_event_init() +--> allocate_buffers() +--> realloc_sampling_buffers() +---> alloc_sample_data_block() Both functions realloc_sampling_buffers() and alloc_sample_data_block() allocate pages and the allocation can fail. This is handled correctly and all allocated pages are freed and error -ENOMEM is returned to the top calling function. Finally the event is not created. Once the event has been created, the amount of initially allocated SDBT and SDB can be too low. This is detected during measurement interrupt handling, where the amount of lost samples is calculated. If the number of lost samples is too high considering sampling frequency and already allocated SBDs, the number of SDBs is enlarged during the next execution of cpumsf_pmu_enable(). If more SBDs need to be allocated, functions realloc_sampling_buffers() +---> alloc-sample_data_block() are called to allocate more pages. Page allocation may fail and the returned error is ignored. A SDBT and SDB setup already exists. However the modified SDBTs and SDBs might end up in a situation where the first entry of an SDBT does not point to an SDB, but another SDBT, basicly an SBDT without payload. This can not be handled by the interrupt handler, where an SDBT must have at least one entry pointing to an SBD. Add a check to avoid SDBTs with out payload (SDBs) when enlarging the buffer setup. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05KVM: s390: unregister debug feature on failing arch initMichael Mueller
[ Upstream commit 308c3e6673b012beecb96ef04cc65f4a0e7cdd99 ] Make sure the debug feature and its allocated resources get released upon unsuccessful architecture initialization. A related indication of the issue will be reported as kernel message. Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Message-Id: <20181130143215.69496-2-mimu@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-28s390/perf: Return error when debug_register failsThomas Richter
[ Upstream commit ec0c0bb489727de0d4dca6a00be6970ab8a3b30a ] Return an error when the function debug_register() fails allocating the debug handle. Also remove the registered debug handle when the initialization fails later on. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-06s390/cmm: fix information leak in cmm_timeout_handler()Yihui ZENG
commit b8e51a6a9db94bc1fb18ae831b3dab106b5a4b5f upstream. The problem is that we were putting the NUL terminator too far: buf[sizeof(buf) - 1] = '\0'; If the user input isn't NUL terminated and they haven't initialized the whole buffer then it leads to an info leak. The NUL terminator should be: buf[len - 1] = '\0'; Signed-off-by: Yihui Zeng <yzeng56@asu.edu> Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> [heiko.carstens@de.ibm.com: keep semantics of how *lenp and *ppos are handled] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-17s390/topology: avoid firing events before kobjs are createdVasily Gorbik
commit f3122a79a1b0a113d3aea748e0ec26f2cb2889de upstream. arch_update_cpu_topology is first called from: kernel_init_freeable->sched_init_smp->sched_init_domains even before cpus has been registered in: kernel_init_freeable->do_one_initcall->s390_smp_init Do not trigger kobject_uevent change events until cpu devices are actually created. Fixes the following kasan findings: BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb40/0xee0 Read of size 8 at addr 0000000000000020 by task swapper/0/1 BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb36/0xee0 Read of size 8 at addr 0000000000000018 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B Hardware name: IBM 3906 M04 704 (LPAR) Call Trace: ([<0000000143c6db7e>] show_stack+0x14e/0x1a8) [<0000000145956498>] dump_stack+0x1d0/0x218 [<000000014429fb4c>] print_address_description+0x64/0x380 [<000000014429f630>] __kasan_report+0x138/0x168 [<0000000145960b96>] kobject_uevent_env+0xb36/0xee0 [<0000000143c7c47c>] arch_update_cpu_topology+0x104/0x108 [<0000000143df9e22>] sched_init_domains+0x62/0xe8 [<000000014644c94a>] sched_init_smp+0x3a/0xc0 [<0000000146433a20>] kernel_init_freeable+0x558/0x958 [<000000014599002a>] kernel_init+0x22/0x160 [<00000001459a71d4>] ret_from_fork+0x28/0x30 [<00000001459a71dc>] kernel_thread_starter+0x0/0x10 Cc: stable@vger.kernel.org Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-17KVM: s390: Test for bad access register and size at the start of S390_MEM_OPThomas Huth
commit a13b03bbb4575b350b46090af4dfd30e735aaed1 upstream. If the KVM_S390_MEM_OP ioctl is called with an access register >= 16, then there is certainly a bug in the calling userspace application. We check for wrong access registers, but only if the vCPU was already in the access register mode before (i.e. the SIE block has recorded it). The check is also buried somewhere deep in the calling chain (in the function ar_translation()), so this is somewhat hard to find. It's better to always report an error to the userspace in case this field is set wrong, and it's safer in the KVM code if we block wrong values here early instead of relying on a check somewhere deep down the calling chain, so let's add another check to kvm_s390_guest_mem_op() directly. We also should check that the "size" is non-zero here (thanks to Janosch Frank for the hint!). If we do not check the size, we could call vmalloc() with this 0 value, and this will cause a kernel warning. Signed-off-by: Thomas Huth <thuth@redhat.com> Link: https://lkml.kernel.org/r/20190829122517.31042-1-thuth@redhat.com Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-07hypfs: Fix error number left in struct pointer memberDavid Howells
[ Upstream commit b54c64f7adeb241423cd46598f458b5486b0375e ] In hypfs_fill_super(), if hypfs_create_update_file() fails, sbi->update_file is left holding an error number. This is passed to hypfs_kill_super() which doesn't check for this. Fix this by not setting sbi->update_value until after we've checked for error. Fixes: 24bbb1faf3f0 ("[PATCH] s390_hypfs filesystem") Signed-off-by: David Howells <dhowells@redhat.com> cc: Martin Schwidefsky <schwidefsky@de.ibm.com> cc: Heiko Carstens <heiko.carstens@de.ibm.com> cc: linux-s390@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-21s390/bpf: use 32-bit index for tail callsIlya Leoshkevich
[ Upstream commit 91b4db5313a2c793aabc2143efb8ed0cf0fdd097 ] "p runtime/jit: pass > 32bit index to tail_call" fails when bpf_jit_enable=1, because the tail call is not executed. This in turn is because the generated code assumes index is 64-bit, while it must be 32-bit, and as a result prog array bounds check fails, while it should pass. Even if bounds check would have passed, the code that follows uses 64-bit index to compute prog array offset. Fix by using clrj instead of clgrj for comparing index with array size, and also by using llgfr for truncating index to 32 bits before using it to compute prog array offset. Fixes: 6651ee070b31 ("s390/bpf: implement bpf_tail_call() helper") Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-21s390/bpf: fix lcgr instruction encodingIlya Leoshkevich
[ Upstream commit bb2d267c448f4bc3a3389d97c56391cb779178ae ] "masking, test in bounds 3" fails on s390, because BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0) ignores the top 32 bits of BPF_REG_2. The reason is that JIT emits lcgfr instead of lcgr. The associated comment indicates that the code was intended to emit lcgr in the first place, it's just that the wrong opcode was used. Fix by using the correct opcode. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-21KVM: s390: Do not leak kernel stack data in the KVM_S390_INTERRUPT ioctlThomas Huth
commit 53936b5bf35e140ae27e4bbf0447a61063f400da upstream. When the userspace program runs the KVM_S390_INTERRUPT ioctl to inject an interrupt, we convert them from the legacy struct kvm_s390_interrupt to the new struct kvm_s390_irq via the s390int_to_s390irq() function. However, this function does not take care of all types of interrupts that we can inject into the guest later (see do_inject_vcpu()). Since we do not clear out the s390irq values before calling s390int_to_s390irq(), there is a chance that we copy random data from the kernel stack which could be leaked to the userspace later. Specifically, the problem exists with the KVM_S390_INT_PFAULT_INIT interrupt: s390int_to_s390irq() does not handle it, and the function __inject_pfault_init() later copies irq->u.ext which contains the random kernel stack data. This data can then be leaked either to the guest memory in __deliver_pfault_init(), or the userspace might retrieve it directly with the KVM_S390_GET_IRQ_STATE ioctl. Fix it by handling that interrupt type in s390int_to_s390irq(), too, and by making sure that the s390irq struct is properly pre-initialized. And while we're at it, make sure that s390int_to_s390irq() now directly returns -EINVAL for unknown interrupt types, so that we immediately get a proper error code in case we add more interrupt types to do_inject_vcpu() without updating s390int_to_s390irq() sometime in the future. Cc: stable@vger.kernel.org Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/kvm/20190912115438.25761-1-thuth@redhat.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-21s390: fix stfle zero paddingHeiko Carstens
commit 4f18d869ffd056c7858f3d617c71345cf19be008 upstream. The stfle inline assembly returns the number of double words written (condition code 0) or the double words it would have written (condition code 3), if the memory array it got as parameter would have been large enough. The current stfle implementation assumes that the array is always large enough and clears those parts of the array that have not been written to with a subsequent memset call. If however the array is not large enough memset will get a negative length parameter, which means that memset clears memory until it gets an exception and the kernel crashes. To fix this simply limit the maximum length. Move also the inline assembly to an extra function to avoid clobbering of register 0, which might happen because of the added min_t invocation together with code instrumentation. The bug was introduced with commit 14375bc4eb8d ("[S390] cleanup facility list handling") but was rather harmless, since it would only write to a rather large array. It became a potential problem with commit 3ab121ab1866 ("[S390] kernel: Add z/VM LGR detection"). Since then it writes to an array with only four double words, while some machines already deliver three double words. As soon as machines have a facility bit within the fifth double a crash on IPL would happen. Fixes: 14375bc4eb8d ("[S390] cleanup facility list handling") Cc: <stable@vger.kernel.org> # v2.6.37+ Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22KVM: s390: fix memory slot handling for KVM_SET_USER_MEMORY_REGIONChristian Borntraeger
[ Upstream commit 19ec166c3f39fe1d3789888a74cc95544ac266d4 ] kselftests exposed a problem in the s390 handling for memory slots. Right now we only do proper memory slot handling for creation of new memory slots. Neither MOVE, nor DELETION are handled properly. Let us implement those. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-06s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPUDavid Hildenbrand
commit 60f1bf29c0b2519989927cae640cd1f50f59dc7f upstream. When calling smp_call_ipl_cpu() from the IPL CPU, we will try to read from pcpu_devices->lowcore. However, due to prefixing, that will result in reading from absolute address 0 on that CPU. We have to go via the actual lowcore instead. This means that right now, we will read lc->nodat_stack == 0 and therfore work on a very wrong stack. This BUG essentially broke rebooting under QEMU TCG (which will report a low address protection exception). And checking under KVM, it is also broken under KVM. With 1 VCPU it can be easily triggered. :/# echo 1 > /proc/sys/kernel/sysrq :/# echo b > /proc/sysrq-trigger [ 28.476745] sysrq: SysRq : Resetting [ 28.476793] Kernel stack overflow. [ 28.476817] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13 [ 28.476820] Hardware name: IBM 2964 NE1 716 (KVM/Linux) [ 28.476826] Krnl PSW : 0400c00180000000 0000000000115c0c (pcpu_delegate+0x12c/0x140) [ 28.476861] R:0 T:1 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 [ 28.476863] Krnl GPRS: ffffffffffffffff 0000000000000000 000000000010dff8 0000000000000000 [ 28.476864] 0000000000000000 0000000000000000 0000000000ab7090 000003e0006efbf0 [ 28.476864] 000000000010dff8 0000000000000000 0000000000000000 0000000000000000 [ 28.476865] 000000007fffc000 0000000000730408 000003e0006efc58 0000000000000000 [ 28.476887] Krnl Code: 0000000000115bfe: 4170f000 la %r7,0(%r15) [ 28.476887] 0000000000115c02: 41f0a000 la %r15,0(%r10) [ 28.476887] #0000000000115c06: e370f0980024 stg %r7,152(%r15) [ 28.476887] >0000000000115c0c: c0e5fffff86e brasl %r14,114ce8 [ 28.476887] 0000000000115c12: 41f07000 la %r15,0(%r7) [ 28.476887] 0000000000115c16: a7f4ffa8 brc 15,115b66 [ 28.476887] 0000000000115c1a: 0707 bcr 0,%r7 [ 28.476887] 0000000000115c1c: 0707 bcr 0,%r7 [ 28.476901] Call Trace: [ 28.476902] Last Breaking-Event-Address: [ 28.476920] [<0000000000a01c4a>] arch_call_rest_init+0x22/0x80 [ 28.476927] Kernel panic - not syncing: Corrupt kernel stack, can't continue. [ 28.476930] CPU: 0 PID: 424 Comm: sh Not tainted 5.0.0-rc1+ #13 [ 28.476932] Hardware name: IBM 2964 NE1 716 (KVM/Linux) [ 28.476932] Call Trace: Fixes: 2f859d0dad81 ("s390/smp: reduce size of struct pcpu") Cc: stable@vger.kernel.org # 4.0+ Reported-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06s390/smp: fix CPU hotplug deadlock with CPU rescanGerald Schaefer
commit b7cb707c373094ce4008d4a6ac9b6b366ec52da5 upstream. smp_rescan_cpus() is called without the device_hotplug_lock, which can lead to a dedlock when a new CPU is found and immediately set online by a udev rule. This was observed on an older kernel version, where the cpu_hotplug_begin() loop was still present, and it resulted in hanging chcpu and systemd-udev processes. This specific deadlock will not show on current kernels. However, there may be other possible deadlocks, and since smp_rescan_cpus() can still trigger a CPU hotplug operation, the device_hotplug_lock should be held. For reference, this was the deadlock with the old cpu_hotplug_begin() loop: chcpu (rescan) systemd-udevd echo 1 > /sys/../rescan -> smp_rescan_cpus() -> (*) get_online_cpus() (increases refcount) -> smp_add_present_cpu() (new CPU found) -> register_cpu() -> device_add() -> udev "add" event triggered -----------> udev rule sets CPU online -> echo 1 > /sys/.../online -> lock_device_hotplug_sysfs() (this is missing in rescan path) -> device_online() -> (**) device_lock(new CPU dev) -> cpu_up() -> cpu_hotplug_begin() (loops until refcount == 0) -> deadlock with (*) -> bus_probe_device() -> device_attach() -> device_lock(new CPU dev) -> deadlock with (**) Fix this by taking the device_hotplug_lock in the CPU rescan path. Cc: <stable@vger.kernel.org> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06s390/early: improve machine detectionChristian Borntraeger
commit 03aa047ef2db4985e444af6ee1c1dd084ad9fb4c upstream. Right now the early machine detection code check stsi 3.2.2 for "KVM" and set MACHINE_IS_VM if this is different. As the console detection uses diagnose 8 if MACHINE_IS_VM returns true this will crash Linux early for any non z/VM system that sets a different value than KVM. So instead of assuming z/VM, do not set any of MACHINE_IS_LPAR, MACHINE_IS_VM, or MACHINE_IS_KVM. CC: stable@vger.kernel.org Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17mm: replace get_user_pages_unlocked() write/force parameters with gup_flagsLorenzo Stoakes
commit c164154f66f0c9b02673f07aa4f044f1d9c70274 upstream. This removes the 'write' and 'force' use from get_user_pages_unlocked() and replaces them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 4.4: - Also update calls from process_vm_rw_single_vec() and async_pf_execute() - Adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17s390/cpum_cf: Reject request for sampling in event initializationThomas Richter
[ Upstream commit 613a41b0d16e617f46776a93b975a1eeea96417c ] On s390 command perf top fails [root@s35lp76 perf] # ./perf top -F100000 --stdio Error: cycles: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat' [root@s35lp76 perf] # Using event -e rb0000 works as designed. Event rb0000 is the event number of the sampling facility for basic sampling. During system start up the following PMUs are installed in the kernel's PMU list (from head to tail): cpum_cf --> s390 PMU counter facility device driver cpum_sf --> s390 PMU sampling facility device driver uprobe kprobe tracepoint task_clock cpu_clock Perf top executes following functions and calls perf_event_open(2) system call with different parameters many times: cmd_top --> __cmd_top --> perf_evlist__add_default --> __perf_evlist__add_default --> perf_evlist__new_cycles (creates event type:0 (HW) config 0 (CPU_CYCLES) --> perf_event_attr__set_max_precise_ip Uses perf_event_open(2) to detect correct precise_ip level. Fails 3 times on s390 which is ok. Then functions cmd_top --> __cmd_top --> perf_top__start_counters -->perf_evlist__config --> perf_can_comm_exec --> perf_probe_api This functions test support for the following events: "cycles:u", "instructions:u", "cpu-clock:u" using --> perf_do_probe_api --> perf_event_open_cloexec Test the close on exec flag support with perf_event_open(2). perf_do_probe_api returns true if the event is supported. The function returns true because event cpu-clock is supported by the PMU cpu_clock. This is achieved by many calls to perf_event_open(2). Function perf_top__start_counters now calls perf_evsel__open() for every event, which is the default event cpu_cycles (config:0) and type HARDWARE (type:0) which a predfined frequence of 4000. Given the above order of the PMU list, the PMU cpum_cf gets called first and returns 0, which indicates support for this sampling. The event is fully allocated in the function perf_event_open (file kernel/event/core.c near line 10521 and the following check fails: event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, NULL, NULL, cgroup_fd); if (IS_ERR(event)) { err = PTR_ERR(event); goto err_cred; } if (is_sampling_event(event)) { if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { err = -EOPNOTSUPP; goto err_alloc; } } The check for the interrupt capabilities fails and the system call perf_event_open() returns -EOPNOTSUPP (-95). Add a check to return -ENODEV when sampling is requested in PMU cpum_cf. This allows common kernel code in the perf_event_open() system call to test the next PMU in above list. Fixes: 97b1198fece0 (" "s390, perf: Use common PMU interrupt disabled code") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-01s390/mm: Check for valid vma before zapping in gmap_discardJanosch Frank
commit 1843abd03250115af6cec0892683e70cf2297c25 upstream. Userspace could have munmapped the area before doing unmapping from the gmap. This would leave us with a valid vmaddr, but an invalid vma from which we would try to zap memory. Let's check before using the vma. Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Message-Id: <20180816082432.78828-1-frankja@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27s390/mm: Fix ERROR: "__node_distance" undefined!Justin M. Forbes
[ Upstream commit a541f0ebcc08ed8bc0cc492eec9a86cb280a9f24 ] Fixes: ERROR: "__node_distance" [drivers/nvme/host/nvme-core.ko] undefined! make[1]: *** [scripts/Makefile.modpost:92: __modpost] Error 1 make: *** [Makefile:1275: modules] Error 2 + exit 1 Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-27s390/vdso: add missing FORCE to build targetsVasily Gorbik
[ Upstream commit b44b136a3773d8a9c7853f8df716bd1483613cbb ] According to Documentation/kbuild/makefiles.txt all build targets using if_changed should use FORCE as well. Add missing FORCE to make sure vdso targets are rebuild properly when not just immediate prerequisites have changed but also when build command differs. Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-10-10s390/extmem: fix gcc 8 stringop-overflow warningVasily Gorbik
[ Upstream commit 6b2ddf33baec23dace85bd647e3fc4ac070963e8 ] arch/s390/mm/extmem.c: In function '__segment_load': arch/s390/mm/extmem.c:436:2: warning: 'strncat' specified bound 7 equals source length [-Wstringop-overflow=] strncat(seg->res_name, " (DCSS)", 7); What gcc complains about here is the misuse of strncat function, which in this case does not limit a number of bytes taken from "src", so it is in the end the same as strcat(seg->res_name, " (DCSS)"); Keeping in mind that a res_name is 15 bytes, strncat in this case would overflow the buffer and write 0 into alignment byte between the fields in the struct. To avoid that increasing res_name size to 16, and reusing strlcat. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15s390/lib: use expoline for all bcr instructionsMartin Schwidefsky
commit 5eda25b10297684c1f46a14199ec00210f3c346e upstream. The memove, memset, memcpy, __memset16, __memset32 and __memset64 function have an additional indirect return branch in form of a "bzr" instruction. These need to use expolines as well. Cc: <stable@vger.kernel.org> # v4.17+ Fixes: 97489e0663 ("s390/lib: use expoline for indirect branches") Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-05s390/pci: fix out of bounds access during irq setupSebastian Ott
commit 866f3576a72b2233a76dffb80290f8086dc49e17 upstream. During interrupt setup we allocate interrupt vectors, walk the list of msi descriptors, and fill in the message data. Requesting more interrupts than supported on s390 can lead to an out of bounds access. When we restrict the number of interrupts we should also stop walking the msi list after all supported interrupts are handled. Cc: stable@vger.kernel.org Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-05s390/qdio: reset old sbal_state flagsJulian Wiedmann
commit 64e03ff72623b8c2ea89ca3cb660094e019ed4ae upstream. When allocating a new AOB fails, handle_outbound() is still capable of transmitting the selected buffer (just without async completion). But if a previous transfer on this queue slot used async completion, its sbal_state flags field is still set to QDIO_OUTBUF_STATE_FLAG_PENDING. So when the upper layer driver sees this stale flag, it expects an async completion that never happens. Fix this by unconditionally clearing the flags field. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Cc: <stable@vger.kernel.org> #v3.2+ Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-05s390: fix br_r1_trampoline for machines without exrlMartin Schwidefsky
commit 26f843848bae973817b3587780ce6b7b0200d3e4 upstream. For machines without the exrl instruction the BFP jit generates code that uses an "br %r1" instruction located in the lowcore page. Unfortunately there is a cut & paste error that puts an additional "larl %r1,.+14" instruction in the code that clobbers the branch target address in %r1. Remove the larl instruction. Cc: <stable@vger.kernel.org> # v4.17+ Fixes: de5cb6eb51 ("s390: use expoline thunks in the BPF JIT") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-05s390/kvm: fix deadlock when killed by oomClaudio Imbrenda
commit 306d6c49ac9ded11114cb53b0925da52f2c2ada1 upstream. When the oom killer kills a userspace process in the page fault handler while in guest context, the fault handler fails to release the mm_sem if the FAULT_FLAG_RETRY_NOWAIT option is set. This leads to a deadlock when tearing down the mm when the process terminates. This bug can only happen when pfault is enabled, so only KVM clients are affected. The problem arises in the rare cases in which handle_mm_fault does not release the mm_sem. This patch fixes the issue by manually releasing the mm_sem when needed. Fixes: 24eb3a824c4f3 ("KVM: s390: Add FAULT_FLAG_RETRY_NOWAIT for guest fault") Cc: <stable@vger.kernel.org> # 3.15+ Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06perf: fix invalid bit in diagnostic entryThomas Richter
[ Upstream commit 3c0a83b14ea71fef5ccc93a3bd2de5f892be3194 ] The s390 CPU measurement facility sampling mode supports basic entries and diagnostic entries. Each entry has a valid bit to indicate the status of the entry as valid or invalid. This bit is bit 31 in the diagnostic entry, but the bit mask definition refers to bit 30. Fix this by making the reserved field one bit larger. Fixes: 7e75fc3ff4cf ("s390/cpum_sf: Add raw data sampling to support the diagnostic-sampling function") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06s390/cpum_sf: Add data entry sizes to sampling trailer entryThomas Richter
[ Upstream commit 77715b7ddb446bd39a06f3376e85f4bb95b29bb8 ] The CPU Measurement sampling facility creates a trailer entry for each Sample-Data-Block of stored samples. The trailer entry contains the sizes (in bytes) of the stored sampling types: - basic-sampling data entry size - diagnostic-sampling data entry size Both sizes are 2 bytes long. This patch changes the trailer entry definition to reflect this. Fixes: fcc77f507333 ("s390/cpum_sf: Atomically reset trailer entry fields of sample-data-blocks") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-11s390: Correct register corruption in critical section cleanupChristian Borntraeger
commit 891f6a726cacbb87e5b06076693ffab53bd378d7 upstream. In the critical section cleanup we must not mess with r1. For march=z9 or older, larl + ex (instead of exrl) are used with r1 as a temporary register. This can clobber r1 in several interrupt handlers. Fix this by using r11 as a temp register. r11 is being saved by all callers of cleanup_critical. Fixes: 6dd85fbb87 ("s390: move expoline assembler macros to a header") Cc: stable@vger.kernel.org #v4.16 Reported-by: Oliver Kurz <okurz@suse.com> Reported-by: Petr Tesařík <ptesarik@suse.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30s390/ftrace: use expoline for indirect branchesMartin Schwidefsky
commit 23a4d7fd34856da8218c4cfc23dba7a6ec0a423a upstream. The return from the ftrace_stub, _mcount, ftrace_caller and return_to_handler functions is done with "br %r14" and "br %r1". These are indirect branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y. The ftrace_caller function is a special case as it returns to the start of a function and may only use %r0 and %r1. For a pre z10 machine the standard execute trampoline uses a LARL + EX to do this, but this requires *two* registers in the range %r1..%r15. To get around this the 'br %r1' located in the lowcore is used, then the EX instruction does not need an address register. But the lowcore trick may only be used for pre z14 machines, with noexec=on the mapping for the first page may not contain instructions. The solution for that is an ALTERNATIVE in the expoline THUNK generated by 'GEN_BR_THUNK %r1' to switch to EXRL, this relies on the fact that a machine that supports noexec=on has EXRL as well. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390: use expoline thunks in the BPF JITMartin Schwidefsky
[ Upstream commit de5cb6eb514ebe241e3edeb290cb41deb380b81d ] The BPF JIT need safe guarding against spectre v2 in the sk_load_xxx assembler stubs and the indirect branches generated by the JIT itself need to be converted to expolines. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390: extend expoline to BC instructionsMartin Schwidefsky
[ Upstream commit 6deaa3bbca804b2a3627fd685f75de64da7be535 ] The BPF JIT uses a 'b <disp>(%r<x>)' instruction in the definition of the sk_load_word and sk_load_half functions. Add support for branch-on-condition instructions contained in the thunk code of an expoline. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390: move spectre sysfs attribute codeMartin Schwidefsky
[ Upstream commit 4253b0e0627ee3461e64c2495c616f1c8f6b127b ] The nospec-branch.c file is compiled without the gcc options to generate expoline thunks. The return branch of the sysfs show functions cpu_show_spectre_v1 and cpu_show_spectre_v2 is an indirect branch as well. These need to be compiled with expolines. Move the sysfs functions for spectre reporting to a separate file and loose an '.' for one of the messages. Cc: stable@vger.kernel.org # 4.16 Fixes: d424986f1d ("s390: add sysfs attributes for spectre") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390/kernel: use expoline for indirect branchesMartin Schwidefsky
[ Upstream commit c50c84c3ac4d5db683904bdb3257798b6ef980ae ] The assember code in arch/s390/kernel uses a few more indirect branches which need to be done with execute trampolines for CONFIG_EXPOLINE=y. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390/lib: use expoline for indirect branchesMartin Schwidefsky
[ Upstream commit 97489e0663fa700d6e7febddc43b58df98d7bcda ] The return from the memmove, memset, memcpy, __memset16, __memset32 and __memset64 functions are done with "br %r14". These are indirect branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390: move expoline assembler macros to a headerMartin Schwidefsky
[ Upstream commit 6dd85fbb87d1d6b87a3b1f02ca28d7b2abd2e7ba ] To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390: add assembler macros for CPU alternativesMartin Schwidefsky
[ Upstream commit fba9eb7946251d6e420df3bdf7bc45195be7be9a ] Add a header with macros usable in assembler files to emit alternative code sequences. It works analog to the alternatives for inline assmeblies in C files, with the same restrictions and capabilities. The syntax is ALTERNATIVE "<default instructions sequence>", \ "<alternative instructions sequence>", \ "<features-bit>" and ALTERNATIVE_2 "<default instructions sequence>", \ "<alternative instructions sqeuence #1>", \ "<feature-bit #1>", "<alternative instructions sqeuence #2>", \ "<feature-bit #2>" Reviewed-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390: remove indirect branch from do_softirq_own_stackMartin Schwidefsky
commit 9f18fff63cfd6f559daa1eaae60640372c65f84b upstream. The inline assembly to call __do_softirq on the irq stack uses an indirect branch. This can be replaced with a normal relative branch. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26s390/cpum_sf: ensure sample frequency of perf event attributes is non-zeroHendrik Brueckner
commit 4bbaf2584b86b0772413edeac22ff448f36351b1 upstream. Correct a trinity finding for the perf_event_open() system call with a perf event attribute structure that uses a frequency but has the sampling frequency set to zero. This causes a FP divide exception during the sample rate initialization for the hardware sampling facility. Fixes: 8c069ff4bd606 ("s390/perf: add support for the CPU-Measurement Sampling Facility") Cc: stable@vger.kernel.org # 3.14+ Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26futex: Remove duplicated code and fix undefined behaviourJiri Slaby
commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream. There is code duplicated over all architecture's headers for futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr, and comparison of the result. Remove this duplication and leave up to the arches only the needed assembly which is now in arch_futex_atomic_op_inuser. This effectively distributes the Will Deacon's arm64 fix for undefined behaviour reported by UBSAN to all architectures. The fix was done in commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump. And as suggested by Thomas, check for negative oparg too, because it was also reported to cause undefined behaviour report. Note that s390 removed access_ok check in d12a29703 ("s390/uaccess: remove pointless access_ok() checks") as access_ok there returns true. We introduce it back to the helper for the sake of simplicity (it gets optimized away anyway). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390] Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile] Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org> Reviewed-by: Will Deacon <will.deacon@arm.com> [core/arm64] Cc: linux-mips@linux-mips.org Cc: Rich Felker <dalias@libc.org> Cc: linux-ia64@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: peterz@infradead.org Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: sparclinux@vger.kernel.org Cc: Jonas Bonn <jonas@southpole.se> Cc: linux-s390@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: linux-hexagon@vger.kernel.org Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-snps-arc@lists.infradead.org Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-xtensa@linux-xtensa.org Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: openrisc@lists.librecores.org Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Stafford Horne <shorne@gmail.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Richard Henderson <rth@twiddle.net> Cc: Chris Zankel <chris@zankel.net> Cc: Michal Simek <monstr@monstr.eu> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-parisc@vger.kernel.org Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: linux-alpha@vger.kernel.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: "David S. Miller" <davem@davemloft.net> Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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