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2021-04-15s390/test_unwind: print test suite start/end infoVasily Gorbik
Add couple of additional info lines to make it easier to match test suite output and results. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-12s390/test_unwind: add WARN if tests failedVasily Gorbik
Trigger a warning if any of unwinder tests fail. This should help to prevent quiet ignoring of test results when panic_on_warn is enabled. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-04-12s390/test_unwind: unify error handling pathsVasily Gorbik
Handle the case of "unwind state reliable but addr is 0" like other error cases in this function and trigger output of failing stacktrace to aid debugging. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-01-19s390: convert to generic entrySven Schnelle
This patch converts s390 to use the generic entry infrastructure from kernel/entry/*. There are a few special things on s390: - PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't know about our PIF flags in exit_to_user_mode_loop(). - The old code had several ways to restart syscalls: a) PIF_SYSCALL_RESTART, which was only set during execve to force a restart after upgrading a process (usually qemu-kvm) to pgste page table extensions. b) PIF_SYSCALL, which is set by do_signal() to indicate that the current syscall should be restarted. This is changed so that do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use PIF_SYSCALL doesn't work with the generic code, and changing it to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART more unique. - On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by executing a svc instruction on the process stack which causes a fault. While handling that fault the fault code sets PIF_SYSCALL to hand over processing to the syscall code on exit to usermode. The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets a return value for a syscall. The s390x ptrace ABI uses r2 both for the syscall number and return value, so ptrace cannot set the syscall number + return value at the same time. The flag makes handling that a bit easier. do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET is set. CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY. CR1/7/13 will be checked both on kernel entry and exit to contain the correct asces. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-12-16s390/delay: remove udelay_simple()Heiko Carstens
udelay_simple() callers can make use of the now simplified udelay() implementation. No need to keep it. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-16s390/delay: simplify udelayHeiko Carstens
udelay is implemented by using quite subtle details to make it possible to load an idle psw and waiting for an interrupt even in irq context or when interrupts are disabled. Also handling (or better: no handling) of softirqs is taken into account. All this is done to optimize for something which should in normal circumstances never happen: calling udelay to busy wait. Therefore get rid of the whole complexity and just busy loop like other architectures are doing it also. It could have been possible to use diag 0x44 instead of cpu_relax() in the busy loop, however we have seen too many bad things happen with diag 0x44 that it seems to be better to simply busy loop. Also note that with this new implementation kernel preemption does work when within the udelay loop. This did not work before. To get a feeling what the former code optimizes for: IPL'ing a kernel with 'defconfig' and afterwards compiling a kernel ends with a total of zero udelay calls. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-16s390/test_unwind: use timer instead of udelayHeiko Carstens
Instead of registering an external interrupt handler and relying on the udelay implementation, simply use a timer to get into irq context. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-16s390/test_unwind: fix CALL_ON_STACK testsHeiko Carstens
The CALL_ON_STACK tests use the no_dat stack to switch to a different stack for unwinding tests. If an interrupt or machine check happens while using that stack, and previously being on the async stack, the interrupt / machine check entry code (SWITCH_ASYNC) will assume that the previous context did not use the async stack and happily use the async stack again. This will lead to stack corruption of the previous context. To solve this disable both interrupts and machine checks before switching to the no_dat stack. Fixes: 7868249fbbc8 ("s390/test_unwind: add CALL_ON_STACK tests") Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-14Merge tag 's390-5.11-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Add support for the hugetlb_cma command line option to allocate gigantic hugepages using CMA - Add arch_get_random_long() support. - Add ap bus userspace notifications. - Increase default size of vmalloc area to 512GB and otherwise let it increase dynamically by the size of physical memory. This should fix all occurrences where the vmalloc area was not large enough. - Completely get rid of set_fs() (aka select SET_FS) and rework address space handling while doing that; making address space handling much more simple. - Reimplement getcpu vdso syscall in C. - Add support for extended SCLP responses (> 4k). This allows e.g. to handle also potential large system configurations. - Simplify KASAN by removing 3-level page table support and only supporting 4-levels from now on. - Improve debug-ability of the kernel decompressor code, which now prints also stack traces and symbols in case of problems to the console. - Remove more power management leftovers. - Other various fixes and improvements all over the place. * tag 's390-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (62 commits) s390/mm: add support to allocate gigantic hugepages using CMA s390/crypto: add arch_get_random_long() support s390/smp: perform initial CPU reset also for SMT siblings s390/mm: use invalid asce for user space when switching to init_mm s390/idle: fix accounting with machine checks s390/idle: add missing mt_cycles calculation s390/boot: add build-id to decompressor s390/kexec_file: fix diag308 subcode when loading crash kernel s390/cio: fix use-after-free in ccw_device_destroy_console s390/cio: remove pm support from ccw bus driver s390/cio: remove pm support from css-bus driver s390/cio: remove pm support from IO subchannel drivers s390/cio: remove pm support from chsc subchannel driver s390/vmur: remove unused pm related functions s390/tape: remove unsupported PM functions s390/cio: remove pm support from eadm-sch drivers s390: remove pm support from console drivers s390/dasd: remove unused pm related functions s390/zfcp: remove pm support from zfcp driver s390/ap: let bus_register() add the AP bus sysfs attributes ...
2020-12-02s390: fix irq state tracingHeiko Carstens
With commit 58c644ba512c ("sched/idle: Fix arch_cpu_idle() vs tracing") common code calls arch_cpu_idle() with a lockdep state that tells irqs are on. This doesn't work very well for s390: psw_idle() will enable interrupts to wait for an interrupt. As soon as an interrupt occurs the interrupt handler will verify if the old context was psw_idle(). If that is the case the interrupt enablement bits in the old program status word will be cleared. A subsequent test in both the external as well as the io interrupt handler checks if in the old context interrupts were enabled. Due to the above patching of the old program status word it is assumed the old context had interrupts disabled, and therefore a call to TRACE_IRQS_OFF (aka trace_hardirqs_off_caller) is skipped. Which in turn makes lockdep incorrectly "think" that interrupts are enabled within the interrupt handler. Fix this by unconditionally calling TRACE_IRQS_OFF when entering interrupt handlers. Also call unconditionally TRACE_IRQS_ON when leaving interrupts handlers. This leaves the special psw_idle() case, which now returns with interrupts disabled, but has an "irqs on" lockdep state. So callers of psw_idle() must adjust the state on their own, if required. This is currently only __udelay_disabled(). Fixes: 58c644ba512c ("sched/idle: Fix arch_cpu_idle() vs tracing") Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23s390/mm: add debug user asce supportHeiko Carstens
Verify on exit to user space that always - the primary ASCE (cr1) is set to kernel ASCE - the secondary ASCE (cr7) is set to user ASCE If this is not the case: panic since something went terribly wrong. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23s390/mm: remove set_fs / rework address space handlingHeiko Carstens
Remove set_fs support from s390. With doing this rework address space handling and simplify it. As a result address spaces are now setup like this: CPU running in | %cr1 ASCE | %cr7 ASCE | %cr13 ASCE ----------------------------|-----------|-----------|----------- user space | user | user | kernel kernel, normal execution | kernel | user | kernel kernel, kvm guest execution | gmap | user | kernel To achieve this the getcpu vdso syscall is removed in order to avoid secondary address mode and a separate vdso address space in for user space. The getcpu vdso syscall will be implemented differently with a subsequent patch. The kernel accesses user space always via secondary address space. This happens in different ways: - with mvcos in home space mode and directly read/write to secondary address space - with mvcs/mvcp in primary space mode and copy from primary space to secondary space or vice versa - with e.g. cs in secondary space mode and access secondary space Switching translation modes happens with sacf before and after instructions which access user space, like before. Lazy handling of control register reloading is removed in the hope to make everything simpler, but at the cost of making kernel entry and exit a bit slower. That is: on kernel entry the primary asce is always changed to contain the kernel asce, and on kernel exit the primary asce is changed again so it contains the user asce. In kernel mode there is only one exception to the primary asce: when kvm guests are executed the primary asce contains the gmap asce (which describes the guest address space). The primary asce is reset to kernel asce whenever kvm guest execution is interrupted, so that this doesn't has to be taken into account for any user space accesses. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-09s390/udelay: make it work for the early codeVasily Gorbik
Currently udelay relies on working EXT interrupts handler, which is not the case during early startup. In such cases udelay_simple() has to be used instead. To avoid mistakes of calling udelay too early, which could happen from the common code as well - make udelay work for the early code by introducing static branch and redirecting all udelay calls to udelay_simple until EXT interrupts handler is fully initialized and async stack is allocated. 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>
2020-10-07s390/lib: fix kernel doc for memcmp()Julian Wiedmann
s/count/n Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-08-11s390/test_unwind: fix possible memleak in test_unwind()Wang Hai
test_unwind() misses to call kfree(bt) in an error path. Add the missed function call to fix it. Fixes: 0610154650f1 ("s390/test_unwind: print verbose unwinding results") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wang Hai <wanghai38@huawei.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-08-07Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "No common topic whatsoever in those, sorry" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: define inode flags using bit numbers iov_iter: Move unnecessary inclusion of crypto/hash.h dlmfs: clean up dlmfs_file_{read,write}() a bit
2020-07-27s390: enable HAVE_FUNCTION_ERROR_INJECTIONIlya Leoshkevich
This kernel feature is required for enabling BPF_KPROBE_OVERRIDE. Define override_function_with_return() and regs_set_return_value() functions, and fix compile errors in syscall_wrapper.h. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-06-30iov_iter: Move unnecessary inclusion of crypto/hash.hHerbert Xu
The header file linux/uio.h includes crypto/hash.h which pulls in most of the Crypto API. Since linux/uio.h is used throughout the kernel this means that every tiny bit of change to the Crypto API causes the entire kernel to get rebuilt. This patch fixes this by moving it into lib/iov_iter.c instead where it is actually used. This patch also fixes the ifdef to use CRYPTO_HASH instead of just CRYPTO which does not guarantee the existence of ahash. Unfortunately a number of drivers were relying on linux/uio.h to provide access to linux/slab.h. This patch adds inclusions of linux/slab.h as detected by build failures. Also skbuff.h was relying on this to provide a declaration for ahash_request. This patch adds a forward declaration instead. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-06-08Merge tag 's390-5.8-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add support for multi-function devices in pci code. - Enable PF-VF linking for architectures using the pdev->no_vf_scan flag (currently just s390). - Add reipl from NVMe support. - Get rid of critical section cleanup in entry.S. - Refactor PNSO CHSC (perform network subchannel operation) in cio and qeth. - QDIO interrupts and error handling fixes and improvements, more refactoring changes. - Align ioremap() with generic code. - Accept requests without the prefetch bit set in vfio-ccw. - Enable path handling via two new regions in vfio-ccw. - Other small fixes and improvements all over the code. * tag 's390-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (52 commits) vfio-ccw: make vfio_ccw_regops variables declarations static vfio-ccw: Add trace for CRW event vfio-ccw: Wire up the CRW irq and CRW region vfio-ccw: Introduce a new CRW region vfio-ccw: Refactor IRQ handlers vfio-ccw: Introduce a new schib region vfio-ccw: Refactor the unregister of the async regions vfio-ccw: Register a chp_event callback for vfio-ccw vfio-ccw: Introduce new helper functions to free/destroy regions vfio-ccw: document possible errors vfio-ccw: Enable transparent CCW IPL from DASD s390/pci: Log new handle in clp_disable_fh() s390/cio, s390/qeth: cleanup PNSO CHSC s390/qdio: remove q->first_to_kick s390/qdio: fix up qdio_start_irq() kerneldoc s390: remove critical section cleanup from entry.S s390: add machine check SIGP s390/pci: ioremap() align with generic code s390/ap: introduce new ap function ap_get_qdev() Documentation/s390: Update / remove developerWorks web links ...
2020-05-28s390: remove critical section cleanup from entry.SSven Schnelle
The current code is rather complex and caused a lot of subtle and hard to debug bugs in the past. Simplify the code by calling the system_call handler with interrupts disabled, save machine state, and re-enable them later. This requires significant changes to the machine check handling code as well. When the machine check interrupt arrived while being in kernel mode the new code will signal pending machine checks with a SIGP external call. When userspace was interrupted, the handler will switch to the kernel stack and directly execute s390_handle_mcck(). Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-21s390/mm: fix page table upgrade vs 2ndary address mode accessesChristian Borntraeger
A page table upgrade in a kernel section that uses secondary address mode will mess up the kernel instructions as follows: Consider the following scenario: two threads are sharing memory. On CPU1 thread 1 does e.g. strnlen_user(). That gets to old_fs = enable_sacf_uaccess(); len = strnlen_user_srst(src, size); and " la %2,0(%1)\n" " la %3,0(%0,%1)\n" " slgr %0,%0\n" " sacf 256\n" "0: srst %3,%2\n" in strnlen_user_srst(). At that point we are in secondary space mode, control register 1 points to kernel page table and instruction fetching happens via c1, rather than usual c13. Interrupts are not disabled, for obvious reasons. On CPU2 thread 2 does MAP_FIXED mmap(), forcing the upgrade of page table from 3-level to e.g. 4-level one. We'd allocated new top-level table, set it up and now we hit this: notify = 1; spin_unlock_bh(&mm->page_table_lock); } if (notify) on_each_cpu(__crst_table_upgrade, mm, 0); OK, we need to actually change over to use of new page table and we need that to happen in all threads that are currently running. Which happens to include the thread 1. IPI is delivered and we have static void __crst_table_upgrade(void *arg) { struct mm_struct *mm = arg; if (current->active_mm == mm) set_user_asce(mm); __tlb_flush_local(); } run on CPU1. That does static inline void set_user_asce(struct mm_struct *mm) { S390_lowcore.user_asce = mm->context.asce; OK, user page table address updated... __ctl_load(S390_lowcore.user_asce, 1, 1); ... and control register 1 set to it. clear_cpu_flag(CIF_ASCE_PRIMARY); } IPI is run in home space mode, so it's fine - insns are fetched using c13, which always points to kernel page table. But as soon as we return from the interrupt, previous PSW is restored, putting CPU1 back into secondary space mode, at which point we no longer get the kernel instructions from the kernel mapping. The fix is to only fixup the control registers that are currently in use for user processes during the page table update. We must also disable interrupts in enable_sacf_uaccess to synchronize the cr and thread.mm_segment updates against the on_each-cpu. Fixes: 0aaba41b58bc ("s390: remove all code using the access register mode") Cc: stable@vger.kernel.org # 4.15+ Reported-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> References: CVE-2020-11884 Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2019-12-11s390/test_unwind: fix spelling mistake "reqister" -> "register"Colin Ian King
There is a spelling mistake in a pr_info message. Fix it. Link: https://lkml.kernel.org/r/20191202090215.28766-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-12-11s390/spinlock: remove confusing comment in arch_spin_lock_waitVasily Gorbik
arch_spin_lock_wait does not take steal time into consideration. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: add program check context testsVasily Gorbik
Add unwinding from program check handler tests. Unwinder should be able to unwind through pt_regs stored by program check handler on task stack. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: add irq context testsVasily Gorbik
Add unwinding from irq context tests. Unwinder should be able to unwind through irq stack to task stack up to task pt_regs. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: print verbose unwinding resultsVasily Gorbik
Add stack name, sp and reliable information into test unwinding results. Also consider ip outside of kernel text as failure if the state is reported reliable. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: add CALL_ON_STACK testsVasily Gorbik
Add CALL_ON_STACK helper testing. Tests make sure that we can unwind from switched stack to original one up to task pt_regs (nodat -> task stack). UWM_SWITCH_STACK could not be used together with UWM_THREAD because get_stack_info explicitly restricts unwinding to task stack if task != current. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/test_unwind: require that unwinding ended successfullyVasily Gorbik
Currently unwinder test passes if unwinding results contain unwindme_func2 and unwindme_func1 functions. Now that unwinder reports success upon reaching task pt_regs, check that unwinding ended successfully in every test. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-30s390/unwind: add a test for the internal APIIlya Leoshkevich
unwind_for_each_frame can take at least 8 different sets of parameters. Add a test to make sure they all are handled in a sane way. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Co-developed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-10-31s390/alternatives: make use of asm_inlineHeiko Carstens
This is the s390 version of commit 40576e5e63ea ("x86: alternative.h: use asm_inline for all alternative variants"). See commit eb111869301e ("compiler-types.h: add asm_inline definition") for more details. With this change the compiler will not generate many out-of-line versions for the three instruction sized arch_spin_unlock() function anymore. Due to this gcc seems to change a lot of other inline decisions which results in a net 6k text size growth according to bloat-o-meter (gcc 9.2 with defconfig). But that's still better than having many out-of-line versions of arch_spin_unlock(). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-09-17Merge tag 's390-5.4-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add support for IBM z15 machines. - Add SHA3 and CCA AES cipher key support in zcrypt and pkey refactoring. - Move to arch_stack_walk infrastructure for the stack unwinder. - Various kasan fixes and improvements. - Various command line parsing fixes. - Improve decompressor phase debuggability. - Lift no bss usage restriction for the early code. - Use refcount_t for reference counters for couple of places in mm code. - Logging improvements and return code fix in vfio-ccw code. - Couple of zpci fixes and minor refactoring. - Remove some outdated documentation. - Fix secure boot detection. - Other various minor code clean ups. * tag 's390-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits) s390: remove pointless drivers-y in drivers/s390/Makefile s390/cpum_sf: Fix line length and format string s390/pci: fix MSI message data s390: add support for IBM z15 machines s390/crypto: Support for SHA3 via CPACF (MSA6) s390/startup: add pgm check info printing s390/crypto: xts-aes-s390 fix extra run-time crypto self tests finding vfio-ccw: fix error return code in vfio_ccw_sch_init() s390: vfio-ap: fix warning reset not completed s390/base: remove unused s390_base_mcck_handler s390/sclp: Fix bit checked for has_sipl s390/zcrypt: fix wrong handling of cca cipher keygenflags s390/kasan: add kdump support s390/setup: avoid using strncmp with hardcoded length s390/sclp: avoid using strncmp with hardcoded length s390/module: avoid using strncmp with hardcoded length s390/pci: avoid using strncmp with hardcoded length s390/kaslr: reserve memory for kasan usage s390/mem_detect: provide single get_mem_detect_end s390/cmma: reuse kstrtobool for option value parsing ...
2019-08-21s390: clean .bss before running uncompressed kernelVasily Gorbik
Clean uncompressed kernel .bss section in the startup code before the uncompressed kernel is executed. At this point of time initrd and certificates have been already rescued. Uncompressed kernel .bss size is known from vmlinux_info. It is also taken into consideration during uncompressed kernel positioning by kaslr (so it is safe to clean it). With that uncompressed kernel is starting with .bss section zeroed and no .bss section usage restrictions apply. Which makes chkbss checks for uncompressed kernel objects obsolete and they can be removed. early_nobss.c is also not needed anymore. Parts of it which are still relevant are moved to early.c. Kasan initialization code is now called directly from head64 (early.c is instrumented and should not be executed before kasan shadow memory is set up). Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-07-29s390/lib: add missing includeVasily Gorbik
Include <asm/xor.h> into arch/s390/lib/xor.c to expose xor_block_xc declaration and avoid the following sparse warning: arch/s390/lib/xor.c:128:27: warning: symbol 'xor_block_xc' was not declared. Should it be static? Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-06-07s390: enforce CONFIG_SMPHeiko Carstens
There never have been distributions that shiped with CONFIG_SMP=n for s390. In addition the kernel currently doesn't even compile with CONFIG_SMP=n for s390. Most likely it wouldn't even work, even if we fix the compile error, since nobody tests it, since there is no use case that I can think of. Therefore simply enforce CONFIG_SMP and get rid of some more or less unused code. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-05-02s390: add missing ENDPROC statements to assembler functionsMartin Schwidefsky
The assembler code in arch/s390 misses proper ENDPROC statements to properly end functions in a few places. Add them. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-01-18s390/kasan: improve string/memory functions checksVasily Gorbik
Avoid using arch specific implementations of string/memory functions with KASAN since gcc cannot instrument asm code memory accesses and many bugs could be missed. Acked-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>
2018-10-09s390/kasan: avoid user access code instrumentationVasily Gorbik
Kasan instrumentation adds "store" check for variables marked as modified by inline assembly. With user pointers containing addresses from another address space this produces false positives. static inline unsigned long clear_user_xc(void __user *to, ...) { asm volatile( ... : "+a" (to) ... User space access functions are wrapped by manually instrumented functions in kasan common code, which should be sufficient to catch errors. So, we just disable uaccess.o instrumentation altogether. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09s390/kasan: replace some memory functionsVasily Gorbik
Follow the common kasan approach: "KASan replaces memory functions with manually instrumented variants. Original functions declared as weak symbols so strong definitions in mm/kasan/kasan.c could replace them. Original functions have aliases with '__' prefix in name, so we could call non-instrumented variant if needed." Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-08-07s390/lib: use expoline for all bcr instructionsMartin Schwidefsky
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>
2018-05-09s390: introduce compile time check for empty .bss sectionVasily Gorbik
Introduce compile time check for files which should avoid using .bss section, because of the following reasons: - .bss section has not been zeroed yet, - initrd has not been moved to a safe location and could be overlapping with .bss section. 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>
2018-05-07s390/lib: use expoline for indirect branchesMartin Schwidefsky
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>
2017-12-15s390: fix preemption race in disable_sacf_uaccessMartin Schwidefsky
With CONFIG_PREEMPT=y there is a possible race in disable_sacf_uaccess. The new set_fs value needs to be stored the the task structure first, the control register update needs to be second. Otherwise a preemptive schedule may interrupt the code right after the control register update has been done and the next time the task is scheduled we get an incorrect value in the control register due to the old set_fs setting. Fixes: 0aaba41b58 ("s390: remove all code using the access register mode") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-14s390/spinlock: fix indentationHeiko Carstens
checkpatch: WARNING: Statements should start on a tabstop #9499: FILE: arch/s390/lib/spinlock.c:231: + return; sparse: arch/s390/lib/spinlock.c:81 arch_load_niai4() warn: inconsistent indenting Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2017-11-14s390: remove all code using the access register modeMartin Schwidefsky
The vdso code for the getcpu() and the clock_gettime() call use the access register mode to access the per-CPU vdso data page with the current code. An alternative to the complicated AR mode is to use the secondary space mode. This makes the vdso faster and quite a bit simpler. The downside is that the uaccess code has to be changed quite a bit. Which instructions are used depends on the machine and what kind of uaccess operation is requested. The instruction dictates which ASCE value needs to be loaded into %cr1 and %cr7. The different cases: * User copy with MVCOS for z10 and newer machines The MVCOS instruction can copy between the primary space (aka user) and the home space (aka kernel) directly. For set_fs(KERNEL_DS) the kernel ASCE is loaded into %cr1. For set_fs(USER_DS) the user space is already loaded in %cr1. * User copy with MVCP/MVCS for older machines To be able to execute the MVCP/MVCS instructions the kernel needs to switch to primary mode. The control register %cr1 has to be set to the kernel ASCE and %cr7 to either the kernel ASCE or the user ASCE dependent on set_fs(KERNEL_DS) vs set_fs(USER_DS). * Data access in the user address space for strnlen / futex To use "normal" instruction with data from the user address space the secondary space mode is used. The kernel needs to switch to primary mode, %cr1 has to contain the kernel ASCE and %cr7 either the user ASCE or the kernel ASCE, dependent on set_fs. To load a new value into %cr1 or %cr7 is an expensive operation, the kernel tries to be lazy about it. E.g. for multiple user copies in a row with MVCP/MVCS the replacement of the vdso ASCE in %cr7 with the user ASCE is done only once. On return to user space a CPU bit is checked that loads the vdso ASCE again. To enable and disable the data access via the secondary space two new functions are added, enable_sacf_uaccess and disable_sacf_uaccess. The fact that a context is in secondary space uaccess mode is stored in the mm_segment_t value for the task. The code of an interrupt may use set_fs as long as it returns to the previous state it got with get_fs with another call to set_fs. The code in finish_arch_post_lock_switch simply has to do a set_fs with the current mm_segment_t value for the task. For CPUs with MVCOS: CPU running in | %cr1 ASCE | %cr7 ASCE | --------------------------------------|-----------|-----------| user space | user | vdso | kernel, USER_DS, normal-mode | user | vdso | kernel, USER_DS, normal-mode, lazy | user | user | kernel, USER_DS, sacf-mode | kernel | user | kernel, KERNEL_DS, normal-mode | kernel | vdso | kernel, KERNEL_DS, normal-mode, lazy | kernel | kernel | kernel, KERNEL_DS, sacf-mode | kernel | kernel | For CPUs without MVCOS: CPU running in | %cr1 ASCE | %cr7 ASCE | --------------------------------------|-----------|-----------| user space | user | vdso | kernel, USER_DS, normal-mode | user | vdso | kernel, USER_DS, normal-mode lazy | kernel | user | kernel, USER_DS, sacf-mode | kernel | user | kernel, KERNEL_DS, normal-mode | kernel | vdso | kernel, KERNEL_DS, normal-mode, lazy | kernel | kernel | kernel, KERNEL_DS, sacf-mode | kernel | kernel | The lines with "lazy" refer to the state after a copy via the secondary space with a delayed reload of %cr1 and %cr7. There are three hardware address spaces that can cause a DAT exception, primary, secondary and home space. The exception can be related to four different fault types: user space fault, vdso fault, kernel fault, and the gmap faults. Dependent on the set_fs state and normal vs. sacf mode there are a number of fault combinations: 1) user address space fault via the primary ASCE 2) gmap address space fault via the primary ASCE 3) kernel address space fault via the primary ASCE for machines with MVCOS and set_fs(KERNEL_DS) 4) vdso address space faults via the secondary ASCE with an invalid address while running in secondary space in problem state 5) user address space fault via the secondary ASCE for user-copy based on the secondary space mode, e.g. futex_ops or strnlen_user 6) kernel address space fault via the secondary ASCE for user-copy with secondary space mode with set_fs(KERNEL_DS) 7) kernel address space fault via the primary ASCE for user-copy with secondary space mode with set_fs(USER_DS) on machines without MVCOS. 8) kernel address space fault via the home space ASCE Replace user_space_fault() with a new function get_fault_type() that can distinguish all four different fault types. With these changes the futex atomic ops from the kernel and the strnlen_user will get a little bit slower, as well as the old style uaccess with MVCP/MVCS. All user accesses based on MVCOS will be as fast as before. On the positive side, the user space vdso code is a lot faster and Linux ceases to use the complicated AR mode. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2017-11-13Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core locking updates from Ingo Molnar: "The main changes in this cycle are: - Another attempt at enabling cross-release lockdep dependency tracking (automatically part of CONFIG_PROVE_LOCKING=y), this time with better performance and fewer false positives. (Byungchul Park) - Introduce lockdep_assert_irqs_enabled()/disabled() and convert open-coded equivalents to lockdep variants. (Frederic Weisbecker) - Add down_read_killable() and use it in the VFS's iterate_dir() method. (Kirill Tkhai) - Convert remaining uses of ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE(). Most of the conversion was Coccinelle driven. (Mark Rutland, Paul E. McKenney) - Get rid of lockless_dereference(), by strengthening Alpha atomics, strengthening READ_ONCE() with smp_read_barrier_depends() and thus being able to convert users of lockless_dereference() to READ_ONCE(). (Will Deacon) - Various micro-optimizations: - better PV qspinlocks (Waiman Long), - better x86 barriers (Michael S. Tsirkin) - better x86 refcounts (Kees Cook) - ... plus other fixes and enhancements. (Borislav Petkov, Juergen Gross, Miguel Bernal Marin)" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE rcu: Use lockdep to assert IRQs are disabled/enabled netpoll: Use lockdep to assert IRQs are disabled/enabled timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled irq_work: Use lockdep to assert IRQs are disabled/enabled irq/timings: Use lockdep to assert IRQs are disabled/enabled perf/core: Use lockdep to assert IRQs are disabled/enabled x86: Use lockdep to assert IRQs are disabled/enabled smp/core: Use lockdep to assert IRQs are disabled/enabled timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled timers/nohz: Use lockdep to assert IRQs are disabled/enabled workqueue: Use lockdep to assert IRQs are disabled/enabled irq/softirqs: Use lockdep to assert IRQs are disabled/enabled locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled() locking/pvqspinlock: Implement hybrid PV queued/unfair locks locking/rwlocks: Fix comments x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion() workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes ...
2017-11-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: "Since Martin is on vacation you get the s390 pull request for the v4.15 merge window this time from me. Besides a lot of cleanups and bug fixes these are the most important changes: - a new regset for runtime instrumentation registers - hardware accelerated AES-GCM support for the aes_s390 module - support for the new CEX6S crypto cards - support for FORTIFY_SOURCE - addition of missing z13 and new z14 instructions to the in-kernel disassembler - generate opcode tables for the in-kernel disassembler out of a simple text file instead of having to manually maintain those tables - fast memset16, memset32 and memset64 implementations - removal of named saved segment support - hardware counter support for z14 - queued spinlocks and queued rwlocks implementations for s390 - use the stack_depth tracking feature for s390 BPF JIT - a new s390_sthyi system call which emulates the sthyi (store hypervisor information) instruction - removal of the old KVM virtio transport - an s390 specific CPU alternatives implementation which is used in the new spinlock code" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (88 commits) MAINTAINERS: add virtio-ccw.h to virtio/s390 section s390/noexec: execute kexec datamover without DAT s390: fix transactional execution control register handling s390/bpf: take advantage of stack_depth tracking s390: simplify transactional execution elf hwcap handling s390/zcrypt: Rework struct ap_qact_ap_info. s390/virtio: remove unused header file kvm_virtio.h s390: avoid undefined behaviour s390/disassembler: generate opcode tables from text file s390/disassembler: remove insn_to_mnemonic() s390/dasd: avoid calling do_gettimeofday() s390: vfio-ccw: Do not attempt to free no-op, test and tic cda. s390: remove named saved segment support s390/archrandom: Reconsider s390 arch random implementation s390/pci: do not require AIS facility s390/qdio: sanitize put_indicator s390/qdio: use atomic_cmpxchg s390/nmi: avoid using long-displacement facility s390: pass endianness info to sparse s390/decompressor: remove informational messages ...
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-18s390/spinlock: use cpu alternatives to enable niai instructionVasily Gorbik
Enable niai instruction in the spinlock code at run-time for machines on which facility 49 is available (zEC12 and newer). Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>