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2015-08-16signal: fix information leak in copy_siginfo_from_user32Amanieu d'Antras
commit 3c00cb5e68dc719f2fc73a33b1b230aadfcb1309 upstream. This function can leak kernel stack data when the user siginfo_t has a positive si_code value. The top 16 bits of si_code descibe which fields in the siginfo_t union are active, but they are treated inconsistently between copy_siginfo_from_user32, copy_siginfo_to_user32 and copy_siginfo_to_user. copy_siginfo_from_user32 is called from rt_sigqueueinfo and rt_tgsigqueueinfo in which the user has full control overthe top 16 bits of si_code. This fixes the following information leaks: x86: 8 bytes leaked when sending a signal from a 32-bit process to itself. This leak grows to 16 bytes if the process uses x32. (si_code = __SI_CHLD) x86: 100 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = -1) sparc: 4 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = any) parsic and s390 have similar bugs, but they are not vulnerable because rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code to a different process. These bugs are also fixed for consistency. Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-10powerpc/perf: Fix book3s kernel to userspace backtracesAnton Blanchard
commit 72e349f1124a114435e599479c9b8d14bfd1ebcd upstream. When we take a PMU exception or a software event we call perf_read_regs(). This overloads regs->result with a boolean that describes if we should use the sampled instruction address register (SIAR) or the regs. If the exception is in kernel, we start with the kernel regs and backtrace through the kernel stack. At this point we switch to the userspace regs and backtrace the user stack with perf_callchain_user(). Unfortunately these regs have not got the perf_read_regs() treatment, so regs->result could be anything. If it is non zero, perf_instruction_pointer() decides to use the SIAR, and we get issues like this: 0.11% qemu-system-ppc [kernel.kallsyms] [k] _raw_spin_lock_irqsave | ---_raw_spin_lock_irqsave | |--52.35%-- 0 | | | |--46.39%-- __hrtimer_start_range_ns | | kvmppc_run_core | | kvmppc_vcpu_run_hv | | kvmppc_vcpu_run | | kvm_arch_vcpu_ioctl_run | | kvm_vcpu_ioctl | | do_vfs_ioctl | | sys_ioctl | | system_call | | | | | |--67.08%-- _raw_spin_lock_irqsave <--- hi mum | | | | | | | --100.00%-- 0x7e714 | | | 0x7e714 Notice the bogus _raw_spin_irqsave when we transition from kernel (system_call) to userspace (0x7e714). We inserted what was in the SIAR. Add a check in regs_use_siar() to check that the regs in question are from a PMU exception. With this fix the backtrace makes sense: 0.47% qemu-system-ppc [kernel.vmlinux] [k] _raw_spin_lock_irqsave | ---_raw_spin_lock_irqsave | |--53.83%-- 0 | | | |--44.73%-- hrtimer_try_to_cancel | | kvmppc_start_thread | | kvmppc_run_core | | kvmppc_vcpu_run_hv | | kvmppc_vcpu_run | | kvm_arch_vcpu_ioctl_run | | kvm_vcpu_ioctl | | do_vfs_ioctl | | sys_ioctl | | system_call | | __ioctl | | 0x7e714 | | 0x7e714 Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-06powerpc: Align TOC to 256 bytesAnton Blanchard
commit 5e95235ccd5442d4a4fe11ec4eb99ba1b7959368 upstream. Recent toolchains force the TOC to be 256 byte aligned. We need to enforce this alignment in our linker script, otherwise pointers to our TOC variables (__toc_start, __prom_init_toc_start) could be incorrect. If they are bad, we die a few hundred instructions into boot. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06nosave: consolidate __nosave_{begin,end} in <asm/sections.h>Geert Uytterhoeven
commit 7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0 upstream. The different architectures used their own (and different) declarations: extern __visible const void __nosave_begin, __nosave_end; extern const void __nosave_begin, __nosave_end; extern long __nosave_begin, __nosave_end; Consolidate them using the first variant in <asm/sections.h>. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06powerpc/cell: Fix cell iommu after it_page_shift changesMichael Ellerman
commit 7261b956b276aa97fbf60d00f1d7717d2ea6ee78 upstream. The patch to add it_page_shift incorrectly changed the increment of uaddr to use it_page_shift, rather then (1 << it_page_shift). This broke booting on at least some Cell blades, as the iommu was basically non-functional. Fixes: 3a553170d35d ("powerpc/iommu: Add it_page_shift field to determine iommu page size") Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06powerpc: Fix missing L2 cache size in /sys/devices/system/cpuDave Olson
commit f7e9e358362557c3aa2c1ec47490f29fe880a09e upstream. This problem appears to have been introduced in 2.6.29 by commit 93197a36a9c1 "Rewrite sysfs processor cache info code". This caused lscpu to error out on at least e500v2 devices, eg: error: cannot open /sys/devices/system/cpu/cpu0/cache/index2/size: No such file or directory Some embedded powerpc systems use cache-size in DTS for the unified L2 cache size, not d-cache-size, so we need to allow for both DTS names. Added a new CACHE_TYPE_UNIFIED_D cache_type_info structure to handle this. Fixes: 93197a36a9c1 ("powerpc: Rewrite sysfs processor cache info code") Signed-off-by: Dave Olson <olson@cumulusnetworks.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTHAnton Blanchard
commit 9a5cbce421a283e6aea3c4007f141735bf9da8c3 upstream. We cap 32bit userspace backtraces to PERF_MAX_STACK_DEPTH (currently 127), but we forgot to do the same for 64bit backtraces. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-29vm: add VM_FAULT_SIGSEGV handling supportLinus Torvalds
commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream. The core VM already knows about VM_FAULT_SIGBUS, but cannot return a "you should SIGSEGV" error, because the SIGSEGV case was generally handled by the caller - usually the architecture fault handler. That results in lots of duplication - all the architecture fault handlers end up doing very similar "look up vma, check permissions, do retries etc" - but it generally works. However, there are cases where the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV. In particular, when accessing the stack guard page, libsigsegv expects a SIGSEGV. And it usually got one, because the stack growth is handled by that duplicated architecture fault handler. However, when the generic VM layer started propagating the error return from the stack expansion in commit fee7e49d4514 ("mm: propagate error from stack expansion even for guard page"), that now exposed the existing VM_FAULT_SIGBUS result to user space. And user space really expected SIGSEGV, not SIGBUS. To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those duplicate architecture fault handlers about it. They all already have the code to handle SIGSEGV, so it's about just tying that new return value to the existing code, but it's all a bit annoying. This is the mindless minimal patch to do this. A more extensive patch would be to try to gather up the mostly shared fault handling logic into one generic helper routine, and long-term we really should do that cleanup. Just from this patch, you can generally see that most architectures just copied (directly or indirectly) the old x86 way of doing things, but in the meantime that original x86 model has been improved to hold the VM semaphore for shorter times etc and to handle VM_FAULT_RETRY and other "newer" things, so it would be a good idea to bring all those improvements to the generic case and teach other architectures about them too. Reported-and-tested-by: Takashi Iwai <tiwai@suse.de> Tested-by: Jan Engelhardt <jengelh@inai.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots" Cc: linux-arch@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [shengyong: Backport to 3.14 - adjust context - ignore modification for arch nios2, because 3.14 does not support it - add SIGSEGV handling to powerpc/cell spu_fault.c, because 3.14 does not separate it to copro_fault.c - add SIGSEGV handling to mm/memory.c, because 3.14 does not separate it to gup.c ] Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-29move d_rcu from overlapping d_child to overlapping d_aliasAl Viro
commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream. move d_rcu from overlapping d_child to overlapping d_alias Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Ben Hutchings <ben@decadent.org.uk> [hujianyang: Backported to 3.14 refer to the work of Ben Hutchings in 3.2: - Apply name changes in all the different places we use d_alias and d_child - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()] Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-13powerpc/mpc85xx: Add ranges to etsec2 nodesScott Wood
commit bb344ca5b90df62b1a3b7a35c6a9d00b306a170d upstream. Commit 746c9e9f92dd "of/base: Fix PowerPC address parsing hack" limited the applicability of the workaround whereby a missing ranges is treated as an empty ranges. This workaround was hiding a bug in the etsec2 device tree nodes, which have children with reg, but did not have ranges. Signed-off-by: Scott Wood <scottwood@freescale.com> Reported-by: Alexander Graf <agraf@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-13powerpc/pseries: Little endian fixes for post mobility device tree updateTyrel Datwyler
commit f6ff04149637723261aa4738958b0098b929ee9e upstream. We currently use the device tree update code in the kernel after resuming from a suspend operation to re-sync the kernels view of the device tree with that of the hypervisor. The code as it stands is not endian safe as it relies on parsing buffers returned by RTAS calls that thusly contains data in big endian format. This patch annotates variables and structure members with __be types as well as performing necessary byte swaps to cpu endian for data that needs to be parsed. Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-13powerpc/book3s: Fix the MCE code to use CONFIG_KVM_BOOK3S_64_HANDLERMahesh Salgaonkar
commit 44d5f6f5901e996744858c175baee320ccf1eda3 upstream. commit id 2ba9f0d has changed CONFIG_KVM_BOOK3S_64_HV to tristate to allow HV/PR bits to be built as modules. But the MCE code still depends on CONFIG_KVM_BOOK3S_64_HV which is wrong. When user selects CONFIG_KVM_BOOK3S_64_HV=m to build HV/PR bits as a separate module the relevant MCE code gets excluded. This patch fixes the MCE code to use CONFIG_KVM_BOOK3S_64_HANDLER. This makes sure that the relevant MCE code is included when HV/PR bits are built as a separate modules. Fixes: 2ba9f0d88750 ("kvm: powerpc: book3s: Support building HV and PR KVM as module") Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-06axonram: Fix bug in direct_accessMatthew Wilcox
commit 91117a20245b59f70b563523edbf998a62fc6383 upstream. The 'pfn' returned by axonram was completely bogus, and has been since 2008. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-05powerpc/xmon: Fix another endiannes issue in RTAS call from xmonLaurent Dufour
commit e6eb2eba494d6f99e69ca3c3748cd37a2544ab38 upstream. The commit 3b8a3c010969 ("powerpc/pseries: Fix endiannes issue in RTAS call from xmon") was fixing an endianness issue in the call made from xmon to RTAS. However, as Michael Ellerman noticed, this fix was not complete, the token value was not byte swapped. This lead to call an unexpected and most of the time unexisting RTAS function, which is silently ignored by RTAS. This fix addresses this hole. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-29crypto: add missing crypto module aliasesMathias Krause
commit 3e14dcf7cb80b34a1f38b55bc96f02d23fdaaaaf upstream. Commit 5d26a105b5a7 ("crypto: prefix module autoloading with "crypto-"") changed the automatic module loading when requesting crypto algorithms to prefix all module requests with "crypto-". This requires all crypto modules to have a crypto specific module alias even if their file name would otherwise match the requested crypto algorithm. Even though commit 5d26a105b5a7 added those aliases for a vast amount of modules, it was missing a few. Add the required MODULE_ALIAS_CRYPTO annotations to those files to make them get loaded automatically, again. This fixes, e.g., requesting 'ecb(blowfish-generic)', which used to work with kernels v3.18 and below. Also change MODULE_ALIAS() lines to MODULE_ALIAS_CRYPTO(). The former won't work for crypto modules any more. Fixes: 5d26a105b5a7 ("crypto: prefix module autoloading with "crypto-"") Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-29crypto: prefix module autoloading with "crypto-"Kees Cook
commit 5d26a105b5a73e5635eae0629b42fa0a90e07b7b upstream. This prefixes all crypto module loading with "crypto-" so we never run the risk of exposing module auto-loading to userspace via a crypto API, as demonstrated by Mathias Krause: https://lkml.org/lkml/2013/3/4/70 Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-16powerpc/book3s: Fix partial invalidation of TLBs in MCE code.Mahesh Salgaonkar
commit 682e77c861c4c60f79ffbeae5e1938ffed24a575 upstream. The existing MCE code calls flush_tlb hook with IS=0 (single page) resulting in partial invalidation of TLBs which is not right. This patch fixes that by passing IS=0xc00 to invalidate whole TLB for successful recovery from TLB and ERAT errors. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-16powerpc: Fix bad NULL pointer check in udbg_uart_getc_poll()Anton Blanchard
commit cd32e2dcc9de6c27ecbbfc0e2079fb64b42bad5f upstream. We have some code in udbg_uart_getc_poll() that tries to protect against a NULL udbg_uart_in, but gets it all wrong. Found with the LLVM static analyzer (scan-build). Fixes: 309257484cc1 ("powerpc: Cleanup udbg_16550 and add support for LPC PIO-only UARTs") Signed-off-by: Anton Blanchard <anton@samba.org> [mpe: Add some newlines for readability while we're here] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-12-16powerpc: 32 bit getcpu VDSO function uses 64 bit instructionsAnton Blanchard
commit 152d44a853e42952f6c8a504fb1f8eefd21fd5fd upstream. I used some 64 bit instructions when adding the 32 bit getcpu VDSO function. Fix it. Fixes: 18ad51dd342a ("powerpc: Add VDSO version of getcpu") Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-12-06powerpc/powernv: Honor the generic "no_64bit_msi" flagBenjamin Herrenschmidt
commit 360743814c4082515581aa23ab1d8e699e1fbe88 upstream. Instead of the arch specific quirk which we are deprecating and that drivers don't understand. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-12-06powerpc/pseries: Fix endiannes issue in RTAS call from xmonLaurent Dufour
commit 3b8a3c01096925a824ed3272601082289d9c23a5 upstream. On pseries system (LPAR) xmon failed to enter when running in LE mode, system is hunging. Inititating xmon will lead to such an output on the console: SysRq : Entering xmon cpu 0x15: Vector: 0 at [c0000003f39ffb10] pc: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70 lr: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70 sp: c0000003f39ffc70 msr: 8000000000009033 current = 0xc0000003fafa7180 paca = 0xc000000007d75e80 softe: 0 irq_happened: 0x01 pid = 14617, comm = bash Bad kernel stack pointer fafb4b0 at eca7cc4 cpu 0x15: Vector: 300 (Data Access) at [c000000007f07d40] pc: 000000000eca7cc4 lr: 000000000eca7c44 sp: fafb4b0 msr: 8000000000001000 dar: 10000000 dsisr: 42000000 current = 0xc0000003fafa7180 paca = 0xc000000007d75e80 softe: 0 irq_happened: 0x01 pid = 14617, comm = bash cpu 0x15: Exception 300 (Data Access) in xmon, returning to main loop xmon: WARNING: bad recursive fault on cpu 0x15 The root cause is that xmon is calling RTAS to turn off the surveillance when entering xmon, and RTAS is requiring big endian parameters. This patch is byte swapping the RTAS arguments when running in LE mode. Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-12-06powerpc/pseries: Honor the generic "no_64bit_msi" flagBenjamin Herrenschmidt
commit 415072a041bf50dbd6d56934ffc0cbbe14c97be8 upstream. Instead of the arch specific quirk which we are deprecating Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-14powerpc: use device_online/offline() instead of cpu_up/down()Dan Streetman
commit 10ccaf178b2b961d8bca252d647ed7ed8aae2a20 upstream. In powerpc pseries platform dlpar operations, use device_online() and device_offline() instead of cpu_up() and cpu_down(). Calling cpu_up/down() directly does not update the cpu device offline field, which is used to online/offline a cpu from sysfs. Calling device_online/offline() instead keeps the sysfs cpu online value correct. The hotplug lock, which is required to be held when calling device_online/offline(), is already held when dlpar_online/offline_cpu() are called, since they are called only from cpu_probe|release_store(). This patch fixes errors on phyp (PowerVM) systems that have cpu(s) added/removed using dlpar operations; without this patch, the /sys/devices/system/cpu/cpuN/online nodes do not correctly show the online state of added/removed cpus. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Fixes: 0902a9044fa5 ("Driver core: Use generic offline/online for CPU offline/online") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30powerpc/iommu/ddw: Fix endiannessAlexey Kardashevskiy
commit 9410e0185e65394c0c6d046033904b53b97a9423 upstream. rtas_call() accepts and returns values in CPU endianness. The ddw_query_response and ddw_create_response structs members are defined and treated as BE but as they are passed to rtas_call() as (u32 *) and they get byteswapped automatically, the data is CPU-endian. This fixes ddw_query_response and ddw_create_response definitions and use. of_read_number() is designed to work with device tree cells - it assumes the input is big-endian and returns data in CPU-endian. However due to the ddw_create_response struct fix, create.addr_hi/lo are already CPU-endian so do not byteswap them. ddw_avail is a pointer to the "ibm,ddw-applicable" property which contains 3 cells which are big-endian as it is a device tree. rtas_call() accepts a RTAS token in CPU-endian. This makes use of of_property_read_u32_array to byte swap and avoid the need for a number of be32_to_cpu calls. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> [aik: folded Anton's patch with of_property_read_u32_array] Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05powerpc: Add smp_mb()s to arch_spin_unlock_wait()Michael Ellerman
commit 78e05b1421fa41ae8457701140933baa5e7d9479 upstream. Similar to the previous commit which described why we need to add a barrier to arch_spin_is_locked(), we have a similar problem with spin_unlock_wait(). We need a barrier on entry to ensure any spinlock we have previously taken is visibly locked prior to the load of lock->slock. It's also not clear if spin_unlock_wait() is intended to have ACQUIRE semantics. For now be conservative and add a barrier on exit to give it ACQUIRE semantics. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05powerpc: Add smp_mb() to arch_spin_is_locked()Michael Ellerman
commit 51d7d5205d3389a32859f9939f1093f267409929 upstream. The kernel defines the function spin_is_locked(), which can be used to check if a spinlock is currently locked. Using spin_is_locked() on a lock you don't hold is obviously racy. That is, even though you may observe that the lock is unlocked, it may become locked at any time. There is (at least) one exception to that, which is if two locks are used as a pair, and the holder of each checks the status of the other before doing any update. Assuming *A and *B are two locks, and *COUNTER is a shared non-atomic value: The first CPU does: spin_lock(*A) if spin_is_locked(*B) # nothing else smp_mb() LOAD r = *COUNTER r++ STORE *COUNTER = r spin_unlock(*A) And the second CPU does: spin_lock(*B) if spin_is_locked(*A) # nothing else smp_mb() LOAD r = *COUNTER r++ STORE *COUNTER = r spin_unlock(*B) Although this is a strange locking construct, it should work. It seems to be understood, but not documented, that spin_is_locked() is not a memory barrier, so in the examples above and below the caller inserts its own memory barrier before acting on the result of spin_is_locked(). For now we assume spin_is_locked() is implemented as below, and we break it out in our examples: bool spin_is_locked(*LOCK) { LOAD l = *LOCK return l.locked } Our intuition is that there should be no problem even if the two code sequences run simultaneously such as: CPU 0 CPU 1 ================================================== spin_lock(*A) spin_lock(*B) LOAD b = *B LOAD a = *A if b.locked # true if a.locked # true # nothing # nothing spin_unlock(*A) spin_unlock(*B) If one CPU gets the lock before the other then it will do the update and the other CPU will back off: CPU 0 CPU 1 ================================================== spin_lock(*A) LOAD b = *B spin_lock(*B) if b.locked # false LOAD a = *A else if a.locked # true smp_mb() # nothing LOAD r1 = *COUNTER spin_unlock(*B) r1++ STORE *COUNTER = r1 spin_unlock(*A) However in reality spin_lock() itself is not indivisible. On powerpc we implement it as a load-and-reserve and store-conditional. Ignoring the retry logic for the lost reservation case, it boils down to: spin_lock(*LOCK) { LOAD l = *LOCK l.locked = true STORE *LOCK = l ACQUIRE_BARRIER } The ACQUIRE_BARRIER is required to give spin_lock() ACQUIRE semantics as defined in memory-barriers.txt: This acts as a one-way permeable barrier. It guarantees that all memory operations after the ACQUIRE operation will appear to happen after the ACQUIRE operation with respect to the other components of the system. On modern powerpc systems we use lwsync for ACQUIRE_BARRIER. lwsync is also know as "lightweight sync", or "sync 1". As described in Power ISA v2.07 section B.2.1.1, in this scenario the lwsync is not the barrier itself. It instead causes the LOAD of *LOCK to act as the barrier, preventing any loads or stores in the locked region from occurring prior to the load of *LOCK. Whether this behaviour is in accordance with the definition of ACQUIRE semantics in memory-barriers.txt is open to discussion, we may switch to a different barrier in future. What this means in practice is that the following can occur: CPU 0 CPU 1 ================================================== LOAD a = *A LOAD b = *B a.locked = true b.locked = true LOAD b = *B LOAD a = *A STORE *A = a STORE *B = b if b.locked # false if a.locked # false else else smp_mb() smp_mb() LOAD r1 = *COUNTER LOAD r2 = *COUNTER r1++ r2++ STORE *COUNTER = r1 STORE *COUNTER = r2 # Lost update spin_unlock(*A) spin_unlock(*B) That is, the load of *B can occur prior to the store that makes *A visibly locked. And similarly for CPU 1. The result is both CPUs hold their lock and believe the other lock is unlocked. The easiest fix for this is to add a full memory barrier to the start of spin_is_locked(), so adding to our previous definition would give us: bool spin_is_locked(*LOCK) { smp_mb() LOAD l = *LOCK return l.locked } The new barrier orders the store to the lock we are locking vs the load of the other lock: CPU 0 CPU 1 ================================================== LOAD a = *A LOAD b = *B a.locked = true b.locked = true STORE *A = a STORE *B = b smp_mb() smp_mb() LOAD b = *B LOAD a = *A if b.locked # true if a.locked # true # nothing # nothing spin_unlock(*A) spin_unlock(*B) Although the above example is theoretical, there is code similar to this example in sem_lock() in ipc/sem.c. This commit in addition to the next commit appears to be a fix for crashes we are seeing in that code where we believe this race happens in practice. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05powerpc/perf: Fix ABIv2 kernel backtracesAnton Blanchard
commit 85101af13bb854a6572fa540df7c7201958624b9 upstream. ABIv2 kernels are failing to backtrace through the kernel. An example: 39.30% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry __GI___libc_read The problem is in valid_next_sp() where we check that the new stack pointer is at least STACK_FRAME_OVERHEAD below the previous one. ABIv1 has a minimum stack frame size of 112 bytes consisting of 48 bytes and 64 bytes of parameter save area. ABIv2 changes that to 32 bytes with no paramter save area. STACK_FRAME_OVERHEAD is in theory the minimum stack frame size, but we over 240 uses of it, some of which assume that it includes space for the parameter area. We need to work through all our stack defines and rationalise them but let's fix perf now by creating STACK_FRAME_MIN_SIZE and using in valid_next_sp(). This fixes the issue: 30.64% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry pagecache_get_page generic_file_read_iter new_sync_read vfs_read sys_read syscall_exit __GI___libc_read Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/thp: Use ACCESS_ONCE when loading pmdpAneesh Kumar K.V
commit 7e467245bf5226db34c4b12d3cbacfa2f7a15a8b upstream. We would get wrong results in compiler recomputed old_pmd. Avoid that by using ACCESS_ONCE Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/thp: Invalidate with vpn in loopAneesh Kumar K.V
commit 969b7b208f7408712a3526856e4ae60ad13f6928 upstream. As per ISA, for 4k base page size we compare 14..65 bits of VA specified with the entry_VA in tlb. That implies we need to make sure we do a tlbie with all the possible 4k va we used to access the 16MB hugepage. With 64k base page size we compare 14..57 bits of VA. Hence we cannot ignore the lower 24 bits of va while tlbie .We also cannot tlb invalidate a 16MB entry with just one tlbie instruction because we don't track which va was used to instantiate the tlb entry. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/thp: Handle combo pages in invalidateAneesh Kumar K.V
commit fc0479557572375100ef16c71170b29a98e0d69a upstream. If we changed base page size of the segment, either via sub_page_protect or via remap_4k_pfn, we do a demote_segment which doesn't flush the hash table entries. We do a lazy hash page table flush for all mapped pages in the demoted segment. This happens when we handle hash page fault for these pages. We use _PAGE_COMBO bit along with _PAGE_HASHPTE to indicate whether a pte is backed by 4K hash pte. If we find _PAGE_COMBO not set on the pte, that implies that we could possibly have older 64K hash pte entries in the hash page table and we need to invalidate those entries. Use _PAGE_COMBO to determine the page size with which we should invalidate the hash table entries on unmap. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/thp: Invalidate old 64K based hash page mapping before insert of 4k pteAneesh Kumar K.V
commit 629149fae478f0ac6bf705a535708b192e9c6b59 upstream. If we changed base page size of the segment, either via sub_page_protect or via remap_4k_pfn, we do a demote_segment which doesn't flush the hash table entries. We do a lazy hash page table flush for all mapped pages in the demoted segment. This happens when we handle hash page fault for these pages. We use _PAGE_COMBO bit along with _PAGE_HASHPTE to indicate whether a pte is backed by 4K hash pte. If we find _PAGE_COMBO not set on the pte, that implies that we could possibly have older 64K hash pte entries in the hash page table and we need to invalidate those entries. Handle this correctly for 16M pages Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/thp: Don't recompute vsid and ssize in loop on invalidateAneesh Kumar K.V
commit fa1f8ae80f8bb996594167ff4750a0b0a5a5bb5d upstream. The segment identifier and segment size will remain the same in the loop, So we can compute it outside. We also change the hugepage_invalidate interface so that we can use it the later patch Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/thp: Add write barrier after updating the valid bitAneesh Kumar K.V
commit b0aa44a3dfae3d8f45bd1264349aa87f87b7774f upstream. With hugepages, we store the hpte valid information in the pte page whose address is stored in the second half of the PMD. Use a write barrier to make sure clearing pmd busy bit and updating hpte valid info are ordered properly. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/pseries: Avoid deadlock on removing ddwGavin Shan
commit 5efbabe09d986f25c02d19954660238fcd7f008a upstream. Function remove_ddw() could be called in of_reconfig_notifier and we potentially remove the dynamic DMA window property, which invokes of_reconfig_notifier again. Eventually, it leads to the deadlock as following backtrace shows. The patch fixes the above issue by deferring releasing the dynamic DMA window property while releasing the device node. ============================================= [ INFO: possible recursive locking detected ] 3.16.0+ #428 Tainted: G W --------------------------------------------- drmgr/2273 is trying to acquire lock: ((of_reconfig_chain).rwsem){.+.+..}, at: [<c000000000091890>] \ .__blocking_notifier_call_chain+0x40/0x78 but task is already holding lock: ((of_reconfig_chain).rwsem){.+.+..}, at: [<c000000000091890>] \ .__blocking_notifier_call_chain+0x40/0x78 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((of_reconfig_chain).rwsem); lock((of_reconfig_chain).rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by drmgr/2273: #0: (sb_writers#4){.+.+.+}, at: [<c0000000001cbe70>] \ .vfs_write+0xb0/0x1f8 #1: ((of_reconfig_chain).rwsem){.+.+..}, at: [<c000000000091890>] \ .__blocking_notifier_call_chain+0x40/0x78 stack backtrace: CPU: 17 PID: 2273 Comm: drmgr Tainted: G W 3.16.0+ #428 Call Trace: [c0000000137e7000] [c000000000013d9c] .show_stack+0x88/0x148 (unreliable) [c0000000137e70b0] [c00000000083cd34] .dump_stack+0x7c/0x9c [c0000000137e7130] [c0000000000b8afc] .__lock_acquire+0x128c/0x1c68 [c0000000137e7280] [c0000000000b9a4c] .lock_acquire+0xe8/0x104 [c0000000137e7350] [c00000000083588c] .down_read+0x4c/0x90 [c0000000137e73e0] [c000000000091890] .__blocking_notifier_call_chain+0x40/0x78 [c0000000137e7490] [c000000000091900] .blocking_notifier_call_chain+0x38/0x48 [c0000000137e7520] [c000000000682a28] .of_reconfig_notify+0x34/0x5c [c0000000137e75b0] [c000000000682a9c] .of_property_notify+0x4c/0x54 [c0000000137e7650] [c000000000682bf0] .of_remove_property+0x30/0xd4 [c0000000137e76f0] [c000000000052a44] .remove_ddw+0x144/0x168 [c0000000137e7790] [c000000000053204] .iommu_reconfig_notifier+0x30/0xe0 [c0000000137e7820] [c00000000009137c] .notifier_call_chain+0x6c/0xb4 [c0000000137e78c0] [c0000000000918ac] .__blocking_notifier_call_chain+0x5c/0x78 [c0000000137e7970] [c000000000091900] .blocking_notifier_call_chain+0x38/0x48 [c0000000137e7a00] [c000000000682a28] .of_reconfig_notify+0x34/0x5c [c0000000137e7a90] [c000000000682e14] .of_detach_node+0x44/0x1fc [c0000000137e7b40] [c0000000000518e4] .ofdt_write+0x3ac/0x688 [c0000000137e7c20] [c000000000238430] .proc_reg_write+0xb8/0xd4 [c0000000137e7cd0] [c0000000001cbeac] .vfs_write+0xec/0x1f8 [c0000000137e7d70] [c0000000001cc3b0] .SyS_write+0x58/0xa0 [c0000000137e7e30] [c00000000000a064] syscall_exit+0x0/0x98 Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/pseries: Failure on removing device nodeGavin Shan
commit f1b3929c232784580e5d8ee324b6bc634e709575 upstream. While running command "drmgr -c phb -r -s 'PHB 528'", following backtrace jumped out because the target device node isn't marked with OF_DETACHED by of_detach_node(), which caused by error returned from memory hotplug related reconfig notifier when disabling CONFIG_MEMORY_HOTREMOVE. The patch fixes it. ERROR: Bad of_node_put() on /pci@800000020000210/ethernet@0 CPU: 14 PID: 2252 Comm: drmgr Tainted: G W 3.16.0+ #427 Call Trace: [c000000012a776a0] [c000000000013d9c] .show_stack+0x88/0x148 (unreliable) [c000000012a77750] [c00000000083cd34] .dump_stack+0x7c/0x9c [c000000012a777d0] [c0000000006807c4] .of_node_release+0x58/0xe0 [c000000012a77860] [c00000000038a7d0] .kobject_release+0x174/0x1b8 [c000000012a77900] [c00000000038a884] .kobject_put+0x70/0x78 [c000000012a77980] [c000000000681680] .of_node_put+0x28/0x34 [c000000012a77a00] [c000000000681ea8] .__of_get_next_child+0x64/0x70 [c000000012a77a90] [c000000000682138] .of_find_node_by_path+0x1b8/0x20c [c000000012a77b40] [c000000000051840] .ofdt_write+0x308/0x688 [c000000012a77c20] [c000000000238430] .proc_reg_write+0xb8/0xd4 [c000000012a77cd0] [c0000000001cbeac] .vfs_write+0xec/0x1f8 [c000000012a77d70] [c0000000001cc3b0] .SyS_write+0x58/0xa0 [c000000012a77e30] [c00000000000a064] syscall_exit+0x0/0x98 Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/mm: Use read barrier when creating real_pteAneesh Kumar K.V
commit 85c1fafd7262e68ad821ee1808686b1392b1167d upstream. On ppc64 we support 4K hash pte with 64K page size. That requires us to track the hash pte slot information on a per 4k basis. We do that by storing the slot details in the second half of pte page. The pte bit _PAGE_COMBO is used to indicate whether the second half need to be looked while building real_pte. We need to use read memory barrier while doing that so that load of hidx is not reordered w.r.t _PAGE_COMBO check. On the store side we already do a lwsync in __hash_page_4K Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17powerpc/mm/numa: Fix break placementAndrey Utkin
commit b00fc6ec1f24f9d7af9b8988b6a198186eb3408c upstream. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81631 Reported-by: David Binderman <dcb314@hotmail.com> Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-05powerpc/powernv: Update dev->dma_mask in pci_set_dma_mask() pathBrian W Hart
commit a32305bf90a2ae0e6a9a93370c7616565f75e15a upstream. powerpc defines various machine-specific routines for handling pci_set_dma_mask(). The routines for machine "PowerNV" may neglect to set dev->dma_mask. This could confuse anyone (e.g. drivers) that consult dev->dma_mask to find the current mask. Set the dma_mask in the PowerNV leaf routine. Signed-off-by: Brian W. Hart <hartb@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-05powerpc/pci: Reorder pci bus/bridge unregistration during PHB removalTyrel Datwyler
commit 7340056567e32b2c9d3554eb146e1977c93da116 upstream. Commit bcdde7e made __sysfs_remove_dir() recursive and introduced a BUG_ON during PHB removal while attempting to delete the power managment attribute group of the bus. This is a result of tearing the bridge and bus devices down out of order in remove_phb_dynamic. Since, the the bus resides below the bridge in the sysfs device tree it should be torn down first. This patch simply moves the device_unregister call for the PHB bridge device after the device_unregister call for the PHB bus. Fixes: bcdde7e221a8 ("sysfs: make __sysfs_remove_dir() recursive") Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-28locking/mutex: Disable optimistic spinning on some architecturesPeter Zijlstra
commit 4badad352a6bb202ec68afa7a574c0bb961e5ebc upstream. The optimistic spin code assumes regular stores and cmpxchg() play nice; this is found to not be true for at least: parisc, sparc32, tile32, metag-lock1, arc-!llsc and hexagon. There is further wreckage, but this in particular seemed easy to trigger, so blacklist this. Opt in for known good archs. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Jason Low <jason.low2@hp.com> Cc: Waiman Long <waiman.long@hp.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: John David Anglin <dave.anglin@bell.net> Cc: James Hogan <james.hogan@imgtec.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17powerpc: Disable RELOCATABLE for COMPILE_TEST with PPC64Guenter Roeck
commit fb43e8477ed9006c4f397f904c691a120503038c upstream. powerpc:allmodconfig has been failing for some time with the following error. arch/powerpc/kernel/exceptions-64s.S: Assembler messages: arch/powerpc/kernel/exceptions-64s.S:1312: Error: attempt to move .org backwards make[1]: *** [arch/powerpc/kernel/head_64.o] Error 1 A number of attempts to fix the problem by moving around code have been unsuccessful and resulted in failed builds for some configurations and the discovery of toolchain bugs. Fix the problem by disabling RELOCATABLE for COMPILE_TEST builds instead. While this is less than perfect, it avoids substantial code changes which would otherwise be necessary just to make COMPILE_TEST builds happy and might have undesired side effects. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17powerpc/perf: Clear MMCR2 when enabling PMUJoel Stanley
commit b50a6c584bb47b370f84bfd746770c0bbe7129b7 upstream. On POWER8 when switching to a KVM guest we set bits in MMCR2 to freeze the PMU counters. Aside from on boot they are then never reset, resulting in stuck perf counters for any user in the guest or host. We now set MMCR2 to 0 whenever enabling the PMU, which provides a sane state for perf to use the PMU counters under either the guest or the host. This was manifesting as a bug with ppc64_cpu --frequency: $ sudo ppc64_cpu --frequency WARNING: couldn't run on cpu 0 WARNING: couldn't run on cpu 8 ... WARNING: couldn't run on cpu 144 WARNING: couldn't run on cpu 152 min: 18446744073.710 GHz (cpu -1) max: 0.000 GHz (cpu -1) avg: 0.000 GHz The command uses a perf counter to measure CPU cycles over a fixed amount of time, in order to approximate the frequency of the machine. The counters were returning zero once a guest was started, regardless of weather it was still running or had been shut down. By dumping the value of MMCR2, it was observed that once a guest is running MMCR2 is set to 1s - which stops counters from running: $ sudo sh -c 'echo p > /proc/sysrq-trigger' CPU: 0 PMU registers, ppmu = POWER8 n_counters = 6 PMC1: 5b635e38 PMC2: 00000000 PMC3: 00000000 PMC4: 00000000 PMC5: 1bf5a646 PMC6: 5793d378 PMC7: deadbeef PMC8: deadbeef MMCR0: 0000000080000000 MMCR1: 000000001e000000 MMCRA: 0000040000000000 MMCR2: fffffffffffffc00 EBBHR: 0000000000000000 EBBRR: 0000000000000000 BESCR: 0000000000000000 SIAR: 00000000000a51cc SDAR: c00000000fc40000 SIER: 0000000001000000 This is done unconditionally in book3s_hv_interrupts.S upon entering the guest, and the original value is only save/restored if the host has indicated it was using the PMU. This is okay, however the user of the PMU needs to ensure that it is in a defined state when it starts using it. Fixes: e05b9b9e5c10 ("powerpc/perf: Power8 PMU support") Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17powerpc/perf: Add PPMU_ARCH_207S defineJoel Stanley
commit 4d9690dd56b0d18f2af8a9d4a279cb205aae3345 upstream. Instead of separate bits for every POWER8 PMU feature, have a single one for v2.07 of the architecture. This saves us adding a MMCR2 define for a future patch. Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17powerpc/perf: Never program book3s PMCs with values >= 0x80000000Anton Blanchard
commit f56029410a13cae3652d1f34788045c40a13ffc7 upstream. We are seeing a lot of PMU warnings on POWER8: Can't find PMC that caused IRQ Looking closer, the active PMC is 0 at this point and we took a PMU exception on the transition from negative to 0. Some versions of POWER8 have an issue where they edge detect and not level detect PMC overflows. A number of places program the PMC with (0x80000000 - period_left), where period_left can be negative. We can either fix all of these or just ensure that period_left is always >= 1. This patch takes the second option. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06powerpc: Don't skip ePAPR spin-table CPUsScott Wood
commit 6663a4fa6711050036562ddfd2086edf735fae21 upstream. Commit 59a53afe70fd530040bdc69581f03d880157f15a "powerpc: Don't setup CPUs with bad status" broke ePAPR SMP booting. ePAPR says that CPUs that aren't presently running shall have status of disabled, with enable-method being used to determine whether the CPU can be enabled. Fix by checking for spin-table, which is currently the only supported enable-method. Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Emil Medve <Emilian.Medve@Freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06powerpc: Add AT_HWCAP2 to indicate V.CRYPTO category supportBenjamin Herrenschmidt
commit dd58a092c4202f2bd490adab7285b3ff77f8e467 upstream. The Vector Crypto category instructions are supported by current POWER8 chips, advertise them to userspace using a specific bit to properly differentiate with chips of the same architecture level that might not have them. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06powerpc: Don't setup CPUs with bad statusMichael Neuling
commit 59a53afe70fd530040bdc69581f03d880157f15a upstream. OPAL will mark a CPU that is guarded as "bad" in the status property of the CPU node. Unfortunatley Linux doesn't check this property and will put the bad CPU in the present map. This has caused hangs on booting when we try to unsplit the core. This patch checks the CPU is avaliable via this status property before putting it in the present map. Signed-off-by: Michael Neuling <mikey@neuling.org> Tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06powerpc: fix typo 'CONFIG_PPC_CPU'Paul Bolle
commit b69a1da94f3d1589d1942b5d1b384d8cfaac4500 upstream. Commit cd64d1697cf0 ("powerpc: mtmsrd not defined") added a check for CONFIG_PPC_CPU were a check for CONFIG_PPC_FPU was clearly intended. Fixes: cd64d1697cf0 ("powerpc: mtmsrd not defined") Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06powerpc/perf: Ensure all EBB register state is cleared on fork()Michael Ellerman
commit 3df48c981d5a9610e02e9270b1bc4274fb536710 upstream. In commit 330a1eb "Core EBB support for 64-bit book3s" I messed up clear_task_ebb(). It clears some but not all of the task's Event Based Branch (EBB) registers when we duplicate a task struct. That allows a child task to observe the EBBHR & EBBRR of its parent, which it should not be able to do. Fix it by clearing EBBHR & EBBRR. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06powerpc: fix typo 'CONFIG_PMAC'Paul Bolle
commit 6e0fdf9af216887e0032c19d276889aad41cad00 upstream. Commit b0d278b7d3ae ("powerpc/perf_event: Reduce latency of calling perf_event_do_pending") added a check for CONFIG_PMAC were a check for CONFIG_PPC_PMAC was clearly intended. Fixes: b0d278b7d3ae ("powerpc/perf_event: Reduce latency of calling perf_event_do_pending") Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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