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2017-11-15s390/topology: make "topology=off" parameter workHeiko Carstens
[ Upstream commit 68cc795d1933285705ced6d841ef66c00ce98cbe ] The "topology=off" kernel parameter is supposed to prevent the kernel to use hardware topology information to generate scheduling domains etc. For an unknown reason I implemented this in a very odd way back then: instead of simply clearing the MACHINE_HAS_TOPOLOGY flag within the lowcore I added a second variable which indicated that topology information should not be used. This is more than suboptimal since it partially doesn't work. For the fake NUMA case topology information is still considered and scheduling domains will be created based on this. To fix this and to simplify the code get rid of the extra variable and implement the "topology=off" case like it is done for other features. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-17s390/kvm: do not rely on the ILC on kvm host protection faulsChristian Borntraeger
commit c0e7bb38c07cbd8269549ee0a0566021a3c729de upstream. For most cases a protection exception in the host (e.g. copy on write or dirty tracking) on the sie instruction will indicate an instruction length of 4. Turns out that there are some corner cases (e.g. runtime instrumentation) where this is not necessarily true and the ILC is unpredictable. Let's replace our 4 byte rewind_pad with 3 byte nops to prepare for all possible ILCs. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25s390/cputime: fix incorrect system timeMartin Schwidefsky
commit 07a63cbe8bcb6ba72fb989dcab1ec55ec6c36c7e upstream. git commit c5328901aa1db134 "[S390] entry[64].S improvements" removed the update of the exit_timer lowcore field from the critical section cleanup of the .Lsysc_restore/.Lsysc_done and .Lio_restore/.Lio_done blocks. If the PSW is updated by the critical section cleanup to point to user space again, the interrupt entry code will do a vtime calculation after the cleanup completed with an exit_timer value which has *not* been updated. Due to this incorrect system time deltas are calculated. If an interrupt occured with an old PSW between .Lsysc_restore/.Lsysc_done or .Lio_restore/.Lio_done update __LC_EXIT_TIMER with the system entry time of the interrupt. Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25s390/kdump: Add final noteMichael Holzheu
commit dcc00b79fc3d076832f7240de8870f492629b171 upstream. Since linux v3.14 with commit 38dfac843cb6d7be1 ("vmcore: prevent PT_NOTE p_memsz overflow during header update") on s390 we get the following message in the kdump kernel: Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x6b6b6b6b, n_descsz=0x6b6b6b6b The reason for this is that we don't create a final zero note in the ELF header which the proc/vmcore code uses to find out the end of the notes section (see also kernel/kexec_core.c:final_note()). It still worked on s390 by chance because we (most of the time?) have the byte pattern 0x6b6b6b6b after the notes section which also makes the notes parsing code stop in update_note_header_size_elf64() because 0x6b6b6b6b is interpreded as note size: if ((real_sz + sz) > max_sz) { pr_warn("Warning: Exceeded p_memsz, dropping P ...); break; } So fix this and add the missing final note to the ELF header. We don't have to adjust the memory size for ELF header ("alloc_size") because the new ELF note still fits into the 0x1000 base memory. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-15s390: use correct input data address for setup_randomnessHeiko Carstens
commit 4920e3cf77347d7d7373552d4839e8d832321313 upstream. The current implementation of setup_randomness uses the stack address and therefore the pointer to the SYSIB 3.2.2 block as input data address. Furthermore the length of the input data is the number of virtual-machine description blocks which is typically one. This means that typically a single zero byte is fed to add_device_randomness. Fix both of these and use the address of the first virtual machine description block as input data address and also use the correct length. Fixes: bcfcbb6bae64 ("s390: add system information as device randomness") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-15s390: make setup_randomness workHeiko Carstens
commit da8fd820f389a0e29080b14c61bf5cf1d8ef5ca1 upstream. Commit bcfcbb6bae64 ("s390: add system information as device randomness") intended to add some virtual machine specific information to the randomness pool. Unfortunately it uses the page allocator before it is ready to use. In result the page allocator always returns NULL and the setup_randomness function never adds anything to the randomness pool. To fix this use memblock_alloc and memblock_free instead. Fixes: bcfcbb6bae64 ("s390: add system information as device randomness") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-15s390/kdump: Use "LINUX" ELF note name instead of "CORE"Michael Holzheu
commit a4a81d8eebdc1d209d034f62a082a5131e4242b5 upstream. In binutils/libbfd (bfd/elf.c) it is enforced that all s390 specific ELF notes like e.g. NT_S390_PREFIX or NT_S390_CTRS have "LINUX" specified as note name. Otherwise the notes are ignored. For /proc/vmcore we currently use "CORE" for these notes. Up to now this has not been a real problem because the dump analysis tool "crash" does not check the note name. But it will break all programs that use libbfd for processing ELF notes. So fix this and use "LINUX" for all s390 specific notes to comply with libbfd. Reported-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01s390/ptrace: Preserve previous registers for short regset writeMartin Schwidefsky
commit 9dce990d2cf57b5ed4e71a9cdbd7eae4335111ff upstream. Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved. convert_vx_to_fp() is adapted to handle only a specified number of registers rather than unconditionally handling all of them: other callers of this function are adapted appropriately. Based on an initial patch by Dave Martin. Reported-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-12s390/topology: always use s390 specific sched_domain_topology_levelHeiko Carstens
commit ebb299a51059017ec253bd30781a83d1f6e11b24 upstream. The s390 specific sched_domain_topology_level should always be used, not only if the machine provides topology information. Luckily this odd behaviour, that was by accident introduced with git commit d05d15da18f5 ("s390/topology: delay initialization of topology cpu masks") has currently no side effect. Fixes: d05d15da18f5 ("s390/topology: delay initialization of topology cpumasks") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-09s390/kexec: use node 0 when re-adding crash kernel memoryHeiko Carstens
commit 9f88eb4df728aebcd2ddd154d99f1d75b428b897 upstream. When re-adding crash kernel memory within setup_resources() the function memblock_add() is used. That function will add memory by default to node "MAX_NUMNODES" instead of node 0, like the memory detection code does. In case of !NUMA this will trigger this warning when the kernel generates the vmemmap: Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead WARNING: CPU: 0 PID: 0 at mm/memblock.c:1261 memblock_virt_alloc_internal+0x76/0x220 CPU: 0 PID: 0 Comm: swapper Not tainted 4.9.0-rc6 #16 Call Trace: [<0000000000d0b2e8>] memblock_virt_alloc_try_nid+0x88/0xc8 [<000000000083c8ea>] __earlyonly_bootmem_alloc.constprop.1+0x42/0x50 [<000000000083e7f4>] vmemmap_populate+0x1ac/0x1e0 [<0000000000840136>] sparse_mem_map_populate+0x46/0x68 [<0000000000d0c59c>] sparse_init+0x184/0x238 [<0000000000cf45f6>] paging_init+0xbe/0xf8 [<0000000000cf1d4a>] setup_arch+0xa02/0xae0 [<0000000000ced75a>] start_kernel+0x72/0x450 [<0000000000100020>] _stext+0x20/0x80 If NUMA is selected numa_setup_memory() will fix the node assignments before the vmemmap will be populated; so this warning will only appear if NUMA is not selected. To fix this simply use memblock_add_node() and re-add crash kernel memory explicitly to node 0. Reported-and-tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Fixes: 4e042af463f8 ("s390/kexec: fix crash on resize of reserved memory") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-11mm: kmemleak: scan .data.ro_after_initJakub Kicinski
Limit the number of kmemleak false positives by including .data.ro_after_init in memory scanning. To achieve this we need to add symbols for start and end of the section to the linker scripts. The problem was been uncovered by commit 56989f6d8568 ("genetlink: mark families as __ro_after_init"). Link: http://lkml.kernel.org/r/1478274173-15218-1-git-send-email-jakub.kicinski@netronome.com Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-24s390/dumpstack: use pr_cont within show_stack and dieHeiko Carstens
Use pr_cont instead of printk calls also within show_stack and die in order to avoid extra line breaks. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-10-17s390/dumpstack: get rid of return_address againHeiko Carstens
With commit ef6000b4c670 ("Disable the __builtin_return_address() warning globally after all)" the kernel does not warn at all again if __builtin_return_address(n) is called with n > 0. Besides the fact that this was a false warning on s390 anyway, due to the always present backchain, we can now revert commit 5606330627ab ("s390/dumpstack: implement and use return_address()") again, to simplify the code again. After all I shouldn't have had return_address() implememted at all to workaround this issue. So get rid of this again. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-10-17s390/disassambler: use pr_cont where appropriateHeiko Carstens
Just like for dumpstack use pr_cont instead of simple printk calls to fix the output when disassembling a piece of code. Before: [ 0.840627] Krnl Code: 000000000017d1c6: a77400f7 brc 7,17d3b4 [ 0.840630] 000000000017d1ca: 92015000 mvi 0(%r5),1 [ 0.840634] #000000000017d1ce: a7f40001 brc 15,17d1d0 After: [ 0.831792] Krnl Code: 000000000017d13e: a77400f7 brc 7,17d32c 000000000017d142: 92015000 mvi 0(%r5),1 #000000000017d146: a7f40001 brc 15,17d148 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-10-17s390/dumpstack: use pr_cont where appropriateHeiko Carstens
Use pr_cont instead of simple printk calls when lines will be continued. This fixes the kernel output of various lines printed on e.g. a warning: Before: [ 0.840604] Krnl PSW : 0404c00180000000 000000000017d1d2 [ 0.840606] (try_to_wake_up+0x382/0x5e0) [ 0.840610] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 [ 0.840611] RI:0 EA:3 After: [ 0.831772] Krnl PSW : 0404c00180000000 000000000017d14a (try_to_wake_up+0x382/0x5e0) [ 0.831776] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-10-17s390/dumpstack: restore reliable indicator for call tracesHeiko Carstens
Before merging all different stack tracers the call traces printed had an indicator if an entry can be considered reliable or not. Unreliable entries were put in braces, reliable not. Currently all lines contain these extra braces. This patch restores the old behaviour by adding an extra "reliable" parameter to the callback functions. Only show_trace makes currently use of it. Before: [ 0.804751] Call Trace: [ 0.804753] ([<000000000017d0e0>] try_to_wake_up+0x318/0x5e0) [ 0.804756] ([<0000000000161d64>] create_worker+0x174/0x1c0) After: [ 0.804751] Call Trace: [ 0.804753] ([<000000000017d0e0>] try_to_wake_up+0x318/0x5e0) [ 0.804756] [<0000000000161d64>] create_worker+0x174/0x1c0 Fixes: 758d39ebd3d5 ("s390/dumpstack: merge all four stack tracers") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-10-14Merge branch 'kbuild' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild updates from Michal Marek: - EXPORT_SYMBOL for asm source by Al Viro. This does bring a regression, because genksyms no longer generates checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is working on a patch to fix this. Plus, we are talking about functions like strcpy(), which rarely change prototypes. - Fixes for PPC fallout of the above by Stephen Rothwell and Nick Piggin - fixdep speedup by Alexey Dobriyan. - preparatory work by Nick Piggin to allow architectures to build with -ffunction-sections, -fdata-sections and --gc-sections - CONFIG_THIN_ARCHIVES support by Stephen Rothwell - fix for filenames with colons in the initramfs source by me. * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits) initramfs: Escape colons in depfile ppc: there is no clear_pages to export powerpc/64: whitelist unresolved modversions CRCs kbuild: -ffunction-sections fix for archs with conflicting sections kbuild: add arch specific post-link Makefile kbuild: allow archs to select link dead code/data elimination kbuild: allow architectures to use thin archives instead of ld -r kbuild: Regenerate genksyms lexer kbuild: genksyms fix for typeof handling fixdep: faster CONFIG_ search ia64: move exports to definitions sparc32: debride memcpy.S a bit [sparc] unify 32bit and 64bit string.h sparc: move exports to definitions ppc: move exports to definitions arm: move exports to definitions s390: move exports to definitions m68k: move exports to definitions alpha: move exports to actual definitions x86: move exports to actual definitions ...
2016-10-08cred: simpler, 1D supplementary groupsAlexey Dobriyan
Current supplementary groups code can massively overallocate memory and is implemented in a way so that access to individual gid is done via 2D array. If number of gids is <= 32, memory allocation is more or less tolerable (140/148 bytes). But if it is not, code allocates full page (!) regardless and, what's even more fun, doesn't reuse small 32-entry array. 2D array means dependent shifts, loads and LEAs without possibility to optimize them (gid is never known at compile time). All of the above is unnecessary. Switch to the usual trailing-zero-len-array scheme. Memory is allocated with kmalloc/vmalloc() and only as much as needed. Accesses become simpler (LEA 8(gi,idx,4) or even without displacement). Maximum number of gids is 65536 which translates to 256KB+8 bytes. I think kernel can handle such allocation. On my usual desktop system with whole 9 (nine) aux groups, struct group_info shrinks from 148 bytes to 44 bytes, yay! Nice side effects: - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing, - fix little mess in net/ipv4/ping.c should have been using GROUP_AT macro but this point becomes moot, - aux group allocation is persistent and should be accounted as such. Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08nmi_backtrace: generate one-line reports for idle cpusChris Metcalf
When doing an nmi backtrace of many cores, most of which are idle, the output is a little overwhelming and very uninformative. Suppress messages for cpus that are idling when they are interrupted and just emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN". We do this by grouping all the cpuidle code together into a new .cpuidle.text section, and then checking the address of the interrupted PC to see if it lies within that section. This commit suitably tags x86 and tile idle routines, and only adds in the minimal framework for other architectures. Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm] Tested-by: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-06Merge tag 'kvm-4.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Radim Krčmář: "All architectures: - move `make kvmconfig` stubs from x86 - use 64 bits for debugfs stats ARM: - Important fixes for not using an in-kernel irqchip - handle SError exceptions and present them to guests if appropriate - proxying of GICV access at EL2 if guest mappings are unsafe - GICv3 on AArch32 on ARMv8 - preparations for GICv3 save/restore, including ABI docs - cleanups and a bit of optimizations MIPS: - A couple of fixes in preparation for supporting MIPS EVA host kernels - MIPS SMP host & TLB invalidation fixes PPC: - Fix the bug which caused guests to falsely report lockups - other minor fixes - a small optimization s390: - Lazy enablement of runtime instrumentation - up to 255 CPUs for nested guests - rework of machine check deliver - cleanups and fixes x86: - IOMMU part of AMD's AVIC for vmexit-less interrupt delivery - Hyper-V TSC page - per-vcpu tsc_offset in debugfs - accelerated INS/OUTS in nVMX - cleanups and fixes" * tag 'kvm-4.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (140 commits) KVM: MIPS: Drop dubious EntryHi optimisation KVM: MIPS: Invalidate TLB by regenerating ASIDs KVM: MIPS: Split kernel/user ASID regeneration KVM: MIPS: Drop other CPU ASIDs on guest MMU changes KVM: arm/arm64: vgic: Don't flush/sync without a working vgic KVM: arm64: Require in-kernel irqchip for PMU support KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register KVM: PPC: Book3S PR: Support 64kB page size on POWER8E and POWER8NVL KVM: PPC: Book3S: Remove duplicate setting of the B field in tlbie KVM: PPC: BookE: Fix a sanity check KVM: PPC: Book3S HV: Take out virtual core piggybacking code KVM: PPC: Book3S: Treat VTB as a per-subcore register, not per-thread ARM: gic-v3: Work around definition of gic_write_bpr1 KVM: nVMX: Fix the NMI IDT-vectoring handling KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactive KVM: nVMX: Fix reload apic access page warning kvmconfig: add virtio-gpu to config fragment config: move x86 kvm_guest.config to a common location arm64: KVM: Remove duplicating init code for setting VMID ARM: KVM: Support vgic-v3 ...
2016-10-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The new features and main improvements in this merge for v4.9 - Support for the UBSAN sanitizer - Set HAVE_EFFICIENT_UNALIGNED_ACCESS, it improves the code in some places - Improvements for the in-kernel fpu code, in particular the overhead for multiple consecutive in kernel fpu users is recuded - Add a SIMD implementation for the RAID6 gen and xor operations - Add RAID6 recovery based on the XC instruction - The PCI DMA flush logic has been improved to increase the speed of the map / unmap operations - The time synchronization code has seen some updates And bug fixes all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits) s390/con3270: fix insufficient space padding s390/con3270: fix use of uninitialised data MAINTAINERS: update DASD maintainer s390/cio: fix accidental interrupt enabling during resume s390/dasd: add missing \n to end of dev_err messages s390/config: Enable config options for Docker s390/dasd: make query host access interruptible s390/dasd: fix panic during offline processing s390/dasd: fix hanging offline processing s390/pci_dma: improve lazy flush for unmap s390/pci_dma: split dma_update_trans s390/pci_dma: improve map_sg s390/pci_dma: simplify dma address calculation s390/pci_dma: remove dma address range check iommu/s390: simplify registration of I/O address translation parameters s390: migrate exception table users off module.h and onto extable.h s390: export header for CLP ioctl s390/vmur: fix irq pointer dereference in int handler s390/dasd: add missing KOBJ_CHANGE event for unformatted devices s390: enable UBSAN ...
2016-09-20s390: migrate exception table users off module.h and onto extable.hPaul Gortmaker
These files were only including module.h for exception table related functions. We've now separated that content out into its own file "extable.h" so now move over to that and avoid all the extra header content in module.h that we don't really need to compile these files. The additions of uaccess.h are to deal with implict includes like: arch/s390/kernel/traps.c: In function 'do_report_trap': arch/s390/kernel/traps.c:56:4: error: implicit declaration of function 'extable_fixup' [-Werror=implicit-function-declaration] arch/s390/kernel/traps.c: In function 'illegal_op': arch/s390/kernel/traps.c:173:3: error: implicit declaration of function 'get_user' [-Werror=implicit-function-declaration] Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-09-20s390: enable UBSANChristian Borntraeger
This enables UBSAN for s390. We have to disable the null sanitizer as s390 code does access memory via a null pointer (the prefix page). Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-09-20s390/crashdump: use list_first_entry_or_nullMasahiro Yamada
The combo of list_empty() check and return list_first_entry() can be replaced with list_first_entry_or_null(). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-09-15Merge branch 'linus' into x86/asm, to pick up recent fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-08KVM: s390: write external damage code on machine checksDavid Hildenbrand
Let's also write the external damage code already provided by struct kvm_s390_mchk_info. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-08-29s390/nmi: improve revalidation of fpu / vector registersMartin Schwidefsky
The machine check handler will do one of two things if the floating-point control, a floating point register or a vector register can not be revalidated: 1) if the PSW indicates user mode the process is terminated 2) if the PSW indicates kernel mode the system is stopped To unconditionally stop the system for 2) is incorrect. There are three possible outcomes if the floating-point control, a floating point register or a vector registers can not be revalidated: 1) The kernel is inside a kernel_fpu_begin/kernel_fpu_end block and needs the register. The system is stopped. 2) No active kernel_fpu_begin/kernel_fpu_end block and the CIF_CPU bit is not set. The user space process needs the register and is killed. 3) No active kernel_fpu_begin/kernel_fpu_end block and the CIF_FPU bit is set. Neither the kernel nor the user space process needs the lost register. Just revalidate it and continue. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-29s390/fpu: improve kernel_fpu_[begin|end]Martin Schwidefsky
In case of nested user of the FPU or vector registers in the kernel the current code uses the mask of the FPU/vector registers of the previous contexts to decide which registers to save and restore. E.g. if the previous context used KERNEL_VXR_V0V7 and the next context wants to use KERNEL_VXR_V24V31 the first 8 vector registers are stored to the FPU state structure. But this is not necessary as the next context does not use these registers. Rework the FPU/vector register save and restore code. The new code does a few things differently: 1) A lowcore field is used instead of a per-cpu variable. 2) The kernel_fpu_end function now has two parameters just like kernel_fpu_begin. The register flags are required by both functions to save / restore the minimal register set. 3) The inline functions kernel_fpu_begin/kernel_fpu_end now do the update of the register masks. If the user space FPU registers have already been stored neither save_fpu_regs nor the __kernel_fpu_begin/__kernel_fpu_end functions have to be called for the first context. In this case kernel_fpu_begin adds 7 instructions and kernel_fpu_end adds 4 instructions. 3) The inline assemblies in __kernel_fpu_begin / __kernel_fpu_end to save / restore the vector registers are simplified a bit. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-29s390/time: avoid races when updating tb_update_countDavid Hildenbrand
The increment might not be atomic and we're not holding the timekeeper_lock. Therefore we might lose an update to count, resulting in VDSO being trapped in a loop. As other archs also simply update the values and count doesn't seem to have an impact on reloading of these values in VDSO code, let's just remove the update of tb_update_count. Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-29s390/time: fixup the clock comparator on all cpusDavid Hildenbrand
By leaving fixup_cc unset, only the clock comparator of the cpu actually doing the sync is fixed up until now. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-29s390/time: cleanup etr leftoversDavid Hildenbrand
There are still some etr leftovers and wrong comments, let's clean that up. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-29s390/time: simplify stp time syncsDavid Hildenbrand
The way we call do_adjtimex() today is broken. It has 0 effect, as ADJ_OFFSET_SINGLESHOT (0x0001) in the kernel maps to !ADJ_ADJTIME (in contrast to user space where it maps to ADJ_OFFSET_SINGLESHOT | ADJ_ADJTIME - 0x8001). !ADJ_ADJTIME will silently ignore all adjustments without STA_PLL being active. We could switch to ADJ_ADJTIME or turn STA_PLL on, but still we would run into some problems: - Even when switching to nanoseconds, we lose accuracy. - Successive calls to do_adjtimex() will simply overwrite any leftovers from the previous call (if not fully handled) - Anything that NTP does using the sysctl heavily interferes with our use. - !ADJ_ADJTIME will silently round stuff > or < than 0.5 seconds Reusing do_adjtimex() here just feels wrong. The whole STP synchronization works right now *somehow* only, as do_adjtimex() does nothing and our TOD clock jumps in time, although it shouldn't. This is especially bad as the clock could jump backwards in time. We will have to find another way to fix this up. As leap seconds are also not properly handled yet, let's just get rid of all this complex logic altogether and use the correct clock_delta for fixing up the clock comparator and keeping the sched_clock monotonic. This change should have 0 effect on the current STP mechanism. Once we know how to best handle sync events and leap second updates, we'll start with a fresh implementation. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-27treewide: replace config_enabled() with IS_ENABLED() (2nd round)Masahiro Yamada
Commit 97f2645f358b ("tree-wide: replace config_enabled() with IS_ENABLED()") mostly killed config_enabled(), but some new users have appeared for v4.8-rc1. They are all used for a boolean option, so can be replaced with IS_ENABLED() safely. Link: http://lkml.kernel.org/r/1471970749-24867-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-24ftrace: Add return address pointer to ftrace_ret_stackJosh Poimboeuf
Storing this value will help prevent unwinders from getting out of sync with the function graph tracer ret_stack. Now instead of needing a stateful iterator, they can compare the return address pointer to find the right ret_stack entry. Note that an array of 50 ftrace_ret_stack structs is allocated for every task. So when an arch implements this, it will add either 200 or 400 bytes of memory usage per task (depending on whether it's a 32-bit or 64-bit platform). Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-08s390: clarify compressed image code pathSascha Silbe
The way the decompressor is hooked into the start-up code is rather subtle, with a mix of multiply-defined symbols and hardcoded address literals. Add some comments at the junction points to clarify how it works. Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-08s390: move exports to definitionsAl Viro
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: - ARM: GICv3 ITS emulation and various fixes. Removal of the old VGIC implementation. - s390: support for trapping software breakpoints, nested virtualization (vSIE), the STHYI opcode, initial extensions for CPU model support. - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups, preliminary to this and the upcoming support for hardware virtualization extensions. - x86: support for execute-only mappings in nested EPT; reduced vmexit latency for TSC deadline timer (by about 30%) on Intel hosts; support for more than 255 vCPUs. - PPC: bugfixes. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits) KVM: PPC: Introduce KVM_CAP_PPC_HTM MIPS: Select HAVE_KVM for MIPS64_R{2,6} MIPS: KVM: Reset CP0_PageMask during host TLB flush MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX() MIPS: KVM: Sign extend MFC0/RDHWR results MIPS: KVM: Fix 64-bit big endian dynamic translation MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase MIPS: KVM: Use 64-bit CP0_EBase when appropriate MIPS: KVM: Set CP0_Status.KX on MIPS64 MIPS: KVM: Make entry code MIPS64 friendly MIPS: KVM: Use kmap instead of CKSEG0ADDR() MIPS: KVM: Use virt_to_phys() to get commpage PFN MIPS: Fix definition of KSEGX() for 64-bit KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD kvm: x86: nVMX: maintain internal copy of current VMCS KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures KVM: arm64: vgic-its: Simplify MAPI error handling KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers KVM: arm64: vgic-its: Turn device_id validation into generic ID validation ...
2016-07-31s390/ftrace/jprobes: Fix conflict between jprobes and function graph tracingJiri Olsa
This fixes the same issue Steven already fixed for x86 in following commit: 237d28db036e ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing It fixes the crash, that happens when function graph tracing and jprobes are used simultaneously. Please refer to above commit for details. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org>
2016-07-31s390/als: fix compile with gcov enabledHeiko Carstens
Fix this one when gcov is enabled: arch/s390/kernel/als.o:(.data+0x118): undefined reference to `__gcov_merge_add' arch/s390/kernel/als.o: In function `_GLOBAL__sub_I_65535_0_verify_facilities': (.text.startup+0x8): undefined reference to `__gcov_init' Please merge with "s390/als: convert architecture level set code to C". Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-31s390/als: print missing facilities on facility mismatchHeiko Carstens
If the kernel needs more facilities to run than the machine provides it is running on, print the facility bit numbers which are missing. This allows to easily tell what went wrong and if simply the machine does not provide a required facility or if either the kernel or the hypervisor may have a bug. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-31s390/als: print machine type on facility mismatchHeiko Carstens
If we have a facility mismatch the kernel only emits a warning that the processor is not recent enough and stops operating. This doesn't give us a lot of an idea of what actually went wrong. As a first step print the machine type in addition. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-31s390/als: convert architecture level set code to CHeiko Carstens
There is no reason to have this code in assembly language. Therefore convert it to C. Note that this code needs special treatment: it is called very early and one of the side effects is that e.g. the bss section is not cleared. Therefore the preferred way for static variables is to put them on the stack which has a size of 16KB. There is no functional change with this patch. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-31s390/sclp: move uninitialized data to data sectionHeiko Carstens
The early sclp code may be called before the bss section is cleared. Therefore move all variables to the data section. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-30Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit updates from Paul Moore: "Six audit patches for 4.8. There are a couple of style and minor whitespace tweaks for the logs, as well as a minor fixup to catch errors on user filter rules, however the major improvements are a fix to the s390 syscall argument masking code (reviewed by the nice s390 folks), some consolidation around the exclude filtering (less code, always a win), and a double-fetch fix for recording the execve arguments" * 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit: audit: fix a double fetch in audit_log_single_execve_arg() audit: fix whitespace in CWD record audit: add fields to exclude filter by reusing user filter s390: ensure that syscall arguments are properly masked on s390 audit: fix some horrible switch statement style crimes audit: fixup: log on errors from filter user rules
2016-07-30Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Highlights: - TPM core and driver updates/fixes - IPv6 security labeling (CALIPSO) - Lots of Apparmor fixes - Seccomp: remove 2-phase API, close hole where ptrace can change syscall #" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (156 commits) apparmor: fix SECURITY_APPARMOR_HASH_DEFAULT parameter handling tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family) tpm: Factor out common startup code tpm: use devm_add_action_or_reset tpm2_i2c_nuvoton: add irq validity check tpm: read burstcount from TPM_STS in one 32-bit transaction tpm: fix byte-order for the value read by tpm2_get_tpm_pt tpm_tis_core: convert max timeouts from msec to jiffies apparmor: fix arg_size computation for when setprocattr is null terminated apparmor: fix oops, validate buffer size in apparmor_setprocattr() apparmor: do not expose kernel stack apparmor: fix module parameters can be changed after policy is locked apparmor: fix oops in profile_unpack() when policy_db is not present apparmor: don't check for vmalloc_addr if kvzalloc() failed apparmor: add missing id bounds check on dfa verification apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another task apparmor: use list_next_entry instead of list_entry_next apparmor: fix refcount race when finding a child profile apparmor: fix ref count leak when profile sha1 hash is read apparmor: check that xindex is in trans_table bounds ...
2016-07-29Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp hotplug updates from Thomas Gleixner: "This is the next part of the hotplug rework. - Convert all notifiers with a priority assigned - Convert all CPU_STARTING/DYING notifiers The final removal of the STARTING/DYING infrastructure will happen when the merge window closes. Another 700 hundred line of unpenetrable maze gone :)" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) timers/core: Correct callback order during CPU hot plug leds/trigger/cpu: Move from CPU_STARTING to ONLINE level powerpc/numa: Convert to hotplug state machine arm/perf: Fix hotplug state machine conversion irqchip/armada: Avoid unused function warnings ARC/time: Convert to hotplug state machine clocksource/atlas7: Convert to hotplug state machine clocksource/armada-370-xp: Convert to hotplug state machine clocksource/exynos_mct: Convert to hotplug state machine clocksource/arm_global_timer: Convert to hotplug state machine rcu: Convert rcutree to hotplug state machine KVM/arm/arm64/vgic-new: Convert to hotplug state machine smp/cfd: Convert core to hotplug state machine x86/x2apic: Convert to CPU hotplug state machine profile: Convert to hotplug state machine timers/core: Convert to hotplug state machine hrtimer: Convert to hotplug state machine x86/tboot: Convert to hotplug state machine arm64/armv8 deprecated: Convert to hotplug state machine hwtracing/coresight-etm4x: Convert to hotplug state machine ...
2016-07-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Unified UDP encapsulation offload methods for drivers, from Alexander Duyck. 2) Make DSA binding more sane, from Andrew Lunn. 3) Support QCA9888 chips in ath10k, from Anilkumar Kolli. 4) Several workqueue usage cleanups, from Bhaktipriya Shridhar. 5) Add XDP (eXpress Data Path), essentially running BPF programs on RX packets as soon as the device sees them, with the option to mirror the packet on TX via the same interface. From Brenden Blanco and others. 6) Allow qdisc/class stats dumps to run lockless, from Eric Dumazet. 7) Add VLAN support to b53 and bcm_sf2, from Florian Fainelli. 8) Simplify netlink conntrack entry layout, from Florian Westphal. 9) Add ipv4 forwarding support to mlxsw spectrum driver, from Ido Schimmel, Yotam Gigi, and Jiri Pirko. 10) Add SKB array infrastructure and convert tun and macvtap over to it. From Michael S Tsirkin and Jason Wang. 11) Support qdisc packet injection in pktgen, from John Fastabend. 12) Add neighbour monitoring framework to TIPC, from Jon Paul Maloy. 13) Add NV congestion control support to TCP, from Lawrence Brakmo. 14) Add GSO support to SCTP, from Marcelo Ricardo Leitner. 15) Allow GRO and RPS to function on macsec devices, from Paolo Abeni. 16) Support MPLS over IPV4, from Simon Horman. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1622 commits) xgene: Fix build warning with ACPI disabled. be2net: perform temperature query in adapter regardless of its interface state l2tp: Correctly return -EBADF from pppol2tp_getname. net/mlx5_core/health: Remove deprecated create_singlethread_workqueue net: ipmr/ip6mr: update lastuse on entry change macsec: ensure rx_sa is set when validation is disabled tipc: dump monitor attributes tipc: add a function to get the bearer name tipc: get monitor threshold for the cluster tipc: make cluster size threshold for monitoring configurable tipc: introduce constants for tipc address validation net: neigh: disallow transition to NUD_STALE if lladdr is unchanged in neigh_update() MAINTAINERS: xgene: Add driver and documentation path Documentation: dtb: xgene: Add MDIO node dtb: xgene: Add MDIO node drivers: net: xgene: ethtool: Use phy_ethtool_gset and sset drivers: net: xgene: Use exported functions drivers: net: xgene: Enable MDIO driver drivers: net: xgene: Add backward compatibility drivers: net: phy: xgene: Add MDIO driver ...
2016-07-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "There are a couple of new things for s390 with this merge request: - a new scheduling domain "drawer" is added to reflect the unusual topology found on z13 machines. Performance tests showed up to 8 percent gain with the additional domain. - the new crc-32 checksum crypto module uses the vector-galois-field multiply and sum SIMD instruction to speed up crc-32 and crc-32c. - proper __ro_after_init support, this requires RO_AFTER_INIT_DATA in the generic vmlinux.lds linker script definitions. - kcov instrumentation support. A prerequisite for that is the inline assembly basic block cleanup, which is the reason for the net/iucv/iucv.c change. - support for 2GB pages is added to the hugetlbfs backend. Then there are two removals: - the oprofile hardware sampling support is dead code and is removed. The oprofile user space uses the perf interface nowadays. - the ETR clock synchronization is removed, this has been superseeded be the STP clock synchronization. And it always has been "interesting" code.. And the usual bug fixes and cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (82 commits) s390/pci: Delete an unnecessary check before the function call "pci_dev_put" s390/smp: clean up a condition s390/cio/chp : Remove deprecated create_singlethread_workqueue s390/chsc: improve channel path descriptor determination s390/chsc: sanitize fmt check for chp_desc determination s390/cio: make fmt1 channel path descriptor optional s390/chsc: fix ioctl CHSC_INFO_CU command s390/cio/device_ops: fix kernel doc s390/cio: allow to reset channel measurement block s390/console: Make preferred console handling more consistent s390/mm: fix gmap tlb flush issues s390/mm: add support for 2GB hugepages s390: have unique symbol for __switch_to address s390/cpuinfo: show maximum thread id s390/ptrace: clarify bits in the per_struct s390: stack address vs thread_info s390: remove pointless load within __switch_to s390: enable kcov support s390/cpumf: use basic block for ecctr inline assembly s390/hypfs: use basic block for diag inline assembly ...
2016-07-18s390/smp: clean up a conditionDan Carpenter
I can never remember precedence rules. Let's add some parenthesis so this code is more clear. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-15perf, events: add non-linear data support for raw recordsDaniel Borkmann
This patch adds support for non-linear data on raw records. It extends raw records to have one or multiple fragments that will be written linearly into the ring slot, where each fragment can optionally have a custom callback handler to walk and extract complex, possibly non-linear data. If a callback handler is provided for a fragment, then the new __output_custom() will be used instead of __output_copy() for the perf_output_sample() part. perf_prepare_sample() does all the size calculation only once, so perf_output_sample() doesn't need to redo the same work anymore, meaning real_size and padding will be cached in the raw record. The raw record becomes 32 bytes in size without holes; to not increase it further and to avoid doing unnecessary recalculations in fast-path, we can reuse next pointer of the last fragment, idea here is borrowed from ZERO_OR_NULL_PTR(), which should keep the perf_output_sample() path for PERF_SAMPLE_RAW minimal. This facility is needed for BPF's event output helper as a first user that will, in a follow-up, add an additional perf_raw_frag to its perf_raw_record in order to be able to more efficiently dump skb context after a linear head meta data related to it. skbs can be non-linear and thus need a custom output function to dump buffers. Currently, the skb data needs to be copied twice; with the help of __output_custom() this work only needs to be done once. Future users could be things like XDP/BPF programs that work on different context though and would thus also have a different callback function. The few users of raw records are adapted to initialize their frag data from the raw record itself, no change in behavior for them. The code is based upon a PoC diff provided by Peter Zijlstra [1]. [1] http://thread.gmane.org/gmane.linux.network/421294 Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>