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* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds2020-06-132-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Fix cfg80211 deadlock, from Johannes Berg. 2) RXRPC fails to send norigications, from David Howells. 3) MPTCP RM_ADDR parsing has an off by one pointer error, fix from Geliang Tang. 4) Fix crash when using MSG_PEEK with sockmap, from Anny Hu. 5) The ucc_geth driver needs __netdev_watchdog_up exported, from Valentin Longchamp. 6) Fix hashtable memory leak in dccp, from Wang Hai. 7) Fix how nexthops are marked as FDB nexthops, from David Ahern. 8) Fix mptcp races between shutdown and recvmsg, from Paolo Abeni. 9) Fix crashes in tipc_disc_rcv(), from Tuong Lien. 10) Fix link speed reporting in iavf driver, from Brett Creeley. 11) When a channel is used for XSK and then reused again later for XSK, we forget to clear out the relevant data structures in mlx5 which causes all kinds of problems. Fix from Maxim Mikityanskiy. 12) Fix memory leak in genetlink, from Cong Wang. 13) Disallow sockmap attachments to UDP sockets, it simply won't work. From Lorenz Bauer. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits) net: ethernet: ti: ale: fix allmulti for nu type ale net: ethernet: ti: am65-cpsw-nuss: fix ale parameters init net: atm: Remove the error message according to the atomic context bpf: Undo internal BPF_PROBE_MEM in BPF insns dump libbpf: Support pre-initializing .bss global variables tools/bpftool: Fix skeleton codegen bpf: Fix memlock accounting for sock_hash bpf: sockmap: Don't attach programs to UDP sockets bpf: tcp: Recv() should return 0 when the peer socket is closed ibmvnic: Flush existing work items before device removal genetlink: clean up family attributes allocations net: ipa: header pad field only valid for AP->modem endpoint net: ipa: program upper nibbles of sequencer type net: ipa: fix modem LAN RX endpoint id net: ipa: program metadata mask differently ionic: add pcie_print_link_status rxrpc: Fix race between incoming ACK parser and retransmitter net/mlx5: E-Switch, Fix some error pointer dereferences net/mlx5: Don't fail driver on failure to create debugfs net/mlx5e: CT: Fix ipv6 nat header rewrite actions ...
| * tracing/probe: Fix bpf_task_fd_query() for kprobes and uprobesJean-Philippe Brucker2020-06-092-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") removed the trace_[ku]probe structure from the trace_event_call->data pointer. As bpf_get_[ku]probe_info() were forgotten in that change, fix them now. These functions are currently only used by the bpf_task_fd_query() syscall handler to collect information about a perf event. Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/bpf/20200608124531.819838-1-jean-philippe@linaro.org
* | Merge tag 'x86-entry-2020-06-12' of ↵Linus Torvalds2020-06-131-5/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 entry updates from Thomas Gleixner: "The x86 entry, exception and interrupt code rework This all started about 6 month ago with the attempt to move the Posix CPU timer heavy lifting out of the timer interrupt code and just have lockless quick checks in that code path. Trivial 5 patches. This unearthed an inconsistency in the KVM handling of task work and the review requested to move all of this into generic code so other architectures can share. Valid request and solved with another 25 patches but those unearthed inconsistencies vs. RCU and instrumentation. Digging into this made it obvious that there are quite some inconsistencies vs. instrumentation in general. The int3 text poke handling in particular was completely unprotected and with the batched update of trace events even more likely to expose to endless int3 recursion. In parallel the RCU implications of instrumenting fragile entry code came up in several discussions. The conclusion of the x86 maintainer team was to go all the way and make the protection against any form of instrumentation of fragile and dangerous code pathes enforcable and verifiable by tooling. A first batch of preparatory work hit mainline with commit d5f744f9a2ac ("Pull x86 entry code updates from Thomas Gleixner") That (almost) full solution introduced a new code section '.noinstr.text' into which all code which needs to be protected from instrumentation of all sorts goes into. Any call into instrumentable code out of this section has to be annotated. objtool has support to validate this. Kprobes now excludes this section fully which also prevents BPF from fiddling with it and all 'noinstr' annotated functions also keep ftrace off. The section, kprobes and objtool changes are already merged. The major changes coming with this are: - Preparatory cleanups - Annotating of relevant functions to move them into the noinstr.text section or enforcing inlining by marking them __always_inline so the compiler cannot misplace or instrument them. - Splitting and simplifying the idtentry macro maze so that it is now clearly separated into simple exception entries and the more interesting ones which use interrupt stacks and have the paranoid handling vs. CR3 and GS. - Move quite some of the low level ASM functionality into C code: - enter_from and exit to user space handling. The ASM code now calls into C after doing the really necessary ASM handling and the return path goes back out without bells and whistels in ASM. - exception entry/exit got the equivivalent treatment - move all IRQ tracepoints from ASM to C so they can be placed as appropriate which is especially important for the int3 recursion issue. - Consolidate the declaration and definition of entry points between 32 and 64 bit. They share a common header and macros now. - Remove the extra device interrupt entry maze and just use the regular exception entry code. - All ASM entry points except NMI are now generated from the shared header file and the corresponding macros in the 32 and 64 bit entry ASM. - The C code entry points are consolidated as well with the help of DEFINE_IDTENTRY*() macros. This allows to ensure at one central point that all corresponding entry points share the same semantics. The actual function body for most entry points is in an instrumentable and sane state. There are special macros for the more sensitive entry points, e.g. INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF. They allow to put the whole entry instrumentation and RCU handling into safe places instead of the previous pray that it is correct approach. - The INT3 text poke handling is now completely isolated and the recursion issue banned. Aside of the entry rework this required other isolation work, e.g. the ability to force inline bsearch. - Prevent #DB on fragile entry code, entry relevant memory and disable it on NMI, #MC entry, which allowed to get rid of the nested #DB IST stack shifting hackery. - A few other cleanups and enhancements which have been made possible through this and already merged changes, e.g. consolidating and further restricting the IDT code so the IDT table becomes RO after init which removes yet another popular attack vector - About 680 lines of ASM maze are gone. There are a few open issues: - An escape out of the noinstr section in the MCE handler which needs some more thought but under the aspect that MCE is a complete trainwreck by design and the propability to survive it is low, this was not high on the priority list. - Paravirtualization When PV is enabled then objtool complains about a bunch of indirect calls out of the noinstr section. There are a few straight forward ways to fix this, but the other issues vs. general correctness were more pressing than parawitz. - KVM KVM is inconsistent as well. Patches have been posted, but they have not yet been commented on or picked up by the KVM folks. - IDLE Pretty much the same problems can be found in the low level idle code especially the parts where RCU stopped watching. This was beyond the scope of the more obvious and exposable problems and is on the todo list. The lesson learned from this brain melting exercise to morph the evolved code base into something which can be validated and understood is that once again the violation of the most important engineering principle "correctness first" has caused quite a few people to spend valuable time on problems which could have been avoided in the first place. The "features first" tinkering mindset really has to stop. With that I want to say thanks to everyone involved in contributing to this effort. Special thanks go to the following people (alphabetical order): Alexandre Chartre, Andy Lutomirski, Borislav Petkov, Brian Gerst, Frederic Weisbecker, Josh Poimboeuf, Juergen Gross, Lai Jiangshan, Macro Elver, Paolo Bonzin,i Paul McKenney, Peter Zijlstra, Vitaly Kuznetsov, and Will Deacon" * tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (142 commits) x86/entry: Force rcu_irq_enter() when in idle task x86/entry: Make NMI use IDTENTRY_RAW x86/entry: Treat BUG/WARN as NMI-like entries x86/entry: Unbreak __irqentry_text_start/end magic x86/entry: __always_inline CR2 for noinstr lockdep: __always_inline more for noinstr x86/entry: Re-order #DB handler to avoid *SAN instrumentation x86/entry: __always_inline arch_atomic_* for noinstr x86/entry: __always_inline irqflags for noinstr x86/entry: __always_inline debugreg for noinstr x86/idt: Consolidate idt functionality x86/idt: Cleanup trap_init() x86/idt: Use proper constants for table size x86/idt: Add comments about early #PF handling x86/idt: Mark init only functions __init x86/entry: Rename trace_hardirqs_off_prepare() x86/entry: Clarify irq_{enter,exit}_rcu() x86/entry: Remove DBn stacks x86/entry: Remove debug IDT frobbing x86/entry: Optimize local_db_save() for virt ...
| * | x86/entry: Rename trace_hardirqs_off_prepare()Peter Zijlstra2020-06-111-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The typical pattern for trace_hardirqs_off_prepare() is: ENTRY lockdep_hardirqs_off(); // because hardware ... do entry magic instrumentation_begin(); trace_hardirqs_off_prepare(); ... do actual work trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(); instrumentation_end(); ... do exit magic lockdep_hardirqs_on(); which shows that it's named wrong, rename it to trace_hardirqs_off_finish(), as it concludes the hardirq_off transition. Also, given that the above is the only correct order, make the traditional all-in-one trace_hardirqs_off() follow suit. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200529213321.415774872@infradead.org
* | | Merge tag 'locking-kcsan-2020-06-11' of ↵Linus Torvalds2020-06-111-0/+3
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull the Kernel Concurrency Sanitizer from Thomas Gleixner: "The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector, which relies on compile-time instrumentation, and uses a watchpoint-based sampling approach to detect races. The feature was under development for quite some time and has already found legitimate bugs. Unfortunately it comes with a limitation, which was only understood late in the development cycle: It requires an up to date CLANG-11 compiler CLANG-11 is not yet released (scheduled for June), but it's the only compiler today which handles the kernel requirements and especially the annotations of functions to exclude them from KCSAN instrumentation correctly. These annotations really need to work so that low level entry code and especially int3 text poke handling can be completely isolated. A detailed discussion of the requirements and compiler issues can be found here: https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/ We came to the conclusion that trying to work around compiler limitations and bugs again would end up in a major trainwreck, so requiring a working compiler seemed to be the best choice. For Continous Integration purposes the compiler restriction is manageable and that's where most xxSAN reports come from. For a change this limitation might make GCC people actually look at their bugs. Some issues with CSAN in GCC are 7 years old and one has been 'fixed' 3 years ago with a half baken solution which 'solved' the reported issue but not the underlying problem. The KCSAN developers also ponder to use a GCC plugin to become independent, but that's not something which will show up in a few days. Blocking KCSAN until wide spread compiler support is available is not a really good alternative because the continuous growth of lockless optimizations in the kernel demands proper tooling support" * tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits) compiler_types.h, kasan: Use __SANITIZE_ADDRESS__ instead of CONFIG_KASAN to decide inlining compiler.h: Move function attributes to compiler_types.h compiler.h: Avoid nested statement expression in data_race() compiler.h: Remove data_race() and unnecessary checks from {READ,WRITE}_ONCE() kcsan: Update Documentation to change supported compilers kcsan: Remove 'noinline' from __no_kcsan_or_inline kcsan: Pass option tsan-instrument-read-before-write to Clang kcsan: Support distinguishing volatile accesses kcsan: Restrict supported compilers kcsan: Avoid inserting __tsan_func_entry/exit if possible ubsan, kcsan: Don't combine sanitizer with kcov on clang objtool, kcsan: Add kcsan_disable_current() and kcsan_enable_current_nowarn() kcsan: Add __kcsan_{enable,disable}_current() variants checkpatch: Warn about data_race() without comment kcsan: Use GFP_ATOMIC under spin lock Improve KCSAN documentation a bit kcsan: Make reporting aware of KCSAN tests kcsan: Fix function matching in report kcsan: Change data_race() to no longer require marking racing accesses kcsan: Move kcsan_{disable,enable}_current() to kcsan-checks.h ...
| * \ \ Rebase locking/kcsan to locking/urgentThomas Gleixner2020-06-111-0/+3
| |\ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge the state of the locking kcsan branch before the read/write_once() and the atomics modifications got merged. Squash the fallout of the rebase on top of the read/write once and atomic fallback work into the merge. The history of the original branch is preserved in tag locking-kcsan-2020-06-02. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * | Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refreshIngo Molnar2020-04-1312-221/+788
| | |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Resolve these conflicts: arch/x86/Kconfig arch/x86/kernel/Makefile Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines in the Kconfig to reduce the probability of future conflicts. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | kcsan, trace: Make KCSAN compatible with tracingMarco Elver2020-03-211-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously the system would lock up if ftrace was enabled together with KCSAN. This is due to recursion on reporting if the tracer code is instrumented with KCSAN. To avoid this for all types of tracing, disable KCSAN instrumentation for all of kernel/trace. Furthermore, since KCSAN relies on udelay() to introduce delay, we have to disable ftrace for udelay() (currently done for x86) in case KCSAN is used together with lockdep and ftrace. The reason is that it may corrupt lockdep IRQ flags tracing state due to a peculiar case of recursion (details in Makefile comment). Reported-by: Qian Cai <cai@lca.pw> Tested-by: Qian Cai <cai@lca.pw> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | Merge tag 'block-5.8-2020-06-11' of git://git.kernel.dk/linux-blockLinus Torvalds2020-06-111-22/+14
|\ \ \ \ \ | |/ / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: "Some followup fixes for this merge window. In particular: - Seqcount write missing preemption disable for stats (Ahmed) - blktrace fixes (Chaitanya) - Redundant initializations (Colin) - Various small NVMe fixes (Chaitanya, Christoph, Daniel, Max, Niklas, Rikard) - loop flag bug regression fix (Martijn) - blk-mq tagging fixes (Christoph, Ming)" * tag 'block-5.8-2020-06-11' of git://git.kernel.dk/linux-block: umem: remove redundant initialization of variable ret pktcdvd: remove redundant initialization of variable ret nvmet: fail outstanding host posted AEN req nvme-pci: use simple suspend when a HMB is enabled nvme-fc: don't call nvme_cleanup_cmd() for AENs nvmet-tcp: constify nvmet_tcp_ops nvme-tcp: constify nvme_tcp_mq_ops and nvme_tcp_admin_mq_ops nvme: do not call del_gendisk() on a disk that was never added blk-mq: fix blk_mq_all_tag_iter blk-mq: split out a __blk_mq_get_driver_tag helper blktrace: fix endianness for blk_log_remap() blktrace: fix endianness in get_pdu_int() blktrace: use errno instead of bi_status block: nr_sects_write(): Disable preemption on seqcount write block: remove the error argument to the block_bio_complete tracepoint loop: Fix wrong masking of status flags block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed
| * | | | blktrace: fix endianness for blk_log_remap()Chaitanya Kulkarni2020-06-041-15/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function blk_log_remap() can be simplified by removing the call to get_pdu_remap() that copies the values into extra variable to print the data, which also fixes the endiannness warning reported by sparse. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | | | blktrace: fix endianness in get_pdu_int()Chaitanya Kulkarni2020-06-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In function get_pdu_len() replace variable type from __u64 to __be64. This fixes sparse warning. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | | | blktrace: use errno instead of bi_statusChaitanya Kulkarni2020-06-041-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In blk_add_trace_spliti() blk_add_trace_bio_remap() use blk_status_to_errno() to pass the error instead of pasing the bi_status. This fixes the sparse warning. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | | | block: remove the error argument to the block_bio_complete tracepointChristoph Hellwig2020-06-041-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The status can be trivially derived from the bio itself. That also avoid callers like NVMe to incorrectly pass a blk_status_t instead of the errno, and the overhead of translating the blk_status_t to the errno in the I/O completion fast path when no tracing is enabled. Fixes: 35fe0d12c8a3 ("nvme: trace bio completion") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | | | | Merge branch 'work.sysctl' of ↵Linus Torvalds2020-06-101-3/+2
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull sysctl fixes from Al Viro: "Fixups to regressions in sysctl series" * 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: sysctl: reject gigantic reads/write to sysctl files cdrom: fix an incorrect __user annotation on cdrom_sysctl_info trace: fix an incorrect __user annotation on stack_trace_sysctl random: fix an incorrect __user annotation on proc_do_entropy net/sysctl: remove leftover __user annotations on neigh_proc_dointvec* net/sysctl: use cpumask_parse in flow_limit_cpu_sysctl
| * | | | | trace: fix an incorrect __user annotation on stack_trace_sysctlChristoph Hellwig2020-06-081-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No user pointers for sysctls anymore. Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Reported-by: build test robot <lkp@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | | Merge tag 'trace-v5.8' of ↵Linus Torvalds2020-06-0910-1814/+2157
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "No new features this release. Mostly clean ups, restructuring and documentation. - Have ftrace_bug() show ftrace errors before the WARN, as the WARN will reboot the box before the error messages are printed if panic_on_warn is set. - Have traceoff_on_warn disable tracing sooner (before prints) - Write a message to the trace buffer that its being disabled when disable_trace_on_warning() is set. - Separate out synthetic events from histogram code to let it be used by other parts of the kernel. - More documentation on histogram design. - Other small fixes and clean ups" * tag 'trace-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Remove obsolete PREEMPTIRQ_EVENTS kconfig option tracing/doc: Fix ascii-art in histogram-design.rst tracing: Add a trace print when traceoff_on_warning is triggered ftrace,bug: Improve traceoff_on_warn selftests/ftrace: Distinguish between hist and synthetic event checks tracing: Move synthetic events to a separate file tracing: Fix events.rst section numbering tracing/doc: Fix typos in histogram-design.rst tracing: Add hist_debug trace event files for histogram debugging tracing: Add histogram-design document tracing: Check state.disabled in synth event trace functions tracing/probe: reverse arguments to list_add tools/bootconfig: Add a summary of test cases and return error ftrace: show debugging information when panic_on_warn set
| * | | | | | tracing: Remove obsolete PREEMPTIRQ_EVENTS kconfig optionMel Gorman2020-06-051-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PREEMPTIRQ_EVENTS option is unused after commit c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage"). Remove it. Note that this option is hazardous as it stands. It enables TRACE_IRQFLAGS event on non-preempt configurations without the irqsoff tracer enabled. TRACE_IRQFLAGS as it stands incurs significant overhead on each IRQ entry/exit. This is because trace_hardirqs_[on|off] does all the per-cpu manipulations and NMI checks even if tracing is completely disabled for some insane reason. For example, netperf running UDP_STREAM on localhost incurs a 4-6% performance penalty without any tracing if IRQFLAGS is set. It can be put behind a static brach but even the function entry/exit costs a little bit. Link: https://lkml.kernel.org/r/20200409104034.GJ3818@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | tracing: Add a trace print when traceoff_on_warning is triggeredSteven Rostedt (VMware)2020-06-011-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When "traceoff_on_warning" is enabled and a warning happens, there can still be many trace events happening on other CPUs between the time the warning occurred and the last trace event on that same CPU. This can cause confusion in examining the trace, as it may not be obvious where the warning happened. By adding a trace print into the trace just before disabling tracing, it makes it obvious where the warning occurred, and the developer doesn't have to look at other means to see what CPU it occurred on. Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | tracing: Move synthetic events to a separate fileTom Zanussi2020-06-015-1786/+1847
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the addition of the in-kernel synthetic event API, synthetic events are no longer specifically tied to the histogram triggers. The synthetic event code is also making trace_event_hist.c very bloated, so for those reasons, move it to a separate file, trace_events_synth.c, along with a new trace_synth.h header file. Because synthetic events are now independent from hist triggers, add a new CONFIG_SYNTH_EVENTS config option, and have CONFIG_HIST_TRIGGERS select it, and have CONFIG_SYNTH_EVENT_GEN_TEST depend on it. Link: http://lkml.kernel.org/r/4d1fa1f85ed5982706ac44844ac92451dcb04715.1590693308.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | tracing: Add hist_debug trace event files for histogram debuggingTom Zanussi2020-06-014-0/+301
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new "hist_debug" file for each trace event, which when read will dump out a bunch of internal details about the hist triggers defined on that event. This is normally off but can be enabled by saying 'y' to the new CONFIG_HIST_TRIGGERS_DEBUG config option. This is in support of the new Documentation file describing histogram internals, Documentation/trace/histogram-design.rst, which was requested by developers trying to understand the internals when extending or making use of the hist triggers for higher-level tools. The histogram-design.rst documentation refers to the hist_debug files and demonstrates their use with output in the test examples. Link: http://lkml.kernel.org/r/77914c22b0ba493d9783c53bbfbc6087d6a7e1b1.1585941485.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | tracing: Check state.disabled in synth event trace functionsTom Zanussi2020-06-011-16/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since trace_state.disabled is set in __synth_event_trace_start() at the same time -ENOENT is returned, don't bother returning -ENOENT - just have callers check trace_state.disabled instead, and avoid the extra return val munging. Link: http://lkml.kernel.org/r/87315c3889af870e8370e82b76cf48b426d70130.1585941485.git.zanussi@kernel.org Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@godmis.org>
| * | | | | | tracing/probe: reverse arguments to list_addJulia Lawall2020-05-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Elsewhere in the file, the function trace_kprobe_has_same_kprobe uses a trace_probe_event.probes object as the second argument of list_for_each_entry, ie as a list head, while the list_for_each_entry iterates over the list fields of the trace_probe structures, making them the list elements. So, exchange the arguments on the list_add call to put the list head in the second argument. Since both list_head structures were just initialized, this problem did not cause any loss of information. Link: https://lkml.kernel.org/r/1588879808-24488-1-git-send-email-Julia.Lawall@inria.fr Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | | ftrace: show debugging information when panic_on_warn setCheng Jian2020-05-191-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an anomaly is detected in the function call modification code, ftrace_bug() is called to disable function tracing as well as give some warn and information that may help debug the problem. But currently, we call FTRACE_WARN_ON_ONCE() first in ftrace_bug(), so when panic_on_warn is set, we can't see the debugging information here. Call FTRACE_WARN_ON_ONCE() at the end of ftrace_bug() to ensure that the debugging information is displayed first. after this patch, the dmesg looks like: ------------[ ftrace bug ]------------ ftrace failed to modify [<ffff800010081004>] bcm2835_handle_irq+0x4/0x58 actual: 1f:20:03:d5 Setting ftrace call site to call ftrace function ftrace record flags: 80000001 (1) expected tramp: ffff80001009d6f0 ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1635 at kernel/trace/ftrace.c:2078 ftrace_bug+0x204/0x238 Kernel panic - not syncing: panic_on_warn set ... CPU: 2 PID: 1635 Comm: sh Not tainted 5.7.0-rc5-00033-gb922183867f5 #14 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x1b0 show_stack+0x20/0x30 dump_stack+0xc0/0x10c panic+0x16c/0x368 __warn+0x120/0x160 report_bug+0xc8/0x160 bug_handler+0x28/0x98 brk_handler+0x70/0xd0 do_debug_exception+0xcc/0x1ac el1_sync_handler+0xe4/0x120 el1_sync+0x7c/0x100 ftrace_bug+0x204/0x238 Link: https://lkml.kernel.org/r/20200515100828.7091-1-cj.chengjian@huawei.com Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | | | | | | maccess: always use strict semantics for probe_kernel_readChristoph Hellwig2020-06-092-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Except for historical confusion in the kprobes/uprobes and bpf tracers, which has been fixed now, there is no good reason to ever allow user memory accesses from probe_kernel_read. Switch probe_kernel_read to only read from kernel memory. [akpm@linux-foundation.org: update it for "mm, dump_page(): do not crash with invalid mapping pointer"] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200521152301.2587579-17-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | tracing/kprobes: handle mixed kernel/userspace probes betterChristoph Hellwig2020-06-091-29/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of using the dangerous probe_kernel_read and strncpy_from_unsafe helpers, rework probes to try a user probe based on the address if the architecture has a common address space for kernel and userspace. [svens@linux.ibm.com:use strncpy_from_kernel_nofault() in fetch_store_string()] Link: http://lkml.kernel.org/r/20200606181903.49384-1-svens@linux.ibm.com Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200521152301.2587579-15-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | bpf: rework the compat kernel probe handlingChristoph Hellwig2020-06-091-42/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of using the dangerous probe_kernel_read and strncpy_from_unsafe helpers, rework the compat probes to check if an address is a kernel or userspace one, and then use the low-level kernel or user probe helper shared by the proper kernel and user probe helpers. This slightly changes behavior as the compat probe on a user address doesn't check the lockdown flags, just as the pure user probes do. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200521152301.2587579-14-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | bpf:bpf_seq_printf(): handle potentially unsafe format string betterAndrew Morton2020-06-091-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | User the proper helper for kernel or userspace addresses based on TASK_SIZE instead of the dangerous strncpy_from_unsafe function. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | bpf: handle the compat string in bpf_trace_copy_string betterChristoph Hellwig2020-06-091-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | User the proper helper for kernel or userspace addresses based on TASK_SIZE instead of the dangerous strncpy_from_unsafe function. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200521152301.2587579-13-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | bpf: factor out a bpf_trace_copy_string helperChristoph Hellwig2020-06-091-18/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split out a helper to do the fault free access to the string pointer to get it out of a crazy indentation level. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200521152301.2587579-12-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | maccess: rename strnlen_unsafe_user to strnlen_user_nofaultChristoph Hellwig2020-06-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This matches the naming of strnlen_user, and also makes it more clear what the function is supposed to do. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200521152301.2587579-9-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofaultChristoph Hellwig2020-06-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This matches the naming of strncpy_from_user_nofault, and also makes it more clear what the function is supposed to do. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200521152301.2587579-8-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofaultChristoph Hellwig2020-06-092-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This matches the naming of strncpy_from_user, and also makes it more clear what the function is supposed to do. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200521152301.2587579-7-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | mmap locking API: use coccinelle to convert mmap_sem rwsem call sitesMichel Lespinasse2020-06-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | kallsyms/printk: add loglvl to print_ip_sym()Dmitry Safonov2020-06-091-4/+4
| |_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Add log level to show_stack()", v3. Add log level argument to show_stack(). Done in three stages: 1. Introducing show_stack_loglvl() for every architecture 2. Migrating old users with an explicit log level 3. Renaming show_stack_loglvl() into show_stack() Justification: - It's a design mistake to move a business-logic decision into platform realization detail. - I have currently two patches sets that would benefit from this work: Removing console_loglevel jumps in sysrq driver [1] Hung task warning before panic [2] - suggested by Tetsuo (but he probably didn't realise what it would involve). - While doing (1), (2) the backtraces were adjusted to headers and other messages for each situation - so there won't be a situation when the backtrace is printed, but the headers are missing because they have lesser log level (or the reverse). - As the result in (2) plays with console_loglevel for kdb are removed. The least important for upstream, but maybe still worth to note that every company I've worked in so far had an off-list patch to print backtrace with the needed log level (but only for the architecture they cared about). If you have other ideas how you will benefit from show_stack() with a log level - please, reply to this cover letter. See also discussion on v1: https://lore.kernel.org/linux-riscv/20191106083538.z5nlpuf64cigxigh@pathway.suse.cz/ This patch (of 50): print_ip_sym() needs to have a log level parameter to comply with other parts being printed. Otherwise, half of the expected backtrace would be printed and other may be missing with some logging level. The following callee(s) are using now the adjusted log level: - microblaze/unwind: the same level as headers & userspace unwind. Note that pr_debug()'s there are for debugging the unwinder itself. - nds32/traps: symbol addresses are printed with the same log level as backtrace headers. - lockdep: ip for locking issues is printed with the same log level as other part of the warning. - sched: ip where preemption was disabled is printed as error like the rest part of the message. - ftrace: bug reports are now consistent in the log level being used. Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Ben Segall <bsegall@google.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Burton <paulburton@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Will Deacon <will@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Dmitry Safonov <dima@arista.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com> Cc: Mark Salter <msalter@redhat.com> Cc: Guo Ren <guoren@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Brian Cain <bcain@codeaurora.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ley Foon Tan <lftan@altera.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Jason Wessel <jason.wessel@windriver.com> Link: http://lkml.kernel.org/r/20200418201944.482088-2-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds2020-06-032-7/+236
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz Augusto von Dentz. 2) Add GSO partial support to igc, from Sasha Neftin. 3) Several cleanups and improvements to r8169 from Heiner Kallweit. 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a device self-test. From Andrew Lunn. 5) Start moving away from custom driver versions, use the globally defined kernel version instead, from Leon Romanovsky. 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin. 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet. 8) Add sriov and vf support to hinic, from Luo bin. 9) Support Media Redundancy Protocol (MRP) in the bridging code, from Horatiu Vultur. 10) Support netmap in the nft_nat code, from Pablo Neira Ayuso. 11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina Dubroca. Also add ipv6 support for espintcp. 12) Lots of ReST conversions of the networking documentation, from Mauro Carvalho Chehab. 13) Support configuration of ethtool rxnfc flows in bcmgenet driver, from Doug Berger. 14) Allow to dump cgroup id and filter by it in inet_diag code, from Dmitry Yakunin. 15) Add infrastructure to export netlink attribute policies to userspace, from Johannes Berg. 16) Several optimizations to sch_fq scheduler, from Eric Dumazet. 17) Fallback to the default qdisc if qdisc init fails because otherwise a packet scheduler init failure will make a device inoperative. From Jesper Dangaard Brouer. 18) Several RISCV bpf jit optimizations, from Luke Nelson. 19) Correct the return type of the ->ndo_start_xmit() method in several drivers, it's netdev_tx_t but many drivers were using 'int'. From Yunjian Wang. 20) Add an ethtool interface for PHY master/slave config, from Oleksij Rempel. 21) Add BPF iterators, from Yonghang Song. 22) Add cable test infrastructure, including ethool interfaces, from Andrew Lunn. Marvell PHY driver is the first to support this facility. 23) Remove zero-length arrays all over, from Gustavo A. R. Silva. 24) Calculate and maintain an explicit frame size in XDP, from Jesper Dangaard Brouer. 25) Add CAP_BPF, from Alexei Starovoitov. 26) Support terse dumps in the packet scheduler, from Vlad Buslov. 27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei. 28) Add devm_register_netdev(), from Bartosz Golaszewski. 29) Minimize qdisc resets, from Cong Wang. 30) Get rid of kernel_getsockopt and kernel_setsockopt in order to eliminate set_fs/get_fs calls. From Christoph Hellwig. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits) selftests: net: ip_defrag: ignore EPERM net_failover: fixed rollback in net_failover_open() Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv" Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv" vmxnet3: allow rx flow hash ops only when rss is enabled hinic: add set_channels ethtool_ops support selftests/bpf: Add a default $(CXX) value tools/bpf: Don't use $(COMPILE.c) bpf, selftests: Use bpf_probe_read_kernel s390/bpf: Use bcr 0,%0 as tail call nop filler s390/bpf: Maintain 8-byte stack alignment selftests/bpf: Fix verifier test selftests/bpf: Fix sample_cnt shared between two threads bpf, selftests: Adapt cls_redirect to call csum_level helper bpf: Add csum_level helper for fixing up csum levels bpf: Fix up bpf_skb_adjust_room helper's skb csum setting sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf() crypto/chtls: IPv6 support for inline TLS Crypto/chcr: Fixes a coccinile check error Crypto/chcr: Fixes compilations warnings ...
| * | | | | | bpf: Use tracing helpers for lsm programsJiri Olsa2020-06-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currenty lsm uses bpf_tracing_func_proto helpers which do not include stack trace or perf event output. It's useful to have those for bpftrace lsm support [1]. Using tracing_prog_func_proto helpers for lsm programs. [1] https://github.com/iovisor/bpftrace/pull/1347 Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: KP Singh <kpsingh@google.com> Link: https://lore.kernel.org/bpf/20200531154255.896551-1-jolsa@kernel.org
| * | | | | | bpf: Use strncpy_from_unsafe_strict() in bpf_seq_printf() helperYonghong Song2020-06-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In bpf_seq_printf() helper, when user specified a "%s" in the format string, strncpy_from_unsafe() is used to read the actual string to a buffer. The string could be a format string or a string in the kernel data structure. It is really unlikely that the string will reside in the user memory. This is different from Commit b2a5212fb634 ("bpf: Restrict bpf_trace_printk()'s %s usage and add %pks, %pus specifier") which still used strncpy_from_unsafe() for "%s" to preserve the old behavior. If in the future, bpf_seq_printf() indeed needs to read user memory, we can implement "%pus" format string. Based on discussion in [1], if the intent is to read kernel memory, strncpy_from_unsafe_strict() should be used. So this patch changed to use strncpy_from_unsafe_strict(). [1]: https://lore.kernel.org/bpf/20200521152301.2587579-1-hch@lst.de/T/ Fixes: 492e639f0c22 ("bpf: Add bpf_seq_printf and bpf_seq_write helpers") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Cc: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/bpf/20200529004810.3352219-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | | bpf: Implement BPF ring buffer and verifier support for itAndrii Nakryiko2020-06-011-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds a new MPSC ring buffer implementation into BPF ecosystem, which allows multiple CPUs to submit data to a single shared ring buffer. On the consumption side, only single consumer is assumed. Motivation ---------- There are two distinctive motivators for this work, which are not satisfied by existing perf buffer, which prompted creation of a new ring buffer implementation. - more efficient memory utilization by sharing ring buffer across CPUs; - preserving ordering of events that happen sequentially in time, even across multiple CPUs (e.g., fork/exec/exit events for a task). These two problems are independent, but perf buffer fails to satisfy both. Both are a result of a choice to have per-CPU perf ring buffer. Both can be also solved by having an MPSC implementation of ring buffer. The ordering problem could technically be solved for perf buffer with some in-kernel counting, but given the first one requires an MPSC buffer, the same solution would solve the second problem automatically. Semantics and APIs ------------------ Single ring buffer is presented to BPF programs as an instance of BPF map of type BPF_MAP_TYPE_RINGBUF. Two other alternatives considered, but ultimately rejected. One way would be to, similar to BPF_MAP_TYPE_PERF_EVENT_ARRAY, make BPF_MAP_TYPE_RINGBUF could represent an array of ring buffers, but not enforce "same CPU only" rule. This would be more familiar interface compatible with existing perf buffer use in BPF, but would fail if application needed more advanced logic to lookup ring buffer by arbitrary key. HASH_OF_MAPS addresses this with current approach. Additionally, given the performance of BPF ringbuf, many use cases would just opt into a simple single ring buffer shared among all CPUs, for which current approach would be an overkill. Another approach could introduce a new concept, alongside BPF map, to represent generic "container" object, which doesn't necessarily have key/value interface with lookup/update/delete operations. This approach would add a lot of extra infrastructure that has to be built for observability and verifier support. It would also add another concept that BPF developers would have to familiarize themselves with, new syntax in libbpf, etc. But then would really provide no additional benefits over the approach of using a map. BPF_MAP_TYPE_RINGBUF doesn't support lookup/update/delete operations, but so doesn't few other map types (e.g., queue and stack; array doesn't support delete, etc). The approach chosen has an advantage of re-using existing BPF map infrastructure (introspection APIs in kernel, libbpf support, etc), being familiar concept (no need to teach users a new type of object in BPF program), and utilizing existing tooling (bpftool). For common scenario of using a single ring buffer for all CPUs, it's as simple and straightforward, as would be with a dedicated "container" object. On the other hand, by being a map, it can be combined with ARRAY_OF_MAPS and HASH_OF_MAPS map-in-maps to implement a wide variety of topologies, from one ring buffer for each CPU (e.g., as a replacement for perf buffer use cases), to a complicated application hashing/sharding of ring buffers (e.g., having a small pool of ring buffers with hashed task's tgid being a look up key to preserve order, but reduce contention). Key and value sizes are enforced to be zero. max_entries is used to specify the size of ring buffer and has to be a power of 2 value. There are a bunch of similarities between perf buffer (BPF_MAP_TYPE_PERF_EVENT_ARRAY) and new BPF ring buffer semantics: - variable-length records; - if there is no more space left in ring buffer, reservation fails, no blocking; - memory-mappable data area for user-space applications for ease of consumption and high performance; - epoll notifications for new incoming data; - but still the ability to do busy polling for new data to achieve the lowest latency, if necessary. BPF ringbuf provides two sets of APIs to BPF programs: - bpf_ringbuf_output() allows to *copy* data from one place to a ring buffer, similarly to bpf_perf_event_output(); - bpf_ringbuf_reserve()/bpf_ringbuf_commit()/bpf_ringbuf_discard() APIs split the whole process into two steps. First, a fixed amount of space is reserved. If successful, a pointer to a data inside ring buffer data area is returned, which BPF programs can use similarly to a data inside array/hash maps. Once ready, this piece of memory is either committed or discarded. Discard is similar to commit, but makes consumer ignore the record. bpf_ringbuf_output() has disadvantage of incurring extra memory copy, because record has to be prepared in some other place first. But it allows to submit records of the length that's not known to verifier beforehand. It also closely matches bpf_perf_event_output(), so will simplify migration significantly. bpf_ringbuf_reserve() avoids the extra copy of memory by providing a memory pointer directly to ring buffer memory. In a lot of cases records are larger than BPF stack space allows, so many programs have use extra per-CPU array as a temporary heap for preparing sample. bpf_ringbuf_reserve() avoid this needs completely. But in exchange, it only allows a known constant size of memory to be reserved, such that verifier can verify that BPF program can't access memory outside its reserved record space. bpf_ringbuf_output(), while slightly slower due to extra memory copy, covers some use cases that are not suitable for bpf_ringbuf_reserve(). The difference between commit and discard is very small. Discard just marks a record as discarded, and such records are supposed to be ignored by consumer code. Discard is useful for some advanced use-cases, such as ensuring all-or-nothing multi-record submission, or emulating temporary malloc()/free() within single BPF program invocation. Each reserved record is tracked by verifier through existing reference-tracking logic, similar to socket ref-tracking. It is thus impossible to reserve a record, but forget to submit (or discard) it. bpf_ringbuf_query() helper allows to query various properties of ring buffer. Currently 4 are supported: - BPF_RB_AVAIL_DATA returns amount of unconsumed data in ring buffer; - BPF_RB_RING_SIZE returns the size of ring buffer; - BPF_RB_CONS_POS/BPF_RB_PROD_POS returns current logical possition of consumer/producer, respectively. Returned values are momentarily snapshots of ring buffer state and could be off by the time helper returns, so this should be used only for debugging/reporting reasons or for implementing various heuristics, that take into account highly-changeable nature of some of those characteristics. One such heuristic might involve more fine-grained control over poll/epoll notifications about new data availability in ring buffer. Together with BPF_RB_NO_WAKEUP/BPF_RB_FORCE_WAKEUP flags for output/commit/discard helpers, it allows BPF program a high degree of control and, e.g., more efficient batched notifications. Default self-balancing strategy, though, should be adequate for most applications and will work reliable and efficiently already. Design and implementation ------------------------- This reserve/commit schema allows a natural way for multiple producers, either on different CPUs or even on the same CPU/in the same BPF program, to reserve independent records and work with them without blocking other producers. This means that if BPF program was interruped by another BPF program sharing the same ring buffer, they will both get a record reserved (provided there is enough space left) and can work with it and submit it independently. This applies to NMI context as well, except that due to using a spinlock during reservation, in NMI context, bpf_ringbuf_reserve() might fail to get a lock, in which case reservation will fail even if ring buffer is not full. The ring buffer itself internally is implemented as a power-of-2 sized circular buffer, with two logical and ever-increasing counters (which might wrap around on 32-bit architectures, that's not a problem): - consumer counter shows up to which logical position consumer consumed the data; - producer counter denotes amount of data reserved by all producers. Each time a record is reserved, producer that "owns" the record will successfully advance producer counter. At that point, data is still not yet ready to be consumed, though. Each record has 8 byte header, which contains the length of reserved record, as well as two extra bits: busy bit to denote that record is still being worked on, and discard bit, which might be set at commit time if record is discarded. In the latter case, consumer is supposed to skip the record and move on to the next one. Record header also encodes record's relative offset from the beginning of ring buffer data area (in pages). This allows bpf_ringbuf_commit()/bpf_ringbuf_discard() to accept only the pointer to the record itself, without requiring also the pointer to ring buffer itself. Ring buffer memory location will be restored from record metadata header. This significantly simplifies verifier, as well as improving API usability. Producer counter increments are serialized under spinlock, so there is a strict ordering between reservations. Commits, on the other hand, are completely lockless and independent. All records become available to consumer in the order of reservations, but only after all previous records where already committed. It is thus possible for slow producers to temporarily hold off submitted records, that were reserved later. Reservation/commit/consumer protocol is verified by litmus tests in Documentation/litmus-test/bpf-rb. One interesting implementation bit, that significantly simplifies (and thus speeds up as well) implementation of both producers and consumers is how data area is mapped twice contiguously back-to-back in the virtual memory. This allows to not take any special measures for samples that have to wrap around at the end of the circular buffer data area, because the next page after the last data page would be first data page again, and thus the sample will still appear completely contiguous in virtual memory. See comment and a simple ASCII diagram showing this visually in bpf_ringbuf_area_alloc(). Another feature that distinguishes BPF ringbuf from perf ring buffer is a self-pacing notifications of new data being availability. bpf_ringbuf_commit() implementation will send a notification of new record being available after commit only if consumer has already caught up right up to the record being committed. If not, consumer still has to catch up and thus will see new data anyways without needing an extra poll notification. Benchmarks (see tools/testing/selftests/bpf/benchs/bench_ringbuf.c) show that this allows to achieve a very high throughput without having to resort to tricks like "notify only every Nth sample", which are necessary with perf buffer. For extreme cases, when BPF program wants more manual control of notifications, commit/discard/output helpers accept BPF_RB_NO_WAKEUP and BPF_RB_FORCE_WAKEUP flags, which give full control over notifications of data availability, but require extra caution and diligence in using this API. Comparison to alternatives -------------------------- Before considering implementing BPF ring buffer from scratch existing alternatives in kernel were evaluated, but didn't seem to meet the needs. They largely fell into few categores: - per-CPU buffers (perf, ftrace, etc), which don't satisfy two motivations outlined above (ordering and memory consumption); - linked list-based implementations; while some were multi-producer designs, consuming these from user-space would be very complicated and most probably not performant; memory-mapping contiguous piece of memory is simpler and more performant for user-space consumers; - io_uring is SPSC, but also requires fixed-sized elements. Naively turning SPSC queue into MPSC w/ lock would have subpar performance compared to locked reserve + lockless commit, as with BPF ring buffer. Fixed sized elements would be too limiting for BPF programs, given existing BPF programs heavily rely on variable-sized perf buffer already; - specialized implementations (like a new printk ring buffer, [0]) with lots of printk-specific limitations and implications, that didn't seem to fit well for intended use with BPF programs. [0] https://lwn.net/Articles/779550/ Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200529075424.3139988-2-andriin@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | | bpf: Extend bpf_base_func_proto helpers with probe_* and *current_task*John Fastabend2020-06-011-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Often it is useful when applying policy to know something about the task. If the administrator has CAP_SYS_ADMIN rights then they can use kprobe + networking hook and link the two programs together to accomplish this. However, this is a bit clunky and also means we have to call both the network program and kprobe program when we could just use a single program and avoid passing metadata through sk_msg/skb->cb, socket, maps, etc. To accomplish this add probe_* helpers to bpf_base_func_proto programs guarded by a perfmon_capable() check. New supported helpers are the following, BPF_FUNC_get_current_task BPF_FUNC_probe_read_user BPF_FUNC_probe_read_kernel BPF_FUNC_probe_read_user_str BPF_FUNC_probe_read_kernel_str Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/159033905529.12355.4368381069655254932.stgit@john-Precision-5820-Tower Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2020-05-158-98/+141
| |\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the bpf verifier trace check into the new switch statement in HEAD. Resolve the overlapping changes in hinic, where bug fixes overlap the addition of VF support. Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | | bpf: Implement CAP_BPFAlexei Starovoitov2020-05-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement permissions as stated in uapi/linux/capability.h In order to do that the verifier allow_ptr_leaks flag is split into four flags and they are set as: env->allow_ptr_leaks = bpf_allow_ptr_leaks(); env->bypass_spec_v1 = bpf_bypass_spec_v1(); env->bypass_spec_v4 = bpf_bypass_spec_v4(); env->bpf_capable = bpf_capable(); The first three currently equivalent to perfmon_capable(), since leaking kernel pointers and reading kernel memory via side channel attacks is roughly equivalent to reading kernel memory with cap_perfmon. 'bpf_capable' enables bounded loops, precision tracking, bpf to bpf calls and other verifier features. 'allow_ptr_leaks' enable ptr leaks, ptr conversions, subtraction of pointers. 'bypass_spec_v1' disables speculative analysis in the verifier, run time mitigations in bpf array, and enables indirect variable access in bpf programs. 'bypass_spec_v4' disables emission of sanitation code by the verifier. That means that the networking BPF program loaded with CAP_BPF + CAP_NET_ADMIN will have speculative checks done by the verifier and other spectre mitigation applied. Such networking BPF program will not be able to leak kernel pointers and will not be able to access arbitrary kernel memory. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200513230355.7858-3-alexei.starovoitov@gmail.com
| * | | | | | bpf: Add bpf_seq_printf and bpf_seq_write helpersYonghong Song2020-05-091-0/+214
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two helpers bpf_seq_printf and bpf_seq_write, are added for writing data to the seq_file buffer. bpf_seq_printf supports common format string flag/width/type fields so at least I can get identical results for netlink and ipv6_route targets. For bpf_seq_printf and bpf_seq_write, return value -EOVERFLOW specifically indicates a write failure due to overflow, which means the object will be repeated in the next bpf invocation if object collection stays the same. Note that if the object collection is changed, depending how collection traversal is done, even if the object still in the collection, it may not be visited. For bpf_seq_printf, format %s, %p{i,I}{4,6} needs to read kernel memory. Reading kernel memory may fail in the following two cases: - invalid kernel address, or - valid kernel address but requiring a major fault If reading kernel memory failed, the %s string will be an empty string and %p{i,I}{4,6} will be all 0. Not returning error to bpf program is consistent with what bpf_trace_printk() does for now. bpf_seq_printf may return -EBUSY meaning that internal percpu buffer for memory copy of strings or other pointees is not available. Bpf program can return 1 to indicate it wants the same object to be repeated. Right now, this should not happen on no-RT kernels since migrate_disable(), which guards bpf prog call, calls preempt_disable(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175914.2476661-1-yhs@fb.com
| * | | | | | Merge branch 'work.sysctl' of ↵Daniel Borkmann2020-04-281-1/+1
| |\ \ \ \ \ \ | | | |/ / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull in Christoph Hellwig's series that changes the sysctl's ->proc_handler methods to take kernel pointers instead. It gets rid of the set_fs address space overrides used by BPF. As per discussion, pull in the feature branch into bpf-next as it relates to BPF sysctl progs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200427071508.GV23230@ZenIV.linux.org.uk/T/
| | * | | | | sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig2020-04-271-1/+1
| | | |_|_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | bpf: add bpf_ktime_get_boot_ns()Maciej Żenczykowski2020-04-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On a device like a cellphone which is constantly suspending and resuming CLOCK_MONOTONIC is not particularly useful for keeping track of or reacting to external network events. Instead you want to use CLOCK_BOOTTIME. Hence add bpf_ktime_get_boot_ns() as a mirror of bpf_ktime_get_ns() based around CLOCK_BOOTTIME instead of CLOCK_MONOTONIC. Signed-off-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | | | | | Merge branch 'work.splice' of ↵Linus Torvalds2020-06-031-10/+1
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull splice updates from Al Viro: "Christoph's assorted splice cleanups" * 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: rename pipe_buf ->steal to ->try_steal fs: make the pipe_buf_operations ->confirm operation optional fs: make the pipe_buf_operations ->steal operation optional trace: remove tracing_pipe_buf_ops pipe: merge anon_pipe_buf*_ops fs: simplify do_splice_from fs: simplify do_splice_to
| * | | | | | fs: make the pipe_buf_operations ->confirm operation optionalChristoph Hellwig2020-05-201-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just return 0 for success if it is not present. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | | fs: make the pipe_buf_operations ->steal operation optionalChristoph Hellwig2020-05-201-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just return 1 for failure if it is not present. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | | trace: remove tracing_pipe_buf_opsChristoph Hellwig2020-05-201-8/+1
| | |/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tracing_pipe_buf_ops has identical ops to default_pipe_buf_ops, so use that instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2020-06-031-0/+39
|\ \ \ \ \ \ | |_|_|_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm updates from Paolo Bonzini: "ARM: - Move the arch-specific code into arch/arm64/kvm - Start the post-32bit cleanup - Cherry-pick a few non-invasive pre-NV patches x86: - Rework of TLB flushing - Rework of event injection, especially with respect to nested virtualization - Nested AMD event injection facelift, building on the rework of generic code and fixing a lot of corner cases - Nested AMD live migration support - Optimization for TSC deadline MSR writes and IPIs - Various cleanups - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree) - Interrupt-based delivery of asynchronous "page ready" events (host side) - Hyper-V MSRs and hypercalls for guest debugging - VMX preemption timer fixes s390: - Cleanups Generic: - switch vCPU thread wakeup from swait to rcuwait The other architectures, and the guest side of the asynchronous page fault work, will come next week" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits) KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test KVM: check userspace_addr for all memslots KVM: selftests: update hyperv_cpuid with SynDBG tests x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls x86/kvm/hyper-v: enable hypercalls regardless of hypercall page x86/kvm/hyper-v: Add support for synthetic debugger interface x86/hyper-v: Add synthetic debugger definitions KVM: selftests: VMX preemption timer migration test KVM: nVMX: Fix VMX preemption timer migration x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit KVM: x86/pmu: Support full width counting KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT KVM: x86: acknowledgment mechanism for async pf page ready notifications KVM: x86: interrupt based APF 'page ready' event delivery KVM: introduce kvm_read_guest_offset_cached() KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present() KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously" KVM: VMX: Replace zero-length array with flexible-array ...