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2020-12-04Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski1-3/+7
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-12-03 The main changes are: 1) Support BTF in kernel modules, from Andrii. 2) Introduce preferred busy-polling, from Björn. 3) bpf_ima_inode_hash() and bpf_bprm_opts_set() helpers, from KP Singh. 4) Memcg-based memory accounting for bpf objects, from Roman. 5) Allow bpf_{s,g}etsockopt from cgroup bind{4,6} hooks, from Stanislav. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (118 commits) selftests/bpf: Fix invalid use of strncat in test_sockmap libbpf: Use memcpy instead of strncpy to please GCC selftests/bpf: Add fentry/fexit/fmod_ret selftest for kernel module selftests/bpf: Add tp_btf CO-RE reloc test for modules libbpf: Support attachment of BPF tracing programs to kernel modules libbpf: Factor out low-level BPF program loading helper bpf: Allow to specify kernel module BTFs when attaching BPF programs bpf: Remove hard-coded btf_vmlinux assumption from BPF verifier selftests/bpf: Add CO-RE relocs selftest relying on kernel module BTF selftests/bpf: Add support for marking sub-tests as skipped selftests/bpf: Add bpf_testmod kernel module for testing libbpf: Add kernel module BTF support for CO-RE relocations libbpf: Refactor CO-RE relocs to not assume a single BTF object libbpf: Add internal helper to load BTF data by FD bpf: Keep module's btf_data_size intact after load bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address() selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP bpf: Adds support for setting window clamp samples/bpf: Fix spelling mistake "recieving" -> "receiving" bpf: Fix cold build of test_progs-no_alu32 ... ==================== Link: https://lore.kernel.org/r/20201204021936.85653-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address()Andrii Nakryiko1-3/+5
__module_address() needs to be called with preemption disabled or with module_mutex taken. preempt_disable() is enough for read-only uses, which is what this fix does. Also, module_put() does internal check for NULL, so drop it as well. Fixes: a38d1107f937 ("bpf: support raw tracepoints in modules") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201203204634.1325171-2-andrii@kernel.org
2020-12-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski5-15/+33
Conflicts: drivers/net/ethernet/ibm/ibmvnic.c Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-02ring-buffer: Add test to validate the time stamp deltasSteven Rostedt (VMware)2-0/+170
While debugging a situation where a delta for an event was calucalted wrong, I realize there was nothing making sure that the delta of events are correct. If a single event has an incorrect delta, then all events after it will also have one. If the discrepency gets large enough, it could cause the time stamps to go backwards when crossing sub buffers, that record a full 64 bit time stamp, and the new deltas are added to that. Add a way to validate the events at most events and when crossing a buffer page. This will help make sure that the deltas are always correct. This test will detect if they are ever corrupted. The test adds a high overhead to the ring buffer recording, as it does the audit for almost every event, and should only be used for testing the ring buffer. This will catch the bug that is fixed by commit 55ea4cf40380 ("ring-buffer: Update write stamp with the correct ts"), which is not applied when this commit is applied. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-02Merge tag 'trace-v5.10-rc6' of ↵Linus Torvalds5-15/+33
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - Use correct timestamp variable for ring buffer write stamp update - Fix up before stamp and write stamp when crossing ring buffer sub buffers - Keep a zero delta in ring buffer in slow path if cmpxchg fails - Fix trace_printk static buffer for archs that care - Fix ftrace record accounting for ftrace ops with trampolines - Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency - Remove WARN_ON in hwlat tracer that triggers on something that is OK - Make "my_tramp" trampoline in ftrace direct sample code global - Fixes in the bootconfig tool for better alignment management * tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Always check to put back before stamp when crossing pages ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency ftrace: Fix updating FTRACE_FL_TRAMP tracing: Fix alignment of static buffer tracing: Remove WARN_ON in start_thread() samples/ftrace: Mark my_tramp[12]? global ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next() ring-buffer: Update write stamp with the correct ts docs: bootconfig: Update file format on initrd image tools/bootconfig: Align the bootconfig applied initrd image size to 4 tools/bootconfig: Fix to check the write failure correctly tools/bootconfig: Fix errno reference after printf()
2020-12-02block: merge struct block_device and struct hd_structChristoph Hellwig1-35/+8
Instead of having two structures that represent each block device with different life time rules, merge them into a single one. This also greatly simplifies the reference counting rules, as we can use the inode reference count as the main reference count for the new struct block_device, with the device model reference front ending it for device model interaction. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-02block: move the start_sect field to struct block_deviceChristoph Hellwig1-8/+3
Move the start_sect field to struct block_device in preparation of killing struct hd_struct. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-02block: remove the nr_sects field in struct hd_structChristoph Hellwig1-1/+1
Now that the hd_struct always has a block device attached to it, there is no need for having two size field that just get out of sync. Additionally the field in hd_struct did not use proper serialization, possibly allowing for torn writes. By only using the block_device field this problem also gets fixed. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: Chao Yu <yuchao0@huawei.com> [f2fs] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01ring-buffer: Always check to put back before stamp when crossing pagesSteven Rostedt (VMware)1-8/+6
The current ring buffer logic checks to see if the updating of the event buffer was interrupted, and if it is, it will try to fix up the before stamp with the write stamp to make them equal again. This logic is flawed, because if it is not interrupted, the two are guaranteed to be different, as the current event just updated the before stamp before allocation. This guarantees that the next event (this one or another interrupting one) will think it interrupted the time updates of a previous event and inject an absolute time stamp to compensate. The correct logic is to always update the timestamps when traversing to a new sub buffer. Cc: stable@vger.kernel.org Fixes: a389d86f7fd09 ("ring-buffer: Have nested events still record running time stamp") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-01ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependencyNaveen N. Rao1-1/+1
DYNAMIC_FTRACE_WITH_DIRECT_CALLS should depend on DYNAMIC_FTRACE_WITH_REGS since we need ftrace_regs_caller(). Link: https://lkml.kernel.org/r/fc4b257ea8689a36f086d2389a9ed989496ca63a.1606412433.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: 763e34e74bb7d5c ("ftrace: Add register_ftrace_direct()") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-01ftrace: Fix updating FTRACE_FL_TRAMPNaveen N. Rao1-1/+21
On powerpc, kprobe-direct.tc triggered FTRACE_WARN_ON() in ftrace_get_addr_new() followed by the below message: Bad trampoline accounting at: 000000004222522f (wake_up_process+0xc/0x20) (f0000001) The set of steps leading to this involved: - modprobe ftrace-direct-too - enable_probe - modprobe ftrace-direct - rmmod ftrace-direct <-- trigger The problem turned out to be that we were not updating flags in the ftrace record properly. From the above message about the trampoline accounting being bad, it can be seen that the ftrace record still has FTRACE_FL_TRAMP set though ftrace-direct module is going away. This happens because we are checking if any ftrace_ops has the FTRACE_FL_TRAMP flag set _before_ updating the filter hash. The fix for this is to look for any _other_ ftrace_ops that also needs FTRACE_FL_TRAMP. Link: https://lkml.kernel.org/r/56c113aa9c3e10c19144a36d9684c7882bf09af5.1606412433.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: a124692b698b0 ("ftrace: Enable trampoline when rec count returns back to one") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-01tracing: Fix alignment of static bufferMinchan Kim1-1/+1
With 5.9 kernel on ARM64, I found ftrace_dump output was broken but it had no problem with normal output "cat /sys/kernel/debug/tracing/trace". With investigation, it seems coping the data into temporal buffer seems to break the align binary printf expects if the static buffer is not aligned with 4-byte. IIUC, get_arg in bstr_printf expects that args has already right align to be decoded and seq_buf_bprintf says ``the arguments are saved in a 32bit word array that is defined by the format string constraints``. So if we don't keep the align under copy to temporal buffer, the output will be broken by shifting some bytes. This patch fixes it. Link: https://lkml.kernel.org/r/20201125225654.1618966-1-minchan@kernel.org Cc: <stable@vger.kernel.org> Fixes: 8e99cf91b99bb ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-01tracing: Remove WARN_ON in start_thread()Vasily Averin1-1/+1
This patch reverts commit 978defee11a5 ("tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists") .start hook can be legally called several times if according tracer is stopped screen window 1 [root@localhost ~]# echo 1 > /sys/kernel/tracing/events/kmem/kfree/enable [root@localhost ~]# echo 1 > /sys/kernel/tracing/options/pause-on-trace [root@localhost ~]# less -F /sys/kernel/tracing/trace screen window 2 [root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on 0 [root@localhost ~]# echo hwlat > /sys/kernel/debug/tracing/current_tracer [root@localhost ~]# echo 1 > /sys/kernel/debug/tracing/tracing_on [root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on 0 [root@localhost ~]# echo 2 > /sys/kernel/debug/tracing/tracing_on triggers warning in dmesg: WARNING: CPU: 3 PID: 1403 at kernel/trace/trace_hwlat.c:371 hwlat_tracer_start+0xc9/0xd0 Link: https://lkml.kernel.org/r/bd4d3e70-400d-9c82-7b73-a2d695e86b58@virtuozzo.com Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 978defee11a5 ("tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()Andrea Righi1-3/+3
In the slow path of __rb_reserve_next() a nested event(s) can happen between evaluating the timestamp delta of the current event and updating write_stamp via local_cmpxchg(); in this case the delta is not valid anymore and it should be set to 0 (same timestamp as the interrupting event), since the event that we are currently processing is not the last event in the buffer. Link: https://lkml.kernel.org/r/X8IVJcp1gRE+FJCJ@xps-13-7390 Cc: Ingo Molnar <mingo@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: stable@vger.kernel.org Link: https://lwn.net/Articles/831207 Fixes: a389d86f7fd0 ("ring-buffer: Have nested events still record running time stamp") Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30ring-buffer: Update write stamp with the correct tsSteven Rostedt (VMware)1-1/+1
The write stamp, used to calculate deltas between events, was updated with the stale "ts" value in the "info" structure, and not with the updated "ts" variable. This caused the deltas between events to be inaccurate, and when crossing into a new sub buffer, had time go backwards. Link: https://lkml.kernel.org/r/20201124223917.795844-1-elavila@google.com Cc: stable@vger.kernel.org Fixes: a389d86f7fd09 ("ring-buffer: Have nested events still record running time stamp") Reported-by: "J. Avila" <elavila@google.com> Tested-by: Daniel Mentz <danielmentz@google.com> Tested-by: Will McVicker <willmcvicker@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-27Merge branch 'linus' into sched/core, to resolve semantic conflictIngo Molnar6-31/+97
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-11-24irq_work: CleanupPeter Zijlstra1-1/+1
Get rid of the __call_single_node union and clean up the API a little to avoid external code relying on the structure layout as much. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
2020-11-20Merge https://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+11
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-19lib/strncpy_from_user.c: Mask out bytes after NUL terminator.Daniel Xu1-0/+10
do_strncpy_from_user() may copy some extra bytes after the NUL terminator into the destination buffer. This usually does not matter for normal string operations. However, when BPF programs key BPF maps with strings, this matters a lot. A BPF program may read strings from user memory by calling the bpf_probe_read_user_str() helper which eventually calls do_strncpy_from_user(). The program can then key a map with the destination buffer. BPF map keys are fixed-width and string-agnostic, meaning that map keys are treated as a set of bytes. The issue is when do_strncpy_from_user() overcopies bytes after the NUL terminator, it can result in seemingly identical strings occupying multiple slots in a BPF map. This behavior is subtle and totally unexpected by the user. This commit masks out the bytes following the NUL while preserving long-sized stride in the fast path. Fixes: 6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers") Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/21efc982b3e9f2f7b0379eed642294caaa0c27a7.1605642949.git.dxu@dxuuu.xyz
2020-11-19bpf: Add bpf_ktime_get_coarse_ns helperDmitrii Banshchikov1-0/+2
The helper uses CLOCK_MONOTONIC_COARSE source of time that is less accurate but more performant. We have a BPF CGROUP_SKB firewall that supports event logging through bpf_perf_event_output(). Each event has a timestamp and currently we use bpf_ktime_get_ns() for it. Use of bpf_ktime_get_coarse_ns() saves ~15-20 ns in time required for event logging. bpf_ktime_get_ns(): EgressLogByRemoteEndpoint 113.82ns 8.79M bpf_ktime_get_coarse_ns(): EgressLogByRemoteEndpoint 95.40ns 10.48M Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201117184549.257280-1-me@ubique.spb.ru
2020-11-16tracepoints: Migrate to use SYSCALL_WORK flagGabriel Krisman Bertazi1-4/+4
On architectures using the generic syscall entry code the architecture independent syscall work is moved to flags in thread_info::syscall_work. This removes architecture dependencies and frees up TIF bits. Define SYSCALL_WORK_SYSCALL_TRACEPOINT, use it in the generic entry code and convert the code which uses the TIF specific helper functions to use the new *_syscall_work() helpers which either resolve to the new mode for users of the generic entry code or to the TIF based functions for the other architectures. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20201116174206.2639648-6-krisman@collabora.com
2020-11-16tracing: Clean up after filter logic rewritingLukas Bulwahn1-21/+0
The functions event_{set,clear,}_no_set_filter_flag were only used in replace_system_preds() [now, renamed to process_system_preds()]. Commit 80765597bc58 ("tracing: Rewrite filter logic to be simpler and faster") removed the use of those functions in replace_system_preds(). Since then, the functions event_{set,clear,}_no_set_filter_flag were unused. Fortunately, make CC=clang W=1 indicates this with -Wunused-function warnings on those three functions. So, clean up these obsolete unused functions. Link: https://lkml.kernel.org/r/20201115155336.20248-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski1-1/+28
Daniel Borkmann says: ==================== pull-request: bpf-next 2020-11-14 1) Add BTF generation for kernel modules and extend BTF infra in kernel e.g. support for split BTF loading and validation, from Andrii Nakryiko. 2) Support for pointers beyond pkt_end to recognize LLVM generated patterns on inlined branch conditions, from Alexei Starovoitov. 3) Implements bpf_local_storage for task_struct for BPF LSM, from KP Singh. 4) Enable FENTRY/FEXIT/RAW_TP tracing program to use the bpf_sk_storage infra, from Martin KaFai Lau. 5) Add XDP bulk APIs that introduce a defer/flush mechanism to optimize the XDP_REDIRECT path, from Lorenzo Bianconi. 6) Fix a potential (although rather theoretical) deadlock of hashtab in NMI context, from Song Liu. 7) Fixes for cross and out-of-tree build of bpftool and runqslower allowing build for different target archs on same source tree, from Jean-Philippe Brucker. 8) Fix error path in htab_map_alloc() triggered from syzbot, from Eric Dumazet. 9) Move functionality from test_tcpbpf_user into the test_progs framework so it can run in BPF CI, from Alexander Duyck. 10) Lift hashtab key_size limit to be larger than MAX_BPF_STACK, from Florian Lehner. Note that for the fix from Song we have seen a sparse report on context imbalance which requires changes in sparse itself for proper annotation detection where this is currently being discussed on linux-sparse among developers [0]. Once we have more clarification/guidance after their fix, Song will follow-up. [0] https://lore.kernel.org/linux-sparse/CAHk-=wh4bx8A8dHnX612MsDO13st6uzAz1mJ1PaHHVevJx_ZCw@mail.gmail.com/T/ https://lore.kernel.org/linux-sparse/20201109221345.uklbp3lzgq6g42zb@ltop.local/T/ * git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (66 commits) net: mlx5: Add xdp tx return bulking support net: mvpp2: Add xdp tx return bulking support net: mvneta: Add xdp tx return bulking support net: page_pool: Add bulk support for ptr_ring net: xdp: Introduce bulking for xdp tx return path bpf: Expose bpf_d_path helper to sleepable LSM hooks bpf: Augment the set of sleepable LSM hooks bpf: selftest: Use bpf_sk_storage in FENTRY/FEXIT/RAW_TP bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP bpf: Rename some functions in bpf_sk_storage bpf: Folding omem_charge() into sk_storage_charge() selftests/bpf: Add asm tests for pkt vs pkt_end comparison. selftests/bpf: Add skb_pkt_end test bpf: Support for pointers beyond pkt_end. tools/bpf: Always run the *-clean recipes tools/bpf: Add bootstrap/ to .gitignore bpf: Fix NULL dereference in bpf_task_storage tools/bpftool: Fix build slowdown tools/runqslower: Build bpftool using HOSTCC tools/runqslower: Enable out-of-tree build ... ==================== Link: https://lore.kernel.org/r/20201114020819.29584-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-13tracing: Remove the useless value assignment in test_create_synth_event()Kaixu Xia1-1/+1
The value of variable ret is overwritten on the delete branch in the test_create_synth_event() and we care more about the above error than this delete portion. Remove it. Link: https://lkml.kernel.org/r/1605283360-6804-1-git-send-email-kaixuxia@tencent.com Reported-by: Tosk Robot <tencent_os_robot@tencent.com> Signed-off-by: Kaixu Xia <kaixuxia@tencent.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13ftrace/x86: Allow for arguments to be passed in to ftrace_regs by defaultSteven Rostedt (VMware)1-0/+9
Currently, the only way to get access to the registers of a function via a ftrace callback is to set the "FL_SAVE_REGS" bit in the ftrace_ops. But as this saves all regs as if a breakpoint were to trigger (for use with kprobes), it is expensive. The regs are already saved on the stack for the default ftrace callbacks, as that is required otherwise a function being traced will get the wrong arguments and possibly crash. And on x86, the arguments are already stored where they would be on a pt_regs structure to use that code for both the regs version of a callback, it makes sense to pass that information always to all functions. If an architecture does this (as x86_64 now does), it is to set HAVE_DYNAMIC_FTRACE_WITH_ARGS, and this will let the generic code that it could have access to arguments without having to set the flags. This also includes having the stack pointer being saved, which could be used for accessing arguments on the stack, as well as having the function graph tracer not require its own trampoline! Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regsSteven Rostedt (VMware)8-31/+35
In preparation to have arguments of a function passed to callbacks attached to functions as default, change the default callback prototype to receive a struct ftrace_regs as the forth parameter instead of a pt_regs. For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they will now need to get the pt_regs via a ftrace_get_regs() helper call. If this is called by a callback that their ftrace_ops did not have a FL_SAVE_REGS flag set, it that helper function will return NULL. This will allow the ftrace_regs to hold enough just to get the parameters and stack pointer, but without the worry that callbacks may have a pt_regs that is not completely filled. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13bpf: Expose bpf_d_path helper to sleepable LSM hooksKP Singh1-1/+7
Sleepable hooks are never called from an NMI/interrupt context, so it is safe to use the bpf_d_path helper in LSM programs attaching to these hooks. The helper is not restricted to sleepable programs and merely uses the list of sleepable hooks as the initial subset of LSM hooks where it can be used. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20201113005930.541956-3-kpsingh@chromium.org
2020-11-13bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TPMartin KaFai Lau1-0/+5
This patch enables the FENTRY/FEXIT/RAW_TP tracing program to use the bpf_sk_storage_(get|delete) helper, so those tracing programs can access the sk's bpf_local_storage and the later selftest will show some examples. The bpf_sk_storage is currently used in bpf-tcp-cc, tc, cg sockops...etc which is running either in softirq or task context. This patch adds bpf_sk_storage_get_tracing_proto and bpf_sk_storage_delete_tracing_proto. They will check in runtime that the helpers can only be called when serving softirq or running in a task context. That should enable most common tracing use cases on sk. During the load time, the new tracing_allowed() function will ensure the tracing prog using the bpf_sk_storage_(get|delete) helper is not tracing any bpf_sk_storage*() function itself. The sk is passed as "void *" when calling into bpf_local_storage. This patch only allows tracing a kernel function. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20201112211313.2587383-1-kafai@fb.com
2020-11-11tracing: Fix some typos in commentsQiujun Huang15-25/+25
s/detetector/detector/ s/enfoced/enforced/ s/writen/written/ s/actualy/actually/ s/bascially/basically/ s/Regarldess/Regardless/ s/zeroes/zeros/ s/followd/followed/ s/incrememented/incremented/ s/separatelly/separately/ s/accesible/accessible/ s/sythetic/synthetic/ s/enabed/enabled/ s/heurisitc/heuristic/ s/assocated/associated/ s/otherwides/otherwise/ s/specfied/specified/ s/seaching/searching/ s/hierachry/hierarchy/ s/internel/internal/ s/Thise/This/ Link: https://lkml.kernel.org/r/20201029150554.3354-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-11ftrace: Remove unused varible 'ret'Alex Shi1-4/+2
'ret' in 2 functions are not used. and one of them is a void function. So remove them to avoid gcc warning: kernel/trace/ftrace.c:4166:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable] kernel/trace/ftrace.c:5571:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable] Link: https://lkml.kernel.org/r/1604674486-52350-1-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-11ring-buffer: Add recording of ring buffer recursion into recursed_functionsSteven Rostedt (VMware)2-1/+25
Add a new config RING_BUFFER_RECORD_RECURSION that will place functions that recurse from the ring buffer into the ftrace recused_functions file. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-11fgraph: Make overruns 4 bytes in graph stack structureSteven Rostedt (VMware)2-3/+3
Inspecting the data structures of the function graph tracer, I found that the overrun value is unsigned long, which is 8 bytes on a 64 bit machine, and not only that, the depth is an int (4 bytes). The overrun can be simply an unsigned int (4 bytes) and pack the ftrace_graph_ret structure better. The depth is moved up next to the func, as it is used more often with func, and improves cache locality. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepareWang Qing1-1/+1
There is a bug when passing zero to PTR_ERR() and return. Fix the smatch error. Fixes: c4d0bfb45068 ("bpf: Add bpf_snprintf_btf helper") Signed-off-by: Wang Qing <wangqing@vivo.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/1604735144-686-1-git-send-email-wangqing@vivo.com
2020-11-07Merge branch 'linus' into perf/kprobesIngo Molnar19-355/+1057
Conflicts: include/asm-generic/atomic-instrumented.h kernel/kprobes.c Use the upstream atomic-instrumented.h checksum, and pick the kprobes version of kernel/kprobes.c, which effectively reverts this upstream workaround: 645f224e7ba2: ("kprobes: Tell lockdep about kprobe nesting") Since the new code *should* be fine without nesting. Knock on wood ... Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-11-07Merge branch 'linus' into perf/kprobesIngo Molnar19-114/+146
Merge recent kprobes updates into perf/kprobes that came from -mm. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-11-06bpf: Implement get_current_task_btf and RET_PTR_TO_BTF_IDKP Singh1-0/+16
The currently available bpf_get_current_task returns an unsigned integer which can be used along with BPF_CORE_READ to read data from the task_struct but still cannot be used as an input argument to a helper that accepts an ARG_PTR_TO_BTF_ID of type task_struct. In order to implement this helper a new return type, RET_PTR_TO_BTF_ID, is added. This is similar to RET_PTR_TO_BTF_ID_OR_NULL but does not require checking the nullness of returned pointer. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201106103747.2780972-6-kpsingh@chromium.org
2020-11-06ftrace: Add recording of functions that caused recursionSteven Rostedt (VMware)8-7/+270
This adds CONFIG_FTRACE_RECORD_RECURSION that will record to a file "recursed_functions" all the functions that caused recursion while a callback to the function tracer was running. Link: https://lkml.kernel.org/r/20201106023548.102375687@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Guo Ren <guoren@kernel.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: x86@kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-csky@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: live-patching@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Reverse what the RECURSION flag means in the ftrace_opsSteven Rostedt (VMware)6-21/+13
Now that all callbacks are recursion safe, reverse the meaning of the RECURSION flag and rename it from RECURSION_SAFE to simply RECURSION. Now only callbacks that request to have recursion protecting it will have the added trampoline to do so. Also remove the outdated comment about "PER_CPU" when determining to use the ftrace_ops_assist_func. Link: https://lkml.kernel.org/r/20201028115613.742454631@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.904270143@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: linux-doc@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06perf/ftrace: Check for rcu_is_watching() in callback functionSteven Rostedt (VMware)1-1/+3
If a ftrace callback requires "rcu_is_watching", then it adds the FTRACE_OPS_FL_RCU flag and it will not be called if RCU is not "watching". But this means that it will use a trampoline when called, and this slows down the function tracing a tad. By checking rcu_is_watching() from within the callback, it no longer needs the RCU flag set in the ftrace_ops and it can be safely called directly. Link: https://lkml.kernel.org/r/20201028115613.591878956@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.711035826@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06perf/ftrace: Add recursion protection to the ftrace callbackSteven Rostedt (VMware)1-1/+8
If a ftrace callback does not supply its own recursion protection and does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will make a helper trampoline to do so before calling the callback instead of just calling the callback directly. The default for ftrace_ops is going to change. It will expect that handlers provide their own recursion protection, unless its ftrace_ops states otherwise. Link: https://lkml.kernel.org/r/20201028115613.444477858@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.466892083@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Add ftrace_test_recursion_trylock() helper functionSteven Rostedt (VMware)1-7/+5
To make it easier for ftrace callbacks to have recursion protection, provide a ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() helper that tests for recursion. Link: https://lkml.kernel.org/r/20201028115612.634927593@goodmis.org Link: https://lkml.kernel.org/r/20201106023546.378584067@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Move the recursion testing into global headersSteven Rostedt (VMware)1-177/+0
Currently, if a callback is registered to a ftrace function and its ftrace_ops does not have the RECURSION flag set, it is encapsulated in a helper function that does the recursion for it. Really, all the callbacks should have their own recursion protection for performance reasons. But they should not all implement their own. Move the recursion helpers to global headers, so that all callbacks can use them. Link: https://lkml.kernel.org/r/20201028115612.460535535@goodmis.org Link: https://lkml.kernel.org/r/20201106023546.166456258@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02tracing: Make -ENOMEM the default error for parse_synth_field()Steven Rostedt (VMware)1-10/+7
parse_synth_field() returns a pointer and requires that errors get surrounded by ERR_PTR(). The ret variable is initialized to zero, but should never be used as zero, and if it is, it could cause a false return code and produce a NULL pointer dereference. It makes no sense to set ret to zero. Set ret to -ENOMEM (the most common error case), and have any other errors set it to something else. This removes the need to initialize ret on *every* error branch. Fixes: 761a8c58db6b ("tracing, synthetic events: Replace buggy strcat() with seq_buf operations") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02ring-buffer: Fix recursion protection transitions between interrupt contextSteven Rostedt (VMware)1-12/+46
The recursion protection of the ring buffer depends on preempt_count() to be correct. But it is possible that the ring buffer gets called after an interrupt comes in but before it updates the preempt_count(). This will trigger a false positive in the recursion code. Use the same trick from the ftrace function callback recursion code which uses a "transition" bit that gets set, to allow for a single recursion for to handle transitions between contexts. Cc: stable@vger.kernel.org Fixes: 567cd4da54ff4 ("ring-buffer: User context bit recursion checking") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02tracing: Fix the checking of stackidx in __ftrace_trace_stackQiujun Huang1-2/+2
The array size is FTRACE_KSTACK_NESTING, so the index FTRACE_KSTACK_NESTING is illegal too. And fix two typos by the way. Link: https://lkml.kernel.org/r/20201031085714.2147-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02ftrace: Handle tracing when switching between contextSteven Rostedt (VMware)2-4/+28
When an interrupt or NMI comes in and switches the context, there's a delay from when the preempt_count() shows the update. As the preempt_count() is used to detect recursion having each context have its own bit get set when tracing starts, and if that bit is already set, it is considered a recursion and the function exits. But if this happens in that section where context has changed but preempt_count() has not been updated, this will be incorrectly flagged as a recursion. To handle this case, create another bit call TRANSITION and test it if the current context bit is already set. Flag the call as a recursion if the TRANSITION bit is already set, and if not, set it and continue. The TRANSITION bit will be cleared normally on the return of the function that set it, or if the current context bit is clear, set it and clear the TRANSITION bit to allow for another transition between the current context and an even higher one. Cc: stable@vger.kernel.org Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02ftrace: Fix recursion check for NMI testSteven Rostedt (VMware)1-1/+2
The code that checks recursion will work to only do the recursion check once if there's nested checks. The top one will do the check, the other nested checks will see recursion was already checked and return zero for its "bit". On the return side, nothing will be done if the "bit" is zero. The problem is that zero is returned for the "good" bit when in NMI context. This will set the bit for NMIs making it look like *all* NMI tracing is recursing, and prevent tracing of anything in NMI context! The simple fix is to return "bit + 1" and subtract that bit on the end to get the real bit. Cc: stable@vger.kernel.org Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02tracing: Fix out of bounds write in get_trace_bufQiujun Huang1-1/+1
The nesting count of trace_printk allows for 4 levels of nesting. The nesting counter starts at zero and is incremented before being used to retrieve the current context's buffer. But the index to the buffer uses the nesting counter after it was incremented, and not its original number, which in needs to do. Link: https://lkml.kernel.org/r/20201029161905.4269-1-hqjagain@gmail.com Cc: stable@vger.kernel.org Fixes: 3d9622c12c887 ("tracing: Add barrier to trace_printk() buffer nesting modification") Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-30timekeeping: remove arch_gettimeoffsetArnd Bergmann1-2/+0
With Arm EBSA110 gone, nothing uses it any more, so the corresponding code and the Kconfig option can be removed. Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-10-28Merge tag 'trace-v5.10-rc1' of ↵Linus Torvalds1-14/+22
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "Fix synthetic event "strcat" overrun New synthetic event code used strcat() and miscalculated the ending, causing the concatenation to write beyond the allocated memory. Instead of using strncat(), the code is switched over to seq_buf which has all the mechanisms in place to protect against writing more than what is allocated, and cleans up the code a bit" * tag 'trace-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing, synthetic events: Replace buggy strcat() with seq_buf operations