user/sven/linux.git/include/linux/trace_events.h, branch v6.6.17

tracing: Have trace_event_file have ref counters

2023-11-08T10:56:21Z

commit bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4 upstream The following can crash the kernel: # cd /sys/kernel/tracing # echo 'p:sched schedule' > kprobe_events # exec 5>>events/kprobes/sched/enable # > kprobe_events # exec 5>&- The above commands: 1. Change directory to the tracefs directory 2. Create a kprobe event (doesn't matter what one) 3. Open bash file descriptor 5 on the enable file of the kprobe event 4. Delete the kprobe event (removes the files too) 5. Close the bash file descriptor 5 The above causes a crash! BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:tracing_release_file_tr+0xc/0x50 What happens here is that the kprobe event creates a trace_event_file "file" descriptor that represents the file in tracefs to the event. It maintains state of the event (is it enabled for the given instance?). Opening the "enable" file gets a reference to the event "file" descriptor via the open file descriptor. When the kprobe event is deleted, the file is also deleted from the tracefs system which also frees the event "file" descriptor. But as the tracefs file is still opened by user space, it will not be totally removed until the final dput() is called on it. But this is not true with the event "file" descriptor that is already freed. If the user does a write to or simply closes the file descriptor it will reference the event "file" descriptor that was just freed, causing a use-after-free bug. To solve this, add a ref count to the event "file" descriptor as well as a new flag called "FREED". The "file" will not be freed until the last reference is released. But the FREE flag will be set when the event is removed to prevent any more modifications to that event from happening, even if there's still a reference to the event "file" descriptor. Link: https://lore.kernel.org/linux-trace-kernel/20231031000031.1e705592@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20231031122453.7a48b923@gandalf.local.home Cc: stable@vger.kernel.org Cc: Mark Rutland Fixes: f5ca233e2e66d ("tracing: Increase trace array ref count on enable and filter files") Reported-by: Beau Belgrave Tested-by: Beau Belgrave Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

tracing/synthetic: Fix order of struct trace_dynamic_info

2023-09-11T22:22:00Z

To make handling BIG and LITTLE endian better the offset/len of dynamic fields of the synthetic events was changed into a structure of: struct trace_dynamic_info { #ifdef CONFIG_CPU_BIG_ENDIAN u16 offset; u16 len; #else u16 len; u16 offset; #endif }; to replace the manual changes of: data_offset = offset & 0xffff; data_offest = len << 16; But if you look closely, the above is: << 16 | offset Which in little endian would be in memory: offset_lo offset_hi len_lo len_hi and in big endian: len_hi len_lo offset_hi offset_lo Which if broken into a structure would be: struct trace_dynamic_info { #ifdef CONFIG_CPU_BIG_ENDIAN u16 len; u16 offset; #else u16 offset; u16 len; #endif }; Which is the opposite of what was defined. Fix this and just to be safe also add "__packed". Link: https://lore.kernel.org/all/20230908154417.5172e343@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20230908163929.2c25f3dc@gandalf.local.home Cc: stable@vger.kernel.org Cc: Mark Rutland Tested-by: Sven Schnelle Acked-by: Masami Hiramatsu (Google) Fixes: ddeea494a16f3 ("tracing/synthetic: Use union instead of casts") Signed-off-by: Steven Rostedt (Google)

tracing: Remove unused trace_event_file dir field

2023-09-09T03:13:02Z

Now that eventfs structure is used to create the events directory via the eventfs dynamically allocate code, the "dir" field of the trace_event_file structure is no longer used. Remove it. Link: https://lkml.kernel.org/r/20230908022001.580400115@goodmis.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Andrew Morton Cc: Ajay Kaher Signed-off-by: Steven Rostedt (Google)

Merge tag 'trace-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2023-09-01T23:34:25Z

Pull tracing updates from Steven Rostedt: "User visible changes: - Added a way to easier filter with cpumasks: # echo 'cpumask & CPUS{17-42}' > /sys/kernel/tracing/events/ipi_send_cpumask/filter - Show actual size of ring buffer after modifying the ring buffer size via buffer_size_kb. Currently it just returns what was written, but the actual size rounds up to the sub buffer size. Show that real size instead. Major changes: - Added "eventfs". This is the code that handles the inodes and dentries of tracefs/events directory. As there are thousands of events, and each event has several inodes and dentries that currently exist even when tracing is never used, they take up precious memory. Instead, eventfs will allocate the inodes and dentries in a JIT way (similar to what procfs does). There is now metadata that handles the events and subdirectories, and will create the inodes and dentries when they are used. Note, I also have patches that remove the subdirectory meta data, but will wait till the next merge window before applying them. It's a little more complex, and I want to make sure the dynamic code works properly before adding more complexity, making it easier to revert if need be. Minor changes: - Optimization to user event list traversal - Remove intermediate permission of tracefs files (note the intermediate permission removes all access to the files so it is not a security concern, but just a clean up) - Add the complex fix to FORTIFY_SOURCE to the kernel stack event logic - Other minor cleanups" * tag 'trace-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (29 commits) tracefs: Remove kerneldoc from struct eventfs_file tracefs: Avoid changing i_mode to a temp value tracing/user_events: Optimize safe list traversals ftrace: Remove empty declaration ftrace_enable_daemon() and ftrace_disable_daemon() tracing: Remove unused function declarations tracing/filters: Document cpumask filtering tracing/filters: Further optimise scalar vs cpumask comparison tracing/filters: Optimise CPU vs cpumask filtering when the user mask is a single CPU tracing/filters: Optimise scalar vs cpumask filtering when the user mask is a single CPU tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU tracing/filters: Enable filtering the CPU common field by a cpumask tracing/filters: Enable filtering a scalar field by a cpumask tracing/filters: Enable filtering a cpumask field by another cpumask tracing/filters: Dynamically allocate filter_pred.regex test: ftrace: Fix kprobe test for eventfs eventfs: Move tracing/events to eventfs eventfs: Implement removal of meta data from eventfs eventfs: Implement functions to create files and dirs when accessed eventfs: Implement eventfs lookup, read, open functions eventfs: Implement eventfs file add functions ...

Merge tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2023-08-29T18:33:01Z

Pull networking updates from Paolo Abeni: "Core: - Increase size limits for to-be-sent skb frag allocations. This allows tun, tap devices and packet sockets to better cope with large writes operations - Store netdevs in an xarray, to simplify iterating over netdevs - Refactor nexthop selection for multipath routes - Improve sched class lifetime handling - Add backup nexthop ID support for bridge - Implement drop reasons support in openvswitch - Several data races annotations and fixes - Constify the sk parameter of routing functions - Prepend kernel version to netconsole message Protocols: - Implement support for TCP probing the peer being under memory pressure - Remove hard coded limitation on IPv6 specific info placement inside the socket struct - Get rid of sysctl_tcp_adv_win_scale and use an auto-estimated per socket scaling factor - Scaling-up the IPv6 expired route GC via a separated list of expiring routes - In-kernel support for the TLS alert protocol - Better support for UDP reuseport with connected sockets - Add NEXT-C-SID support for SRv6 End.X behavior, reducing the SR header size - Get rid of additional ancillary per MPTCP connection struct socket - Implement support for BPF-based MPTCP packet schedulers - Format MPTCP subtests selftests results in TAP - Several new SMC 2.1 features including unique experimental options, max connections per lgr negotiation, max links per lgr negotiation BPF: - Multi-buffer support in AF_XDP - Add multi uprobe BPF links for attaching multiple uprobes and usdt probes, which is significantly faster and saves extra fds - Implement an fd-based tc BPF attach API (TCX) and BPF link support on top of it - Add SO_REUSEPORT support for TC bpf_sk_assign - Support new instructions from cpu v4 to simplify the generated code and feature completeness, for x86, arm64, riscv64 - Support defragmenting IPv(4|6) packets in BPF - Teach verifier actual bounds of bpf_get_smp_processor_id() and fix perf+libbpf issue related to custom section handling - Introduce bpf map element count and enable it for all program types - Add a BPF hook in sys_socket() to change the protocol ID from IPPROTO_TCP to IPPROTO_MPTCP to cover migration for legacy - Introduce bpf_me_mcache_free_rcu() and fix OOM under stress - Add uprobe support for the bpf_get_func_ip helper - Check skb ownership against full socket - Support for up to 12 arguments in BPF trampoline - Extend link_info for kprobe_multi and perf_event links Netfilter: - Speed-up process exit by aborting ruleset validation if a fatal signal is pending - Allow NLA_POLICY_MASK to be used with BE16/BE32 types Driver API: - Page pool optimizations, to improve data locality and cache usage - Introduce ndo_hwtstamp_get() and ndo_hwtstamp_set() to avoid the need for raw ioctl() handling in drivers - Simplify genetlink dump operations (doit/dumpit) providing them the common information already populated in struct genl_info - Extend and use the yaml devlink specs to [re]generate the split ops - Introduce devlink selective dumps, to allow SF filtering SF based on handle and other attributes - Add yaml netlink spec for netlink-raw families, allow route, link and address related queries via the ynl tool - Remove phylink legacy mode support - Support offload LED blinking to phy - Add devlink port function attributes for IPsec New hardware / drivers: - Ethernet: - Broadcom ASP 2.0 (72165) ethernet controller - MediaTek MT7988 SoC - Texas Instruments AM654 SoC - Texas Instruments IEP driver - Atheros qca8081 phy - Marvell 88Q2110 phy - NXP TJA1120 phy - WiFi: - MediaTek mt7981 support - Can: - Kvaser SmartFusion2 PCI Express devices - Allwinner T113 controllers - Texas Instruments tcan4552/4553 chips - Bluetooth: - Intel Gale Peak - Qualcomm WCN3988 and WCN7850 - NXP AW693 and IW624 - Mediatek MT2925 Drivers: - Ethernet NICs: - nVidia/Mellanox: - mlx5: - support UDP encapsulation in packet offload mode - IPsec packet offload support in eswitch mode - improve aRFS observability by adding new set of counters - extends MACsec offload support to cover RoCE traffic - dynamic completion EQs - mlx4: - convert to use auxiliary bus instead of custom interface logic - Intel - ice: - implement switchdev bridge offload, even for LAG interfaces - implement SRIOV support for LAG interfaces - igc: - add support for multiple in-flight TX timestamps - Broadcom: - bnxt: - use the unified RX page pool buffers for XDP and non-XDP - use the NAPI skb allocation cache - OcteonTX2: - support Round Robin scheduling HTB offload - TC flower offload support for SPI field - Freescale: - add XDP_TX feature support - AMD: - ionic: add support for PCI FLR event - sfc: - basic conntrack offload - introduce eth, ipv4 and ipv6 pedit offloads - ST Microelectronics: - stmmac: maximze PTP timestamping resolution - Virtual NICs: - Microsoft vNIC: - batch ringing RX queue doorbell on receiving packets - add page pool for RX buffers - Virtio vNIC: - add per queue interrupt coalescing support - Google vNIC: - add queue-page-list mode support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add port range matching tc-flower offload - permit enslavement to netdevices with uppers - Ethernet embedded switches: - Marvell (mv88e6xxx): - convert to phylink_pcs - Renesas: - r8A779fx: add speed change support - rzn1: enables vlan support - Ethernet PHYs: - convert mv88e6xxx to phylink_pcs - WiFi: - Qualcomm Wi-Fi 7 (ath12k): - extremely High Throughput (EHT) PHY support - RealTek (rtl8xxxu): - enable AP mode for: RTL8192FU, RTL8710BU (RTL8188GU), RTL8192EU and RTL8723BU - RealTek (rtw89): - Introduce Time Averaged SAR (TAS) support - Connector: - support for event filtering" * tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1806 commits) net: ethernet: mtk_wed: minor change in wed_{tx,rx}info_show net: ethernet: mtk_wed: add some more info in wed_txinfo_show handler net: stmmac: clarify difference between "interface" and "phy_interface" r8152: add vendor/device ID pair for D-Link DUB-E250 devlink: move devlink_notify_register/unregister() to dev.c devlink: move small_ops definition into netlink.c devlink: move tracepoint definitions into core.c devlink: push linecard related code into separate file devlink: push rate related code into separate file devlink: push trap related code into separate file devlink: use tracepoint_enabled() helper devlink: push region related code into separate file devlink: push param related code into separate file devlink: push resource related code into separate file devlink: push dpipe related code into separate file devlink: move and rename devlink_dpipe_send_and_alloc_skb() helper devlink: push shared buffer related code into separate file devlink: push port related code into separate file devlink: push object register/unregister notifications into separate helpers inet: fix IP_TRANSPARENT error handling ...

tracing/filters: Enable filtering a cpumask field by another cpumask

2023-08-22T09:13:28Z

The recently introduced ipi_send_cpumask trace event contains a cpumask field, but it currently cannot be used in filter expressions. Make event filtering aware of cpumask fields, and allow these to be filtered by a user-provided cpumask. The user-provided cpumask is to be given in cpulist format and wrapped as: "CPUS{$cpulist}". The use of curly braces instead of parentheses is to prevent predicate_parse() from parsing the contents of CPUS{...} as a full-fledged predicate subexpression. This enables e.g.: $ trace-cmd record -e 'ipi_send_cpumask' -f 'cpumask & CPUS{2,4,6,8-32}' Link: https://lkml.kernel.org/r/20230707172155.70873-3-vschneid@redhat.com Cc: Masami Hiramatsu Cc: Jonathan Corbet Cc: Juri Lelli Cc: Daniel Bristot de Oliveira Cc: Marcelo Tosatti Cc: Leonardo Bras Cc: Frederic Weisbecker Signed-off-by: Valentin Schneider Signed-off-by: Steven Rostedt (Google)

bpf: Add multi uprobe link

2023-08-21T22:51:25Z

Adding new multi uprobe link that allows to attach bpf program to multiple uprobes. Uprobes to attach are specified via new link_create uprobe_multi union: struct { __aligned_u64 path; __aligned_u64 offsets; __aligned_u64 ref_ctr_offsets; __u32 cnt; __u32 flags; } uprobe_multi; Uprobes are defined for single binary specified in path and multiple calling sites specified in offsets array with optional reference counters specified in ref_ctr_offsets array. All specified arrays have length of 'cnt'. The 'flags' supports single bit for now that marks the uprobe as return probe. Acked-by: Andrii Nakryiko Acked-by: Yafang Shao Signed-off-by: Jiri Olsa Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230809083440.3209381-4-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

tracing/synthetic: Use union instead of casts

2023-08-16T20:33:27Z

The current code uses a lot of casts to access the fields member in struct synth_trace_events with different sizes. This makes the code hard to read, and had already introduced an endianness bug. Use a union and struct instead. Link: https://lkml.kernel.org/r/20230816154928.4171614-2-svens@linux.ibm.com Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Fixes: 00cf3d672a9dd ("tracing: Allow synthetic events to pass around stacktraces") Signed-off-by: Sven Schnelle Signed-off-by: Steven Rostedt (Google)

eventfs: Move tracing/events to eventfs

2023-07-31T15:55:55Z

Up until now, /sys/kernel/tracing/events was no different than any other part of tracefs. The files and directories within the events directory was created when the tracefs was mounted, and also created for the instances in /sys/kernel/tracing/instances//events. Most of these files and directories will never be referenced. Since there are thousands of these files and directories they spend their time wasting precious memory resources. Move the "events" directory to the new eventfs. The eventfs will take the meta data of the events that they represent and store that. When the files in the events directory are referenced, the dentry and inodes to represent them are then created. When the files are no longer referenced, they are freed. This saves the precious memory resources that were wasted on these seldom referenced dentries and inodes. Running the following: ~# cat /proc/meminfo /proc/slabinfo > before.out ~# mkdir /sys/kernel/tracing/instances/foo ~# cat /proc/meminfo /proc/slabinfo > after.out to test the changes produces the following deltas: Before this change: Before after deltas for meminfo: MemFree: -32260 MemAvailable: -21496 KReclaimable: 21528 Slab: 22440 SReclaimable: 21528 SUnreclaim: 912 VmallocUsed: 16 Before after deltas for slabinfo: : [ * = ] tracefs_inode_cache: 14472 [* 1184 = 17134848] buffer_head: 24 [* 168 = 4032] hmem_inode_cache: 28 [* 1480 = 41440] dentry: 14450 [* 312 = 4508400] lsm_inode_cache: 14453 [* 32 = 462496] vma_lock: 11 [* 152 = 1672] vm_area_struct: 2 [* 184 = 368] trace_event_file: 1748 [* 88 = 153824] kmalloc-256: 1072 [* 256 = 274432] kmalloc-64: 2842 [* 64 = 181888] Total slab additions in size: 22,763,400 bytes With this change: Before after deltas for meminfo: MemFree: -12600 MemAvailable: -12580 Cached: 24 Active: 12 Inactive: 68 Inactive(anon): 48 Active(file): 12 Inactive(file): 20 Dirty: -4 AnonPages: 68 KReclaimable: 12 Slab: 1856 SReclaimable: 12 SUnreclaim: 1844 KernelStack: 16 PageTables: 36 VmallocUsed: 16 Before after deltas for slabinfo: : [ * = ] tracefs_inode_cache: 108 [* 1184 = 127872] buffer_head: 24 [* 168 = 4032] hmem_inode_cache: 18 [* 1480 = 26640] dentry: 127 [* 312 = 39624] lsm_inode_cache: 152 [* 32 = 4864] vma_lock: 67 [* 152 = 10184] vm_area_struct: -12 [* 184 = -2208] trace_event_file: 1764 [* 96 = 169344] kmalloc-96: 14322 [* 96 = 1374912] kmalloc-64: 2814 [* 64 = 180096] kmalloc-32: 1103 [* 32 = 35296] kmalloc-16: 2308 [* 16 = 36928] kmalloc-8: 12800 [* 8 = 102400] Total slab additions in size: 2,109,984 bytes Which is a savings of 20,653,416 bytes (20 MB) per tracing instance. Link: https://lkml.kernel.org/r/1690568452-46553-10-git-send-email-akaher@vmware.com Signed-off-by: Ajay Kaher Co-developed-by: Steven Rostedt (VMware) Signed-off-by: Steven Rostedt (VMware) Tested-by: Ching-lin Yu Signed-off-by: Steven Rostedt (Google)

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2023-07-14T02:13:24Z

Alexei Starovoitov says: ==================== pull-request: bpf-next 2023-07-13 We've added 67 non-merge commits during the last 15 day(s) which contain a total of 106 files changed, 4444 insertions(+), 619 deletions(-). The main changes are: 1) Fix bpftool build in presence of stale vmlinux.h, from Alexander Lobakin. 2) Introduce bpf_me_mcache_free_rcu() and fix OOM under stress, from Alexei Starovoitov. 3) Teach verifier actual bounds of bpf_get_smp_processor_id() and fix perf+libbpf issue related to custom section handling, from Andrii Nakryiko. 4) Introduce bpf map element count, from Anton Protopopov. 5) Check skb ownership against full socket, from Kui-Feng Lee. 6) Support for up to 12 arguments in BPF trampoline, from Menglong Dong. 7) Export rcu_request_urgent_qs_task, from Paul E. McKenney. 8) Fix BTF walking of unions, from Yafang Shao. 9) Extend link_info for kprobe_multi and perf_event links, from Yafang Shao. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (67 commits) selftests/bpf: Add selftest for PTR_UNTRUSTED bpf: Fix an error in verifying a field in a union selftests/bpf: Add selftests for nested_trust bpf: Fix an error around PTR_UNTRUSTED selftests/bpf: add testcase for TRACING with 6+ arguments bpf, x86: allow function arguments up to 12 for TRACING bpf, x86: save/restore regs with BPF_DW size bpftool: Use "fallthrough;" keyword instead of comments bpf: Add object leak check. bpf: Convert bpf_cpumask to bpf_mem_cache_free_rcu. bpf: Introduce bpf_mem_free_rcu() similar to kfree_rcu(). selftests/bpf: Improve test coverage of bpf_mem_alloc. rcu: Export rcu_request_urgent_qs_task() bpf: Allow reuse from waiting_for_gp_ttrace list. bpf: Add a hint to allocated objects. bpf: Change bpf_mem_cache draining process. bpf: Further refactor alloc_bulk(). bpf: Factor out inc/dec of active flag into helpers. bpf: Refactor alloc_bulk(). bpf: Let free_all() return the number of freed elements. ... ==================== Link: https://lore.kernel.org/r/20230714020910.80794-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski