user/sven/linux.git/kernel/trace/trace.c, branch v5.9.8

tracing: Fix out of bounds write in get_trace_buf

2020-11-10T11:39:02Z

commit c1acb4ac1a892cf08d27efcb964ad281728b0545 upstream. 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 Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing: Fix trace_find_next_entry() accounting of temp buffer size

2020-09-29T16:46:22Z

The temp buffer size variable for trace_find_next_entry() was incorrectly being updated when the size did not change. The temp buffer size should only be updated when it is reallocated. This is mostly an issue when used with ftrace_dump(). That's because ftrace_dump() can not allocate a new buffer, and instead uses a temporary buffer with a fix size. But the variable that keeps track of that size is incorrectly updated with each call, and it could fall into the path that would try to reallocate the buffer and produce a warning. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1601 at kernel/trace/trace.c:3548 trace_find_next_entry+0xd0/0xe0 Modules linked in [..] CPU: 1 PID: 1601 Comm: bash Not tainted 5.9.0-rc5-test+ #521 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:trace_find_next_entry+0xd0/0xe0 Code: 40 21 00 00 4c 89 e1 31 d2 4c 89 ee 48 89 df e8 c6 9e ff ff 89 ab 54 21 00 00 5b 5d 41 5c 41 5d c3 48 63 d5 eb bf 31 c0 eb f0 <0f> 0b 48 63 d5 eb b4 66 0f 1f 84 00 00 00 00 00 53 48 8d 8f 60 21 RSP: 0018:ffff95a4f2e8bd70 EFLAGS: 00010046 RAX: ffffffff96679fc0 RBX: ffffffff97910de0 RCX: ffffffff96679fc0 RDX: ffff95a4f2e8bd98 RSI: ffff95a4ee321098 RDI: ffffffff97913000 RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000046 R12: ffff95a4f2e8bd98 R13: 0000000000000000 R14: ffff95a4ee321098 R15: 00000000009aa301 FS: 00007f8565484740(0000) GS:ffff95a55aa40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055876bd43d90 CR3: 00000000b76e6003 CR4: 00000000001706e0 Call Trace: trace_print_lat_context+0x58/0x2d0 ? cpumask_next+0x16/0x20 print_trace_line+0x1a4/0x4f0 ftrace_dump.cold+0xad/0x12c __handle_sysrq.cold+0x51/0x126 write_sysrq_trigger+0x3f/0x4a proc_reg_write+0x53/0x80 vfs_write+0xca/0x210 ksys_write+0x70/0xf0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f8565579487 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 RSP: 002b:00007ffd40707948 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f8565579487 RDX: 0000000000000002 RSI: 000055876bd74de0 RDI: 0000000000000001 RBP: 000055876bd74de0 R08: 000000000000000a R09: 0000000000000001 R10: 000055876bdec280 R11: 0000000000000246 R12: 0000000000000002 R13: 00007f856564a500 R14: 0000000000000002 R15: 00007f856564a700 irq event stamp: 109958 ---[ end trace 7aab5b7e51484b00 ]--- Not only fix the updating of the temp buffer, but also do not free the temp buffer before a new buffer is allocated (there's no reason to not continue to use the current temp buffer if an allocation fails). Cc: stable@vger.kernel.org Fixes: 8e99cf91b99bb ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic") Reported-by: Anna-Maria Behnsen Signed-off-by: Steven Rostedt (VMware)

tracing: Make the space reserved for the pid wider

2020-09-18T16:42:11Z

For 64bit CONFIG_BASE_SMALL=0 systems PID_MAX_LIMIT is set by default to 4194304. During boot the kernel sets a new value based on number of CPUs but no lower than 32768. It is 1024 per CPU so with 128 CPUs the default becomes 131072 which needs six digits. This value can be increased during run time but must not exceed the initial upper limit. Systemd sometime after v241 sets it to the upper limit during boot. The result is that when the pid exceeds five digits, the trace output is a little hard to read because it is no longer properly padded (same like on big iron with 98+ CPUs). Increase the pid padding to seven digits. Link: https://lkml.kernel.org/r/20200904082331.dcdkrr3bkn3e4qlg@linutronix.de Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2020-08-08T01:29:15Z

Pull tracing updates from Steven Rostedt: - The biggest news in that the tracing ring buffer can now time events that interrupted other ring buffer events. Before this change, if an interrupt came in while recording another event, and that interrupt also had an event, those events would all have the same time stamp as the event it interrupted. Now, with the new design, those events will have a unique time stamp and rightfully display the time for those events that were recorded while interrupting another event. - Bootconfig how has an "override" operator that lets the users have a default config, but then add options to override the default. - A fix was made to properly filter function graph tracing to the ftrace PIDs. This came in at the end of the -rc cycle, and needs to be backported. - Several clean ups, performance updates, and minor fixes as well. * tag 'trace-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (39 commits) tracing: Add trace_array_init_printk() to initialize instance trace_printk() buffers kprobes: Fix compiler warning for !CONFIG_KPROBES_ON_FTRACE tracing: Use trace_sched_process_free() instead of exit() for pid tracing bootconfig: Fix to find the initargs correctly Documentation: bootconfig: Add bootconfig override operator tools/bootconfig: Add testcases for value override operator lib/bootconfig: Add override operator support kprobes: Remove show_registers() function prototype tracing/uprobe: Remove dead code in trace_uprobe_register() kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler ftrace: Fix ftrace_trace_task return value tracepoint: Use __used attribute definitions from compiler_attributes.h tracepoint: Mark __tracepoint_string's __used trace : Have tracing buffer info use kvzalloc instead of kzalloc tracing: Remove outdated comment in stack handling ftrace: Do not let direct or IPMODIFY ftrace_ops be added to module and set trampolines ftrace: Setup correct FTRACE_FL_REGS flags for module tracing/hwlat: Honor the tracing_cpumask tracing/hwlat: Drop the duplicate assignment in start_kthread() tracing: Save one trace_event->type by using __TRACE_LAST_TYPE ...

tracing: Add trace_array_init_printk() to initialize instance trace_printk() buffers

2020-08-07T21:05:01Z

As trace_array_printk() used with not global instances will not add noise to the main buffer, they are OK to have in the kernel (unlike trace_printk()). This require the subsystem to create their own tracing instance, and the trace_array_printk() only writes into those instances. Add trace_array_init_printk() to initialize the trace_printk() buffers without printing out the WARNING message. Reported-by: Sean Paul Reviewed-by: Sean Paul Signed-off-by: Steven Rostedt (VMware)

Merge tag 'fsnotify_for_v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

2020-08-07T02:29:51Z

Pull fsnotify updates from Jan Kara: - fanotify fix for softlockups when there are many queued events - performance improvement to reduce fsnotify overhead when not used - Amir's implementation of fanotify events with names. With these you can now efficiently monitor whole filesystem, eg to mirror changes to another machine. * tag 'fsnotify_for_v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (37 commits) fanotify: compare fsid when merging name event fsnotify: create method handle_inode_event() in fsnotify_operations fanotify: report parent fid + child fid fanotify: report parent fid + name + child fid fanotify: add support for FAN_REPORT_NAME fanotify: report events with parent dir fid to sb/mount/non-dir marks fanotify: add basic support for FAN_REPORT_DIR_FID fsnotify: remove check that source dentry is positive fsnotify: send event with parent/name info to sb/mount/non-dir marks audit: do not set FS_EVENT_ON_CHILD in audit marks mask inotify: do not set FS_EVENT_ON_CHILD in non-dir mark mask fsnotify: pass dir and inode arguments to fsnotify() fsnotify: create helper fsnotify_inode() fsnotify: send event to parent and child with single callback inotify: report both events on parent and child with single callback dnotify: report both events on parent and child with single callback fanotify: no external fh buffer in fanotify_name_event fanotify: use struct fanotify_info to parcel the variable size buffer fsnotify: add object type "child" to object type iterator fanotify: use FAN_EVENT_ON_CHILD as implicit flag on sb/mount/non-dir marks ...

trace : Have tracing buffer info use kvzalloc instead of kzalloc

2020-08-03T15:52:20Z

High order memory stuff within trace could introduce OOM, use kvzalloc instead. Please find the bellowing for the call stack we run across in an android system. The scenario happens when traced_probes is woken up to get a large quantity of trace even if free memory is even higher than watermark_low. traced_probes invoked oom-killer: gfp_mask=0x140c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null), order=2, oom_score_adj=-1 traced_probes cpuset=system-background mems_allowed=0 CPU: 3 PID: 588 Comm: traced_probes Tainted: G W O 4.14.181 #1 Hardware name: Generic DT based system (unwind_backtrace) from [] (show_stack+0x20/0x24) (show_stack) from [] (dump_stack+0xa8/0xec) (dump_stack) from [] (dump_header+0x9c/0x220) (dump_header) from [] (oom_kill_process+0xc0/0x5c4) (oom_kill_process) from [] (out_of_memory+0x220/0x310) (out_of_memory) from [] (__alloc_pages_nodemask+0xff8/0x13a4) (__alloc_pages_nodemask) from [] (kmalloc_order+0x30/0x48) (kmalloc_order) from [] (kmalloc_order_trace+0x30/0x118) (kmalloc_order_trace) from [] (tracing_buffers_open+0x50/0xfc) (tracing_buffers_open) from [] (do_dentry_open+0x278/0x34c) (do_dentry_open) from [] (vfs_open+0x50/0x70) (vfs_open) from [] (path_openat+0x5fc/0x169c) (path_openat) from [] (do_filp_open+0x94/0xf8) (do_filp_open) from [] (do_sys_open+0x168/0x26c) (do_sys_open) from [] (SyS_openat+0x34/0x38) (SyS_openat) from [] (ret_fast_syscall+0x0/0x28) Link: https://lkml.kernel.org/r/1596155265-32365-1-git-send-email-zhaoyang.huang@unisoc.com Signed-off-by: Zhaoyang Huang Signed-off-by: Steven Rostedt (VMware)

tracing: Remove outdated comment in stack handling

2020-07-31T02:54:50Z

This comment describes the behaviour before commit 2a820bf74918 ("tracing: Use percpu stack trace buffer more intelligently"). Since that commit, interrupts and NMIs do use the per-cpu stacks so the comment is no longer correct. Remove it. (Note that the FTRACE_STACK_SIZE mentioned in the comment has never existed, it probably should have said FTRACE_STACK_ENTRIES.) Link: https://lkml.kernel.org/r/20200727092840.18659-1-vincent.whitchurch@axis.com Signed-off-by: Vincent Whitchurch Signed-off-by: Steven Rostedt (VMware)

fsnotify: create helper fsnotify_inode()

2020-07-27T21:13:51Z

Simple helper to consolidate biolerplate code. Link: https://lore.kernel.org/r/20200722125849.17418-5-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

tracefs: Remove unnecessary debug_fs checks.

2020-07-23T15:10:25Z

This is a preparation for debugfs restricted mode. We don't need debugfs to trace, the removed check stop tracefs to work if debugfs is not initialised. We instead tries to automount within debugfs and relay on it's handling. The code path is to create a backward compatibility from when tracefs was part of debugfs, it is now standalone and does not need debugfs. When debugfs is in restricted it is compiled in but not active and return EPERM to clients and tracefs wont work if it assumes it is active it is compiled in kernel. Reported-by: kernel test robot Signed-off-by: Peter Enderborg Reviewed-by: Greg Kroah-Hartman Acked-by: Steven Rostedt (VMware) Link: https://lore.kernel.org/r/20200716071511.26864-2-peter.enderborg@sony.com Signed-off-by: Greg Kroah-Hartman