BMC/Intel-BMC/linux.git/kernel/trace/ftrace.c, branch dev-4.10

ftrace: Fix function pid filter on instances

2017-04-21T07:32:41+00:00

commit d879d0b8c183aabeb9a65eba91f3f9e3c7e7b905 upstream. When function tracer has a pid filter, it adds a probe to sched_switch to track if current task can be ignored. The probe checks the ftrace_ignore_pid from current tr to filter tasks. But it misses to delete the probe when removing an instance so that it can cause a crash due to the invalid tr pointer (use-after-free). This is easily reproducible with the following: # cd /sys/kernel/debug/tracing # mkdir instances/buggy # echo $$ > instances/buggy/set_ftrace_pid # rmdir instances/buggy ============================================================================ BUG: KASAN: use-after-free in ftrace_filter_pid_sched_switch_probe+0x3d/0x90 Read of size 8 by task kworker/0:1/17 CPU: 0 PID: 17 Comm: kworker/0:1 Tainted: G B 4.11.0-rc3 #198 Call Trace: dump_stack+0x68/0x9f kasan_object_err+0x21/0x70 kasan_report.part.1+0x22b/0x500 ? ftrace_filter_pid_sched_switch_probe+0x3d/0x90 kasan_report+0x25/0x30 __asan_load8+0x5e/0x70 ftrace_filter_pid_sched_switch_probe+0x3d/0x90 ? fpid_start+0x130/0x130 __schedule+0x571/0xce0 ... To fix it, use ftrace_clear_pids() to unregister the probe. As instance_rmdir() already updated ftrace codes, it can just free the filter safely. Link: http://lkml.kernel.org/r/20170417024430.21194-2-namhyung@kernel.org Fixes: 0c8916c34203 ("tracing: Add rmdir to remove multibuffer instances") Cc: Ingo Molnar Reviewed-by: Masami Hiramatsu Signed-off-by: Namhyung Kim Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

ftrace: Fix removing of second function probe

2017-04-21T07:32:40+00:00

commit 82cc4fc2e70ec5baeff8f776f2773abc8b2cc0ae upstream. When two function probes are added to set_ftrace_filter, and then one of them is removed, the update to the function locations is not performed, and the record keeping of the function states are corrupted, and causes an ftrace_bug() to occur. This is easily reproducable by adding two probes, removing one, and then adding it back again. # cd /sys/kernel/debug/tracing # echo schedule:traceoff > set_ftrace_filter # echo do_IRQ:traceoff > set_ftrace_filter # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter # echo do_IRQ:traceoff > set_ftrace_filter Causes: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1098 at kernel/trace/ftrace.c:2369 ftrace_get_addr_curr+0x143/0x220 Modules linked in: [...] CPU: 2 PID: 1098 Comm: bash Not tainted 4.10.0-test+ #405 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 Call Trace: dump_stack+0x68/0x9f __warn+0x111/0x130 ? trace_irq_work_interrupt+0xa0/0xa0 warn_slowpath_null+0x1d/0x20 ftrace_get_addr_curr+0x143/0x220 ? __fentry__+0x10/0x10 ftrace_replace_code+0xe3/0x4f0 ? ftrace_int3_handler+0x90/0x90 ? printk+0x99/0xb5 ? 0xffffffff81000000 ftrace_modify_all_code+0x97/0x110 arch_ftrace_update_code+0x10/0x20 ftrace_run_update_code+0x1c/0x60 ftrace_run_modify_code.isra.48.constprop.62+0x8e/0xd0 register_ftrace_function_probe+0x4b6/0x590 ? ftrace_startup+0x310/0x310 ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30 ? update_stack_state+0x88/0x110 ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320 ? preempt_count_sub+0x18/0xd0 ? mutex_lock_nested+0x104/0x800 ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320 ? __unwind_start+0x1c0/0x1c0 ? _mutex_lock_nest_lock+0x800/0x800 ftrace_trace_probe_callback.isra.3+0xc0/0x130 ? func_set_flag+0xe0/0xe0 ? __lock_acquire+0x642/0x1790 ? __might_fault+0x1e/0x20 ? trace_get_user+0x398/0x470 ? strcmp+0x35/0x60 ftrace_trace_onoff_callback+0x48/0x70 ftrace_regex_write.isra.43.part.44+0x251/0x320 ? match_records+0x420/0x420 ftrace_filter_write+0x2b/0x30 __vfs_write+0xd7/0x330 ? do_loop_readv_writev+0x120/0x120 ? locks_remove_posix+0x90/0x2f0 ? do_lock_file_wait+0x160/0x160 ? __lock_is_held+0x93/0x100 ? rcu_read_lock_sched_held+0x5c/0xb0 ? preempt_count_sub+0x18/0xd0 ? __sb_start_write+0x10a/0x230 ? vfs_write+0x222/0x240 vfs_write+0xef/0x240 SyS_write+0xab/0x130 ? SyS_read+0x130/0x130 ? trace_hardirqs_on_caller+0x182/0x280 ? trace_hardirqs_on_thunk+0x1a/0x1c entry_SYSCALL_64_fastpath+0x18/0xad RIP: 0033:0x7fe61c157c30 RSP: 002b:00007ffe87890258 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: ffffffff8114a410 RCX: 00007fe61c157c30 RDX: 0000000000000010 RSI: 000055814798f5e0 RDI: 0000000000000001 RBP: ffff8800c9027f98 R08: 00007fe61c422740 R09: 00007fe61ca53700 R10: 0000000000000073 R11: 0000000000000246 R12: 0000558147a36400 R13: 00007ffe8788f160 R14: 0000000000000024 R15: 00007ffe8788f15c ? trace_hardirqs_off_caller+0xc0/0x110 ---[ end trace 99fa09b3d9869c2c ]--- Bad trampoline accounting at: ffffffff81cc3b00 (do_IRQ+0x0/0x150) Fixes: 59df055f1991 ("ftrace: trace different functions with a different tracer") Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

clocksource: Use a plain u64 instead of cycle_t

2016-12-25T10:04:12+00:00

There is no point in having an extra type for extra confusion. u64 is unambiguous. Conversion was done with the following coccinelle script: @rem@ @@ -typedef u64 cycle_t; @fix@ typedef cycle_t; @@ -cycle_t +u64 Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: John Stultz

Merge tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-12-15T21:49:34+00:00

Pull tracing updates from Steven Rostedt: "This release has a few updates: - STM can hook into the function tracer - Function filtering now supports more advance glob matching - Ftrace selftests updates and added tests - Softirq tag in traces now show only softirqs - ARM nop added to non traced locations at compile time - New trace_marker_raw file that allows for binary input - Optimizations to the ring buffer - Removal of kmap in trace_marker - Wakeup and irqsoff tracers now adhere to the set_graph_notrace file - Other various fixes and clean ups" * tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (42 commits) selftests: ftrace: Shift down default message verbosity kprobes/trace: Fix kprobe selftest for newer gcc tracing/kprobes: Add a helper method to return number of probe hits tracing/rb: Init the CPU mask on allocation tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too fgraph: Handle a case where a tracer ignores set_graph_notrace tracing: Replace kmap with copy_from_user() in trace_marker writing ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it tracing: Allow benchmark to be enabled at early_initcall() tracing: Have system enable return error if one of the events fail tracing: Do not start benchmark on boot up tracing: Have the reg function allow to fail ring-buffer: Force rb_end_commit() and rb_set_commit_to_write() inline ring-buffer: Froce rb_update_write_stamp() to be inlined ring-buffer: Force inline of hotpath helper functions tracing: Make __buffer_unlock_commit() always_inline tracing: Make tracepoint_printk a static_key ring-buffer: Always inline rb_event_data() ring-buffer: Make rb_reserve_next_event() always inlined ...

Merge tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2016-12-13T17:16:11+00:00

Pull pstore updates from Kees Cook: "Improvements and fixes to pstore subsystem: - add additional checks for bad platform data - remove bounce buffer in console writer - protect read/unlink race with a mutex - correctly give up during dump locking failures - increase ftrace bandwidth by splitting ftrace buffers per CPU" * tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: ramoops: add pdata NULL check to ramoops_probe pstore: Convert console write to use ->write_buf pstore: Protect unlink with read_mutex pstore: Use global ftrace filters for function trace filtering ftrace: Provide API to use global filtering for ftrace ops pstore: Clarify context field przs as dprzs pstore: improve error report for failed setup pstore: Merge per-CPU ftrace records into one pstore: Add ftrace timestamp counter ramoops: Split ftrace buffer space into per-CPU zones pstore: Make ramoops_init_przs generic for other prz arrays pstore: Allow prz to control need for locking pstore: Warn on PSTORE_TYPE_PMSG using deprecated function pstore: Make spinlock per zone instead of global pstore: Actually give up during locking failure

ftrace: Provide API to use global filtering for ftrace ops

2016-11-16T00:34:30+00:00

Currently the global_ops filtering hash is not available to outside users registering for function tracing. Provide an API for those users to be able to choose global filtering. This is in preparation for pstore's ftrace feature to be able to use the global filters. Suggested-by: Steven Rostedt Cc: Anton Vorontsov Cc: Colin Cross Cc: Kees Cook Cc: Tony Luck Signed-off-by: Joel Fernandes Acked-by: Steven Rostedt Signed-off-by: Kees Cook

ftrace: Support full glob matching

2016-11-14T21:42:58+00:00

Use glob_match() to support flexible glob wildcards (*,?) and character classes ([) for ftrace. Since the full glob matching is slower than the current partial matching routines(*pat, pat*, *pat*), this leaves those routines and just add MATCH_GLOB for complex glob expression. e.g. ---- [root@localhost tracing]# echo 'sched*group' > set_ftrace_filter [root@localhost tracing]# cat set_ftrace_filter sched_free_group sched_change_group sched_create_group sched_online_group sched_destroy_group sched_offline_group [root@localhost tracing]# echo '[Ss]y[Ss]_*' > set_ftrace_filter [root@localhost tracing]# head set_ftrace_filter sys_arch_prctl sys_rt_sigreturn sys_ioperm SyS_iopl sys_modify_ldt SyS_mmap SyS_set_thread_area SyS_get_thread_area SyS_set_tid_address sys_fork ---- Link: http://lkml.kernel.org/r/147566869501.29136.6462645009894738056.stgit@devbox Acked-by: Namhyung Kim Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt

ftrace: Add more checks for FTRACE_FL_DISABLED in processing ip records

2016-11-14T21:31:49+00:00

When a module is first loaded and its function ip records are added to the ftrace list of functions to modify, they are set to DISABLED, as their text is still in a read only state. When the module is fully loaded, and can be updated, the flag is cleared, and if their's any functions that should be tracing them, it is updated at that moment. But there's several locations that do record accounting and should ignore records that are marked as disabled, or they can cause issues. Alexei already fixed one location, but others need to be addressed. Cc: stable@vger.kernel.org Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Reported-by: Alexei Starovoitov Signed-off-by: Steven Rostedt

ftrace: Ignore FTRACE_FL_DISABLED while walking dyn_ftrace records

2016-11-14T21:31:41+00:00

ftrace_shutdown() checks for sanity of ftrace records and if dyn_ftrace->flags is not zero, it will warn. It can happen that 'flags' are set to FTRACE_FL_DISABLED at this point, since some module was loaded, but before ftrace_module_enable() cleared the flags for this module. In other words the module.c is doing: ftrace_module_init(mod); // calls ftrace_update_code() that sets flags=FTRACE_FL_DISABLED ... // here ftrace_shutdown() is called that warns, since err = prepare_coming_module(mod); // didn't have a chance to clear FTRACE_FL_DISABLED Fix it by ignoring disabled records. It's similar to what __ftrace_hash_rec_update() is already doing. Link: http://lkml.kernel.org/r/1478560460-3818619-1-git-send-email-ast@fb.com Cc: stable@vger.kernel.org Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Signed-off-by: Alexei Starovoitov Signed-off-by: Steven Rostedt

ftrace: Access ret_stack->subtime only in the function profiler

2016-09-01T16:19:40+00:00

The subtime is used only for function profiler with function graph tracer enabled. Move the definition of subtime under CONFIG_FUNCTION_PROFILER to reduce the memory usage. Also move the initialization of subtime into the graph entry callback. Link: http://lkml.kernel.org/r/20160831025529.24018-1-namhyung@kernel.org Cc: Ingo Molnar Cc: Josh Poimboeuf Signed-off-by: Namhyung Kim Signed-off-by: Steven Rostedt