forked from luck/tmp_suning_uos_patched
c143b7753b
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> |
||
|---|---|---|
| .. | ||
| blktrace.c | ||
| bpf_trace.c | ||
| fgraph.c | ||
| ftrace_internal.h | ||
| ftrace.c | ||
| Kconfig | ||
| kprobe_event_gen_test.c | ||
| Makefile | ||
| power-traces.c | ||
| preemptirq_delay_test.c | ||
| ring_buffer_benchmark.c | ||
| ring_buffer.c | ||
| rpm-traces.c | ||
| synth_event_gen_test.c | ||
| trace_benchmark.c | ||
| trace_benchmark.h | ||
| trace_boot.c | ||
| trace_branch.c | ||
| trace_clock.c | ||
| trace_dynevent.c | ||
| trace_dynevent.h | ||
| trace_entries.h | ||
| trace_event_perf.c | ||
| trace_events_filter_test.h | ||
| trace_events_filter.c | ||
| trace_events_hist.c | ||
| trace_events_inject.c | ||
| trace_events_trigger.c | ||
| trace_events.c | ||
| trace_export.c | ||
| trace_functions_graph.c | ||
| trace_functions.c | ||
| trace_hwlat.c | ||
| trace_irqsoff.c | ||
| trace_kdb.c | ||
| trace_kprobe_selftest.c | ||
| trace_kprobe_selftest.h | ||
| trace_kprobe.c | ||
| trace_mmiotrace.c | ||
| trace_nop.c | ||
| trace_output.c | ||
| trace_output.h | ||
| trace_preemptirq.c | ||
| trace_printk.c | ||
| trace_probe_tmpl.h | ||
| trace_probe.c | ||
| trace_probe.h | ||
| trace_sched_switch.c | ||
| trace_sched_wakeup.c | ||
| trace_selftest_dynamic.c | ||
| trace_selftest.c | ||
| trace_seq.c | ||
| trace_stack.c | ||
| trace_stat.c | ||
| trace_stat.h | ||
| trace_syscalls.c | ||
| trace_uprobe.c | ||
| trace.c | ||
| trace.h | ||
| tracing_map.c | ||
| tracing_map.h | ||