linux/kernel/trace
Alexei Starovoitov 8d3b7dce86 bpf: add support for %s specifier to bpf_trace_printk()
%s specifier makes bpf program and kernel debugging easier.
To make sure that trace_printk won't crash the unsafe string
is copied into stack and unsafe pointer is substituted.

The following C program:
 #include <linux/fs.h>
int foo(struct pt_regs *ctx, struct filename *filename)
{
  void *name = 0;

  bpf_probe_read(&name, sizeof(name), &filename->name);
  bpf_trace_printk("executed %s\n", name);
  return 0;
}

when attached to kprobe do_execve()
will produce output in /sys/kernel/debug/tracing/trace_pipe :
    make-13492 [002] d..1  3250.997277: : executed /bin/sh
      sh-13493 [004] d..1  3250.998716: : executed /usr/bin/gcc
     gcc-13494 [002] d..1  3250.999822: : executed /usr/lib/gcc/x86_64-linux-gnu/4.7/cc1
     gcc-13495 [002] d..1  3251.006731: : executed /usr/bin/as
     gcc-13496 [002] d..1  3251.011831: : executed /usr/lib/gcc/x86_64-linux-gnu/4.7/collect2
collect2-13497 [000] d..1  3251.012941: : executed /usr/bin/ld

Suggested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-28 16:27:27 -07:00
..
blktrace.c This patch series contains several clean ups and even a new trace clock 2015-06-26 14:02:43 -07:00
bpf_trace.c bpf: add support for %s specifier to bpf_trace_printk() 2015-08-28 16:27:27 -07:00
ftrace.c ftrace: Fix breakage of set_ftrace_pid 2015-07-24 13:58:14 -04:00
Kconfig Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-14 14:37:47 -07:00
Makefile bpf: Fix the build on BPF_SYSCALL=y && !CONFIG_TRACING kernels, make it more configurable 2015-04-02 16:28:06 +02:00
power-traces.c PM / sleep: export suspend_resume trace event 2015-01-30 02:10:41 +01:00
ring_buffer.c ring-buffer: Add enum names for the context levels 2015-05-29 10:39:08 -04:00
ring_buffer_benchmark.c This patch series contains several clean ups and even a new trace clock 2015-06-26 14:02:43 -07:00
rpm-traces.c PM / Runtime: Introduce trace points for tracing rpm_* functions 2011-09-27 22:53:27 +02:00
trace.c tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_* 2015-05-13 15:24:57 -04:00
trace.h tracing: Have branch tracer use recursive field of task struct 2015-07-08 11:53:45 -04:00
trace_benchmark.c tracing: Only calculate stats of tracepoint benchmarks for 2^32 times 2014-06-06 00:41:38 -04:00
trace_benchmark.h tracing: Add tracepoint benchmark tracepoint 2014-05-29 22:49:54 -04:00
trace_branch.c tracing: Have branch tracer use recursive field of task struct 2015-07-08 11:53:45 -04:00
trace_clock.c tracing: Export tracing clock functions 2015-05-12 15:56:57 -04:00
trace_entries.h tracing: %pF is only for function pointers 2015-03-25 08:57:22 -04:00
trace_event_perf.c tracing: Rename ftrace_event_{call,class} to trace_event_{call,class} 2015-05-13 14:06:10 -04:00
trace_events.c tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_* 2015-05-13 15:24:57 -04:00
trace_events_filter.c This patch series contains several clean ups and even a new trace clock 2015-06-26 14:02:43 -07:00
trace_events_filter_test.h tracing/filter: Add startup tests for events filter 2011-08-19 14:35:59 -04:00
trace_events_trigger.c tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##call 2015-05-13 21:48:40 -04:00
trace_export.c tracing: Rename ftrace_event_{call,class} to trace_event_{call,class} 2015-05-13 14:06:10 -04:00
trace_functions.c tracing/trivial: Fix typos and make an int into a bool 2014-11-20 10:05:36 -05:00
trace_functions_graph.c tracing: Rename ftrace_event_{call,class} to trace_event_{call,class} 2015-05-13 14:06:10 -04:00
trace_irqsoff.c tracing: Remove unneeded includes of debugfs.h and fs.h 2015-01-22 11:19:48 -05:00
trace_kdb.c KGDB/KDB fixes and cleanups 2015-01-09 20:51:10 -08:00
trace_kprobe.c lib: introduce strncpy_from_unsafe() 2015-08-28 16:27:27 -07:00
trace_mmiotrace.c tracing: Rename ftrace_event_{call,class} to trace_event_{call,class} 2015-05-13 14:06:10 -04:00
trace_nop.c tracing: Remove unneeded includes of debugfs.h and fs.h 2015-01-22 11:19:48 -05:00
trace_output.c tracing: Rename ftrace_event_name() to trace_event_name() 2015-05-13 14:20:14 -04:00
trace_output.h tracing: Rename (un)register_ftrace_event() to (un)register_trace_event() 2015-05-13 14:05:14 -04:00
trace_printk.c tracing: Use IS_ERR() check for return value of tracing_init_dentry() 2015-01-22 11:19:49 -05:00
trace_probe.c trace: Don't use __weak in header files 2015-03-25 08:57:23 -04:00
trace_probe.h tracing: Rename ftrace_event_{call,class} to trace_event_{call,class} 2015-05-13 14:06:10 -04:00
trace_sched_switch.c tracing: Remove unneeded includes of debugfs.h and fs.h 2015-01-22 11:19:48 -05:00
trace_sched_wakeup.c tracing: Rename ftrace_event_{call,class} to trace_event_{call,class} 2015-05-13 14:06:10 -04:00
trace_selftest.c Seems that Peter Zijlstra added a new check that is making old 2014-10-12 07:28:55 -04:00
trace_selftest_dynamic.c ftrace: Add self-tests for multiple function trace users 2011-05-18 19:24:51 -04:00
trace_seq.c tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
trace_stack.c tracing: remove use of seq_printf return value 2015-04-15 16:35:25 -07:00
trace_stat.c tracing: Convert the tracing facility over to use tracefs 2015-02-03 12:48:41 -05:00
trace_stat.h
trace_syscalls.c tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled() 2015-05-13 15:25:39 -04:00
trace_uprobe.c tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled() 2015-05-13 15:25:39 -04:00