1. 24 Jul, 2014 2 commits
    • Steven Rostedt (Red Hat)'s avatar
      ftrace: Add warning if tramp hash does not match nr_trampolines · dc6f03f2
      Steven Rostedt (Red Hat) authored
      After adding all the records to the tramp_hash, add a check that makes
      sure that the number of records added matches the number of records
      expected to match and do a WARN_ON and disable ftrace if they do
      not match.
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      dc6f03f2
    • Steven Rostedt (Red Hat)'s avatar
      ftrace: Fix trampoline hash update check on rec->flags · 2a0343ba
      Steven Rostedt (Red Hat) authored
      In the loop of ftrace_save_ops_tramp_hash(), it adds all the recs
      to the ops hash if the rec has only one callback attached and the
      ops is connected to the rec. It gives a nasty warning and shuts down
      ftrace if the rec doesn't have a trampoline set for it. But this
      can happen with the following scenario:
      
        # cd /sys/kernel/debug/tracing
        # echo schedule do_IRQ > set_ftrace_filter
        # mkdir instances/foo
        # echo schedule > instances/foo/set_ftrace_filter
        # echo function_graph > current_function
        # echo function > instances/foo/current_function
        # echo nop > instances/foo/current_function
      
      The above would then trigger the following warning and disable
      ftrace:
      
       ------------[ cut here ]------------
       WARNING: CPU: 0 PID: 3145 at kernel/trace/ftrace.c:2212 ftrace_run_update_code+0xe4/0x15b()
       Modules linked in: ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ip [...]
       CPU: 1 PID: 3145 Comm: bash Not tainted 3.16.0-rc3-test+ #136
       Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
        0000000000000000 ffffffff81808a88 ffffffff81502130 0000000000000000
        ffffffff81040ca1 ffff880077c08000 ffffffff810bd286 0000000000000001
        ffffffff81a56830 ffff88007a041be0 ffff88007a872d60 00000000000001be
       Call Trace:
        [<ffffffff81502130>] ? dump_stack+0x4a/0x75
        [<ffffffff81040ca1>] ? warn_slowpath_common+0x7e/0x97
        [<ffffffff810bd286>] ? ftrace_run_update_code+0xe4/0x15b
        [<ffffffff810bd286>] ? ftrace_run_update_code+0xe4/0x15b
        [<ffffffff810bda1a>] ? ftrace_shutdown+0x11c/0x16b
        [<ffffffff810bda87>] ? unregister_ftrace_function+0x1e/0x38
        [<ffffffff810cc7e1>] ? function_trace_reset+0x1a/0x28
        [<ffffffff810c924f>] ? tracing_set_tracer+0xc1/0x276
        [<ffffffff810c9477>] ? tracing_set_trace_write+0x73/0x91
        [<ffffffff81132383>] ? __sb_start_write+0x9a/0xcc
        [<ffffffff8120478f>] ? security_file_permission+0x1b/0x31
        [<ffffffff81130e49>] ? vfs_write+0xac/0x11c
        [<ffffffff8113115d>] ? SyS_write+0x60/0x8e
        [<ffffffff81508112>] ? system_call_fastpath+0x16/0x1b
       ---[ end trace 938c4415cbc7dc96 ]---
       ------------[ cut here ]------------
      
      Link: http://lkml.kernel.org/r/20140723120805.GB21376@redhat.comReported-by: default avatarOleg Nesterov <oleg@redhat.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      2a0343ba
  2. 23 Jul, 2014 2 commits
  3. 19 Jul, 2014 1 commit
  4. 18 Jul, 2014 25 commits
  5. 17 Jul, 2014 5 commits
  6. 16 Jul, 2014 1 commit
  7. 09 Jul, 2014 1 commit
  8. 01 Jul, 2014 3 commits