Re: [BUG] ftrace: available_filter_functions empty after unloadingmodule

[Steven Rostedt]

On Fri, 2012-12-07 at 09:06 +0100, Piotr Haber wrote:
> On 12/06/12 19:10, Steven Rostedt wrote:

> Hi,
> sorry to disappoint you, but there is really nothing more around the
> warning.
> I know it is not helpful, maybe i can do some more tracing if you tell
> me how

Ah, I was looking at a different version of ftrace.c and didn't get the
correct line where the warning was. Yeah, that warning that you hit was
something different, and it doesn't give more info there. :-/

> 
> Here it is with broader context:

Thanks

> 
> Dec  6 15:22:27 lb-bun-52 kernel: cfg80211: Calling CRDA to update world
> regulatory domain
> Dec  6 15:22:27 lb-bun-52 kernel: cfg80211: World regulatory domain updated:
> Dec  6 15:22:27 lb-bun-52 kernel: cfg80211:   (start_freq - end_freq @
> bandwidth), (max_antenna_gain, max_eirp)
> Dec  6 15:22:27 lb-bun-52 kernel: cfg80211:   (2402000 KHz - 2472000 KHz
> @ 40000 KHz), (300 mBi, 2000 mBm)
> Dec  6 15:22:27 lb-bun-52 kernel: cfg80211:   (2457000 KHz - 2482000 KHz
> @ 20000 KHz), (300 mBi, 2000 mBm)
> Dec  6 15:22:27 lb-bun-52 kernel: cfg80211:   (2474000 KHz - 2494000 KHz
> @ 20000 KHz), (300 mBi, 2000 mBm)
> Dec  6 15:22:27 lb-bun-52 kernel: cfg80211:   (5170000 KHz - 5250000 KHz
> @ 40000 KHz), (300 mBi, 2000 mBm)
> Dec  6 15:22:27 lb-bun-52 kernel: cfg80211:   (5735000 KHz - 5835000 KHz
> @ 40000 KHz), (300 mBi, 2000 mBm)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus0: Found chip with id 0xA8D8,
> rev 0x01 and package 0x0A
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus0: Core 0 found: ChipCommon
> (manuf 0x4BF, id 0x800, rev 0x22, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus0: Core 1 found: IEEE 802.11
> (manuf 0x4BF, id 0x812, rev 0x17, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus0: Core 2 found: PCIe (manuf
> 0x4BF, id 0x820, rev 0x0F, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus0: Bus registered
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus1: Found chip with id 0x4313,
> rev 0x01 and package 0x08
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus1: Core 0 found: ChipCommon
> (manuf 0x4BF, id 0x800, rev 0x24, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus1: Core 1 found: IEEE 802.11
> (manuf 0x4BF, id 0x812, rev 0x18, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus1: Core 2 found: PCIe (manuf
> 0x4BF, id 0x820, rev 0x11, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus1: Bus registered
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus2: Found chip with id 0x4313,
> rev 0x01 and package 0x08
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus2: Core 0 found: ChipCommon
> (manuf 0x4BF, id 0x800, rev 0x24, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus2: Core 1 found: IEEE 802.11
> (manuf 0x4BF, id 0x812, rev 0x18, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus2: Core 2 found: PCIe (manuf
> 0x4BF, id 0x820, rev 0x11, class 0x0)
> Dec  6 15:22:27 lb-bun-52 kernel: bcma: bus2: Bus registered
> Dec  6 15:22:27 lb-bun-52 kernel: brcmsmac bcma0:0: mfg 4bf core 812 rev
> 23 class 0 irq 16
> Dec  6 15:22:27 lb-bun-52 kernel: ieee80211 phy0: Selected rate control
> algorithm 'minstrel_ht'
> Dec  6 15:22:27 lb-bun-52 kernel: Registered led device: brcmsmac-phy0:radio
> Dec  6 15:22:27 lb-bun-52 kernel: brcmsmac bcma1:0: mfg 4bf core 812 rev
> 24 class 0 irq 17
> Dec  6 15:22:27 lb-bun-52 kernel: ieee80211 phy1: Selected rate control
> algorithm 'minstrel_ht'
> Dec  6 15:22:27 lb-bun-52 kernel: Registered led device: brcmsmac-phy1:radio
> Dec  6 15:22:27 lb-bun-52 kernel: brcmsmac bcma2:0: mfg 4bf core 812 rev
> 24 class 0 irq 16
> Dec  6 15:22:27 lb-bun-52 kernel: ieee80211 phy2: Selected rate control
> algorithm 'minstrel_ht'
> Dec  6 15:22:27 lb-bun-52 kernel: Registered led device: brcmsmac-phy2:radio
> Dec  6 15:22:34 lb-bun-52 kernel: ------------[ cut here ]------------
> Dec  6 15:22:34 lb-bun-52 kernel: WARNING: at kernel/trace/ftrace.c:1564
> __ftrace_hash_rec_update.part.34+0x20d/0x250()
> Dec  6 15:22:34 lb-bun-52 kernel: Hardware name: Latitude E6420
> Dec  6 15:22:34 lb-bun-52 kernel: Modules linked in: brcmsmac(O)
> brcmutil(O) bcma(O) mac80211(O) cfg80211(O) rfkill(O) arc4 cordic fuse
> ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_i
> pv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_CHECKSUM
> iptable_mangle iptable_filter ip_tables bridge stp llc
> snd_hda_codec_hdmi snd_hda_codec_idt coretemp kvm_intel snd_hda_intel
> kvm snd_h
> da_codec nouveau ttm drm_kms_helper drm ghash_clmulni_intel aesni_intel
> snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm ablk_helper snd_seq_dummy
> snd_seq_oss i2c_algo_bit i2c_core mxm_wmi cryptd lrw pl2
> 303 usbserial snd_seq_midi aes_x86_64 snd_rawmidi xts snd_seq_midi_event
> gf128mul snd_seq video snd_timer ppdev dell_laptop dell_wmi serio_raw
> sparse_keymap dcdbas snd_seq_device snd microcode lpc_i
> ch mfd_core parport_pc wmi soundcore snd_page_alloc lp parport ipv6 ext4
> mbcache jbd2 sd_mod crc_t10dif sr_mod cdrom crc32c_intel ahci libahci
> sdhci_pci sdhci mmc_core e1000e [last unloaded: rfkill]
> Dec  6 15:22:34 lb-bun-52 kernel: Pid: 2498, comm: bash Tainted: G
>      O 3.7.0-rc8 #3
> Dec  6 15:22:34 lb-bun-52 kernel: Call Trace:
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff810574ff>]
> warn_slowpath_common+0x7f/0xc0
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff8105755a>]
> warn_slowpath_null+0x1a/0x20
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff810fdd7d>]
> __ftrace_hash_rec_update.part.34+0x20d/0x250
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff810fea15>]
> ftrace_hash_move+0x1c5/0x1e0
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff81100388>]
> ftrace_regex_release+0x98/0x150
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff8118f7ac>] __fput+0xcc/0x290
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff8118f97e>] ____fput+0xe/0x10
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff810798e7>]
> task_work_run+0xa7/0xe0

So you unloaded a module that you were tracing, correct? Hmm, the
warning that you hit was an accounting error. The accounting of what
functions are traced and what isn't. For some reason it tried to disable
a function that wasn't being traced.

Can you easily reproduce this? If so, can you give my your .config and
the steps you used to trigger it.

-- Steve

> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff81015a64>]
> do_notify_resume+0x74/0x80
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff81289eee>] ?
> trace_hardirqs_on_thunk+0x3a/0x3f
> Dec  6 15:22:34 lb-bun-52 kernel: [<ffffffff8157ed12>] int_signal+0x12/0x17
> Dec  6 15:22:34 lb-bun-52 kernel: ---[ end trace 476f7270ba7905df ]---
> Dec  6 15:35:41 lb-bun-52 kernel: cfg80211: Calling CRDA to update world
> regulatory domain
> Dec  6 15:35:41 lb-bun-52 kernel: cfg80211: World regulatory domain updated:


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