Hi David,
I started seeing crashes during s2ram and poweroff on all my ARM boards,
like:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
...
[<c04116d4>] (__list_del_entry_valid) from [<c05e8948>] (led_trigger_unregister+0x34/0xcc)
[<c05e8948>] (led_trigger_unregister) from [<c05336c4>] (phy_led_triggers_unregister+0x28/0x34)
[<c05336c4>] (phy_led_triggers_unregister) from [<c0531d44>] (phy_detach+0x30/0x74)
[<c0531d44>] (phy_detach) from [<c0538bdc>] (sh_eth_close+0x64/0x9c)
[<c0538bdc>] (sh_eth_close) from [<c04d4ce0>] (dpm_run_callback+0x48/0xc8)
or:
list_del corruption. prev->next should be dede6540, but was 2e323931
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:52!
...
[<c02f6d70>] (__list_del_entry_valid) from [<c0425168>] (led_trigger_unregister+0x34/0xcc)
[<c0425168>] (led_trigger_unregister) from [<c03a05a0>] (phy_led_triggers_unregister+0x28/0x34)
[<c03a05a0>] (phy_led_triggers_unregister) from [<c039ec04>] (phy_detach+0x30/0x74)
[<c039ec04>] (phy_detach) from [<c03a4fc0>] (sh_eth_close+0x6c/0xa4)
[<c03a4fc0>] (sh_eth_close) from [<c0483234>] (__dev_close_many+0xac/0xd0)
As the only clue was a kernel message like
sh-eth ee700000.ethernet eth0: No phy led trigger registered for speed(100)
I had to bisected this, leading to commit 4567d686f5c6d955 ("phy:
increase size of MII_BUS_ID_SIZE and bus_id"). Reverting that commit
fixed the issue.
More investigation revealed the crashes are due to the combination of
two things:
- Truncated LED trigger names, leading to duplicate names, and
registration failures,
- Bad error handling in case of registration failures.
Both are fixed by this patch series.
Thanks!
Geert Uytterhoeven (2):
net: phy: leds: Clear phy_num_led_triggers on failure to avoid crash
net: phy: leds: Fix truncated LED trigger names
drivers/net/phy/phy_led_triggers.c | 8 ++++++--
include/linux/phy.h | 3 ++-
include/linux/phy_led_triggers.h | 3 +--
3 files changed, 9 insertions(+), 5 deletions(-)
--
1.9.1
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
