David S. Miller
d5bdc021ec
Geert Uytterhoeven says:
====================
net: phy: leds: Fix truncated LED trigger names and crashes
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 4567d686f5 ("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.
Changes compared to v1:
- Add Reviewed-by,
- New patch "net: phy: leds: Break dependency of phy.h on
phy_led_triggers.h",
- Drop moving the include of <linux/phy_led_triggers.h>, as
<linux/phy.h> no longer includes it,
- #include <linux/phy.h> from <linux/phy_led_triggers.h>.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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