linux/drivers/net/phy/phy_led_triggers.c

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/* Copyright (C) 2016 National Instruments Corp.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/leds.h>
#include <linux/phy.h>
#include <linux/phy_led_triggers.h>
#include <linux/netdevice.h>
static struct phy_led_trigger *phy_speed_to_led_trigger(struct phy_device *phy,
unsigned int speed)
{
unsigned int i;
for (i = 0; i < phy->phy_num_led_triggers; i++) {
if (phy->phy_led_triggers[i].speed == speed)
return &phy->phy_led_triggers[i];
}
return NULL;
}
void phy_led_trigger_change_speed(struct phy_device *phy)
{
struct phy_led_trigger *plt;
if (!phy->link)
goto out_change_speed;
if (phy->speed == 0)
return;
plt = phy_speed_to_led_trigger(phy, phy->speed);
if (!plt) {
netdev_alert(phy->attached_dev,
"No phy led trigger registered for speed(%d)\n",
phy->speed);
goto out_change_speed;
}
if (plt != phy->last_triggered) {
led_trigger_event(&phy->last_triggered->trigger, LED_OFF);
led_trigger_event(&plt->trigger, LED_FULL);
phy->last_triggered = plt;
}
return;
out_change_speed:
if (phy->last_triggered) {
led_trigger_event(&phy->last_triggered->trigger,
LED_OFF);
phy->last_triggered = NULL;
}
}
EXPORT_SYMBOL_GPL(phy_led_trigger_change_speed);
static int phy_led_trigger_register(struct phy_device *phy,
struct phy_led_trigger *plt,
unsigned int speed)
{
char name_suffix[PHY_LED_TRIGGER_SPEED_SUFFIX_SIZE];
plt->speed = speed;
if (speed < SPEED_1000)
snprintf(name_suffix, sizeof(name_suffix), "%dMbps", speed);
else if (speed == SPEED_2500)
snprintf(name_suffix, sizeof(name_suffix), "2.5Gbps");
else
snprintf(name_suffix, sizeof(name_suffix), "%dGbps",
DIV_ROUND_CLOSEST(speed, 1000));
snprintf(plt->name, sizeof(plt->name), PHY_ID_FMT ":%s",
phy->mdio.bus->id, phy->mdio.addr, name_suffix);
plt->trigger.name = plt->name;
return led_trigger_register(&plt->trigger);
}
static void phy_led_trigger_unregister(struct phy_led_trigger *plt)
{
led_trigger_unregister(&plt->trigger);
}
int phy_led_triggers_register(struct phy_device *phy)
{
int i, err;
unsigned int speeds[50];
phy->phy_num_led_triggers = phy_supported_speeds(phy, speeds,
ARRAY_SIZE(speeds));
if (!phy->phy_num_led_triggers)
return 0;
phy->phy_led_triggers = devm_kzalloc(&phy->mdio.dev,
sizeof(struct phy_led_trigger) *
phy->phy_num_led_triggers,
GFP_KERNEL);
net: phy: leds: Clear phy_num_led_triggers on failure to avoid crash phy_attach_direct() ignores errors returned by phy_led_triggers_register(). I think that's OK, as LED triggers can be considered a non-critical feature. However, this causes problems later: - phy_led_trigger_change_speed() will access the array phy_device.phy_led_triggers, which has been freed in the error path of phy_led_triggers_register(), which may lead to a crash. - phy_led_triggers_unregister() will access the same array, leading to crashes during s2ram or poweroff, 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) To fix this, clear phy_device.phy_num_led_triggers in the error path of phy_led_triggers_register() fails. Note that the "No phy led trigger registered for speed" message will still be printed on link speed changes, which is a good cue that something went wrong with the LED triggers. Fixes: 2e0bc452f4721520 ("net: phy: leds: add support for led triggers on phy link state change") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-25 10:39:48 +00:00
if (!phy->phy_led_triggers) {
err = -ENOMEM;
goto out_clear;
}
for (i = 0; i < phy->phy_num_led_triggers; i++) {
err = phy_led_trigger_register(phy, &phy->phy_led_triggers[i],
speeds[i]);
if (err)
goto out_unreg;
}
phy->last_triggered = NULL;
phy_led_trigger_change_speed(phy);
return 0;
out_unreg:
while (i--)
phy_led_trigger_unregister(&phy->phy_led_triggers[i]);
devm_kfree(&phy->mdio.dev, phy->phy_led_triggers);
net: phy: leds: Clear phy_num_led_triggers on failure to avoid crash phy_attach_direct() ignores errors returned by phy_led_triggers_register(). I think that's OK, as LED triggers can be considered a non-critical feature. However, this causes problems later: - phy_led_trigger_change_speed() will access the array phy_device.phy_led_triggers, which has been freed in the error path of phy_led_triggers_register(), which may lead to a crash. - phy_led_triggers_unregister() will access the same array, leading to crashes during s2ram or poweroff, 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) To fix this, clear phy_device.phy_num_led_triggers in the error path of phy_led_triggers_register() fails. Note that the "No phy led trigger registered for speed" message will still be printed on link speed changes, which is a good cue that something went wrong with the LED triggers. Fixes: 2e0bc452f4721520 ("net: phy: leds: add support for led triggers on phy link state change") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-25 10:39:48 +00:00
out_clear:
phy->phy_num_led_triggers = 0;
return err;
}
EXPORT_SYMBOL_GPL(phy_led_triggers_register);
void phy_led_triggers_unregister(struct phy_device *phy)
{
int i;
for (i = 0; i < phy->phy_num_led_triggers; i++)
phy_led_trigger_unregister(&phy->phy_led_triggers[i]);
}
EXPORT_SYMBOL_GPL(phy_led_triggers_unregister);