Merge branch 'phy-truncated-led-names'

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>

drivers/net/phy/phy.c

@@ -29,6 +29,7 @@
 #include <linux/mii.h>
 #include <linux/ethtool.h>
 #include <linux/phy.h>
+#include <linux/phy_led_triggers.h>
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 #include <linux/mdio.h>

drivers/net/phy/phy_led_triggers.c

@@ -12,6 +12,7 @@
  */
 #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,
@@ -102,8 +103,10 @@ int phy_led_triggers_register(struct phy_device *phy)
 					    sizeof(struct phy_led_trigger) *
 						   phy->phy_num_led_triggers,
 					    GFP_KERNEL);
-	if (!phy->phy_led_triggers)
-		return -ENOMEM;
+	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],
@@ -120,6 +123,8 @@ out_unreg:
 	while (i--)
 		phy_led_trigger_unregister(&phy->phy_led_triggers[i]);
 	devm_kfree(&phy->mdio.dev, phy->phy_led_triggers);
+out_clear:
+	phy->phy_num_led_triggers = 0;
 	return err;
 }
 EXPORT_SYMBOL_GPL(phy_led_triggers_register);

include/linux/phy.h

@@ -25,7 +25,6 @@
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 #include <linux/mod_devicetable.h>
-#include <linux/phy_led_triggers.h>
 
 #include <linux/atomic.h>
 

include/linux/phy_led_triggers.h

@@ -18,11 +18,11 @@ struct phy_device;
 #ifdef CONFIG_LED_TRIGGER_PHY
 
 #include <linux/leds.h>
+#include <linux/phy.h>
 
 #define PHY_LED_TRIGGER_SPEED_SUFFIX_SIZE	10
-#define PHY_MII_BUS_ID_SIZE	(20 - 3)
 
-#define PHY_LINK_LED_TRIGGER_NAME_SIZE (PHY_MII_BUS_ID_SIZE + \
+#define PHY_LINK_LED_TRIGGER_NAME_SIZE (MII_BUS_ID_SIZE + \
 				       FIELD_SIZEOF(struct mdio_device, addr)+\
 				       PHY_LED_TRIGGER_SPEED_SUFFIX_SIZE)