lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Sun, 10 Nov 2019 14:07:14 +0000
From:   Russell King <rmk+kernel@...linux.org.uk>
To:     Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        Heiner Kallweit <hkallweit1@...il.com>
Cc:     "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Subject: [PATCH net-next 13/17] net: sfp: track upstream's attachment state in
 state machine

Track the upstream's attachment state in the state machine rather than
maintaining a boolean, which ensures that we have a strict order of
ATTACH followed by an UP event - we can never believe that a newly
attached upstream will be anything but down.

Rearrange the order of state machines so we run the module state
machine after the upstream device's state machine, so the module state
machine can check the current state of the device and take action to
e.g. reset back to empty state when the upstream is detached.

This is to allow the module detection to run independently of the
network device becoming available.

Signed-off-by: Russell King <rmk+kernel@...linux.org.uk>
---
 drivers/net/phy/sfp.c | 42 +++++++++++++++++++++++++++++-------------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 91fd218ba6b6..95e0dd4a52df 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -36,6 +36,8 @@ enum {
 
 	SFP_E_INSERT = 0,
 	SFP_E_REMOVE,
+	SFP_E_DEV_ATTACH,
+	SFP_E_DEV_DETACH,
 	SFP_E_DEV_DOWN,
 	SFP_E_DEV_UP,
 	SFP_E_TX_FAULT,
@@ -50,7 +52,8 @@ enum {
 	SFP_MOD_PRESENT,
 	SFP_MOD_ERROR,
 
-	SFP_DEV_DOWN = 0,
+	SFP_DEV_DETACHED = 0,
+	SFP_DEV_DOWN,
 	SFP_DEV_UP,
 
 	SFP_S_DOWN = 0,
@@ -80,6 +83,7 @@ static const char *mod_state_to_str(unsigned short mod_state)
 }
 
 static const char * const dev_state_strings[] = {
+	[SFP_DEV_DETACHED] = "detached",
 	[SFP_DEV_DOWN] = "down",
 	[SFP_DEV_UP] = "up",
 };
@@ -94,6 +98,8 @@ static const char *dev_state_to_str(unsigned short dev_state)
 static const char * const event_strings[] = {
 	[SFP_E_INSERT] = "insert",
 	[SFP_E_REMOVE] = "remove",
+	[SFP_E_DEV_ATTACH] = "dev_attach",
+	[SFP_E_DEV_DETACH] = "dev_detach",
 	[SFP_E_DEV_DOWN] = "dev_down",
 	[SFP_E_DEV_UP] = "dev_up",
 	[SFP_E_TX_FAULT] = "tx_fault",
@@ -188,7 +194,6 @@ struct sfp {
 	struct gpio_desc *gpio[GPIO_MAX];
 	int gpio_irq[GPIO_MAX];
 
-	bool attached;
 	struct mutex st_mutex;			/* Protects state */
 	unsigned int state;
 	struct delayed_work poll;
@@ -1496,17 +1501,26 @@ static void sfp_sm_mod_remove(struct sfp *sfp)
 	dev_info(sfp->dev, "module removed\n");
 }
 
-/* This state machine tracks the netdev up/down state */
+/* This state machine tracks the upstream's state */
 static void sfp_sm_device(struct sfp *sfp, unsigned int event)
 {
 	switch (sfp->sm_dev_state) {
 	default:
-		if (event == SFP_E_DEV_UP)
+		if (event == SFP_E_DEV_ATTACH)
+			sfp->sm_dev_state = SFP_DEV_DOWN;
+		break;
+
+	case SFP_DEV_DOWN:
+		if (event == SFP_E_DEV_DETACH)
+			sfp->sm_dev_state = SFP_DEV_DETACHED;
+		else if (event == SFP_E_DEV_UP)
 			sfp->sm_dev_state = SFP_DEV_UP;
 		break;
 
 	case SFP_DEV_UP:
-		if (event == SFP_E_DEV_DOWN)
+		if (event == SFP_E_DEV_DETACH)
+			sfp->sm_dev_state = SFP_DEV_DETACHED;
+		else if (event == SFP_E_DEV_DOWN)
 			sfp->sm_dev_state = SFP_DEV_DOWN;
 		break;
 	}
@@ -1517,17 +1531,20 @@ static void sfp_sm_device(struct sfp *sfp, unsigned int event)
  */
 static void sfp_sm_module(struct sfp *sfp, unsigned int event)
 {
-	/* Handle remove event globally, it resets this state machine */
-	if (event == SFP_E_REMOVE) {
+	/* Handle remove event globally, it resets this state machine.
+	 * Also deal with upstream detachment.
+	 */
+	if (event == SFP_E_REMOVE || sfp->sm_dev_state < SFP_DEV_DOWN) {
 		if (sfp->sm_mod_state > SFP_MOD_PROBE)
 			sfp_sm_mod_remove(sfp);
-		sfp_sm_mod_next(sfp, SFP_MOD_EMPTY, 0);
+		if (sfp->sm_mod_state != SFP_MOD_EMPTY)
+			sfp_sm_mod_next(sfp, SFP_MOD_EMPTY, 0);
 		return;
 	}
 
 	switch (sfp->sm_mod_state) {
 	default:
-		if (event == SFP_E_INSERT && sfp->attached)
+		if (event == SFP_E_INSERT)
 			sfp_sm_mod_next(sfp, SFP_MOD_PROBE, T_SERIAL);
 		break;
 
@@ -1693,8 +1710,8 @@ static void sfp_sm_event(struct sfp *sfp, unsigned int event)
 		sm_state_to_str(sfp->sm_state),
 		event_to_str(event));
 
-	sfp_sm_module(sfp, event);
 	sfp_sm_device(sfp, event);
+	sfp_sm_module(sfp, event);
 	sfp_sm_main(sfp, event);
 
 	dev_dbg(sfp->dev, "SM: exit %s:%s:%s\n",
@@ -1707,15 +1724,14 @@ static void sfp_sm_event(struct sfp *sfp, unsigned int event)
 
 static void sfp_attach(struct sfp *sfp)
 {
-	sfp->attached = true;
+	sfp_sm_event(sfp, SFP_E_DEV_ATTACH);
 	if (sfp->state & SFP_F_PRESENT)
 		sfp_sm_event(sfp, SFP_E_INSERT);
 }
 
 static void sfp_detach(struct sfp *sfp)
 {
-	sfp->attached = false;
-	sfp_sm_event(sfp, SFP_E_REMOVE);
+	sfp_sm_event(sfp, SFP_E_DEV_DETACH);
 }
 
 static void sfp_start(struct sfp *sfp)
-- 
2.20.1

Powered by blists - more mailing lists