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* FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 7.0-stable tree
@ 2026-05-28 13:50 gregkh
  2026-06-01 13:36 ` [PATCH 7.0.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
  0 siblings, 1 reply; 6+ messages in thread
From: gregkh @ 2026-05-28 13:50 UTC (permalink / raw)
  To: abdurrahman, bartosz.golaszewski, linux; +Cc: stable


The patch below does not apply to the 7.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-7.0.y
git checkout FETCH_HEAD
git cherry-pick -x bab8c6fb5af8df7e753d196c1262cb78e92ca872
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026052840-vigorous-cosponsor-eb81@gregkh' --subject-prefix 'PATCH 7.0.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bab8c6fb5af8df7e753d196c1262cb78e92ca872 Mon Sep 17 00:00:00 2001
From: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Date: Mon, 18 May 2026 17:52:30 -0700
Subject: [PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with
 pmbus_lock

adm1266_gpio_get(), adm1266_gpio_get_multiple(), and
adm1266_gpio_dbg_show() all issue PMBus reads against the device but
none of them take pmbus_lock.  The pmbus_core framework holds
pmbus_lock around its own multi-transaction sequences (notably the
"set PAGE, then read paged register" pattern used by hwmon
attributes), so an unlocked GPIO accessor can land between a PAGE
write and the subsequent paged read in another thread and corrupt
either side's view of the device state machine.

Take pmbus_lock at the top of each of the three accessors via the
scope-based guard().  The lock is uncontended in the common case and
adds only a single mutex round-trip per call.

Fixes: d98dfad35c38 ("hwmon: (pmbus/adm1266) Add support for GPIOs")
Cc: stable@vger.kernel.org
Signed-off-by: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-6-e425e4f88139@nexthop.ai
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index 3e8f2619cb9b..0eef58dd69a6 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -173,6 +173,8 @@ static int adm1266_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	else
 		pmbus_cmd = ADM1266_PDIO_STATUS;
 
+	guard(pmbus_lock)(data->client);
+
 	ret = i2c_smbus_read_block_data(data->client, pmbus_cmd, read_buf);
 	if (ret < 0)
 		return ret;
@@ -195,6 +197,8 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
 	unsigned int gpio_nr;
 	int ret;
 
+	guard(pmbus_lock)(data->client);
+
 	ret = i2c_smbus_read_block_data(data->client, ADM1266_GPIO_STATUS, read_buf);
 	if (ret < 0)
 		return ret;
@@ -236,6 +240,8 @@ static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 	int ret;
 	int i;
 
+	guard(pmbus_lock)(data->client);
+
 	for (i = 0; i < ADM1266_GPIO_NR; i++) {
 		write_cmd = adm1266_gpio_mapping[i][1];
 		ret = adm1266_pmbus_block_xfer(data, ADM1266_GPIO_CONFIG, 1, &write_cmd, read_buf);


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read" failed to apply to 7.0-stable tree
@ 2026-05-28 13:51 gregkh
  2026-06-01 12:37 ` [PATCH 7.0.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
  0 siblings, 1 reply; 6+ messages in thread
From: gregkh @ 2026-05-28 13:51 UTC (permalink / raw)
  To: abdurrahman, linux; +Cc: stable


The patch below does not apply to the 7.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-7.0.y
git checkout FETCH_HEAD
git cherry-pick -x 4e4af55aaca7f6d7673d5f9889ad0529db86a048
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026052822-saloon-auction-5094@gregkh' --subject-prefix 'PATCH 7.0.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4e4af55aaca7f6d7673d5f9889ad0529db86a048 Mon Sep 17 00:00:00 2001
From: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Date: Mon, 18 May 2026 17:52:32 -0700
Subject: [PATCH] hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read
 with pmbus_lock

adm1266_state_read() backs the sequencer_state debugfs entry and
issues an i2c_smbus_read_word_data(client, ADM1266_READ_STATE)
against the device without taking pmbus_lock.  pmbus_core holds
pmbus_lock around its own multi-transaction sequences (notably the
"set PAGE, then read paged register" pattern used by hwmon
attributes), so an unlocked debugfs reader can land between a PAGE
write and the subsequent paged read in another thread.  READ_STATE
itself is not paged, so it cannot corrupt PAGE in flight, but the
same defensive serialisation that applies to the GPIO accessors
applies here: any direct device access from outside pmbus_core
should be ordered with respect to pmbus_core's own.

Take pmbus_lock at the top of adm1266_state_read() via the
scope-based guard().

Fixes: ed1ff457e187 ("hwmon: (pmbus/adm1266) add debugfs for states")
Cc: stable@vger.kernel.org
Signed-off-by: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-8-e425e4f88139@nexthop.ai
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index 5ddca5701032..6f6ad7b20e9a 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -335,6 +335,7 @@ static int adm1266_state_read(struct seq_file *s, void *pdata)
 	struct i2c_client *client = to_i2c_client(dev);
 	int ret;
 
+	guard(pmbus_lock)(client);
 	ret = i2c_smbus_read_word_data(client, ADM1266_READ_STATE);
 	if (ret < 0)
 		return ret;


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize NVMEM blackbox read with" failed to apply to 7.0-stable tree
@ 2026-05-28 13:48 gregkh
  2026-06-01 13:36 ` [PATCH 7.0.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
  2026-06-01 13:36 ` Sasha Levin
  0 siblings, 2 replies; 6+ messages in thread
From: gregkh @ 2026-05-28 13:48 UTC (permalink / raw)
  To: abdurrahman, linux; +Cc: stable


The patch below does not apply to the 7.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-7.0.y
git checkout FETCH_HEAD
git cherry-pick -x 9f1dd8f9491eb840cbea7ffdf4cad031e25f8ae0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026052829-nutshell-shank-d239@gregkh' --subject-prefix 'PATCH 7.0.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9f1dd8f9491eb840cbea7ffdf4cad031e25f8ae0 Mon Sep 17 00:00:00 2001
From: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Date: Mon, 18 May 2026 17:52:31 -0700
Subject: [PATCH] hwmon: (pmbus/adm1266) serialize NVMEM blackbox read with
 pmbus_lock

adm1266_nvmem_read() is the reg_read callback the NVMEM core invokes
when userspace reads /sys/bus/nvmem/devices/.../nvmem on this chip.
On the first byte of every read it does a memset of data->dev_mem,
walks the device blackbox through adm1266_nvmem_read_blackbox()
(which issues a chain of PMBus block transactions), and then memcpys
the refreshed buffer out to userspace.  None of that runs under
pmbus_lock today.

Two consequences:

  - The PMBus traffic the refresh issues is not serialised against
    pmbus_core's own multi-step PAGE+register sequences.  A paged
    hwmon attribute read from another thread can land between a
    PAGE write and the paged read in either direction and corrupt
    one side's view of the device state machine.

  - The NVMEM core does not serialise concurrent reg_read calls, so
    two userspace readers racing at offset 0 can interleave the
    memset of data->dev_mem with another reader's
    adm1266_nvmem_read_blackbox() refill or memcpy out, returning
    torn data to userspace.

Take pmbus_lock at the top of adm1266_nvmem_read() via the
scope-based guard().  Patch 5 of this series moves
adm1266_config_nvmem() past pmbus_do_probe() so the lock is
guaranteed to be live before the callback is reachable from
userspace.

Fixes: 15609d189302 ("hwmon: (pmbus/adm1266) read blackbox")
Cc: stable@vger.kernel.org
Signed-off-by: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-7-e425e4f88139@nexthop.ai
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index 0eef58dd69a6..5ddca5701032 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -400,6 +400,8 @@ static int adm1266_nvmem_read(void *priv, unsigned int offset, void *val, size_t
 	if (offset + bytes > data->nvmem_config.size)
 		return -EINVAL;
 
+	guard(pmbus_lock)(data->client);
+
 	if (offset == 0) {
 		memset(data->dev_mem, 0, data->nvmem_config.size);
 


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-06-01 13:36 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2026-05-28 13:50 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with" failed to apply to 7.0-stable tree gregkh
2026-06-01 13:36 ` [PATCH 7.0.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
2026-06-01 13:36   ` [PATCH 7.0.y 2/2] hwmon: (pmbus/adm1266) serialize GPIO PMBus accesses with pmbus_lock Sasha Levin
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2026-05-28 13:51 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read" failed to apply to 7.0-stable tree gregkh
2026-06-01 12:37 ` [PATCH 7.0.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
2026-05-28 13:48 FAILED: patch "[PATCH] hwmon: (pmbus/adm1266) serialize NVMEM blackbox read with" failed to apply to 7.0-stable tree gregkh
2026-06-01 13:36 ` [PATCH 7.0.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock Sasha Levin
2026-06-01 13:36 ` Sasha Levin

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