In case the PM domain fails to be powered on in genpd_dev_pm_attach(), it
returns -EPROBE_DEFER, but keeping the device attached to its PM domain.
This leads to problems when the next attempt to attach is re-tried. More
precisely, in that situation an -EEXIST error code is returned, because the
device already has its PM domain pointer assigned, from the first attempt.
Now, because of the sloppy error handling by the existing callers of
dev_pm_domain_attach(), probing is allowed to continue when -EEXIST is
returned. However, in such case there are no guarantees that the PM domain
is powered on by genpd, which may lead to hangs when buses/drivers tried to
access their devices.
Let's fix this behaviour, simply by detaching the device when powering on
fails in genpd_dev_pm_attach().
Cc: <stable(a)vger.kernel.org> # v4.11+
Signed-off-by: Ulf Hansson <ulf.hansson(a)linaro.org>
---
drivers/base/power/domain.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 1ea0e25..ef6cf3d5 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2246,6 +2246,9 @@ int genpd_dev_pm_attach(struct device *dev)
genpd_lock(pd);
ret = genpd_power_on(pd, 0);
genpd_unlock(pd);
+
+ if (ret)
+ genpd_remove_device(pd, dev);
out:
return ret ? -EPROBE_DEFER : 0;
}
--
2.7.4
This is a note to let you know that I've just added the patch titled
ARM: amba: Fix race condition with driver_override
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 6a7228d90d42bcacfe38786756ba62762b91c20a Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas(a)glider.be>
Date: Tue, 10 Apr 2018 15:21:44 +0200
Subject: ARM: amba: Fix race condition with driver_override
The driver_override implementation is susceptible to a race condition
when different threads are reading vs storing a different driver
override. Add locking to avoid this race condition.
Cfr. commits 6265539776a0810b ("driver core: platform: fix race
condition with driver_override") and 9561475db680f714 ("PCI: Fix race
condition with driver_override").
Fixes: 3cf385713460eb2b ("ARM: 8256/1: driver coamba: add device binding path 'driver_override'")
Signed-off-by: Geert Uytterhoeven <geert+renesas(a)glider.be>
Reviewed-by: Todd Kjos <tkjos(a)google.com>
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/amba/bus.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index f8c01fbef64d..4a3ac31c07d0 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -69,8 +69,12 @@ static ssize_t driver_override_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct amba_device *dev = to_amba_device(_dev);
+ ssize_t len;
- return sprintf(buf, "%s\n", dev->driver_override);
+ device_lock(_dev);
+ len = sprintf(buf, "%s\n", dev->driver_override);
+ device_unlock(_dev);
+ return len;
}
static ssize_t driver_override_store(struct device *_dev,
@@ -78,7 +82,7 @@ static ssize_t driver_override_store(struct device *_dev,
const char *buf, size_t count)
{
struct amba_device *dev = to_amba_device(_dev);
- char *driver_override, *old = dev->driver_override, *cp;
+ char *driver_override, *old, *cp;
/* We need to keep extra room for a newline */
if (count >= (PAGE_SIZE - 1))
@@ -92,12 +96,15 @@ static ssize_t driver_override_store(struct device *_dev,
if (cp)
*cp = '\0';
+ device_lock(_dev);
+ old = dev->driver_override;
if (strlen(driver_override)) {
dev->driver_override = driver_override;
} else {
kfree(driver_override);
dev->driver_override = NULL;
}
+ device_unlock(_dev);
kfree(old);
--
2.17.0
This is a note to let you know that I've just added the patch titled
ARM: amba: Make driver_override output consistent with other buses
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 5f53624662eaac89598641cee6cd54fc192572d9 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas(a)glider.be>
Date: Tue, 10 Apr 2018 15:21:43 +0200
Subject: ARM: amba: Make driver_override output consistent with other buses
For AMBA devices with unconfigured driver override, the
"driver_override" sysfs virtual file is empty, while it contains
"(null)" for platform and PCI devices.
Make AMBA consistent with other buses by dropping the test for a NULL
pointer.
Note that contrary to popular belief, sprintf() handles NULL pointers
fine; they are printed as "(null)".
Signed-off-by: Geert Uytterhoeven <geert+renesas(a)glider.be>
Cc: stable <stable(a)vger.kernel.org>
Reviewed-by: Todd Kjos <tkjos(a)google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/amba/bus.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index fac8e36de11e..f8c01fbef64d 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -70,9 +70,6 @@ static ssize_t driver_override_show(struct device *_dev,
{
struct amba_device *dev = to_amba_device(_dev);
- if (!dev->driver_override)
- return 0;
-
return sprintf(buf, "%s\n", dev->driver_override);
}
--
2.17.0
This is a note to let you know that I've just added the patch titled
Revert "ARM: amba: Fix race condition with driver_override"
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 2891d4feae7c2cf0a56d84bf38519aae6c5060b5 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Date: Thu, 26 Apr 2018 10:29:57 +0200
Subject: Revert "ARM: amba: Fix race condition with driver_override"
This reverts commit 6b614a87f3f477571e319281e84dba11e0ea0a76.
My backport was incorrect, as Geert pointed out :(
Reported-by: Geert Uytterhoeven <geert(a)linux-m68k.org>
Cc: Todd Kjos <tkjos(a)google.com>
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/amba/bus.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 8e6ac3031662..fac8e36de11e 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -69,15 +69,11 @@ static ssize_t driver_override_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct amba_device *dev = to_amba_device(_dev);
- ssize_t len;
if (!dev->driver_override)
return 0;
- device_lock(_dev);
- len = sprintf(buf, "%s\n", dev->driver_override);
- device_unlock(_dev);
- return len;
+ return sprintf(buf, "%s\n", dev->driver_override);
}
static ssize_t driver_override_store(struct device *_dev,
@@ -85,7 +81,7 @@ static ssize_t driver_override_store(struct device *_dev,
const char *buf, size_t count)
{
struct amba_device *dev = to_amba_device(_dev);
- char *driver_override, *old, *cp;
+ char *driver_override, *old = dev->driver_override, *cp;
/* We need to keep extra room for a newline */
if (count >= (PAGE_SIZE - 1))
@@ -99,15 +95,12 @@ static ssize_t driver_override_store(struct device *_dev,
if (cp)
*cp = '\0';
- device_lock(_dev);
- old = dev->driver_override;
if (strlen(driver_override)) {
dev->driver_override = driver_override;
} else {
kfree(driver_override);
dev->driver_override = NULL;
}
- device_unlock(_dev);
kfree(old);
--
2.17.0
File /sys/kernel/debug/kprobes/blacklist displays random addresses:
[root@s8360046 linux]# cat /sys/kernel/debug/kprobes/blacklist
0x0000000047149a90-0x00000000bfcb099a print_type_x8
....
This breaks 'perf probe' which uses the blacklist file to prohibit
probes on certain functions by checking the address range.
Fix this by printing the correct (unhashed) address.
The file mode is read all but this is not an issue as the file
hierarchy points out:
# ls -ld /sys/ /sys/kernel/ /sys/kernel/debug/ /sys/kernel/debug/kprobes/
/sys/kernel/debug/kprobes/blacklist
dr-xr-xr-x 12 root root 0 Apr 19 07:56 /sys/
drwxr-xr-x 8 root root 0 Apr 19 07:56 /sys/kernel/
drwx------ 16 root root 0 Apr 19 06:56 /sys/kernel/debug/
drwxr-xr-x 2 root root 0 Apr 19 06:56 /sys/kernel/debug/kprobes/
-r--r--r-- 1 root root 0 Apr 19 06:56 /sys/kernel/debug/kprobes/blacklist
Everything in and below /sys/kernel/debug is rwx to root only,
no group or others have access.
Background:
Directory /sys/kernel/debug/kprobes is created by debugfs_create_dir()
which sets the mode bits to rwxr-xr-x. Maybe change that to use the
parent's directory mode bits instead?
Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Cc: <stable(a)vger.kernel.org> # v4.15+
Cc: <linux-kernel(a)vger.kernel.org>
To: Ananth N Mavinakayanahalli <ananth(a)linux.vnet.ibm.com>
To: Anil S Keshavamurthy <anil.s.keshavamurthy(a)intel.com>
To: David S Miller <davem(a)davemloft.net>
To: Masami Hiramatsu <mhiramat(a)kernel.org>
To: Andrew Morton <akpm(a)linux-foundation.org>
To: acme(a)kernel.org
To: Steven Rostedt <rostedt(a)goodmis.org>
Signed-off-by: Thomas Richter <tmricht(a)linux.ibm.com>
---
kernel/kprobes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 102160ff5c66..ea619021d901 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2428,7 +2428,7 @@ static int kprobe_blacklist_seq_show(struct seq_file *m, void *v)
struct kprobe_blacklist_entry *ent =
list_entry(v, struct kprobe_blacklist_entry, list);
- seq_printf(m, "0x%p-0x%p\t%ps\n", (void *)ent->start_addr,
+ seq_printf(m, "0x%px-0x%px\t%ps\n", (void *)ent->start_addr,
(void *)ent->end_addr, (void *)ent->start_addr);
return 0;
}
--
2.14.3
This is a note to let you know that I've just added the patch titled
ARM: amba: Fix race condition with driver_override
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 6b614a87f3f477571e319281e84dba11e0ea0a76 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas(a)glider.be>
Date: Tue, 10 Apr 2018 15:21:44 +0200
Subject: ARM: amba: Fix race condition with driver_override
The driver_override implementation is susceptible to a race condition
when different threads are reading vs storing a different driver
override. Add locking to avoid this race condition.
Cfr. commits 6265539776a0810b ("driver core: platform: fix race
condition with driver_override") and 9561475db680f714 ("PCI: Fix race
condition with driver_override").
Fixes: 3cf385713460eb2b ("ARM: 8256/1: driver coamba: add device binding path 'driver_override'")
Signed-off-by: Geert Uytterhoeven <geert+renesas(a)glider.be>
Reviewed-by: Todd Kjos <tkjos(a)google.com>
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/amba/bus.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 594c228d2f02..c77eb6e65646 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -69,11 +69,15 @@ static ssize_t driver_override_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct amba_device *dev = to_amba_device(_dev);
+ ssize_t len;
if (!dev->driver_override)
return 0;
- return sprintf(buf, "%s\n", dev->driver_override);
+ device_lock(_dev);
+ len = sprintf(buf, "%s\n", dev->driver_override);
+ device_unlock(_dev);
+ return len;
}
static ssize_t driver_override_store(struct device *_dev,
@@ -81,7 +85,7 @@ static ssize_t driver_override_store(struct device *_dev,
const char *buf, size_t count)
{
struct amba_device *dev = to_amba_device(_dev);
- char *driver_override, *old = dev->driver_override, *cp;
+ char *driver_override, *old, *cp;
if (count > PATH_MAX)
return -EINVAL;
@@ -94,12 +98,15 @@ static ssize_t driver_override_store(struct device *_dev,
if (cp)
*cp = '\0';
+ device_lock(_dev);
+ old = dev->driver_override;
if (strlen(driver_override)) {
dev->driver_override = driver_override;
} else {
kfree(driver_override);
dev->driver_override = NULL;
}
+ device_unlock(_dev);
kfree(old);
--
2.17.0
This is a note to let you know that I've just added the patch titled
usb: do not reset if a low-speed or full-speed device timed out
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 6e01827ed93947895680fbdad68c072a0f4e2450 Mon Sep 17 00:00:00 2001
From: Maxim Moseychuk <franchesko.salias.hudro.pedros(a)gmail.com>
Date: Thu, 4 Jan 2018 21:43:03 +0300
Subject: usb: do not reset if a low-speed or full-speed device timed out
Some low-speed and full-speed devices (for example, bluetooth)
do not have time to initialize. For them, ETIMEDOUT is a valid error.
We need to give them another try. Otherwise, they will
never be initialized correctly and in dmesg will be messages
"Bluetooth: hci0 command 0x1002 tx timeout" or similars.
Fixes: 264904ccc33c ("usb: retry reset if a device times out")
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Maxim Moseychuk <franchesko.salias.hudro.pedros(a)gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/core/hub.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 92378594a86e..a86591772352 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4555,7 +4555,9 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
* reset. But only on the first attempt,
* lest we get into a time out/reset loop
*/
- if (r == 0 || (r == -ETIMEDOUT && retries == 0))
+ if (r == 0 || (r == -ETIMEDOUT &&
+ retries == 0 &&
+ udev->speed > USB_SPEED_FULL))
break;
}
udev->descriptor.bMaxPacketSize0 =
--
2.17.0