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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jul 26, 2019 at 01:50:27PM +0530, Sai Prakash Ranjan wrote: > On 7/26/2019 12:34 PM, Greg Kroah-Hartman wrote: > > On Fri, Jul 26, 2019 at 11:49:19AM +0530, Sai Prakash Ranjan wrote: > > > Hi, > > > > > > When trying to test my coresight patches, I found that etr,etf and stm > > > device nodes are missing from /dev. > > > > I have no idea what those device nodes are. > > > > > Bisection gives this as the bad commit. > > > > > > 1be01d4a57142ded23bdb9e0c8d9369e693b26cc is the first bad commit > > > commit 1be01d4a57142ded23bdb9e0c8d9369e693b26cc > > > Author: Geert Uytterhoeven > > > Date: Thu Mar 14 12:13:50 2019 +0100 > > > > > > driver: base: Disable CONFIG_UEVENT_HELPER by default > > > > > > Since commit 7934779a69f1184f ("Driver-Core: disable /sbin/hotplug by > > > default"), the help text for the /sbin/hotplug fork-bomb says > > > "This should not be used today [...] creates a high system load, or > > > [...] out-of-memory situations during bootup". The rationale for this > > > was that no recent mainstream system used this anymore (in 2010!). > > > > > > A few years later, the complete uevent helper support was made optional > > > in commit 86d56134f1b67d0c ("kobject: Make support for uevent_helper > > > optional."). However, if was still left enabled by default, to support > > > ancient userland. > > > > > > Time passed by, and nothing should use this anymore, so it can be > > > disabled by default. > > > > > > Signed-off-by: Geert Uytterhoeven > > > Signed-off-by: Greg Kroah-Hartman > > > > > > drivers/base/Kconfig | 1 - > > > 1 file changed, 1 deletion(-) > > > > > > > > > Any idea on this? > > > > That means that who ever created those device nodes is relying on udev > > to do this, and is not doing the correct thing within the kernel and > > using devtmpfs. > > > > Any pointers to where in the kernel those devices are trying to be > > created? > > > > Somewhere in drivers/hwtracing/coresight/* probably. I am not sure, > Mathieu/Suzuki would be able to point you to the exact code. > > Also just to add on some more details, I am using *initramfs* Are you using devtmpfs for your /dev/ mount? If you enable this option, what does: ls -l /dev/etr ls -l /dev/etf ls -l /dev/stm result in? What are these device nodes for? Are they symlinks? Real devices that show up in /sys/dev/char/ as a real value? Or something else? Do you have udev rules that create these nodes somehow? thanks, greg k-h _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel