On Thu, Jun 09, 2016 at 07:24:52PM +0200, Vincent Stehlé wrote: > On Wed, Jun 08, 2016 at 01:38:46PM -0700, Darren Hart wrote: > > Under what circumstances can the .remove op be called with a NULL struct > > acpi_device * as a parameter? From what I can see, most acpi_* calls accpeting > > an acpi_device rely on it not being null, and they are regularly called from > > driver remove functions. > > Did you observe an explicit failure or can you describe a call path where this > > can occur? > > Hi Darren, > > Thank you for reviewing. > > I am not sure about when the .remove() functions are called with a NULL > pointer, or if that can ever happen. I just noticed that dereferencing the > pointer and checking for NULL after did not seem to be the right thing to > do. So I wanted to replicate instead the same construct as e.g. > xen_acpi_processor_remove(). > > Your remark encouraged me to do some more digging into the sources and it > appears that 13 .remove() functions do indeed check their input device > pointer for NULL, while 26 do not (the remaining do not use their input > pointer at all). Now I am puzzled about the necessity to check the pointer > for NULL or not, and there does not seem to be a definitive answer in the > docs either... Either way, some change appears to be needed. Rafael, with respect to acpi .remove functions, is it even possible to be called with a NULL struct acpi_device *? -- Darren Hart Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
