3.2-stable review patch. If anyone has any objections, please let me know.
------------------ From: "Rafael J. Wysocki" <rafael.j.wyso...@intel.com> commit a6b5e88c0e42093b9057856f35770966c8c591e3 upstream. During resume from system suspend the 'data' field of struct pnp_dev in pnpacpi_set_resources() may be a stale pointer, due to removal of the associated ACPI device node object in the previous suspend-resume cycle. This happens, for example, if a dockable machine is booted in the docking station and then suspended and resumed and suspended again. If that happens, pnpacpi_build_resource_template() called from pnpacpi_set_resources() attempts to use that pointer and crashes. However, pnpacpi_set_resources() actually checks the device's ACPI handle, attempts to find the ACPI device node object attached to it and returns an error code if that fails, so in fact it knows what the correct value of dev->data should be. Use this observation to update dev->data with the correct value if necessary and dump a call trace if that's the case (once). We still need to fix the root cause of this issue, but preventing systems from crashing because of it is an improvement too. Reported-and-tested-by: Zdenek Kabelac <zdenek.kabe...@gmail.com> References: https://bugzilla.kernel.org/show_bug.cgi?id=51071 Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Signed-off-by: Ben Hutchings <b...@decadent.org.uk> --- drivers/pnp/pnpacpi/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c index 26b5d4b..ec8e914 100644 --- a/drivers/pnp/pnpacpi/core.c +++ b/drivers/pnp/pnpacpi/core.c @@ -95,6 +95,9 @@ static int pnpacpi_set_resources(struct pnp_dev *dev) return -ENODEV; } + if (WARN_ON_ONCE(acpi_dev != dev->data)) + dev->data = acpi_dev; + ret = pnpacpi_build_resource_template(dev, &buffer); if (ret) return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
