On Tue, 2012-03-20 at 22:37 -0700, Haren Myneni wrote: > Some power systems do not have legacy ISA devices. So, /dev/port is not > a valid interface on these systems. User level tools such as kbdrate is > trying to access the device using this interface which is causing the > system crash. > > This patch will fix this issue by not creating this interface on these > powerpc systems.
Doesn't fix 32-bit... not a big deal for now I suppose... But I'd rather you change the patch a tiny bit to change legacy_isa_device_found() to arch_has_dev_port() instead. There may be other reason than legacy ISA to enable dev/port or not so let's make the arch hook more generic. Another approach which might be even better is to filter per-access, ie for each read/write to /dev/port, have a hook to check if that specific port is valid, but that may be overkill for what is essentially a legacy interface that should have died a long time ago :) Cheers, Ben. > Signed-off-by: Haren Myneni <[email protected]> > > > diff -Naurp linux.orig/arch/powerpc/kernel/isa-bridge.c > linux/arch/powerpc/kernel/isa-bridge.c > --- linux.orig/arch/powerpc/kernel/isa-bridge.c 2012-02-11 > 02:08:08.780005293 -0800 > +++ linux/arch/powerpc/kernel/isa-bridge.c 2012-02-11 02:16:25.080003386 > -0800 > @@ -255,6 +255,14 @@ static struct notifier_block isa_bridge_ > .notifier_call = isa_bridge_notify > }; > > +int __init legacy_isa_device_found(void) > +{ > + if (isa_bridge_pcidev) > + return 1; > + > + return 0; > +} > + > /** > * isa_bridge_init - register to be notified of ISA bridge > addition/removal > * > diff -Naurp linux.orig/drivers/char/mem.c linux/drivers/char/mem.c > --- linux.orig/drivers/char/mem.c 2012-02-11 02:08:42.710002440 -0800 > +++ linux/drivers/char/mem.c 2012-03-20 20:40:43.650000003 -0700 > @@ -35,6 +35,8 @@ > # include <linux/efi.h> > #endif > > +#define DEVPORT_MINOR 4 > + > static inline unsigned long size_inside_page(unsigned long start, > unsigned long size) > { > @@ -910,6 +912,11 @@ static char *mem_devnode(struct device * > > static struct class *mem_class; > > +int __init __weak legacy_isa_device_found(void) > +{ > + return 1; > +} > + > static int __init chr_dev_init(void) > { > int minor; > @@ -930,6 +937,13 @@ static int __init chr_dev_init(void) > for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) { > if (!devlist[minor].name) > continue; > + > + /* > + * Create /dev/port? > + */ > + if ((minor == DEVPORT_MINOR) && !legacy_isa_device_found()) > + continue; > + > device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor), > NULL, devlist[minor].name); > } > diff -Naurp linux.orig/include/linux/isa.h linux/include/linux/isa.h > --- linux.orig/include/linux/isa.h 2012-02-11 02:07:52.030019810 -0800 > +++ linux/include/linux/isa.h 2012-02-11 02:16:49.810002296 -0800 > @@ -36,4 +36,5 @@ static inline void isa_unregister_driver > } > #endif > > +extern int __init legacy_isa_device_found(void); > #endif /* __LINUX_ISA_H */ > _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
