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    SubjectIs register_cpu() now obligatory?
    Hi!

    In Linus' tree as of today UML is broken.
    It's crashing because get_cpu_device() in topology_add_dev()
    returns a device with an invalid kobj (address is 0x10).

    The code seems to assume that each arch has to register their CPUs
    using register_cpu().

    Is this a regression or was UML always faulty because it did not register it's CPU?

    The below patch fixes the issue for UML.

    Thanks,
    //richard

    ---
    diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
    index bc49474..f3b43fe 100644
    --- a/arch/um/kernel/Makefile
    +++ b/arch/um/kernel/Makefile
    @@ -12,7 +12,7 @@ clean-files :=
    obj-y = config.o exec.o exitcode.o init_task.o irq.o ksyms.o mem.o \
    physmem.o process.o ptrace.o reboot.o sigio.o \
    signal.o smp.o syscall.o sysrq.o time.o tlb.o trap.o \
    - um_arch.o umid.o skas/
    + um_arch.o umid.o cpu.o skas/

    obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
    obj-$(CONFIG_GPROF) += gprof_syms.o
    diff --git a/arch/um/kernel/cpu.c b/arch/um/kernel/cpu.c
    new file mode 100644
    index 0000000..4914df2
    --- /dev/null
    +++ b/arch/um/kernel/cpu.c
    @@ -0,0 +1,19 @@
    +#include <linux/init.h>
    +#include <linux/device.h>
    +#include <linux/cpu.h>
    +#include <linux/percpu.h>
    +
    +static DEFINE_PER_CPU(struct cpu, cpu_devices);
    +
    +static int __init topology_init(void)
    +{
    + int cpu;
    +
    + for_each_possible_cpu(cpu) {
    + struct cpu *c = &per_cpu(cpu_devices, cpu);
    + register_cpu(c, cpu);
    + }
    +
    + return 0;
    +}
    +subsys_initcall(topology_init);
    [unhandled content-type:application/pgp-signature]
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