• James Morse's avatar
    KVM: arm/arm64: Stop leaking vcpu pid references · 591d215a
    James Morse authored
    kvm provides kvm_vcpu_uninit(), which amongst other things, releases the
    last reference to the struct pid of the task that was last running the vcpu.
    
    On arm64 built with CONFIG_DEBUG_KMEMLEAK, starting a guest with kvmtool,
    then killing it with SIGKILL results (after some considerable time) in:
    > cat /sys/kernel/debug/kmemleak
    > unreferenced object 0xffff80007d5ea080 (size 128):
    >  comm "lkvm", pid 2025, jiffies 4294942645 (age 1107.776s)
    >  hex dump (first 32 bytes):
    >    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    >    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    >  backtrace:
    >    [<ffff8000001b30ec>] create_object+0xfc/0x278
    >    [<ffff80000071da34>] kmemleak_alloc+0x34/0x70
    >    [<ffff80000019fa2c>] kmem_cache_alloc+0x16c/0x1d8
    >    [<ffff8000000d0474>] alloc_pid+0x34/0x4d0
    >    [<ffff8000000b5674>] copy_process.isra.6+0x79c/0x1338
    >    [<ffff8000000b633c>] _do_fork+0x74/0x320
    >    [<ffff8000000b66b0>] SyS_clone+0x18/0x20
    >    [<ffff800000085cb0>] el0_svc_naked+0x24/0x28
    >    [<ffffffffffffffff>] 0xffffffffffffffff
    
    On x86 kvm_vcpu_uninit() is called on the path from kvm_arch_destroy_vm(),
    on arm no equivalent call is made. Add the call to kvm_arch_vcpu_free().
    Signed-off-by: default avatarJames Morse <james.morse@arm.com>
    Fixes: 749cf76c ("KVM: ARM: Initial skeleton to compile KVM support")
    Cc: <stable@vger.kernel.org> # 3.10+
    Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
    Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
    591d215a
arm.c 31.1 KB