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    Subject[PATCH v12 12/21] x86/xen: Add xen_cpuid() and xen_setup_gdt() to stacktool whitelists
    Date
    stacktool reports the following false positive warnings:

    stacktool: arch/x86/xen/enlighten.o: xen_cpuid()+0x41: can't find jump dest instruction at .text+0x108
    stacktool: arch/x86/xen/enlighten.o: xen_setup_gdt.constprop.23()+0x2e: kernel entry/exit from callable instruction

    The first warning is due to xen_cpuid()'s use of XEN_EMULATE_PREFIX to
    insert some fake instructions which stacktool doesn't know how to
    decode.

    The second warning is due to xen_setup_gdt()'s use of an lret
    instruction, which stacktool normally doesn't allow in callable
    functions. But this seems to be a valid use of the instruction.

    Add both functions to the stacktool whitelist.

    Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
    Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
    Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
    Cc: David Vrabel <david.vrabel@citrix.com>
    ---
    arch/x86/xen/enlighten.c | 4 +++-
    1 file changed, 3 insertions(+), 1 deletion(-)

    diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
    index d9cfa45..6cc682d 100644
    --- a/arch/x86/xen/enlighten.c
    +++ b/arch/x86/xen/enlighten.c
    @@ -32,6 +32,7 @@
    #include <linux/gfp.h>
    #include <linux/memblock.h>
    #include <linux/edd.h>
    +#include <linux/stacktool.h>

    #include <xen/xen.h>
    #include <xen/events.h>
    @@ -345,8 +346,8 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
    *cx &= maskecx;
    *cx |= setecx;
    *dx &= maskedx;
    -
    }
    +STACKTOOL_IGNORE_FUNC(xen_cpuid);

    static bool __init xen_check_mwait(void)
    {
    @@ -1443,6 +1444,7 @@ static void __ref xen_setup_gdt(int cpu)
    pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
    pv_cpu_ops.load_gdt = xen_load_gdt;
    }
    +STACKTOOL_IGNORE_FUNC(xen_setup_gdt);

    #ifdef CONFIG_XEN_PVH
    /*
    --
    2.4.3


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