Re: [PATCH 2/6] x86/xen: Mark pv stub assembler symbol visible

Boris Ostrovsky
2018-01-15T17:18:18Z

On 12/21/2017 07:18 PM, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> With LTO any external assembler symbol has to be marked __visible.
> Mark the generated asm PV stubs __visible to prevent a linker error.
>
> Signed-off-by: Andi Kleen <ak@linux.intel.com>

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

> ---
> arch/x86/include/asm/paravirt.h | 3 ++-
> drivers/xen/time.c | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
> index 892df375b615..f03445fbbe2f 100644
> --- a/arch/x86/include/asm/paravirt.h
> +++ b/arch/x86/include/asm/paravirt.h
> @@ -745,7 +745,8 @@ static __always_inline bool pv_vcpu_is_preempted(long cpu)
> */
> #define PV_THUNK_NAME(func) "__raw_callee_save_" #func
> #define PV_CALLEE_SAVE_REGS_THUNK(func) \
> - extern typeof(func) __raw_callee_save_##func; \
> + extern __visible typeof(func) __raw_callee_save_##func; \
> + extern __visible typeof(func) func; \
> \
> asm(".pushsection .text;" \
> ".globl " PV_THUNK_NAME(func) ";" \
> diff --git a/drivers/xen/time.c b/drivers/xen/time.c
> index 3e741cd1409c..708a00c337d7 100644
> --- a/drivers/xen/time.c
> +++ b/drivers/xen/time.c
> @@ -144,7 +144,7 @@ void xen_get_runstate_snapshot(struct vcpu_runstate_info *res)
> }
>
> /* return true when a vcpu could run but has no real cpu to run on */
> -bool xen_vcpu_stolen(int vcpu)
> +__visible bool xen_vcpu_stolen(int vcpu)
> {
> return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable;
> }
>