Re: [Xen-devel] Ping: [PATCH] x86: replace literal numbers

[Keir Fraser <keir.xen@xxxxxxxxx>]

On 28/09/2012 09:21, "Jan Beulich" <JBeulich@xxxxxxxx> wrote:

> In various cases, 256 was being used instead of NR_VECTORS or a derived
> ARRAY_SIZE() expression. In one case (guest_has_trap_callback()), a
> wrong (unrelated) constant was used instead of NR_VECTORS.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Acked-by: Keir Fraser <keir@xxxxxxx>

> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -374,8 +374,9 @@ int switch_compat(struct domain *d)
>  
>  static inline bool_t standalone_trap_ctxt(struct vcpu *v)
>  {
> -    BUILD_BUG_ON(256 * sizeof(*v->arch.pv_vcpu.trap_ctxt) > PAGE_SIZE);
> -    return 256 * sizeof(*v->arch.pv_vcpu.trap_ctxt) + sizeof(*v) > PAGE_SIZE;
> +    BUILD_BUG_ON(NR_VECTORS * sizeof(*v->arch.pv_vcpu.trap_ctxt) >
> PAGE_SIZE);
> +    return NR_VECTORS * sizeof(*v->arch.pv_vcpu.trap_ctxt) + sizeof(*v)
> +           > PAGE_SIZE;
>  }
>  
>  int vcpu_initialise(struct vcpu *v)
> @@ -432,7 +433,7 @@ int vcpu_initialise(struct vcpu *v)
>          }
>          else
>              v->arch.pv_vcpu.trap_ctxt = (void *)v + PAGE_SIZE -
> -                256 * sizeof(*v->arch.pv_vcpu.trap_ctxt);
> +                NR_VECTORS * sizeof(*v->arch.pv_vcpu.trap_ctxt);
>  
>          /* PV guests by default have a 100Hz ticker. */
>          v->periodic_period = MILLISECS(10);
> @@ -702,7 +703,7 @@ int arch_set_info_guest(
>              fixup_guest_stack_selector(d, c.nat->kernel_ss);
>              fixup_guest_code_selector(d, c.nat->user_regs.cs);
>  
> -            for ( i = 0; i < 256; i++ )
> +            for ( i = 0; i < ARRAY_SIZE(c.nat->trap_ctxt); i++ )
>              {
>                  if ( !is_canonical_address(c.nat->trap_ctxt[i].address) )
>                      return -EINVAL;
> @@ -725,7 +726,7 @@ int arch_set_info_guest(
>              fixup_guest_code_selector(d, c.cmp->event_callback_cs);
>              fixup_guest_code_selector(d, c.cmp->failsafe_callback_cs);
>  
> -            for ( i = 0; i < 256; i++ )
> +            for ( i = 0; i < ARRAY_SIZE(c.cmp->trap_ctxt); i++ )
>                  fixup_guest_code_selector(d, c.cmp->trap_ctxt[i].cs);
>  
>              /* LDT safety checks. */
> --- a/xen/arch/x86/traps.c
> +++ b/xen/arch/x86/traps.c
> @@ -3506,7 +3506,7 @@ int guest_has_trap_callback(struct domai
>      BUG_ON(vcpuid >= d->max_vcpus);
>  
>      /* Sanity check - XXX should be more fine grained. */
> -    BUG_ON(trap_nr > TRAP_syscall);
> +    BUG_ON(trap_nr >= NR_VECTORS);
>  
>      v = d->vcpu[vcpuid];
>      t = &v->arch.pv_vcpu.trap_ctxt[trap_nr];
> @@ -3574,7 +3574,7 @@ long do_set_trap_table(XEN_GUEST_HANDLE(
>      /* If no table is presented then clear the entire virtual IDT. */
>      if ( guest_handle_is_null(traps) )
>      {
> -        memset(dst, 0, 256 * sizeof(*dst));
> +        memset(dst, 0, NR_VECTORS * sizeof(*dst));
>          init_int80_direct_trap(curr);
>          return 0;
>      }
> --- a/xen/arch/x86/x86_64/compat/traps.c
> +++ b/xen/arch/x86/x86_64/compat/traps.c
> @@ -317,7 +317,7 @@ int compat_set_trap_table(XEN_GUEST_HAND
>      /* If no table is presented then clear the entire virtual IDT. */
>      if ( guest_handle_is_null(traps) )
>      {
> -        memset(dst, 0, 256 * sizeof(*dst));
> +        memset(dst, 0, NR_VECTORS * sizeof(*dst));
>          return 0;
>      }
>  
> 
> 
> 
> _______________________________________________
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> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel



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