Re: [PATCH v2] make use of .startof.() and .sizeof.() assembler expressions

[Julien Grall <julien.grall@arm.com>]

Hi Jan,

On 24/08/16 08:44, Jan Beulich wrote:
> --- a/xen/arch/arm/device.c
> +++ b/xen/arch/arm/device.c
> @@ -21,8 +21,8 @@
>  #include <xen/errno.h>
>  #include <xen/lib.h>
>
> -extern const struct device_desc _sdevice[], _edevice[];
> -extern const struct acpi_device_desc _asdevice[], _aedevice[];
> +extern const struct device_desc _sdevice[] asm(".startof.(.dev.info)");
> +extern const struct device_desc _edevice[];
>
>  int __init device_init(struct dt_device_node *dev, enum device_class class,
>                         const void *data)
> @@ -51,6 +51,11 @@ int __init device_init(struct dt_device_
>      return -EBADF;
>  }
>
> +#ifdef CONFIG_ACPI

Why did you add the #ifdef CONFIG_ACPI here? It is not explained in the 
commit message.

If you want to add it, it should be a separate patch and we should go 
further by removing the section in the linker script.

> +
> +extern const struct acpi_device_desc _asdevice[] asm(".startof.(.adev.info)");
> +extern const struct acpi_device_desc _aedevice[];
> +
>  int __init acpi_device_init(enum device_class class, const void *data, int class_type)
>  {
>      const struct acpi_device_desc *desc;
> @@ -68,6 +73,8 @@ int __init acpi_device_init(enum device_
>      return -EBADF;
>  }
>
> +#endif
> +
>  enum device_class device_get_class(const struct dt_device_node *dev)
>  {
>      const struct device_desc *desc;
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -2058,7 +2058,7 @@ static void __init find_gnttab_region(st
>       * enough space for a large grant table
>       */
>      kinfo->gnttab_start = __pa(_stext);
> -    kinfo->gnttab_size = (_etext - _stext) & PAGE_MASK;
> +    kinfo->gnttab_size = _sizeof_text & PAGE_MASK;
>
>      /* Make sure the grant table will fit in the region */
>      if ( (kinfo->gnttab_size >> PAGE_SHIFT) < max_grant_frames )
> --- a/xen/arch/arm/platform.c
> +++ b/xen/arch/arm/platform.c
> @@ -22,7 +22,8 @@
>  #include <xen/init.h>
>  #include <asm/psci.h>
>
> -extern const struct platform_desc _splatform[], _eplatform[];
> +extern const struct platform_desc _splatform[] asm(".startof.(.arch.info)");
> +extern const struct platform_desc _eplatform[];
>
>  /* Pointer to the current platform description */
>  static const struct platform_desc *platform;
> --- a/xen/arch/arm/xen.lds.S
> +++ b/xen/arch/arm/xen.lds.S
> @@ -31,7 +31,6 @@ SECTIONS
>    . = XEN_VIRT_START;
>    _start = .;
>    .text : /* XXX should be AT ( XEN_PHYS_START ) */ {
> -        _stext = .;            /* Text section */

I don't see any removal of _stext in xen/arch/arm/alternative.c.

>         *(.text)
>         *(.text.cold)
>         *(.text.unlikely)
> @@ -42,7 +41,6 @@ SECTIONS
>
>    . = ALIGN(PAGE_SIZE);
>    .rodata : {
> -        _srodata = .;          /* Read-only data */
>          /* Bug frames table */
>         __start_bug_frames = .;
>         *(.bug_frames.0)
> @@ -104,21 +102,18 @@ SECTIONS
>
>    . = ALIGN(8);
>    .arch.info : {
> -      _splatform = .;
>        *(.arch.info)
>        _eplatform = .;
>    } :text
>
>    . = ALIGN(8);
>    .dev.info : {
> -      _sdevice = .;
>        *(.dev.info)
>        _edevice = .;
>    } :text
>
>    . = ALIGN(8);
>    .adev.info : {
> -      _asdevice = .;
>        *(.adev.info)
>        _aedevice = .;
>    } :text
> @@ -126,7 +121,6 @@ SECTIONS
>    . = ALIGN(PAGE_SIZE);             /* Init code and data */
>    __init_begin = .;
>    .init.text : {
> -       _sinittext = .;
>         *(.init.text)
>         _einittext = .;
>    } :text
> @@ -174,7 +168,6 @@ SECTIONS
>    __init_end = .;
>
>    .bss : {                     /* BSS */
> -       __bss_start = .;
>         *(.bss.stack_aligned)
>         . = ALIGN(PAGE_SIZE);
>         *(.bss.page_aligned)
> @@ -186,7 +179,6 @@ SECTIONS
>         *(.bss.percpu.read_mostly)
>         . = ALIGN(SMP_CACHE_BYTES);
>         __per_cpu_data_end = .;
> -       __bss_end = .;
>    } :text
>    _end = . ;

Regards,

-- 
Julien Grall

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