Re: [PATCH 1/2] disk: Add support for device-specific malloc function

[Andrei Borzenkov]

19.02.2016 19:18, Leif Lindholm пишет:
> Some disk types have allocation requirements beyond normal grub_malloc.
> Add a function pointer to grub_disk_t and a wrapper function in
> kern/disk.c making use of that function if available, to enable these
> disk drivers to implement their own malloc.
> ---
>  grub-core/kern/disk.c | 13 +++++++++++--
>  include/grub/disk.h   |  5 +++++
>  2 files changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/grub-core/kern/disk.c b/grub-core/kern/disk.c
> index 789f8c0..e186586 100644
> --- a/grub-core/kern/disk.c
> +++ b/grub-core/kern/disk.c
> @@ -184,6 +184,15 @@ find_part_sep (const char *name)
>    return NULL;
>  }
>  
> +static void *
> +disk_malloc (struct grub_disk *disk, grub_size_t size)
> +{
> +  if (disk->malloc)
> +    return disk->malloc (disk, size);
> +
> +  return grub_malloc (size);
> +}

Just initialize disk->malloc to grub_alloc in all other drivers then, no
need for repeated runtime check.

> +
>  grub_disk_t
>  grub_disk_open (const char *name)
>  {
> @@ -331,7 +340,7 @@ grub_disk_read_small_real (grub_disk_t disk, 
> grub_disk_addr_t sector,
>      }
>  
>    /* Allocate a temporary buffer.  */
> -  tmp_buf = grub_malloc (GRUB_DISK_SECTOR_SIZE << GRUB_DISK_CACHE_BITS);
> +  tmp_buf = disk_malloc (disk, GRUB_DISK_SECTOR_SIZE << 
> GRUB_DISK_CACHE_BITS);
>    if (! tmp_buf)
>      return grub_errno;
>  
> @@ -373,7 +382,7 @@ grub_disk_read_small_real (grub_disk_t disk, 
> grub_disk_addr_t sector,
>      num = ((size + offset + (1ULL << (disk->log_sector_size))
>           - 1) >> (disk->log_sector_size));
>  
> -    tmp_buf = grub_malloc (num << disk->log_sector_size);
> +    tmp_buf = disk_malloc (disk, num << disk->log_sector_size);
>      if (!tmp_buf)
>        return grub_errno;
>      
> diff --git a/include/grub/disk.h b/include/grub/disk.h
> index b385af8..0fdd779 100644
> --- a/include/grub/disk.h
> +++ b/include/grub/disk.h
> @@ -111,6 +111,8 @@ typedef void (*grub_disk_read_hook_t) (grub_disk_addr_t 
> sector,
>                                      unsigned offset, unsigned length,
>                                      void *data);
>  
> +typedef void *(*grub_disk_malloc_t) (struct grub_disk *disk, grub_size_t 
> size);
> +
>  /* Disk.  */
>  struct grub_disk
>  {
> @@ -144,6 +146,9 @@ struct grub_disk
>  
>    /* Device-specific data.  */
>    void *data;
> +
> +  /* Device-specific malloc function. */
> +  grub_disk_malloc_t malloc;
>  };
>  typedef struct grub_disk *grub_disk_t;
>  
>