[Patch] kexec: remove duplicated backup_src_start field from struct crash_elf_info

Vivek Goyal vgoyal at redhat.com
Wed Apr 27 11:01:51 EDT 2011


On Wed, Apr 27, 2011 at 11:33:27AM +0800, Amerigo Wang wrote:
> Vivek pointed out that we have duplicated ->backup_src_start
> in struct crash_elf_info and struct kexec_info.
> 
> This patch removes the ->backup_src_start and ->backup_src_end
> from struct crash_elf_info.
> 
> I tested it on both i686 and ppc64, and used a test case from
> Dave Anderson to confirm the backup region is correct on i686.
> 
> Signed-off-by: WANG Cong <amwang at redhat.com>
> Cc: Vivek Goyal <vgoyal at redhat.com>
> Cc: Simon Horman <horms at verge.net.au>
> 
> ---
> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> index 01f470d..98cda72 100644
> --- a/kexec/arch/i386/crashdump-x86.c
> +++ b/kexec/arch/i386/crashdump-x86.c
> @@ -721,16 +721,15 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
>  	struct memory_range *mem_range, *memmap_p;
>  	struct crash_elf_info elf_info;
>  	unsigned kexec_arch;
> +	unsigned long tmp_backup_end = 0;
>  
>  	memset(&elf_info, 0x0, sizeof(elf_info));
>  
>  	/* Constant parts of the elf_info */
>  	memset(&elf_info, 0, sizeof(elf_info));
>  	elf_info.data             = ELFDATA2LSB;
> -	get_backup_area(&elf_info.backup_src_start, &elf_info.backup_src_end);
> -	info->backup_src_start = elf_info.backup_src_start;
> -	info->backup_src_size = elf_info.backup_src_end
> -				- elf_info.backup_src_start + 1;
> +	get_backup_area(&info->backup_src_start, &tmp_backup_end);
> +	info->backup_src_size = tmp_backup_end - info->backup_src_start + 1;
>  
>  	/* Get the architecture of the running kernel */
>  	kexec_arch = info->kexec_flags & KEXEC_ARCH_MASK;
> @@ -785,15 +784,13 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
>  	sz = (sizeof(struct memory_range) * (KEXEC_MAX_SEGMENTS + 1));
>  	memmap_p = xmalloc(sz);
>  	memset(memmap_p, 0, sz);
> -	add_memmap(memmap_p, elf_info.backup_src_start,
> -		   elf_info.backup_src_end - elf_info.backup_src_start + 1);
> +	add_memmap(memmap_p, info->backup_src_start, info->backup_src_size);
>  	sz = crash_reserved_mem.end - crash_reserved_mem.start +1;
>  	add_memmap(memmap_p, crash_reserved_mem.start, sz);
>  
>  	/* Create a backup region segment to store backup data*/
>  	if (!(info->kexec_flags & KEXEC_PRESERVE_CONTEXT)) {
> -		sz = (elf_info.backup_src_end - elf_info.backup_src_start + align)
> -		     & ~(align - 1);
> +		sz = (info->backup_src_size + align) & ~(align - 1);
>  		tmp = xmalloc(sz);
>  		memset(tmp, 0, sz);
>  		info->backup_start = add_buffer(info, tmp, sz, sz, align,
> diff --git a/kexec/arch/mips/crashdump-mips.c b/kexec/arch/mips/crashdump-mips.c
> index aa50109..4fd6c30 100644
> --- a/kexec/arch/mips/crashdump-mips.c
> +++ b/kexec/arch/mips/crashdump-mips.c
> @@ -329,8 +329,6 @@ static struct crash_elf_info elf_info64 = {
>  	class: ELFCLASS64,
>  	data : ELFDATA2MSB,
>  	machine : EM_MIPS,
> -	backup_src_start : BACKUP_SRC_START,
> -	backup_src_end : BACKUP_SRC_END,
>  	page_offset : PAGE_OFFSET,
>  	lowmem_limit : MAXMEM,
>  };
> @@ -339,8 +337,6 @@ static struct crash_elf_info elf_info32 = {
>  	class: ELFCLASS32,
>  	data : ELFDATA2MSB,
>  	machine : EM_MIPS,
> -	backup_src_start : BACKUP_SRC_START,
> -	backup_src_end : BACKUP_SRC_END,
>  	page_offset : PAGE_OFFSET,
>  	lowmem_limit : MAXMEM,
>  };
> diff --git a/kexec/arch/ppc/crashdump-powerpc.c b/kexec/arch/ppc/crashdump-powerpc.c
> index 7bfad20..eb82122 100644
> --- a/kexec/arch/ppc/crashdump-powerpc.c
> +++ b/kexec/arch/ppc/crashdump-powerpc.c
> @@ -21,8 +21,6 @@ static struct crash_elf_info elf_info64 = {
>  class: ELFCLASS64,
>  data: ELFDATA2MSB,
>  machine: EM_PPC64,
> -backup_src_start: BACKUP_SRC_START,
> -backup_src_end: BACKUP_SRC_END,

Amerigo,

Now who will do following initialization for ppc?

info->backup_src_start = BACKUP_SRC_START;
info->backup_sz = BACKUP_SRC_END - BACKUP_SRC_START + 1;

I think I have concern for mips too.

Thanks
Vivek

>  page_offset: PAGE_OFFSET,
>  lowmem_limit: MAXMEM,
>  };
> @@ -35,8 +33,6 @@ machine: EM_PPC64,
>  #else
>  machine: EM_PPC,
>  #endif
> -backup_src_start: BACKUP_SRC_START,
> -backup_src_end: BACKUP_SRC_END,
>  page_offset: PAGE_OFFSET,
>  lowmem_limit: MAXMEM,
>  };
> diff --git a/kexec/arch/ppc64/crashdump-ppc64.c b/kexec/arch/ppc64/crashdump-ppc64.c
> index 0176bc7..6a66f2a 100644
> --- a/kexec/arch/ppc64/crashdump-ppc64.c
> +++ b/kexec/arch/ppc64/crashdump-ppc64.c
> @@ -40,8 +40,6 @@ static struct crash_elf_info elf_info64 =
>  	class: ELFCLASS64,
>  	data: ELFDATA2MSB,
>  	machine: EM_PPC64,
> -	backup_src_start: BACKUP_SRC_START,
> -	backup_src_end: BACKUP_SRC_END,
>  	page_offset: PAGE_OFFSET,
>  	lowmem_limit: MAXMEM,
>  };
> @@ -51,8 +49,6 @@ static struct crash_elf_info elf_info32 =
>  	class: ELFCLASS32,
>  	data: ELFDATA2MSB,
>  	machine: EM_PPC64,
> -	backup_src_start: BACKUP_SRC_START,
> -	backup_src_end: BACKUP_SRC_END,
>  	page_offset: PAGE_OFFSET,
>  	lowmem_limit: MAXMEM,
>  };
> diff --git a/kexec/crashdump-elf.c b/kexec/crashdump-elf.c
> index 954d670..8d82db9 100644
> --- a/kexec/crashdump-elf.c
> +++ b/kexec/crashdump-elf.c
> @@ -227,8 +227,8 @@ int FUNC(struct kexec_info *info,
>  		phdr->p_flags	= PF_R|PF_W|PF_X;
>  		phdr->p_offset	= mstart;
>  
> -		if (mstart == elf_info->backup_src_start
> -		    && mend == elf_info->backup_src_end)
> +		if (mstart == info->backup_src_start
> +		    && (mend - mstart + 1) == info->backup_src_size)
>  			phdr->p_offset	= info->backup_start;
>  
>  		/* We already prepared the header for kernel text. Map
> diff --git a/kexec/crashdump.h b/kexec/crashdump.h
> index 5a597eb..0f7c2ea 100644
> --- a/kexec/crashdump.h
> +++ b/kexec/crashdump.h
> @@ -23,9 +23,6 @@ struct crash_elf_info {
>  	unsigned long data;
>  	unsigned long machine;
>  
> -	unsigned long backup_src_start;
> -	unsigned long backup_src_end;
> -
>  	unsigned long long page_offset;
>  	unsigned long long kern_vaddr_start;
>  	unsigned long long kern_paddr_start;



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