Re: [PATCH] powerpc/kexec: Simplify kdump_extra_elfcorehdr_size()

["Christophe Leroy (CS GROUP)" <chleroy@kernel.org>]

Le 30/07/2026 à 15:19, Thorsten Blum a écrit :
> Return the size directly and drop the extra_sz variable to simplify
> kdump_extra_elfcorehdr_size(). The two warning paths now fall through
> to the existing return 0 at the end of the function.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>   arch/powerpc/kexec/file_load_64.c | 6 +-----
>   1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
> index c3503d698428..d0c544079e03 100644
> --- a/arch/powerpc/kexec/file_load_64.c
> +++ b/arch/powerpc/kexec/file_load_64.c
> @@ -377,16 +377,12 @@ static int load_backup_segment(struct kimage *image, struct kexec_buf *kbuf)
>   static unsigned int kdump_extra_elfcorehdr_size(struct crash_mem *cmem)
>   {
>   #if defined(CONFIG_CRASH_HOTPLUG) && defined(CONFIG_MEMORY_HOTPLUG)
> -	unsigned int extra_sz = 0;
> -
>   	if (CONFIG_CRASH_MAX_MEMORY_RANGES > (unsigned int)PN_XNUM)
>   		pr_warn("Number of Phdrs %u exceeds max\n", CONFIG_CRASH_MAX_MEMORY_RANGES);
>   	else if (cmem->nr_ranges >= CONFIG_CRASH_MAX_MEMORY_RANGES)
>   		pr_warn("Configured crash mem ranges may not be enough\n");
>   	else
> -		extra_sz = (CONFIG_CRASH_MAX_MEMORY_RANGES - cmem->nr_ranges) * sizeof(Elf64_Phdr);
> -
> -	return extra_sz;
> +		return (CONFIG_CRASH_MAX_MEMORY_RANGES - cmem->nr_ranges) * sizeof(Elf64_Phdr);

I don't understand.

Previously, when cmem->nr_ranges >= CONFIG_CRASH_MAX_MEMORY_RANGES you 
would return 0. Now you will return something different. For instance if 
cmem->nr_ranges is (CONFIG_CRASH_MAX_MEMORY_RANGES + 1) you will return 
(unsigned int)(-1 * sizeof(Elf64_Phdr))

>   #endif
>   	return 0;
>   }