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

On Thu, Jul 30, 2026 at 04:33:18PM +0200, Christophe Leroy (CS GROUP) wrote:

Le 30/07/2026 à 15:19, Thorsten Blum a écrit :

quoted

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))

It still returns 0.

When cmem->nr_ranges >= CONFIG_CRASH_MAX_MEMORY_RANGES, the else if
branch prints the warning and then falls through to the return 0 at the
end of the function. The final else branch is not entered in that case.

No functional changes are intended.

quoted

  #endif
  	return 0;
  }