Re: [PATCH v2 2/7] objtool/klp: Fix size of empty special section entries

On Wed, Aug 05, 2026 at 01:36:26PM -0700, Song Liu wrote:
> On Wed, Aug 5, 2026 at 7:30 AM Josh Poimboeuf <[email protected]> wrote:
> >
> [...]
> >
> > diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c
> > index 492d7a012cffe..11e8f3ddbb0e6 100644
> > --- a/tools/objtool/klp-diff.c
> > +++ b/tools/objtool/klp-diff.c
> > @@ -1627,6 +1627,7 @@ static int create_fake_symbols(struct elf *elf)
> >         for_each_reloc(sec->rsec, reloc) {
> >                 unsigned long offset, size;
> >                 struct reloc *next_reloc;
> > +               bool last = true;
> >
> >                 if (annotype(elf, sec, reloc) != ANNOTYPE_DATA_SPECIAL)
> >                         continue;
> > @@ -1641,10 +1642,11 @@ static int create_fake_symbols(struct elf *elf)
> >                                 continue;
> >
> >                         size = reloc_addend(next_reloc) - offset;
> > +                       last = false;
> >                         break;
> >                 }
> >
> > -               if (!size)
> > +               if (last)
> >                         size = sec_size(reloc->sym->sec) - offset;
> 
> Some comments about "last" logic here can be very helpful.
> 
> Also, with the last flag, "size = 0;" before the for_each_reloc_continue()
> loop can be removed.
> 
> Other than these nitpicks:
> 
> Acked-by: Song Liu <[email protected]>

How about this on top?

diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c
index 11e8f3ddbb0e6..38fae861d12c7 100644
--- a/tools/objtool/klp-diff.c
+++ b/tools/objtool/klp-diff.c
@@ -1634,7 +1634,10 @@ static int create_fake_symbols(struct elf *elf)
 
 		offset = reloc_addend(reloc);
 
-		size = 0;
+		/*
+		 * Find the start of the next entry so the fake symbol size can
+		 * be calculated.
+		 */
 		next_reloc = reloc;
 		for_each_reloc_continue(sec->rsec, next_reloc) {
 			if (annotype(elf, sec, next_reloc) != ANNOTYPE_DATA_SPECIAL ||
@@ -1646,6 +1649,10 @@ static int create_fake_symbols(struct elf *elf)
 			break;
 		}
 
+		/*
+		 * If no next entry found, this is the last entry, so its size
+		 * is from the current offset to the end of the section.
+		 */
 		if (last)
 			size = sec_size(reloc->sym->sec) - offset;