[PATCH 17/48] objtool: Fix reloc hash collision in find_reloc_by_dest_range()

[Josh Poimboeuf]

In find_reloc_by_dest_range(), hash collisions can cause a high-offset
relocation to appear when probing a low-offset hash bucket.

Only return early when the best match found so far genuinely belongs to
the current bucket (its offset is within the bucket's stride range).
Otherwise, continue scanning later buckets which may contain
lower-offset matches.

Fixes: 74b873e49d92 ("objtool: Optimize find_rela_by_dest_range()")
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 tools/objtool/elf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index a5486e172e5c..c4cb371e72b2 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -370,11 +370,11 @@ struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *se
 					r = reloc;
 			}
 		}
-		if (r)
+		if (r && (reloc_offset(r) & OFFSET_STRIDE_MASK) == o)
 			return r;
 	}
 
-	return NULL;
+	return r;
 }
 
 struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset)
-- 
2.53.0