6.1-stable review patch. If anyone has any objections, please let me know.
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From: Josh Poimboeuf jpoimboe@kernel.org
[ Upstream commit 72567c630d32bc31f671977f78228c80937ed80e ]
find_symbol_hole_containing() fails to find a symbol hole (aka stripped weak symbol) if its section has no symbols before the hole. This breaks weak symbol detection if -ffunction-sections is enabled.
Fix that by allowing the interval tree to contain section symbols, which are always at offset zero for a given section.
Fixes a bunch of (-ffunction-sections) warnings like:
vmlinux.o: warning: objtool: .text.__x64_sys_io_setup+0x10: unreachable instruction
Fixes: 4adb23686795 ("objtool: Ignore extra-symbol code") Acked-by: Petr Mladek pmladek@suse.com Tested-by: Joe Lawrence joe.lawrence@redhat.com Signed-off-by: Josh Poimboeuf jpoimboe@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/objtool/elf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 89b37cd4ab1dc..905253421e8c8 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -74,7 +74,7 @@ struct symbol_hole { };
/* - * Find !section symbol where @offset is after it. + * Find the last symbol before @offset. */ static int symbol_hole_by_offset(const void *key, const struct rb_node *node) { @@ -85,8 +85,7 @@ static int symbol_hole_by_offset(const void *key, const struct rb_node *node) return -1;
if (sh->key >= s->offset + s->len) { - if (s->type != STT_SECTION) - sh->sym = s; + sh->sym = s; return 1; }
@@ -369,7 +368,8 @@ static void elf_add_symbol(struct elf *elf, struct symbol *sym) sym->len = sym->sym.st_size;
__sym_for_each(iter, &sym->sec->symbol_tree, sym->offset, sym->offset) { - if (iter->offset == sym->offset && iter->type == sym->type) + if (iter->offset == sym->offset && iter->type == sym->type && + iter->len == sym->len) iter->alias = sym; }