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authorJosh Poimboeuf <jpoimboe@redhat.com>2021-01-14 16:14:01 -0600
committerJosh Poimboeuf <jpoimboe@redhat.com>2021-01-21 15:49:58 -0600
commit1d489151e9f9d1647110277ff77282fe4d96d09b (patch)
treebe12758e05f70ca75ca391f9219a7015a6247f6a /tools/objtool
parent655cf86548a3938538642a6df27dd359e13c86bd (diff)
downloadlinux-1d489151e9f9d1647110277ff77282fe4d96d09b.tar.gz
objtool: Don't fail on missing symbol table
Thanks to a recent binutils change which doesn't generate unused
symbols, it's now possible for thunk_64.o be completely empty without
CONFIG_PREEMPTION: no text, no data, no symbols.

We could edit the Makefile to only build that file when
CONFIG_PREEMPTION is enabled, but that will likely create confusion
if/when the thunks end up getting used by some other code again.

Just ignore it and move on.

Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1254
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Diffstat (limited to 'tools/objtool')
-rw-r--r--tools/objtool/elf.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index f9682db33cca..d8421e1d06be 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -380,8 +380,11 @@ static int read_symbols(struct elf *elf)
 
 	symtab = find_section_by_name(elf, ".symtab");
 	if (!symtab) {
-		WARN("missing symbol table");
-		return -1;
+		/*
+		 * A missing symbol table is actually possible if it's an empty
+		 * .o file.  This can happen for thunk_64.o.
+		 */
+		return 0;
 	}
 
 	symtab_shndx = find_section_by_name(elf, ".symtab_shndx");