[PATCH 2/2] kallsyms: expand symbol name into comment for debugging

From: Arnd Bergmann
Date: Mon Mar 06 2023 - 05:16:03 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

The assembler output of kallsyms.c is not meant for people to understand,
and is generally not helpful when debugging "Inconsistent kallsyms data"
warnings. I have previously struggled with these, but found it helpful
to list which symbols changed between the first and second pass in the
.tmp_vmlinux.kallsyms*.S files.

As this file is preprocessed, it's possible to add a C-style multiline
comment with the full type/name tuple.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
No idea if there is already a better way to debug this kind of problem,
or if this causes a notable slowdown.
---
scripts/kallsyms.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index a239a87e7bec..ea1e3d3aaa6b 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -525,7 +525,8 @@ static void write_src(void)
table[i]->addr);
exit(EXIT_FAILURE);
}
- printf("\t.long\t%#x\n", (int)offset);
+ expand_symbol(table[i]->sym, table[i]->len, buf);
+ printf("\t.long\t%#x /* %s */\n", (int)offset, buf);
} else if (!symbol_absolute(table[i])) {
output_address(table[i]->addr);
} else {
--
2.39.2