[PATCH] modpost: improve the section mismatch warning format
From: Masahiro Yamada
Date: Mon Aug 12 2024 - 12:55:28 EST
This commit improves the section mismatch warning format when there is
no suitable symbol name to print.
The section mismatch warning prints the reference source in the form
of <symbol_name>+<offset> and the reference destination in the form
of <symbol_name>.
However, there are some corner cases where <symbol_name> becomes
"(unknown)", as reported in commit 23dfd914d2bf ("modpost: fix null
pointer dereference").
In such cases, it is better to print the symbol address.
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---
scripts/mod/modpost.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index d0f138803207..3e474291258c 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -705,10 +705,7 @@ static char *get_modinfo(struct elf_info *info, const char *tag)
static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
{
- if (sym)
- return elf->strtab + sym->st_name;
- else
- return "(unknown)";
+ return sym ? elf->strtab + sym->st_name : "";
}
/*
@@ -1021,6 +1018,7 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf,
Elf_Sym *from;
const char *tosym;
const char *fromsym;
+ char taddr_str[16];
from = find_fromsym(elf, faddr, fsecndx);
fromsym = sym_name(elf, from);
@@ -1034,10 +1032,17 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf,
sec_mismatch_count++;
- warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
- modname, fromsym,
- (unsigned int)(faddr - (from ? from->st_value : 0)),
- fromsec, tosym, tosec);
+ if (!tosym[0])
+ snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr);
+
+ /*
+ * The format for the reference source: <symbol_name>+<offset> or <address>
+ * The format for the reference destination: <symbol_name> or <address>
+ */
+ warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n",
+ modname, fromsym, fromsym[0] ? "+" : "",
+ (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)),
+ fromsec, tosym[0] ? tosym : taddr_str, tosec);
if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
if (match(tosec, mismatch->bad_tosec))
--
2.43.0