From 1743694eb2357b47cd9951079f9ab0d728c916bf Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Fri, 15 Nov 2019 02:42:24 +0900
Subject: [PATCH] modpost: stop symbol preloading for modversion CRC
It is complicated to add mocked-up symbols for pre-handling CRC.
Handle CRC after all the export symbols in the relevant module
are registered.
Call handle_modversion() after the handle_symbol() iteration.
In some cases, I see atand-alone __crc_* without __ksymtab_*.
For example, ARCH=arm allyesconfig produces __crc_ccitt_veneer and
__crc_itu_t_veneer. I guess they come from crc_ccitt, crc_itu_t,
respectively. Since __*_veneer are auto-generated symbols, just
ignore them.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
scripts/mod/modpost.c | 71 ++++++++++++++++++++++++-------------------
1 file changed, 39 insertions(+), 32 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 6735ae3da4c22..1c22cf7aa732c 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -169,7 +169,7 @@ struct symbol {
unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
unsigned int kernel:1; /* 1 if symbol is from kernel
* (only for external modules) **/
- unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
+ unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
unsigned int is_static:1; /* 1 if symbol is not global */
enum export export; /* Type of export */
char name[0];
@@ -410,16 +410,17 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod,
return s;
}
-static void sym_update_crc(const char *name, struct module *mod,
- unsigned int crc, enum export export)
+static void sym_set_crc(const char *name, unsigned int crc)
{
struct symbol *s = find_symbol(name);
- if (!s) {
- s = new_symbol(name, mod, export);
- /* Don't complain when we find it later. */
- s->preloaded = 1;
- }
+ /*
+ * Ignore stand-alone __crc_*, which might be auto-generated symbols
+ * such as __*_veneer in ARM ELF.
+ */
+ if (!s)
+ return;
+
s->crc = crc;
s->crc_valid = 1;
}
@@ -683,12 +684,34 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
return 0;
}
+static void handle_modversion(const struct module *mod,
+ const struct elf_info *info,
+ const Elf_Sym *sym, const char *symname)
+{
+ unsigned int crc;
+
+ if (sym->st_shndx == SHN_UNDEF) {
+ warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n",
+ symname, mod->name, is_vmlinux(mod->name) ? "":".ko");
+ return;
+ }
+
+ if (sym->st_shndx == SHN_ABS) {
+ crc = sym->st_value;
+ } else {
+ unsigned int *crcp;
+
+ /* symbol points to the CRC in the ELF object */
+ crcp = sym_get_data(info, sym);
+ crc = TO_NATIVE(*crcp);
+ }
+ sym_set_crc(symname, crc);
+}
+
static void handle_symbol(struct module *mod, struct elf_info *info,
const Elf_Sym *sym, const char *symname)
{
- unsigned int crc;
enum export export;
- bool is_crc = false;
const char *name;
if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
@@ -697,21 +720,6 @@ static void handle_symbol(struct module *mod, struct elf_info *info,
else
export = export_from_sec(info, get_secindex(info, sym));
- /* CRC'd symbol */
- if (strstarts(symname, "__crc_")) {
- is_crc = true;
- crc = (unsigned int) sym->st_value;
- if (sym->st_shndx != SHN_UNDEF && sym->st_shndx != SHN_ABS) {
- unsigned int *crcp;
-
- /* symbol points to the CRC in the ELF object */
- crcp = sym_get_data(info, sym);
- crc = TO_NATIVE(*crcp);
- }
- sym_update_crc(symname + strlen("__crc_"), mod, crc,
- export);
- }
-
switch (sym->st_shndx) {
case SHN_COMMON:
if (strstarts(symname, "__gnu_lto_")) {
@@ -746,11 +754,6 @@ static void handle_symbol(struct module *mod, struct elf_info *info,
}
#endif
- if (is_crc) {
- const char *e = is_vmlinux(mod->name) ?"":".ko";
- warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n",
- symname + strlen("__crc_"), mod->name, e);
- }
mod->unres = alloc_symbol(symname,
ELF_ST_BIND(sym->st_info) == STB_WEAK,
mod->unres);
@@ -2055,14 +2058,18 @@ static void read_symbols(const char *modname)
handle_moddevtable(mod, &info, sym, symname);
}
- /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
symname = remove_dot(info.strtab + sym->st_name);
+ /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
if (strstarts(symname, "__kstrtabns_"))
sym_update_namespace(symname + strlen("__kstrtabns_"),
namespace_from_kstrtabns(&info,
sym));
+
+ if (strstarts(symname, "__crc_"))
+ handle_modversion(mod, &info, sym,
+ symname + strlen("__crc_"));
}
// check for static EXPORT_SYMBOL_* functions && global vars
@@ -2476,7 +2483,7 @@ static void read_dump(const char *fname, unsigned int kernel)
s->kernel = kernel;
s->preloaded = 1;
s->is_static = 0;
- sym_update_crc(symname, mod, crc, export_no(export));
+ sym_set_crc(symname, crc);
sym_update_namespace(symname, namespace);
}
release_file(file, size);
--
2.30.2