From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: linux-kbuild@vger.kernel.org
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
linux-kernel@vger.kernel.org
Subject: [PATCH 4/6] modpost: stop symbol preloading for modversion CRC
Date: Fri, 15 Nov 2019 02:42:24 +0900 [thread overview]
Message-ID: <20191114174226.7201-4-yamada.masahiro@socionext.com> (raw)
In-Reply-To: <20191114174226.7201-1-yamada.masahiro@socionext.com>
It is complicated to add mocked-up symbols to pre-handle CRC.
Handle CRC after all the export symbols in the relevant module
are registered.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
scripts/mod/modpost.c | 64 +++++++++++++++++++++++--------------------
1 file changed, 35 insertions(+), 29 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 6735ae3da4c2..73bdf27c41fe 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];
@@ -410,15 +410,15 @@ 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, const struct module *mod,
+ 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;
+ warn("%s: '__crc_%s' is invalid use. __crc_* is reserved for modversion\n",
+ mod->name, name);
+ return;
}
s->crc = crc;
s->crc_valid = 1;
@@ -683,12 +683,34 @@ 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, mod, 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 +719,6 @@ 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 +753,6 @@ 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);
@@ -2063,6 +2065,10 @@ static void read_symbols(const char *modname)
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 +2482,7 @@ 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, mod, crc);
sym_update_namespace(symname, namespace);
}
release_file(file, size);
--
2.17.1
next prev parent reply other threads:[~2019-11-14 17:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-14 17:42 [PATCH 1/6] modpost: add a helper to get data pointed by a symbol Masahiro Yamada
2019-11-14 17:42 ` [PATCH 2/6] modpost: refactor namespace_from_kstrtabns() to not hard-code section name Masahiro Yamada
2019-11-14 17:46 ` Masahiro Yamada
2019-11-14 17:42 ` [PATCH 3/6] modpost: rename handle_modversions() to handle_symbol() Masahiro Yamada
2019-11-14 17:42 ` Masahiro Yamada [this message]
2019-11-23 6:42 ` [PATCH 4/6] modpost: stop symbol preloading for modversion CRC Masahiro Yamada
2019-11-14 17:42 ` [PATCH 5/6] modpost: do not set ->preloaded for symbols from Module.symvers Masahiro Yamada
2019-11-14 17:42 ` [PATCH 6/6] modpost: respect the previous export when 'exported twice' is warned Masahiro Yamada
2019-11-14 17:45 ` [PATCH 1/6] modpost: add a helper to get data pointed by a symbol Masahiro Yamada
2019-11-23 7:22 ` Masahiro Yamada
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