* Sam Ravnborg <sam@ravnborg.org> wrote:
btw., please add a .config option to trigger the -fno-unit-at-a-time
flags. Something like CONFIG_SECTION_ERRORS=y - plus perhaps combine it
with the patch below that turns such section bugs into detectable build
errors. A distro does not want to build a kernel that could potentially
corrupt kernel memory. (it's a security risk as well.) If we make the
err=1 dependent on CONFIG_SECTION_ERRORS then we'll have this
configurable.
Ingo
---------------->
Subject: x86: link mismatch error
From: Ingo Molnar <mingo@elte.hu>
turn the build warning into a build error.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
scripts/mod/modpost.c | 63 ++++++++++++++++++++++++++++++--------------------
1 file changed, 39 insertions(+), 24 deletions(-)
Index: linux/scripts/mod/modpost.c
===================================================================
--- linux.orig/scripts/mod/modpost.c
+++ linux/scripts/mod/modpost.c
@@ -863,8 +863,8 @@ static void find_symbols_between(struct
* Try to find symbols near it so user can find it.
* Check whitelist before warning - it may be a false positive.
**/
-static void warn_sec_mismatch(const char *modname, const char *fromsec,
- struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)
+static int error_sec_mismatch(const char *modname, const char *fromsec,
+ struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)
{
const char *refsymname = "";
Elf_Sym *before, *after;
@@ -874,6 +874,7 @@ static void warn_sec_mismatch(const char
const char *secstrings = (void *)hdr +
sechdrs[hdr->e_shstrndx].sh_offset;
const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name;
+ int err = 0;
find_symbols_between(elf, r.r_offset, fromsec, &before, &after);
@@ -885,32 +886,38 @@ static void warn_sec_mismatch(const char
if (secref_whitelist(modname, secname, fromsec,
before ? elf->strtab + before->st_name : "",
refsymname))
- return;
+ goto out;
if (before && after) {
- warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
+ merror("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
"(between '%s' and '%s')\n",
modname, fromsec, (unsigned long long)r.r_offset,
secname, refsymname,
elf->strtab + before->st_name,
elf->strtab + after->st_name);
+ err = 1;
} else if (before) {
- warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
+ merror("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
"(after '%s')\n",
modname, fromsec, (unsigned long long)r.r_offset,
secname, refsymname,
elf->strtab + before->st_name);
+ err = 1;
} else if (after) {
- warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
+ merror("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
"before '%s' (at offset -0x%llx)\n",
modname, fromsec, (unsigned long long)r.r_offset,
secname, refsymname,
elf->strtab + after->st_name);
+ err = 1;
} else {
- warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",
+ merror("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",
modname, fromsec, (unsigned long long)r.r_offset,
secname, refsymname);
+ err = 1;
}
+out:
+ return err;
}
static unsigned int *reloc_location(struct elf_info *elf,
@@ -997,10 +1004,10 @@ static int addend_mips_rel(struct elf_in
* to find all references to a section that reference a section that will
* be discarded and warns about it.
**/
-static void check_sec_ref(struct module *mod, const char *modname,
- struct elf_info *elf,
- int section(const char*),
- int section_ref_ok(const char *))
+static int check_sec_ref(struct module *mod, const char *modname,
+ struct elf_info *elf,
+ int section(const char*),
+ int section_ref_ok(const char *))
{
int i;
Elf_Sym *sym;
@@ -1049,9 +1056,11 @@ static void check_sec_ref(struct module
secname = secstrings +
sechdrs[sym->st_shndx].sh_name;
- if (section(secname))
- warn_sec_mismatch(modname, name,
- elf, sym, r);
+ if (section(secname)) {
+ if (error_sec_mismatch(modname, name,
+ elf, sym, r))
+ return 1;
+ }
}
} else if (sechdrs[i].sh_type == SHT_REL) {
Elf_Rel *rel;
@@ -1100,12 +1109,15 @@ static void check_sec_ref(struct module
secname = secstrings +
sechdrs[sym->st_shndx].sh_name;
- if (section(secname))
- warn_sec_mismatch(modname, name,
- elf, sym, r);
+ if (section(secname)) {
+ if (error_sec_mismatch(modname, name,
+ elf, sym, r))
+ return 1;
+ }
}
}
}
+ return 0;
}
/*
@@ -1249,7 +1261,7 @@ static int exit_section_ref_ok(const cha
return 0;
}
-static void read_symbols(char *modname)
+static int read_symbols(char *modname)
{
const char *symname;
char *version;
@@ -1257,9 +1269,10 @@ static void read_symbols(char *modname)
struct module *mod;
struct elf_info info = { };
Elf_Sym *sym;
+ int err = 0;
if (!parse_elf(&info, modname))
- return;
+ goto out;
mod = new_module(modname);
@@ -1289,8 +1302,8 @@ static void read_symbols(char *modname)
handle_moddevtable(mod, &info, sym, symname);
}
if (is_vmlinux(modname) && vmlinux_section_warnings) {
- check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
- check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
+ err |= check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
+ err |= check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
}
version = get_modinfo(info.modinfo, info.modinfo_len, "version");
@@ -1309,6 +1322,8 @@ static void read_symbols(char *modname)
* important anyhow */
if (modversions)
mod->unres = alloc_symbol("struct_module", 0, mod->unres);
+out:
+ return err;
}
#define SZ 500
@@ -1693,8 +1708,10 @@ int main(int argc, char **argv)
if (module_read)
read_dump(module_read, 0);
+ err = 0;
+
while (optind < argc) {
- read_symbols(argv[optind++]);
+ err |= read_symbols(argv[optind++]);
}
for (mod = modules; mod; mod = mod->next) {
@@ -1703,8 +1720,6 @@ int main(int argc, char **argv)
check_exports(mod);
}
- err = 0;
-
for (mod = modules; mod; mod = mod->next) {
if (mod->skip)
continue;
--
