On Fri, Sep 27, 2019 at 06:35:59PM +0900, Masahiro Yamada wrote:
The module namespace produces __strtab_ns_<sym> symbols to store
namespace strings, but it does not guarantee the name uniqueness.
This is a potential problem because we have exported symbols staring
with "ns_".
For example, kernel/capability.c exports the following symbols:
EXPORT_SYMBOL(ns_capable);
EXPORT_SYMBOL(capable);
Assume a situation where those are converted as follows:
EXPORT_SYMBOL_NS(ns_capable, some_namespace);
EXPORT_SYMBOL_NS(capable, some_namespace);
The former expands to "__kstrtab_ns_capable" and "__kstrtab_ns_ns_capable",
and the latter to "__kstrtab_capable" and "__kstrtab_ns_capable".
Then, we have the duplication for "__kstrtab_ns_capable".
To ensure the uniqueness, rename "__kstrtab_ns_*" to "__kstrtabns_*".
Again, thanks for catching this!
Reviewed-by: Matthias Maennich <maenn...@google.com>
Cheers,
Matthias
Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com>
---
include/linux/export.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/export.h b/include/linux/export.h
index 0695d4e847d9..621158ecd2e2 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -55,7 +55,7 @@ extern struct module __this_module;
"__ksymtab_" #ns NS_SEPARATOR #sym ": \n" \
" .long " #sym "- . \n" \
" .long __kstrtab_" #sym "- . \n" \
- " .long __kstrtab_ns_" #sym "- . \n" \
+ " .long __kstrtabns_" #sym "- . \n"
\
" .previous \n")
#define __KSYMTAB_ENTRY(sym, sec) \
@@ -79,7 +79,7 @@ struct kernel_symbol {
asm("__ksymtab_" #ns NS_SEPARATOR #sym) \
__attribute__((section("___ksymtab" sec "+" #sym), used)) \
__aligned(sizeof(void *)) \
- = { (unsigned long)&sym, __kstrtab_##sym, __kstrtab_ns_##sym }
+ = { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym }
#define __KSYMTAB_ENTRY(sym, sec) \
static const struct kernel_symbol __ksymtab_##sym \
@@ -112,7 +112,7 @@ struct kernel_symbol {
/* For every exported symbol, place a struct in the __ksymtab section */
#define ___EXPORT_SYMBOL_NS(sym, sec, ns) \
___export_symbol_common(sym, sec); \
- static const char __kstrtab_ns_##sym[] \
+ static const char __kstrtabns_##sym[] \
__attribute__((section("__ksymtab_strings"), used, aligned(1))) \
= #ns; \
__KSYMTAB_ENTRY_NS(sym, sec, ns)
--
2.17.1
