module: rename __kstrtab_ns_* to __kstrtabns_* to avoid symbol conflict
authorMasahiro Yamada <yamada.masahiro@socionext.com>
Thu, 3 Oct 2019 07:58:23 +0000 (16:58 +0900)
committerJessica Yu <jeyu@kernel.org>
Mon, 7 Oct 2019 16:25:06 +0000 (18:25 +0200)
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 starting
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 duplicated "__kstrtab_ns_capable".

To ensure the uniqueness, rename "__kstrtab_ns_*" to "__kstrtabns_*".

Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
include/linux/export.h

index 0695d4e847d9feb749667fa7217dce6268ee083e..621158ecd2e2146c697e3ab7cc7b0a3dd6bbc714 100644 (file)
@@ -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)