Le 18/02/2022 à 22:25, Aaron Tomlin a écrit : > No functional change. > > This patch migrates code that makes module text > and rodata memory read-only and non-text memory > non-executable from core module code into > kernel/module/strict_rwx.c. > > Signed-off-by: Aaron Tomlin <atomlin@xxxxxxxxxx> > --- > kernel/module/Makefile | 1 + > kernel/module/internal.h | 38 +++++++++++++++ > kernel/module/main.c | 99 +------------------------------------- > kernel/module/strict_rwx.c | 84 ++++++++++++++++++++++++++++++++ > 4 files changed, 125 insertions(+), 97 deletions(-) > create mode 100644 kernel/module/strict_rwx.c > > diff --git a/kernel/module/Makefile b/kernel/module/Makefile > index 6fb21ebe1aa3..3f48343636ff 100644 > --- a/kernel/module/Makefile > +++ b/kernel/module/Makefile > @@ -10,4 +10,5 @@ obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o > obj-$(CONFIG_LIVEPATCH) += livepatch.o > ifdef CONFIG_MODULES > obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o > +obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o > endif > diff --git a/kernel/module/internal.h b/kernel/module/internal.h > index 57a715454c9e..f4b7e123d625 100644 > --- a/kernel/module/internal.h > +++ b/kernel/module/internal.h > @@ -20,6 +20,17 @@ > /* Maximum number of characters written by module_flags() */ > #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) > > +/* > + * Modules' sections will be aligned on page boundaries > + * to ensure complete separation of code and data, but > + * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y > + */ > +#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX > +# define debug_align(X) PAGE_ALIGN(X) > +#else > +# define debug_align(X) (X) > +#endif > + > extern struct mutex module_mutex; > extern struct list_head modules; > > @@ -126,3 +137,30 @@ static inline struct module *mod_find(unsigned long addr) > return NULL; > } > #endif /* CONFIG_MODULES_TREE_LOOKUP */ > + > +#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX > +void frob_text(const struct module_layout *layout, int (*set_memory)(unsigned long start, > + int num_pages)); > +#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ > + > +#ifdef CONFIG_STRICT_MODULE_RWX > +void frob_rodata(const struct module_layout *layout, > + int (*set_memory)(unsigned long start, int num_pages)); > +void frob_ro_after_init(const struct module_layout *layout, > + int (*set_memory)(unsigned long start, int num_pages)); > +void frob_writable_data(const struct module_layout *layout, > + int (*set_memory)(unsigned long start, int num_pages)); Those three frob_() functions are only used in strict_rwx.c, they should not appear in internal.h and should be static in strict_rwx.c > +void module_enable_ro(const struct module *mod, bool after_init); > +void module_enable_nx(const struct module *mod); > +int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, > + char *secstrings, struct module *mod); > + > +#else /* !CONFIG_STRICT_MODULE_RWX */ > +static void module_enable_nx(const struct module *mod) { } > +static void module_enable_ro(const struct module *mod, bool after_init) {} > +static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, > + char *secstrings, struct module *mod) Those three must be static inline > +{ > + return 0; > +} > +#endif /* CONFIG_STRICT_MODULE_RWX */ Christophe