[RFC PATCH v9 23/27] ELF: Introduce arch_setup_elf_property()

Yu-cheng Yu
2020-02-05T18:21:29Z

An ELF file's .note.gnu.property indicates architecture features of the
file. These features are extracted earlier and stored in the struct
'arch_elf_state'. Introduce arch_setup_elf_property() to setup and enable
these features. The first use-case of this function is Shadow Stack and
Indirect Branch Tracking, which are introduced later.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
fs/binfmt_elf.c | 4 ++++
include/linux/elf.h | 6 ++++++
2 files changed, 10 insertions(+)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 054446f93442..56fe6cd437fe 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1213,6 +1213,10 @@ static int load_elf_binary(struct linux_binprm *bprm)

set_binfmt(&elf_format);

+ retval = arch_setup_elf_property(&arch_state);
+ if (retval < 0)
+ goto out;
+
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
retval = arch_setup_additional_pages(bprm, !!interpreter);
if (retval < 0)
diff --git a/include/linux/elf.h b/include/linux/elf.h
index 7bdc6da160c7..81f2161fa4a8 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -78,9 +78,15 @@ static inline int arch_parse_elf_property(u32 type, const void *data,
{
return 0;
}
+
+static inline int arch_setup_elf_property(struct arch_elf_state *arch)
+{
+ return 0;
+}
#else
extern int arch_parse_elf_property(u32 type, const void *data, size_t datasz,
bool compat, struct arch_elf_state *arch);
+extern int arch_setup_elf_property(struct arch_elf_state *arch);
#endif

#endif /* _LINUX_ELF_H */
--
2.21.0