[PATCH v10 21/26] ELF: UAPI and Kconfig additions for ELF program properties

From: Yu-cheng Yu
Date: Wed Apr 29 2020 - 18:09:46 EST


Introduce basic ELF definitions relating to the NT_GNU_PROPERTY_TYPE_0
note.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
v10:
- Merge GNU_PROPERTY_X86_FEATURE_1_* from a separate patch.

fs/Kconfig.binfmt | 3 +++
include/linux/elf.h | 8 ++++++++
include/uapi/linux/elf.h | 8 ++++++++
3 files changed, 19 insertions(+)

diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index 62dc4f577ba1..d2cfe0729a73 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -36,6 +36,9 @@ config COMPAT_BINFMT_ELF
config ARCH_BINFMT_ELF_STATE
bool

+config ARCH_USE_GNU_PROPERTY
+ bool
+
config BINFMT_ELF_FDPIC
bool "Kernel support for FDPIC ELF binaries"
default y if !BINFMT_ELF
diff --git a/include/linux/elf.h b/include/linux/elf.h
index e3649b3e970e..459cddcceaac 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -2,6 +2,7 @@
#ifndef _LINUX_ELF_H
#define _LINUX_ELF_H

+#include <linux/types.h>
#include <asm/elf.h>
#include <uapi/linux/elf.h>

@@ -56,4 +57,11 @@ static inline int elf_coredump_extra_notes_write(struct coredump_params *cprm) {
extern int elf_coredump_extra_notes_size(void);
extern int elf_coredump_extra_notes_write(struct coredump_params *cprm);
#endif
+
+/* NT_GNU_PROPERTY_TYPE_0 header */
+struct gnu_property {
+ u32 pr_type;
+ u32 pr_datasz;
+};
+
#endif /* _LINUX_ELF_H */
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index 34c02e4290fe..61251ecabdd7 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -36,6 +36,7 @@ typedef __s64 Elf64_Sxword;
#define PT_LOPROC 0x70000000
#define PT_HIPROC 0x7fffffff
#define PT_GNU_EH_FRAME 0x6474e550
+#define PT_GNU_PROPERTY 0x6474e553

#define PT_GNU_STACK (PT_LOOS + 0x474e551)

@@ -443,4 +444,11 @@ typedef struct elf64_note {
Elf64_Word n_type; /* Content type */
} Elf64_Nhdr;

+/* .note.gnu.property types */
+#define GNU_PROPERTY_X86_FEATURE_1_AND 0xc0000002
+
+/* Bits of GNU_PROPERTY_X86_FEATURE_1_AND */
+#define GNU_PROPERTY_X86_FEATURE_1_IBT 0x00000001
+#define GNU_PROPERTY_X86_FEATURE_1_SHSTK 0x00000002
+
#endif /* _UAPI_LINUX_ELF_H */
--
2.21.0