linux-stable/include/linux/elf.h
Dave Martin fe0f67660e elf: Allow arch to tweak initial mmap prot flags
An arch may want to tweak the mmap prot flags for an
ELFexecutable's initial mappings.  For example, arm64 is going to
need to add PROT_BTI for executable pages in an ELF process whose
executable is marked as using Branch Target Identification (an
ARMv8.5-A control flow integrity feature).

So that this can be done in a generic way, add a hook
arch_elf_adjust_prot() to modify the prot flags as desired: arches
can select CONFIG_HAVE_ELF_PROT and implement their own backend
where necessary.

By default, leave the prot flags unchanged.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-16 17:19:48 +00:00

102 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_ELF_H
#define _LINUX_ELF_H
#include <linux/types.h>
#include <asm/elf.h>
#include <uapi/linux/elf.h>
#ifndef elf_read_implies_exec
/* Executables for which elf_read_implies_exec() returns TRUE will
have the READ_IMPLIES_EXEC personality flag set automatically.
Override in asm/elf.h as needed. */
# define elf_read_implies_exec(ex, have_pt_gnu_stack) 0
#endif
#ifndef SET_PERSONALITY
#define SET_PERSONALITY(ex) \
set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
#endif
#ifndef SET_PERSONALITY2
#define SET_PERSONALITY2(ex, state) \
SET_PERSONALITY(ex)
#endif
#define ELF32_GNU_PROPERTY_ALIGN 4
#define ELF64_GNU_PROPERTY_ALIGN 8
#if ELF_CLASS == ELFCLASS32
extern Elf32_Dyn _DYNAMIC [];
#define elfhdr elf32_hdr
#define elf_phdr elf32_phdr
#define elf_shdr elf32_shdr
#define elf_note elf32_note
#define elf_addr_t Elf32_Off
#define Elf_Half Elf32_Half
#define Elf_Word Elf32_Word
#define ELF_GNU_PROPERTY_ALIGN ELF32_GNU_PROPERTY_ALIGN
#else
extern Elf64_Dyn _DYNAMIC [];
#define elfhdr elf64_hdr
#define elf_phdr elf64_phdr
#define elf_shdr elf64_shdr
#define elf_note elf64_note
#define elf_addr_t Elf64_Off
#define Elf_Half Elf64_Half
#define Elf_Word Elf64_Word
#define ELF_GNU_PROPERTY_ALIGN ELF64_GNU_PROPERTY_ALIGN
#endif
/* Optional callbacks to write extra ELF notes. */
struct file;
struct coredump_params;
#ifndef ARCH_HAVE_EXTRA_ELF_NOTES
static inline int elf_coredump_extra_notes_size(void) { return 0; }
static inline int elf_coredump_extra_notes_write(struct coredump_params *cprm) { return 0; }
#else
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:
* Keep this internal until/unless there is an agreed UAPI definition.
* pr_type values (GNU_PROPERTY_*) are public and defined in the UAPI header.
*/
struct gnu_property {
u32 pr_type;
u32 pr_datasz;
};
struct arch_elf_state;
#ifndef CONFIG_ARCH_USE_GNU_PROPERTY
static inline int arch_parse_elf_property(u32 type, const void *data,
size_t datasz, bool compat,
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);
#endif
#ifdef CONFIG_ARCH_HAVE_ELF_PROT
int arch_elf_adjust_prot(int prot, const struct arch_elf_state *state,
bool has_interp, bool is_interp);
#else
static inline int arch_elf_adjust_prot(int prot,
const struct arch_elf_state *state,
bool has_interp, bool is_interp)
{
return prot;
}
#endif
#endif /* _LINUX_ELF_H */