Commit f1955f2f authored by Yury Norov's avatar Yury Norov Committed by Chen Jun
Browse files

arm64: introduce binfmt_elf32.c 

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

Reference: https://github.com/norov/linux/commits/ilp32-5.2



--------------------------------

As we support more than one compat formats, it looks more reasonable
to not use fs/compat_binfmt.c. Custom binfmt_elf32.c allows to move aarch32
specific definitions there and make code more maintainable and readable.

Signed-off-by: default avatarYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: default avatarYury Norov <ynorov@marvell.com>

 Conflicts:
	arch/arm64/include/asm/elf.h
	arch/arm64/kernel/Makefile

Signed-off-by: default avatarXiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: default avatarXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: default avatarChen Jun <chenjun102@huawei.com>
parent 88f4e81b

arch/arm64/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -1217,7 +1217,6 @@ config ARM64_TAGGED_ADDR_ABI 
menuconfig AARCH32_EL0

	bool "Kernel support for 32-bit EL0"

	depends on ARM64_4K_PAGES || EXPERT

	select COMPAT_BINFMT_ELF if BINFMT_ELF

	select HAVE_UID16

	select OLD_SIGSUSPEND3

	select COMPAT_OLD_SIGACTION

arch/arm64/include/asm/elf.h

+5 −22
Original line number Diff line number Diff line
@@ -206,29 +206,14 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm, 


/* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */

#define COMPAT_ELF_ET_DYN_BASE		0x000400000UL

#endif /*CONFIG_COMPAT */



#ifdef CONFIG_AARCH32_EL0

/* AArch32 registers. */

#define COMPAT_ELF_NGREG		18

typedef unsigned int			compat_elf_greg_t;

typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];



/* AArch32 EABI. */

#define EF_ARM_EABI_MASK		0xff000000

#define compat_elf_check_arch(x)	(system_supports_32bit_el0() && \

					 ((x)->e_machine == EM_ARM) && \

					 ((x)->e_flags & EF_ARM_EABI_MASK))



#define compat_start_thread		compat_start_thread

/*

 * Unlike the native SET_PERSONALITY macro, the compat version maintains

 * READ_IMPLIES_EXEC across an execve() since this is the behaviour on

 * arch/arm/.

 */

#define COMPAT_SET_PERSONALITY(ex)					\

({									\

	clear_thread_flag(TIF_32BIT_AARCH64);				\

	set_thread_flag(TIF_32BIT);					\

 })

#ifdef CONFIG_COMPAT_VDSO

#define COMPAT_ARCH_DLINFO						\

do {									\
@@ -244,12 +229,10 @@ do { \ 
#else

#define COMPAT_ARCH_DLINFO

#endif



extern int aarch32_setup_additional_pages(struct linux_binprm *bprm,

				      int uses_interp);

#define compat_arch_setup_additional_pages \

					aarch32_setup_additional_pages



#endif /* CONFIG_COMPAT */

#endif /* CONFIG_AARCH32_EL0 */



struct arch_elf_state {

	int flags;

arch/arm64/include/asm/hwcap.h

+0 −2
Original line number Diff line number Diff line
@@ -114,8 +114,6 @@ 
#define ELF_HWCAP2		cpu_get_elf_hwcap2()



#ifdef CONFIG_AARCH32_EL0

#define COMPAT_ELF_HWCAP	(compat_elf_hwcap)

#define COMPAT_ELF_HWCAP2	(compat_elf_hwcap2)

extern unsigned int compat_elf_hwcap, compat_elf_hwcap2;

#endif

arch/arm64/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ OBJCOPYFLAGS := --prefix-symbols=__efistub_ 
$(obj)/%.stub.o: $(obj)/%.o FORCE

	$(call if_changed,objcopy)



obj-$(CONFIG_AARCH32_EL0)			+= sys32.o signal32.o			\

obj-$(CONFIG_AARCH32_EL0)			+= binfmt_elf32.o sys32.o signal32.o			\

					   sys_compat.o

obj-$(CONFIG_AARCH32_EL0)			+= sigreturn32.o

obj-$(CONFIG_KUSER_HELPERS)		+= kuser32.o

arch/arm64/kernel/binfmt_elf32.c

0 → 100644
+34 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



/*

 * Support for AArch32 Linux ELF binaries.

 */



/* AArch32 EABI. */

#define EF_ARM_EABI_MASK		0xff000000



#define compat_start_thread		compat_start_thread

/*

 * Unlike the native SET_PERSONALITY macro, the compat version inherits

 * READ_IMPLIES_EXEC across a fork() since this is the behaviour on

 * arch/arm/.

 */

#define COMPAT_SET_PERSONALITY(ex)					\

({									\

	clear_thread_flag(TIF_32BIT_AARCH64);				\

	set_thread_flag(TIF_32BIT);					\

})



#define COMPAT_ARCH_DLINFO

#define COMPAT_ELF_HWCAP		(compat_elf_hwcap)

#define COMPAT_ELF_HWCAP2		(compat_elf_hwcap2)



#define compat_arch_setup_additional_pages \

					aarch32_setup_additional_pages



/* AArch32 EABI. */

#define compat_elf_check_arch(x)	(system_supports_32bit_el0() && \

					 ((x)->e_machine == EM_ARM) && \

					 ((x)->e_flags & EF_ARM_EABI_MASK))



#include "../../../fs/compat_binfmt_elf.c"