Commit e9353665 authored by Yury Norov's avatar Yury Norov Committed by Chen Jun
Browse files

arm64: ilp32: introduce ilp32-specific sigframe and ucontext 

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

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



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

ILP32 uses AARCH32 compat structures and syscall handlers for signals. But
ILP32 rt_sigframe and ucontext structures differ from both LP64 and AARCH32.
>From software point of view ILP32 is typical 32-bit compat ABI, and from
hardware point of view, it's just like LP64.

struct rt_sigframe defined in this patch in
arch/arm64/kernel/signal_ilp32.c redefines one in
arch/arm64/kernel/signal.c. And functions located in
arch/arm64/include/signal_common.h pick up new structure to generate the
code suitable for ILP32.

Signed-off-by: default avatarYury Norov <ynorov@caviumnetworks.com>
Signed-off-by: default avatarYury Norov <ynorov@marvell.com>
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 47648303

arch/arm64/include/asm/signal_ilp32.h

0 → 100644
+23 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */



#ifndef __ASM_SIGNAL_ILP32_H

#define __ASM_SIGNAL_ILP32_H



#ifdef CONFIG_ARM64_ILP32



#include <linux/compat.h>



int ilp32_setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set,

			  struct pt_regs *regs);



#else



static inline int ilp32_setup_rt_frame(int usig, struct ksignal *ksig,

					sigset_t *set, struct pt_regs *regs)

{

	return -ENOSYS;

}



#endif /* CONFIG_ARM64_ILP32 */



#endif /* __ASM_SIGNAL_ILP32_H */

arch/arm64/kernel/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -29,7 +29,8 @@ 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

obj-$(CONFIG_ARM64_ILP32)		+= binfmt_ilp32.o sys_ilp32.o

obj-$(CONFIG_ARM64_ILP32)		+= binfmt_ilp32.o sys_ilp32.o 		\

					   signal_ilp32.o

obj-$(CONFIG_COMPAT)		+= sys32_common.o signal32_common.o

obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace.o entry-ftrace.o

obj-$(CONFIG_MODULES)			+= module.o

arch/arm64/kernel/signal.c

+3 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#include <asm/signal32.h>

#include <asm/traps.h>

#include <asm/vdso.h>

#include <asm/signal_ilp32.h>



#define get_sigset(s, m) __copy_from_user(s, m, sizeof(*s))

#define put_sigset(s, m) __copy_to_user(m, s, sizeof(*s))
@@ -591,6 +592,8 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) 
			ret = a32_setup_rt_frame(usig, ksig, oldset, regs);

		else

			ret = a32_setup_frame(usig, ksig, oldset, regs);

	} else if (is_ilp32_compat_task()) {

		ret = ilp32_setup_rt_frame(usig, ksig, oldset, regs);

	} else {

		ret = setup_rt_frame(usig, ksig, oldset, regs);

	}

arch/arm64/kernel/signal_ilp32.c

0 → 100644
+67 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



/*

 * Copyright (C) 1995-2009 Russell King

 * Copyright (C) 2012 ARM Ltd.

 * Copyright (C) 2018 Cavium Networks.

 * Yury Norov <ynorov@caviumnetworks.com>

 */



#include <linux/compat.h>

#include <linux/signal.h>

#include <linux/syscalls.h>



#include <asm/fpsimd.h>

#include <asm/unistd.h>

#include <asm/ucontext.h>

#include <asm/vdso.h>



#include <asm/signal_ilp32.h>

#include <asm/signal32_common.h>



#define get_sigset(s, m) get_sigset_t(s, m)

#define put_sigset(s, m) put_sigset_t(m, s)



#define restore_altstack(stack) compat_restore_altstack(stack)

#define __save_altstack(stack, sp) __compat_save_altstack(stack, sp)

#define copy_siginfo_to_user(frame_info, ksig_info) \

		copy_siginfo_to_user32(frame_info, ksig_info)



#define setup_return(regs, ka, user_layout, usig)			\

{									\

	__setup_return(regs, ka, user_layout, usig);			\

	regs->regs[30] =						\

		(unsigned long)VDSO_SYMBOL(current->mm->context.vdso,	\

						    sigtramp_ilp32);	\

}



struct ilp32_ucontext {

	u32		uc_flags;

	u32		uc_link;

	compat_stack_t	uc_stack;

	compat_sigset_t	uc_sigmask;

	/* glibc uses a 1024-bit sigset_t */

	__u8		__unused[1024 / 8 - sizeof(compat_sigset_t)];

	/* last for future expansion */

	struct sigcontext uc_mcontext;

};



struct rt_sigframe {

	struct compat_siginfo info;

	struct ilp32_ucontext uc;

};



#include <asm/signal_common.h>



COMPAT_SYSCALL_DEFINE0(ilp32_rt_sigreturn)

{

	struct pt_regs *regs = current_pt_regs();



	return __sys_rt_sigreturn(regs);

}



int ilp32_setup_rt_frame(int usig, struct ksignal *ksig,

			  sigset_t *set, struct pt_regs *regs)

{

	return __setup_rt_frame(usig, ksig, set, regs);

}

arch/arm64/kernel/sys_ilp32.c

+6 −0
Original line number Diff line number Diff line
@@ -55,6 +55,12 @@ 
#define __arm64_compat_sys_msgctl		__arm64_compat_sys_old_msgctl

#define __arm64_compat_sys_shmctl		__arm64_compat_sys_old_shmctl



/*

 * Using custom wrapper for rt_sigreturn() to handle custom

 * struct rt_sigframe.

 */

#define __arm64_compat_sys_rt_sigreturn		__arm64_compat_sys_ilp32_rt_sigreturn



/*

 * Wrappers to pass the pt_regs argument.

 */