Re: [PATCH 12/18] arm64: ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it

[Bamvor Jian Zhang <bamvor.zhangjian@huawei.com>]

Hi, Yury

On 08/17/2016 07:46 PM, Yury Norov wrote:
> From: Andrew Pinski <apinski@cavium.com>
> 
[...]
> diff --git a/arch/arm64/kernel/sys_ilp32.c b/arch/arm64/kernel/sys_ilp32.c
> new file mode 100644
> index 0000000..10fc0ca
> --- /dev/null
> +++ b/arch/arm64/kernel/sys_ilp32.c
> @@ -0,0 +1,86 @@
> +/*
> + * AArch64- ILP32 specific system calls implementation
> + *
> + * Copyright (C) 2016 Cavium Inc.
> + * Author: Andrew Pinski <apinski@cavium.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#define __SYSCALL_COMPAT
> +
> +#include <linux/compiler.h>
> +#include <linux/errno.h>
> +#include <linux/fs.h>
> +#include <linux/mm.h>
> +#include <linux/msg.h>
> +#include <linux/export.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/syscalls.h>
> +#include <linux/compat.h>
> +#include <asm-generic/syscalls.h>
> +
> +/*
> + * Using aarch32 syscall handlerss where off_t is passed.
> + */
> +#define compat_sys_fadvise64_64		compat_sys_fadvise64_64_wrapper
> +#define compat_sys_fallocate		compat_sys_fallocate_wrapper
> +#define compat_sys_fcntl64		sys_fcntl
> +#define compat_sys_ftruncate64		compat_sys_ftruncate64_wrapper
> +#define compat_sys_pread64		compat_sys_pread64_wrapper
> +#define compat_sys_pwrite64		compat_sys_pwrite64_wrapper
> +#define compat_sys_readahead		compat_sys_readahead_wrapper
> +#define compat_sys_shmat		sys_shmat
> +#define compat_sys_sync_file_range	compat_sys_sync_file_range2_wrapper
> +#define compat_sys_truncate64		compat_sys_truncate64_wrapper
When we test sync_file_range with our own testcase, we found that the parameter
sequence is not correct for sync_file_range2 because glibc think kernel use
the sync_file_range. So, in this patch we force to sync_file_range2.

Is it make sense to you?

Regards

Bamvor

From e730e4db23bca4dd0ff6bcca0bc4c04e5c13b5c7 Mon Sep 17 00:00:00 2001
From: Bamvor Jian Zhang <bamvor.zhangjian@huawei.com>
Date: Sat, 27 Aug 2016 12:26:31 +0800
Subject: [PATCH] arm64:ilp32: force sync_file_range2

Define __ARCH_WANT_SYNC_FILE_RANGE2 in order to select correct
sync_file_range parameters sequence in glibc and kernel.

Tested-by: Jianguo Chen <chenjianguo3@huawei.com>
Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@huawei.com>
---
 arch/arm64/include/uapi/asm/unistd.h | 5 +++++
 arch/arm64/kernel/sys_ilp32.c        | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/uapi/asm/unistd.h b/arch/arm64/include/uapi/asm/unistd.h
index 043d17a..78bea1d 100644
--- a/arch/arm64/include/uapi/asm/unistd.h
+++ b/arch/arm64/include/uapi/asm/unistd.h
@@ -16,4 +16,9 @@

 #define __ARCH_WANT_RENAMEAT

+/* We need to make sure it works for both userspace and kernel(sys_ilp32.c) */
+#if defined(__ILP32__) || defined(__SYSCALL_COMPAT)
+#define __ARCH_WANT_SYNC_FILE_RANGE2
+#endif
+
 #include <asm-generic/unistd.h>
diff --git a/arch/arm64/kernel/sys_ilp32.c b/arch/arm64/kernel/sys_ilp32.c
index 10fc0ca..13c9c9d 100644
--- a/arch/arm64/kernel/sys_ilp32.c
+++ b/arch/arm64/kernel/sys_ilp32.c
@@ -42,7 +42,7 @@
 #define compat_sys_pwrite64            compat_sys_pwrite64_wrapper
 #define compat_sys_readahead           compat_sys_readahead_wrapper
 #define compat_sys_shmat               sys_shmat
-#define compat_sys_sync_file_range     compat_sys_sync_file_range2_wrapper
+#define compat_sys_sync_file_range2    compat_sys_sync_file_range2_wrapper
 #define compat_sys_truncate64          compat_sys_truncate64_wrapper
 #define sys_mmap2                      compat_sys_mmap2_wrapper
 #define sys_ptrace                     compat_sys_ptrace
-- 
1.8.4.5

> +#define sys_mmap2			compat_sys_mmap2_wrapper
> +#define sys_ptrace			compat_sys_ptrace
> +
> +/*
> + * Use non-compat syscall handlers where rlimit, stat and statfs
> + * structure pointers are passed, as their layout is identical to LP64.
> + */
> +#define compat_sys_fstatfs64		sys_fstatfs
> +#define compat_sys_statfs64		sys_statfs
> +#define sys_fstat64			sys_newfstat
> +#define sys_fstatat64			sys_newfstatat
> +#define compat_sys_getrlimit		sys_getrlimit
> +#define compat_sys_setrlimit		sys_setrlimit
> +
> +asmlinkage long compat_sys_fadvise64_64_wrapper(void);
> +asmlinkage long compat_sys_fallocate_wrapper(void);
> +asmlinkage long compat_sys_ftruncate64_wrapper(void);
> +asmlinkage long compat_sys_mmap2_wrapper(void);
> +asmlinkage long compat_sys_pread64_wrapper(void);
> +asmlinkage long compat_sys_pwrite64_wrapper(void);
> +asmlinkage long compat_sys_readahead_wrapper(void);
> +asmlinkage long compat_sys_sync_file_range2_wrapper(void);
> +asmlinkage long compat_sys_truncate64_wrapper(void);
> +
> +asmlinkage long ilp32_sys_rt_sigreturn_wrapper(void);
> +#define compat_sys_rt_sigreturn        ilp32_sys_rt_sigreturn_wrapper
> +
> +#include <asm/syscall.h>
> +
> +#undef __SYSCALL
> +#define __SYSCALL(nr, sym)	[nr] = sym,
> +
> +/*
> + * The sys_call_ilp32_table array must be 4K aligned to be accessible from
> + * kernel/entry.S.
> + */
> +void *sys_call_ilp32_table[__NR_syscalls] __aligned(4096) = {
> +	[0 ... __NR_syscalls - 1] = sys_ni_syscall,
> +#include <asm/unistd.h>
> +};
>