Re: [PATCH V9 11/20] riscv: compat: syscall: Add compat_sys_call_table implementation

Guo Ren
2022-03-23T13:41:01Z

Hi Palmer & Arnd,

Fixup fadvise64_64 arguments problem.

On Tue, Mar 22, 2022 at 10:41 PM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> Implement compat sys_call_table and some system call functions:
> truncate64, ftruncate64, fallocate, pread64, pwrite64,
> sync_file_range, readahead, fadvise64_64 which need argument
> translation.
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
> Tested-by: Heiko Stuebner <heiko@sntech.de>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> ---
> arch/riscv/include/asm/syscall.h | 1 +
> arch/riscv/include/asm/unistd.h | 11 +++++++
> arch/riscv/include/uapi/asm/unistd.h | 2 +-
> arch/riscv/kernel/Makefile | 1 +
> arch/riscv/kernel/compat_syscall_table.c | 19 ++++++++++++
> arch/riscv/kernel/sys_riscv.c | 6 ++--
> fs/open.c | 24 +++++++++++++++
> fs/read_write.c | 16 ++++++++++
> fs/sync.c | 9 ++++++
> include/asm-generic/compat.h | 7 +++++
> include/linux/compat.h | 37 ++++++++++++++++++++++++
> mm/fadvise.c | 11 +++++++
> mm/readahead.c | 7 +++++
> 13 files changed, 148 insertions(+), 3 deletions(-)
> create mode 100644 arch/riscv/kernel/compat_syscall_table.c
>
> diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
> index 7ac6a0e275f2..384a63b86420 100644
> --- a/arch/riscv/include/asm/syscall.h
> +++ b/arch/riscv/include/asm/syscall.h
> @@ -16,6 +16,7 @@
>
> /* The array of function pointers for syscalls. */
> extern void * const sys_call_table[];
> +extern void * const compat_sys_call_table[];
>
> /*
> * Only the low 32 bits of orig_r0 are meaningful, so we return int.
> diff --git a/arch/riscv/include/asm/unistd.h b/arch/riscv/include/asm/unistd.h
> index 6c316093a1e5..5ddac412b578 100644
> --- a/arch/riscv/include/asm/unistd.h
> +++ b/arch/riscv/include/asm/unistd.h
> @@ -11,6 +11,17 @@
> #define __ARCH_WANT_SYS_CLONE
> #define __ARCH_WANT_MEMFD_SECRET
>
> +#ifdef CONFIG_COMPAT
> +#define __ARCH_WANT_COMPAT_TRUNCATE64
> +#define __ARCH_WANT_COMPAT_FTRUNCATE64
> +#define __ARCH_WANT_COMPAT_FALLOCATE
> +#define __ARCH_WANT_COMPAT_PREAD64
> +#define __ARCH_WANT_COMPAT_PWRITE64
> +#define __ARCH_WANT_COMPAT_SYNC_FILE_RANGE
> +#define __ARCH_WANT_COMPAT_READAHEAD
> +#define __ARCH_WANT_COMPAT_FADVISE64_64
> +#endif
> +
> #include <uapi/asm/unistd.h>
>
> #define NR_syscalls (__NR_syscalls)
> diff --git a/arch/riscv/include/uapi/asm/unistd.h b/arch/riscv/include/uapi/asm/unistd.h
> index 8062996c2dfd..c9e50eed14aa 100644
> --- a/arch/riscv/include/uapi/asm/unistd.h
> +++ b/arch/riscv/include/uapi/asm/unistd.h
> @@ -15,7 +15,7 @@
> * along with this program. If not, see <https://www.gnu.org/licenses/>.
> */
>
> -#ifdef __LP64__
> +#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
> #define __ARCH_WANT_NEW_STAT
> #define __ARCH_WANT_SET_GET_RLIMIT
> #endif /* __LP64__ */
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index ffc87e76b1dd..3b3e425aadd2 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -68,3 +68,4 @@ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
> obj-$(CONFIG_JUMP_LABEL) += jump_label.o
>
> obj-$(CONFIG_EFI) += efi.o
> +obj-$(CONFIG_COMPAT) += compat_syscall_table.o
> diff --git a/arch/riscv/kernel/compat_syscall_table.c b/arch/riscv/kernel/compat_syscall_table.c
> new file mode 100644
> index 000000000000..651f2b009c28
> --- /dev/null
> +++ b/arch/riscv/kernel/compat_syscall_table.c
> @@ -0,0 +1,19 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#define __SYSCALL_COMPAT
> +
> +#include <linux/compat.h>
> +#include <linux/syscalls.h>
> +#include <asm-generic/mman-common.h>
> +#include <asm-generic/syscalls.h>
> +#include <asm/syscall.h>
> +
> +#undef __SYSCALL
> +#define __SYSCALL(nr, call) [nr] = (call),
> +
> +asmlinkage long compat_sys_rt_sigreturn(void);
> +
> +void * const compat_sys_call_table[__NR_syscalls] = {
> + [0 ... __NR_syscalls - 1] = sys_ni_syscall,
> +#include <asm/unistd.h>
> +};
> diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
> index 12f8a7fce78b..9c0194f176fc 100644
> --- a/arch/riscv/kernel/sys_riscv.c
> +++ b/arch/riscv/kernel/sys_riscv.c
> @@ -33,7 +33,9 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
> {
> return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 0);
> }
> -#else
> +#endif
> +
> +#if defined(CONFIG_32BIT) || defined(CONFIG_COMPAT)
> SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
> unsigned long, prot, unsigned long, flags,
> unsigned long, fd, off_t, offset)
> @@ -44,7 +46,7 @@ SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
> */
> return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12);
> }
> -#endif /* !CONFIG_64BIT */
> +#endif
>
> /*
> * Allows the instruction cache to be flushed from userspace. Despite RISC-V
> diff --git a/fs/open.c b/fs/open.c
> index 9ff2f621b760..b25613f7c0a7 100644
> --- a/fs/open.c
> +++ b/fs/open.c
> @@ -224,6 +224,21 @@ SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length)
> }
> #endif /* BITS_PER_LONG == 32 */
>
> +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_TRUNCATE64)
> +COMPAT_SYSCALL_DEFINE3(truncate64, const char __user *, pathname,
> + compat_arg_u64_dual(length))
> +{
> + return ksys_truncate(pathname, compat_arg_u64_glue(length));
> +}
> +#endif
> +
> +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_FTRUNCATE64)
> +COMPAT_SYSCALL_DEFINE3(ftruncate64, unsigned int, fd,
> + compat_arg_u64_dual(length))
> +{
> + return ksys_ftruncate(fd, compat_arg_u64_glue(length));
> +}
> +#endif
>
> int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
> {
> @@ -339,6 +354,15 @@ SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
> return ksys_fallocate(fd, mode, offset, len);
> }
>
> +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_FALLOCATE)
> +COMPAT_SYSCALL_DEFINE6(fallocate, int, fd, int, mode, compat_arg_u64_dual(offset),
> + compat_arg_u64_dual(len))
> +{
> + return ksys_fallocate(fd, mode, compat_arg_u64_glue(offset),
> + compat_arg_u64_glue(len));
> +}
> +#endif
> +
> /*
> * access() needs to use the real uid/gid, not the effective uid/gid.
> * We do this by temporarily clearing all FS-related capabilities and
> diff --git a/fs/read_write.c b/fs/read_write.c
> index 0074afa7ecb3..548657c462e8 100644
> --- a/fs/read_write.c
> +++ b/fs/read_write.c
> @@ -681,6 +681,14 @@ SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
> return ksys_pread64(fd, buf, count, pos);
> }
>
> +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PREAD64)
> +COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, buf,
> + size_t, count, compat_arg_u64_dual(pos))
> +{
> + return ksys_pread64(fd, buf, count, compat_arg_u64_glue(pos));
> +}
> +#endif
> +
> ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
> size_t count, loff_t pos)
> {
> @@ -707,6 +715,14 @@ SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
> return ksys_pwrite64(fd, buf, count, pos);
> }
>
> +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PWRITE64)
> +COMPAT_SYSCALL_DEFINE5(pwrite64, unsigned int, fd, const char __user *, buf,
> + size_t, count, compat_arg_u64_dual(pos))
> +{
> + return ksys_pwrite64(fd, buf, count, compat_arg_u64_glue(pos));
> +}
> +#endif
> +
> static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
> loff_t *ppos, int type, rwf_t flags)
> {
> diff --git a/fs/sync.c b/fs/sync.c
> index c7690016453e..dc725914e1ed 100644
> --- a/fs/sync.c
> +++ b/fs/sync.c
> @@ -373,6 +373,15 @@ SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
> return ksys_sync_file_range(fd, offset, nbytes, flags);
> }
>
> +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_SYNC_FILE_RANGE)
> +COMPAT_SYSCALL_DEFINE6(sync_file_range, int, fd, compat_arg_u64_dual(offset),
> + compat_arg_u64_dual(nbytes), unsigned int, flags)
> +{
> + return ksys_sync_file_range(fd, compat_arg_u64_glue(offset),
> + compat_arg_u64_glue(nbytes), flags);
> +}
> +#endif
> +
> /* It would be nice if people remember that not all the world's an i386
> when they introduce new system calls */
> SYSCALL_DEFINE4(sync_file_range2, int, fd, unsigned int, flags,
> diff --git a/include/asm-generic/compat.h b/include/asm-generic/compat.h
> index 11653d6846cc..d06308a2a7a8 100644
> --- a/include/asm-generic/compat.h
> +++ b/include/asm-generic/compat.h
> @@ -14,6 +14,13 @@
> #define COMPAT_OFF_T_MAX 0x7fffffff
> #endif
>
> +#if !defined(compat_arg_u64) && !defined(CONFIG_CPU_BIG_ENDIAN)
> +#define compat_arg_u64(name) u32 name##_lo, u32 name##_hi
> +#define compat_arg_u64_dual(name) u32, name##_lo, u32, name##_hi
> +#define compat_arg_u64_glue(name) (((u64)name##_lo & 0xffffffffUL) | \
> + ((u64)name##_hi << 32))
> +#endif
> +
> /* These types are common across all compat ABIs */
> typedef u32 compat_size_t;
> typedef s32 compat_ssize_t;
> diff --git a/include/linux/compat.h b/include/linux/compat.h
> index a0481fe6c5d5..8779e283a1e9 100644
> --- a/include/linux/compat.h
> +++ b/include/linux/compat.h
> @@ -926,6 +926,43 @@ asmlinkage long compat_sys_sigaction(int sig,
> /* obsolete: net/socket.c */
> asmlinkage long compat_sys_socketcall(int call, u32 __user *args);
>
> +#ifdef __ARCH_WANT_COMPAT_TRUNCATE64
> +asmlinkage long compat_sys_truncate64(const char __user *pathname, compat_arg_u64(len));
> +#endif
> +
> +#ifdef __ARCH_WANT_COMPAT_FTRUNCATE64
> +asmlinkage long compat_sys_ftruncate64(unsigned int fd, compat_arg_u64(len));
> +#endif
> +
> +#ifdef __ARCH_WANT_COMPAT_FALLOCATE
> +asmlinkage long compat_sys_fallocate(int fd, int mode, compat_arg_u64(offset),
> + compat_arg_u64(len));
> +#endif
> +
> +#ifdef __ARCH_WANT_COMPAT_PREAD64
> +asmlinkage long compat_sys_pread64(unsigned int fd, char __user *buf, size_t count,
> + compat_arg_u64(pos));
> +#endif
> +
> +#ifdef __ARCH_WANT_COMPAT_PWRITE64
> +asmlinkage long compat_sys_pwrite64(unsigned int fd, const char __user *buf, size_t count,
> + compat_arg_u64(pos));
> +#endif
> +
> +#ifdef __ARCH_WANT_COMPAT_SYNC_FILE_RANGE
> +asmlinkage long compat_sys_sync_file_range(int fd, compat_arg_u64(pos),
> + compat_arg_u64(nbytes), unsigned int flags);
> +#endif
> +
> +#ifdef __ARCH_WANT_COMPAT_FADVISE64_64
> +asmlinkage long compat_sys_fadvise64_64(int fd, int advice, compat_arg_u64(pos),
> + compat_arg_u64(len));
This should be:
+asmlinkage long compat_sys_fadvise64_64(int fd, compat_arg_u64(pos),
+ compat_arg_u64(len), int advice);

> +#endif
> +
> +#ifdef __ARCH_WANT_COMPAT_READAHEAD
> +asmlinkage long compat_sys_readahead(int fd, compat_arg_u64(offset), size_t count);
> +#endif
> +
> #endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
>
> /**
> diff --git a/mm/fadvise.c b/mm/fadvise.c
> index d6baa4f451c5..8950f7c05d20 100644
> --- a/mm/fadvise.c
> +++ b/mm/fadvise.c
> @@ -215,5 +215,16 @@ SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
> return ksys_fadvise64_64(fd, offset, len, advice);
> }
>
> +#endif
> +
> +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_FADVISE64_64)
> +
> +COMPAT_SYSCALL_DEFINE6(fadvise64_64, int, fd, int, advice, compat_arg_u64_dual(offset),
> + compat_arg_u64_dual(len))
Ditto, this should be.

+COMPAT_SYSCALL_DEFINE6(fadvise64_64, int, fd, compat_arg_u64_dual(offset),
+ compat_arg_u64_dual(len), int, advice)

> +{
> + return ksys_fadvise64_64(fd, compat_arg_u64_glue(offset),
> + compat_arg_u64_glue(len), advice);
> +}
> +
> #endif
> #endif
> diff --git a/mm/readahead.c b/mm/readahead.c
> index cf0dcf89eb69..9adf57044299 100644
> --- a/mm/readahead.c
> +++ b/mm/readahead.c
> @@ -640,6 +640,13 @@ SYSCALL_DEFINE3(readahead, int, fd, loff_t, offset, size_t, count)
> return ksys_readahead(fd, offset, count);
> }
>
> +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_READAHEAD)
> +COMPAT_SYSCALL_DEFINE4(readahead, int, fd, compat_arg_u64_dual(offset), size_t, count)
> +{
> + return ksys_readahead(fd, compat_arg_u64_glue(offset), count);
> +}
> +#endif
> +
> /**
> * readahead_expand - Expand a readahead request
> * @ractl: The request to be expanded
> --
> 2.25.1
>

--
Best Regards
Guo Ren

ML: https://lore.kernel.org/linux-csky/