[PATCH V5 11/21] riscv: compat: syscall: Add compat_sys_call_table implementation

guoren
2022-02-01T15:07:21Z

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>
Cc: Arnd Bergmann <arnd@arndb.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 612556faa527..954dc7043ad2 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -66,3 +66,4 @@ 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 3ce8e2137f31..75edb7a664e5 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -367,6 +367,15 @@ 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..5ed55aa616b1 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##_hi << 32) | \
+ ((u64)name##_lo & 0xffffffffUL))
+#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));
+#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))
+{
+ 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