diff mbox series

[V6,11/20] riscv: compat: syscall: Add compat_sys_call_table implementation

Message ID 20220224085410.399351-12-guoren@kernel.org
State New
Headers show
Series riscv: compat: Add COMPAT mode support for rv64 | expand

Commit Message

Guo Ren Feb. 24, 2022, 8:54 a.m. UTC
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

Comments

Arnd Bergmann Feb. 24, 2022, 9:31 a.m. UTC | #1
On Thu, Feb 24, 2022 at 9:54 AM <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>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>

Here, I was hoping you'd convert some of the other architectures to use
the same code, but the changes you did do look correct.

Please at least add the missing bit for big-endian architectures here:

+#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

with the lo/hi words swapped. With that change:

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Guo Ren Feb. 24, 2022, 10:30 a.m. UTC | #2
On Thu, Feb 24, 2022 at 5:38 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Thu, Feb 24, 2022 at 9:54 AM <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>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Palmer Dabbelt <palmer@dabbelt.com>
>
> Here, I was hoping you'd convert some of the other architectures to use
> the same code, but the changes you did do look correct.
>
> Please at least add the missing bit for big-endian architectures here:
>
> +#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
>
> with the lo/hi words swapped. With that change:
Got it, I would change it in next version of patch.

>
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
diff mbox series

Patch

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 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..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