[PATCH 2/5] ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390

[PATCH 2/5] ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390

[Arnd Bergmann]

The sys_ipc() and compat_ksys_ipc() functions are meant to only
be used from the system call table, not called by another function.

Introduce ksys_*() interfaces for this purpose, as we have done
for many other system calls.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/s390/kernel/compat_linux.c |  2 +-
 arch/s390/kernel/sys_s390.c     |  2 +-
 include/linux/syscalls.h        |  4 ++++
 ipc/syscall.c                   | 20 ++++++++++++++++----
 4 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 8ac38d51ed7d..a47f6d3c6d5b 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -296,7 +296,7 @@ COMPAT_SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, compat_ulong_t, second,
 {
 	if (call >> 16)		/* hack for backward compatibility */
 		return -EINVAL;
-	return compat_sys_ipc(call, first, second, third, ptr, third);
+	return compat_ksys_ipc(call, first, second, third, ptr, third);
 }
 #endif
 
diff --git a/arch/s390/kernel/sys_s390.c b/arch/s390/kernel/sys_s390.c
index 560bdaf8a74f..6aa8fe00b39e 100644
--- a/arch/s390/kernel/sys_s390.c
+++ b/arch/s390/kernel/sys_s390.c
@@ -74,7 +74,7 @@ SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
 	 * Therefore we can call the generic variant by simply passing the
 	 * third parameter also as fifth parameter.
 	 */
-	return sys_ipc(call, first, second, third, ptr, third);
+	return ksys_ipc(call, first, second, third, ptr, third);
 }
 
 SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 257cccba3062..fb63045a0fb6 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1185,6 +1185,10 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
 			      unsigned long prot, unsigned long flags,
 			      unsigned long fd, unsigned long pgoff);
 ssize_t ksys_readahead(int fd, loff_t offset, size_t count);
+int ksys_ipc(unsigned int call, int first, unsigned long second,
+	unsigned long third, void __user * ptr, long fifth);
+int compat_ksys_ipc(u32 call, int first, int second,
+	u32 third, u32 ptr, u32 fifth);
 
 /*
  * The following kernel syscall equivalents are just wrappers to fs-internal
diff --git a/ipc/syscall.c b/ipc/syscall.c
index 1ac06e3983c0..3cf8ad703a4d 100644
--- a/ipc/syscall.c
+++ b/ipc/syscall.c
@@ -17,8 +17,8 @@
 #include <linux/shm.h>
 #include <linux/uaccess.h>
 
-SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
-		unsigned long, third, void __user *, ptr, long, fifth)
+int ksys_ipc(unsigned int call, int first, unsigned long second,
+	unsigned long third, void __user * ptr, long fifth)
 {
 	int version, ret;
 
@@ -106,6 +106,12 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
 		return -ENOSYS;
 	}
 }
+
+SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
+		unsigned long, third, void __user *, ptr, long, fifth)
+{
+	return ksys_ipc(call, first, second, third, ptr, fifth);
+}
 #endif
 
 #ifdef CONFIG_COMPAT
@@ -121,8 +127,8 @@ struct compat_ipc_kludge {
 };
 
 #ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
-COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
-	u32, third, compat_uptr_t, ptr, u32, fifth)
+int compat_ksys_ipc(u32 call, int first, int second,
+	u32 third, compat_uptr_t ptr, u32 fifth)
 {
 	int version;
 	u32 pad;
@@ -195,5 +201,11 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
 
 	return -ENOSYS;
 }
+
+COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
+	u32, third, compat_uptr_t, ptr, u32, fifth)
+{
+	return compat_ksys_ipc(call, first, second, third, ptr, fifth);
+}
 #endif
 #endif
-- 
2.20.0

Re: [PATCH 2/5] ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390

[Heiko Carstens]

On Wed, Jan 16, 2019 at 02:15:20PM +0100, Arnd Bergmann wrote:
> The sys_ipc() and compat_ksys_ipc() functions are meant to only
> be used from the system call table, not called by another function.
> 
> Introduce ksys_*() interfaces for this purpose, as we have done
> for many other system calls.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  arch/s390/kernel/compat_linux.c |  2 +-
>  arch/s390/kernel/sys_s390.c     |  2 +-
>  include/linux/syscalls.h        |  4 ++++
>  ipc/syscall.c                   | 20 ++++++++++++++++----
>  4 files changed, 22 insertions(+), 6 deletions(-)

The patch below is needed as compile fix (allnoconfig).
I will add this to your patch, no resend needed.

diff --git a/arch/s390/kernel/sys_s390.c b/arch/s390/kernel/sys_s390.c
index 6aa8fe00b39e..fd0cbbed4d9f 100644
--- a/arch/s390/kernel/sys_s390.c
+++ b/arch/s390/kernel/sys_s390.c
@@ -58,6 +58,7 @@ SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
 	return error;
 }
 
+#ifdef CONFIG_SYSVIPC
 /*
  * sys_ipc() is the de-multiplexer for the SysV IPC calls.
  */
@@ -76,6 +77,7 @@ SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
 	 */
 	return ksys_ipc(call, first, second, third, ptr, third);
 }
+#endif /* CONFIG_SYSVIPC */
 
 SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
 {
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index ab9d0e3c6d50..ad016a7db0ea 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -366,7 +366,7 @@ COND_SYSCALL(kexec_file_load);
 /* s390 */
 COND_SYSCALL(s390_pci_mmio_read);
 COND_SYSCALL(s390_pci_mmio_write);
-COND_SYSCALL_COMPAT(s390_ipc);
+COND_SYSCALL(s390_ipc);
 
 /* powerpc */
 COND_SYSCALL(rtas);

Re: [PATCH 2/5] ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390

[Arnd Bergmann]

On Thu, Jan 17, 2019 at 2:29 PM Heiko Carstens
<heiko.carstens@de.ibm.com> wrote:

> diff --git a/arch/s390/kernel/sys_s390.c b/arch/s390/kernel/sys_s390.c
> index 6aa8fe00b39e..fd0cbbed4d9f 100644
> --- a/arch/s390/kernel/sys_s390.c
> +++ b/arch/s390/kernel/sys_s390.c
> @@ -58,6 +58,7 @@ SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
>         return error;
>  }
>
> +#ifdef CONFIG_SYSVIPC
>  /*
>   * sys_ipc() is the de-multiplexer for the SysV IPC calls.
>   */
> @@ -76,6 +77,7 @@ SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
>          */
>         return ksys_ipc(call, first, second, third, ptr, third);
>  }
> +#endif /* CONFIG_SYSVIPC */

Ack.

>  SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
>  {
> diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
> index ab9d0e3c6d50..ad016a7db0ea 100644
> --- a/kernel/sys_ni.c
> +++ b/kernel/sys_ni.c
> @@ -366,7 +366,7 @@ COND_SYSCALL(kexec_file_load);
>  /* s390 */
>  COND_SYSCALL(s390_pci_mmio_read);
>  COND_SYSCALL(s390_pci_mmio_write);
> -COND_SYSCALL_COMPAT(s390_ipc);
> +COND_SYSCALL(s390_ipc);
>
>  /* powerpc */
>  COND_SYSCALL(rtas);

I think you need to keep the

COND_SYSCALL_COMPAT(s390_ipc);

here, otherwise it still fails with CONFIG_SYSV_IPC=n, CONFIG_COMPAT=y, right?

       Arnd

Re: [PATCH 2/5] ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390

[Heiko Carstens]

On Thu, Jan 17, 2019 at 05:29:55PM +0100, Arnd Bergmann wrote:
> On Thu, Jan 17, 2019 at 2:29 PM Heiko Carstens
> >  SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
> >  {
> > diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
> > index ab9d0e3c6d50..ad016a7db0ea 100644
> > --- a/kernel/sys_ni.c
> > +++ b/kernel/sys_ni.c
> > @@ -366,7 +366,7 @@ COND_SYSCALL(kexec_file_load);
> >  /* s390 */
> >  COND_SYSCALL(s390_pci_mmio_read);
> >  COND_SYSCALL(s390_pci_mmio_write);
> > -COND_SYSCALL_COMPAT(s390_ipc);
> > +COND_SYSCALL(s390_ipc);
> >
> >  /* powerpc */
> >  COND_SYSCALL(rtas);
> 
> I think you need to keep the
> 
> COND_SYSCALL_COMPAT(s390_ipc);
> 
> here, otherwise it still fails with CONFIG_SYSV_IPC=n, CONFIG_COMPAT=y, right?

Yes, you're right.