From d68dbb0c9ac8b1ff52eb09aa58ce6358400fa939 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 21 Jun 2019 01:26:35 +0200 Subject: [PATCH] arch: handle arches who do not yet define clone3 This cleanly handles arches who do not yet define clone3. clone3() was initially placed under __ARCH_WANT_SYS_CLONE under the assumption that this would cleanly handle all architectures. It does not. Architectures such as nios2 or h8300 simply take the asm-generic syscall definitions and generate their syscall table from it. Since they don't define __ARCH_WANT_SYS_CLONE the build would fail complaining about sys_clone3 missing. The reason this doesn't happen for legacy clone is that nios2 and h8300 provide assembly stubs for sys_clone. This seems to be done for architectural reasons. The build failures for nios2 and h8300 were caught int -next luckily. The solution is to define __ARCH_WANT_SYS_CLONE3 that architectures can add. Additionally, we need a cond_syscall(clone3) for architectures such as nios2 or h8300 that generate their syscall table in the way I explained above. Fixes: 8f3220a80654 ("arch: wire-up clone3() syscall") Signed-off-by: Christian Brauner Cc: Arnd Bergmann Cc: Kees Cook Cc: David Howells Cc: Andrew Morton Cc: Oleg Nesterov Cc: Adrian Reber Cc: Linus Torvalds Cc: Al Viro Cc: Florian Weimer Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org --- arch/arm/include/asm/unistd.h | 1 + arch/arm64/include/asm/unistd.h | 1 + arch/x86/include/asm/unistd.h | 1 + arch/xtensa/include/asm/unistd.h | 1 + kernel/fork.c | 2 ++ kernel/sys_ni.c | 2 ++ 6 files changed, 8 insertions(+) diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h index 7a39e77984ef..aa35aa5d68dc 100644 --- a/arch/arm/include/asm/unistd.h +++ b/arch/arm/include/asm/unistd.h @@ -40,6 +40,7 @@ #define __ARCH_WANT_SYS_FORK #define __ARCH_WANT_SYS_VFORK #define __ARCH_WANT_SYS_CLONE +#define __ARCH_WANT_SYS_CLONE3 /* * Unimplemented (or alternatively implemented) syscalls diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 24480c2d95da..e4e0523102e2 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -48,6 +48,7 @@ #endif #define __ARCH_WANT_SYS_CLONE +#define __ARCH_WANT_SYS_CLONE3 #ifndef __COMPAT_SYSCALL_NR #include diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h index 146859efd83c..097589753fec 100644 --- a/arch/x86/include/asm/unistd.h +++ b/arch/x86/include/asm/unistd.h @@ -54,5 +54,6 @@ # define __ARCH_WANT_SYS_FORK # define __ARCH_WANT_SYS_VFORK # define __ARCH_WANT_SYS_CLONE +# define __ARCH_WANT_SYS_CLONE3 #endif /* _ASM_X86_UNISTD_H */ diff --git a/arch/xtensa/include/asm/unistd.h b/arch/xtensa/include/asm/unistd.h index 30af4dc3ce7b..b52236245e51 100644 --- a/arch/xtensa/include/asm/unistd.h +++ b/arch/xtensa/include/asm/unistd.h @@ -3,6 +3,7 @@ #define _XTENSA_UNISTD_H #define __ARCH_WANT_SYS_CLONE +#define __ARCH_WANT_SYS_CLONE3 #include #define __ARCH_WANT_NEW_STAT diff --git a/kernel/fork.c b/kernel/fork.c index 08ff131f26b4..98abea995629 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2490,7 +2490,9 @@ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, return _do_fork(&args); } +#endif +#ifdef __ARCH_WANT_SYS_CLONE3 noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs, struct clone_args __user *uargs, size_t size) diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 4d9ae5ea6caf..34b76895b81e 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -137,6 +137,8 @@ COND_SYSCALL(capset); /* kernel/exit.c */ /* kernel/fork.c */ +/* __ARCH_WANT_SYS_CLONE3 */ +COND_SYSCALL(clone3); /* kernel/futex.c */ COND_SYSCALL(futex);