[PATCH v2 4/4] nios2: implement architecture-specific portion of sys_clone3

Simon Schuster via B4 Relay
2025-09-01T13:10:49Z

From: Simon Schuster <schuster.simon@siemens-energy.com>

This commit adds the sys_clone3 entry point for nios2. An
architecture-specific wrapper (__sys_clone3) is required to save and
restore additional registers to the kernel stack via SAVE_SWITCH_STACK
and RESTORE_SWITCH_STACK.

Signed-off-by: Simon Schuster <schuster.simon@siemens-energy.com>
---
arch/nios2/include/asm/syscalls.h | 1 +
arch/nios2/include/asm/unistd.h | 2 --
arch/nios2/kernel/entry.S | 6 ++++++
arch/nios2/kernel/syscall_table.c | 1 +
4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/nios2/include/asm/syscalls.h b/arch/nios2/include/asm/syscalls.h
index b4d4ed3bf9c8..0e214b0a0ac8 100644
--- a/arch/nios2/include/asm/syscalls.h
+++ b/arch/nios2/include/asm/syscalls.h
@@ -7,6 +7,7 @@

int sys_cacheflush(unsigned long addr, unsigned long len,
unsigned int op);
+asmlinkage long __sys_clone3(struct clone_args __user *uargs, size_t size);

#include <asm-generic/syscalls.h>

diff --git a/arch/nios2/include/asm/unistd.h b/arch/nios2/include/asm/unistd.h
index 1146e56473c5..213f6de3cf7b 100644
--- a/arch/nios2/include/asm/unistd.h
+++ b/arch/nios2/include/asm/unistd.h
@@ -7,6 +7,4 @@
#define __ARCH_WANT_STAT64
#define __ARCH_WANT_SET_GET_RLIMIT

-#define __ARCH_BROKEN_SYS_CLONE3
-
#endif
diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S
index 99f0a65e6234..dd40dfd908e5 100644
--- a/arch/nios2/kernel/entry.S
+++ b/arch/nios2/kernel/entry.S
@@ -403,6 +403,12 @@ ENTRY(sys_clone)
addi sp, sp, 4
RESTORE_SWITCH_STACK
ret
+/* long syscall(SYS_clone3, struct clone_args *cl_args, size_t size); */
+ENTRY(__sys_clone3)
+ SAVE_SWITCH_STACK
+ call sys_clone3
+ RESTORE_SWITCH_STACK
+ ret

ENTRY(sys_rt_sigreturn)
SAVE_SWITCH_STACK
diff --git a/arch/nios2/kernel/syscall_table.c b/arch/nios2/kernel/syscall_table.c
index 434694067d8f..c99818aac9e1 100644
--- a/arch/nios2/kernel/syscall_table.c
+++ b/arch/nios2/kernel/syscall_table.c
@@ -13,6 +13,7 @@
#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)

#define sys_mmap2 sys_mmap_pgoff
+#define sys_clone3 __sys_clone3

void *sys_call_table[__NR_syscalls] = {
[0 ... __NR_syscalls-1] = sys_ni_syscall,

--
2.39.5