Add support for the clone3 system call to the SPARC architectures. The implementation follows the pattern of the original clone syscall. However, instead of explicitly calling kernel_clone, the clone3 handler calls the generic sys_clone3 handler in kernel/fork. In case no stack is provided, the parents stack is reused.
The return call conventions for clone on SPARC are kept for clone3: Parent --> %o0 == child's pid, %o1 == 0 Child --> %o0 == parent's pid, %o1 == 1 Closes: https://github.com/sparclinux/issues/issues/10 Signed-off-by: Ludwig Rydberg <[email protected]> --- arch/sparc/include/asm/syscalls.h | 1 + arch/sparc/include/asm/unistd.h | 2 -- arch/sparc/kernel/entry.S | 15 +++++++++++++++ arch/sparc/kernel/kernel.h | 1 + arch/sparc/kernel/process.c | 25 +++++++++++++++++++++++++ arch/sparc/kernel/process_32.c | 2 +- arch/sparc/kernel/process_64.c | 2 +- arch/sparc/kernel/syscalls.S | 6 ++++++ arch/sparc/kernel/syscalls/syscall.tbl | 2 +- 9 files changed, 51 insertions(+), 5 deletions(-) diff --git a/arch/sparc/include/asm/syscalls.h b/arch/sparc/include/asm/syscalls.h index 35575fbfb9dc..282e62b66518 100644 --- a/arch/sparc/include/asm/syscalls.h +++ b/arch/sparc/include/asm/syscalls.h @@ -7,5 +7,6 @@ struct pt_regs; asmlinkage long sparc_fork(struct pt_regs *regs); asmlinkage long sparc_vfork(struct pt_regs *regs); asmlinkage long sparc_clone(struct pt_regs *regs); +asmlinkage long sparc_clone3(struct pt_regs *regs); #endif /* _SPARC64_SYSCALLS_H */ diff --git a/arch/sparc/include/asm/unistd.h b/arch/sparc/include/asm/unistd.h index 3380411a4537..d6bc76706a7a 100644 --- a/arch/sparc/include/asm/unistd.h +++ b/arch/sparc/include/asm/unistd.h @@ -49,8 +49,6 @@ #define __ARCH_WANT_COMPAT_STAT #endif -#define __ARCH_BROKEN_SYS_CLONE3 - #ifdef __32bit_syscall_numbers__ /* Sparc 32-bit only has the "setresuid32", "getresuid32" variants, * it never had the plain ones and there is no value to adding those diff --git a/arch/sparc/kernel/entry.S b/arch/sparc/kernel/entry.S index a3fdee4cd6fa..ea51ef52c952 100644 --- a/arch/sparc/kernel/entry.S +++ b/arch/sparc/kernel/entry.S @@ -907,6 +907,21 @@ flush_patch_four: jmpl %l1 + %lo(sparc_vfork), %g0 add %sp, STACKFRAME_SZ, %o0 + .globl __sys_clone3, flush_patch_five +__sys_clone3: + mov %o7, %l5 +flush_patch_five: + FLUSH_ALL_KERNEL_WINDOWS; + ld [%curptr + TI_TASK], %o4 + rd %psr, %g4 + WRITE_PAUSE + rd %wim, %g5 + WRITE_PAUSE + std %g4, [%o4 + AOFF_task_thread + AOFF_thread_fork_kpsr] + add %sp, STACKFRAME_SZ, %o0 + call sparc_clone3 + mov %l5, %o7 + .align 4 linux_sparc_ni_syscall: sethi %hi(sys_ni_syscall), %l7 diff --git a/arch/sparc/kernel/kernel.h b/arch/sparc/kernel/kernel.h index 8328a3b78a44..4ee85051521a 100644 --- a/arch/sparc/kernel/kernel.h +++ b/arch/sparc/kernel/kernel.h @@ -18,6 +18,7 @@ extern int ncpus_probed; asmlinkage long sparc_clone(struct pt_regs *regs); asmlinkage long sparc_fork(struct pt_regs *regs); asmlinkage long sparc_vfork(struct pt_regs *regs); +asmlinkage long sparc_clone3(struct pt_regs *regs); #ifdef CONFIG_SPARC64 /* setup_64.c */ diff --git a/arch/sparc/kernel/process.c b/arch/sparc/kernel/process.c index 7d69877511fa..b8e23295db69 100644 --- a/arch/sparc/kernel/process.c +++ b/arch/sparc/kernel/process.c @@ -12,6 +12,7 @@ #include <linux/sched/task.h> #include <linux/sched/task_stack.h> #include <linux/signal.h> +#include <linux/syscalls.h> #include "kernel.h" @@ -118,3 +119,27 @@ asmlinkage long sparc_clone(struct pt_regs *regs) return ret; } + +asmlinkage long sparc_clone3(struct pt_regs *regs) +{ + unsigned long sz; + long ret; + struct clone_args __user *cl_args; + + synchronize_user_stack(); + + cl_args = (struct clone_args __user *)regs->u_regs[UREG_I0]; + sz = regs->u_regs[UREG_I1]; + + ret = sys_clone3(cl_args, sz); + + /* If we get an error and potentially restart the system + * call, we're screwed because copy_thread() clobbered + * the parent's %o1. So detect that case and restore it + * here. + */ + if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) + regs->u_regs[UREG_I1] = sz; + + return ret; +} diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c index 5a28c0e91bf1..216c07971c81 100644 --- a/arch/sparc/kernel/process_32.c +++ b/arch/sparc/kernel/process_32.c @@ -261,11 +261,11 @@ extern void ret_from_kernel_thread(void); int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { u64 clone_flags = args->flags; - unsigned long sp = args->stack; unsigned long tls = args->tls; struct thread_info *ti = task_thread_info(p); struct pt_regs *childregs, *regs = current_pt_regs(); char *new_stack; + unsigned long sp = args->stack ? args->stack : regs->u_regs[UREG_FP]; #ifndef CONFIG_SMP if(last_task_used_math == current) { diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index 25781923788a..885d617ba29d 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -568,13 +568,13 @@ void fault_in_user_windows(struct pt_regs *regs) int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { u64 clone_flags = args->flags; - unsigned long sp = args->stack; unsigned long tls = args->tls; struct thread_info *t = task_thread_info(p); struct pt_regs *regs = current_pt_regs(); struct sparc_stackf *parent_sf; unsigned long child_stack_sz; char *child_trap_frame; + unsigned long sp = args->stack ? args->stack : regs->u_regs[UREG_FP]; /* Calculate offset to stack_frame & pt_regs */ child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ); diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S index 0e8ab0602c36..c8d374a37f98 100644 --- a/arch/sparc/kernel/syscalls.S +++ b/arch/sparc/kernel/syscalls.S @@ -103,6 +103,12 @@ sys_clone: ba,pt %xcc, sparc_clone add %sp, PTREGS_OFF, %o0 + .align 32 +__sys_clone3: + flushw + ba,pt %xcc, sparc_clone3 + add %sp, PTREGS_OFF, %o0 + .globl ret_from_fork ret_from_fork: /* Clear current_thread_info()->new_child. */ diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index 39aa26b6a50b..c0307bb09892 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -480,7 +480,7 @@ 432 common fsmount sys_fsmount 433 common fspick sys_fspick 434 common pidfd_open sys_pidfd_open -# 435 reserved for clone3 +435 common clone3 __sys_clone3 436 common close_range sys_close_range 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd -- 2.35.3
