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 value convention for clone3 follows the regular kernel return value convention (in contrast to the original clone/fork on SPARC). 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 | 14 +++++++++++++ arch/sparc/kernel/process_32.c | 23 ++++++++++++++++------ arch/sparc/kernel/process_64.c | 27 ++++++++++++++++++++------ arch/sparc/kernel/syscalls.S | 8 ++++++++ arch/sparc/kernel/syscalls/syscall.tbl | 2 +- 9 files changed, 78 insertions(+), 15 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..d72fa0665943 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 +119,16 @@ asmlinkage long sparc_clone(struct pt_regs *regs) return ret; } + +asmlinkage long sparc_clone3(struct pt_regs *regs) +{ + unsigned long sz; + 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]; + + return sys_clone3(cl_args, sz); +} diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c index 5a28c0e91bf1..dd8c6c02b0f1 100644 --- a/arch/sparc/kernel/process_32.c +++ b/arch/sparc/kernel/process_32.c @@ -247,6 +247,8 @@ clone_stackframe(struct sparc_stackf __user *dst, * Parent --> %o0 == childs pid, %o1 == 0 * Child --> %o0 == parents pid, %o1 == 1 * + * clone3() - Uses regular kernel return value conventions + * * NOTE: We have a separate fork kpsr/kwim because * the parent could change these values between * sys_fork invocation and when we reach here @@ -261,11 +263,11 @@ 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) { @@ -350,13 +352,22 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childregs->psr &= ~PSR_EF; clear_tsk_thread_flag(p, TIF_USEDFPU); #endif + /* Handle return value conventions */ + if (regs->u_regs[UREG_G1] == __NR_clone3) { + /* clone3() - use regular kernel return value convention */ + + /* Set the return value for the child. */ + childregs->u_regs[UREG_I0] = 0; + } else { + /* clone()/fork() - use SunOS return value convention */ - /* Set the return value for the child. */ - childregs->u_regs[UREG_I0] = current->pid; - childregs->u_regs[UREG_I1] = 1; + /* Set the return value for the child. */ + childregs->u_regs[UREG_I0] = current->pid; + childregs->u_regs[UREG_I1] = 1; - /* Set the return value for the parent. */ - regs->u_regs[UREG_I1] = 0; + /* Set the return value for the parent. */ + regs->u_regs[UREG_I1] = 0; + } if (clone_flags & CLONE_SETTLS) childregs->u_regs[UREG_G7] = tls; diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index 25781923788a..e889da8e4835 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -564,17 +564,19 @@ void fault_in_user_windows(struct pt_regs *regs) * under SunOS are nothing short of bletcherous: * Parent --> %o0 == childs pid, %o1 == 0 * Child --> %o0 == parents pid, %o1 == 1 + * + * clone3() - Uses regular kernel return value conventions */ 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); @@ -616,12 +618,25 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (t->utraps) t->utraps[0]++; - /* Set the return value for the child. */ - t->kregs->u_regs[UREG_I0] = current->pid; - t->kregs->u_regs[UREG_I1] = 1; + /* Handle return value conventions */ + if (regs->u_regs[UREG_G1] == __NR_clone3) { + /* clone3() - use regular kernel return value convention */ + + /* Set the return value for the child. */ + t->kregs->u_regs[UREG_I0] = 0; + + /* Clear g1 to indicate user thread */ + t->kregs->u_regs[UREG_G1] = 0; + } else { + /* clone()/fork() - use SunOS return value convention */ + + /* Set the return value for the child. */ + t->kregs->u_regs[UREG_I0] = current->pid; + t->kregs->u_regs[UREG_I1] = 1; - /* Set the second return value for the parent. */ - regs->u_regs[UREG_I1] = 0; + /* Set the second return value for the parent. */ + regs->u_regs[UREG_I1] = 0; + } if (clone_flags & CLONE_SETTLS) t->kregs->u_regs[UREG_G7] = tls; diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S index 0e8ab0602c36..96fe8763d70c 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. */ @@ -113,6 +119,8 @@ ret_from_fork: brnz,pt %o0, ret_sys_call ldx [%g6 + TI_FLAGS], %l0 ldx [%sp + PTREGS_OFF + PT_V9_G1], %l1 + brz,pt %l1, ret_sys_call + nop call %l1 ldx [%sp + PTREGS_OFF + PT_V9_G2], %o0 ba,pt %xcc, ret_sys_call 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
