diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ff9b80a0e3e3..72015dba72ab 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -28,6 +28,7 @@ #include <linux/static_call.h> #include <trace/events/power.h> #include <linux/hw_breakpoint.h> +#include <linux/entry-common.h> #include <asm/cpu.h> #include <asm/apic.h> #include <linux/uaccess.h> @@ -134,6 +135,25 @@ static int set_new_tls(struct task_struct *p, unsigned long tls) return do_set_thread_area_64(p, ARCH_SET_FS, tls); } +__visible void ret_from_fork(struct task_struct *prev, struct pt_regs *regs, + int (*fn)(void *), void *fn_arg) +{ + schedule_tail(prev); + + /* Is this a kernel thread? */ + if (unlikely(fn)) { + fn(fn_arg); + /* + * A kernel thread is allowed to return here after successfully + * calling kernel_execve(). Exit to userspace to complete the + * execve() syscall. + */ + regs->ax = 0; + } + + syscall_exit_to_user_mode(regs); +} + int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; @@ -149,7 +169,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) frame = &fork_frame->frame; frame->bp = encode_frame_pointer(childregs); - frame->ret_addr = (unsigned long) ret_from_fork; + frame->ret_addr = (unsigned long) ret_from_fork_asm; p->thread.sp = (unsigned long) fork_frame; p->thread.io_bitmap = NULL; p->thread.iopl_warn = 0; |