From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ying Han Subject: Re: How much of a mess does OpenVZ make? ;) Was: What can OpenVZ do? Date: Thu, 12 Mar 2009 23:19:43 -0700 Message-ID: <604427e00903122319y4d98ffc3ub62547960181a2bf@mail.gmail.com> References: <1234475483.30155.194.camel@nimitz> <1234479845.30155.220.camel@nimitz> <20090226155755.GA1456@x200.localdomain> <20090310215305.GA2078@x200.localdomain> <49B775B4.1040800@free.fr> <20090312145311.GC12390@us.ibm.com> <1236891719.32630.14.camel@bahia> <20090312212124.GA25019@us.ibm.com> <604427e00903122129y37ad791aq5fe7ef2552415da9@mail.gmail.com> <20090313053458.GA28833@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20090313053458.GA28833-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sukadev Bhattiprolu Cc: "Serge E. Hallyn" , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Dave Hansen , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, mingo-X9Un+BFzKDI@public.gmane.org, mpm-VDJrAJ4Gl5ZBDgjK7y7TUQ@public.gmane.org, Andrew Morton , xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, Alexey Dobriyan List-Id: linux-api@vger.kernel.org Thank you Sukadev for your comments. I will try to clean up my patch and repost it. --Ying On Thu, Mar 12, 2009 at 10:34 PM, Sukadev Bhattiprolu wrote: > Ying Han [yinghan-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org] wrote: > | Hi Serge: > | I made a patch based on Oren's tree recently which implement a new > | syscall clone_with_pid. I tested with checkpoint/restart process tr= ee > | and it works as expected. > > Yes, I think we had a version of clone() with pid a while ago. > > But it would be easier to review if you break it up into smaller > patches. and remove the unnecessary diffs in this patch like... > > > | This patch has some hack in it which i made a copy of libc's clone = and > | made modifications of passing one more argument(pid number). I will > | try to clean up the code and do more testing. > | > | New syscall clone_with_pid > | Implement a new syscall which clone a thread with a preselected pid= number. > | > | clone_with_pid(child_func, child_stack + CHILD_STACK - 16, > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 CLONE_WITH_PID|SIGCHLD,= pid, NULL); > | > | Signed-off-by: Ying Han > | > | diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm= /syscalls.h > | index 87803da..b5a1b03 100644 > | --- a/arch/x86/include/asm/syscalls.h > | +++ b/arch/x86/include/asm/syscalls.h > | @@ -26,6 +26,7 @@ asmlinkage int sys_fork(struct pt_regs); > | =A0asmlinkage int sys_clone(struct pt_regs); > | =A0asmlinkage int sys_vfork(struct pt_regs); > | =A0asmlinkage int sys_execve(struct pt_regs); > | +asmlinkage int sys_clone_with_pid(struct pt_regs); > | > | =A0/* kernel/signal_32.c */ > | =A0asmlinkage int sys_sigsuspend(int, int, old_sigset_t); > | diff --git a/arch/x86/include/asm/unistd_32.h b/arch/x86/include/as= m/unistd_32 > | index a5f9e09..f10ca0e 100644 > | --- a/arch/x86/include/asm/unistd_32.h > | +++ b/arch/x86/include/asm/unistd_32.h > | @@ -340,6 +340,7 @@ > | =A0#define __NR_inotify_init1 =A0 332 > | =A0#define __NR_checkpoint =A0 =A0 =A0 =A0 =A0 =A0 =A0333 > | =A0#define __NR_restart =A0 =A0 =A0 =A0 334 > | +#define __NR_clone_with_pid =A0335 > | > | =A0#ifdef __KERNEL__ > | > | diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process= _32.c > | index 0a1302f..88ae634 100644 > | --- a/arch/x86/kernel/process_32.c > | +++ b/arch/x86/kernel/process_32.c > | @@ -8,7 +8,6 @@ > | =A0/* > | =A0 * This file handles the architecture-dependent parts of process= handling.. > | =A0 */ > | - > > these > > | =A0#include > | > | =A0#include > | @@ -652,6 +651,28 @@ asmlinkage int sys_clone(struct pt_regs regs) > | =A0 =A0 =A0 return do_fork(clone_flags, newsp, ®s, 0, parent_tid= ptr, child_tidptr); > | =A0} > | > | +/** > | + * sys_clone_with_pid - clone a thread with pre-select pid number. > | + */ > | +asmlinkage int sys_clone_with_pid(struct pt_regs regs) > | +{ > | + =A0 =A0 unsigned long clone_flags; > | + =A0 =A0 unsigned long newsp; > | + =A0 =A0 int __user *parent_tidptr, *child_tidptr; > | + =A0 =A0 pid_t pid_nr; > | + > | + =A0 =A0 clone_flags =3D regs.bx; > | + =A0 =A0 newsp =3D regs.cx; > | + =A0 =A0 parent_tidptr =3D (int __user *)regs.dx; > | + =A0 =A0 child_tidptr =3D (int __user *)regs.di; > | + =A0 =A0 pid_nr =3D regs.bp; > | + > | + =A0 =A0 if (!newsp) > | + =A0 =A0 =A0 =A0 =A0 =A0 newsp =3D regs.sp; > | + =A0 =A0 return do_fork(clone_flags, newsp, ®s, pid_nr, parent_= tidptr, > | + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 child_tidptr); > | +} > | + > | =A0/* > | =A0 * This is trivial, and on the face of it looks like it > | =A0 * could equally well be done in user mode. > | diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/s= yscall_tabl > | index 5543136..5191117 100644 > | --- a/arch/x86/kernel/syscall_table_32.S > | +++ b/arch/x86/kernel/syscall_table_32.S > | @@ -334,3 +334,4 @@ ENTRY(sys_call_table) > | =A0 =A0 =A0 .long sys_inotify_init1 > | =A0 =A0 =A0 .long sys_checkpoint > | =A0 =A0 =A0 .long sys_restart > | + =A0 =A0 .long sys_clone_with_pid > | diff --git a/arch/x86/mm/checkpoint.c b/arch/x86/mm/checkpoint.c > | index 50bde9a..a4aee65 100644 > | --- a/arch/x86/mm/checkpoint.c > | +++ b/arch/x86/mm/checkpoint.c > | @@ -7,7 +7,6 @@ > | =A0 * =A0License. =A0See the file COPYING in the main directory of = the Linux > | =A0 * =A0distribution for more details. > | =A0 */ > | - > | =A0#include > | =A0#include > | > | diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c > | index 64155de..b7de611 100644 > | --- a/checkpoint/checkpoint.c > | +++ b/checkpoint/checkpoint.c > | @@ -8,6 +8,7 @@ > | =A0 * =A0distribution for more details. > | =A0 */ > | > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | @@ -564,3 +565,4 @@ int do_checkpoint(struct cr_ctx *ctx, pid_t pid= ) > | =A0 out: > | =A0 =A0 =A0 return ret; > | =A0} > | + > | diff --git a/checkpoint/ckpt_file.c b/checkpoint/ckpt_file.c > | index e3097ac..a8c5ad5 100644 > | --- a/checkpoint/ckpt_file.c > | +++ b/checkpoint/ckpt_file.c > | @@ -7,7 +7,7 @@ > | =A0 * =A0License. =A0See the file COPYING in the main directory of = the Linux > | =A0 * =A0distribution for more details. > | =A0 */ > | - > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | diff --git a/checkpoint/ckpt_mem.c b/checkpoint/ckpt_mem.c > | index 4925ff2..ca5840b 100644 > | --- a/checkpoint/ckpt_mem.c > | +++ b/checkpoint/ckpt_mem.c > | @@ -7,7 +7,7 @@ > | =A0 * =A0License. =A0See the file COPYING in the main directory of = the Linux > | =A0 * =A0distribution for more details. > | =A0 */ > | - > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | diff --git a/checkpoint/restart.c b/checkpoint/restart.c > | index 7ec4de4..30e43c2 100644 > | --- a/checkpoint/restart.c > | +++ b/checkpoint/restart.c > | @@ -8,6 +8,7 @@ > | =A0 * =A0distribution for more details. > | =A0 */ > | > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | @@ -242,7 +243,7 @@ static int cr_read_task_struct(struct cr_ctx *c= tx) > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 memcpy(t->comm, buf, min(hh->task_comm_= len, TASK_COMM_LEN)); > | =A0 =A0 =A0 } > | =A0 =A0 =A0 kfree(buf); > | - > | + =A0 =A0 pr_debug("read task %s\n", t->comm); > | =A0 =A0 =A0 /* FIXME: restore remaining relevant task_struct fields= */ > | =A0 out: > | =A0 =A0 =A0 cr_hbuf_put(ctx, sizeof(*hh)); > | diff --git a/checkpoint/rstr_file.c b/checkpoint/rstr_file.c > | index f44b081..755e40e 100644 > | --- a/checkpoint/rstr_file.c > | +++ b/checkpoint/rstr_file.c > | @@ -7,7 +7,7 @@ > | =A0 * =A0License. =A0See the file COPYING in the main directory of = the Linux > | =A0 * =A0distribution for more details. > | =A0 */ > | - > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | diff --git a/checkpoint/rstr_mem.c b/checkpoint/rstr_mem.c > | index 4d5ce1a..8330468 100644 > | --- a/checkpoint/rstr_mem.c > | +++ b/checkpoint/rstr_mem.c > | @@ -7,7 +7,7 @@ > | =A0 * =A0License. =A0See the file COPYING in the main directory of = the Linux > | =A0 * =A0distribution for more details. > | =A0 */ > | - > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | diff --git a/checkpoint/sys.c b/checkpoint/sys.c > | index f26b0c6..d1a5394 100644 > | --- a/checkpoint/sys.c > | +++ b/checkpoint/sys.c > | @@ -7,7 +7,7 @@ > | =A0 * =A0License. =A0See the file COPYING in the main directory of = the Linux > | =A0 * =A0distribution for more details. > | =A0 */ > | - > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | @@ -263,7 +263,6 @@ asmlinkage long sys_checkpoint(pid_t pid, int f= d, unsigned > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 return PTR_ERR(ctx); > | > | =A0 =A0 =A0 ret =3D do_checkpoint(ctx, pid); > | - > | =A0 =A0 =A0 if (!ret) > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 ret =3D ctx->crid; > | > | @@ -304,3 +303,4 @@ asmlinkage long sys_restart(int crid, int fd, u= nsigned lon > | =A0 =A0 =A0 cr_ctx_put(ctx); > | =A0 =A0 =A0 return ret; > | =A0} > | + > | diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.= h > | index 217cf6e..bc2c202 100644 > | --- a/include/linux/checkpoint.h > | +++ b/include/linux/checkpoint.h > | @@ -114,7 +114,6 @@ extern int cr_write_files(struct cr_ctx *ctx, s= truct task_ > | =A0extern int do_restart(struct cr_ctx *ctx, pid_t pid); > | =A0extern int cr_read_mm(struct cr_ctx *ctx); > | =A0extern int cr_read_files(struct cr_ctx *ctx); > | - > | =A0#ifdef pr_fmt > | =A0#undef pr_fmt > | =A0#endif > | diff --git a/include/linux/pid.h b/include/linux/pid.h > | index d7e98ff..86e2f61 100644 > | --- a/include/linux/pid.h > | +++ b/include/linux/pid.h > | @@ -119,7 +119,7 @@ extern struct pid *find_get_pid(int nr); > | =A0extern struct pid *find_ge_pid(int nr, struct pid_namespace *); > | =A0int next_pidmap(struct pid_namespace *pid_ns, int last); > | > | -extern struct pid *alloc_pid(struct pid_namespace *ns); > | +extern struct pid *alloc_pid(struct pid_namespace *ns, pid_t pid_n= r); > | =A0extern void free_pid(struct pid *pid); > | > | =A0/* > | diff --git a/include/linux/sched.h b/include/linux/sched.h > | index 0150e90..7fb4e28 100644 > | --- a/include/linux/sched.h > | +++ b/include/linux/sched.h > | @@ -28,6 +28,7 @@ > | =A0#define CLONE_NEWPID =A0 =A0 =A0 =A0 0x20000000 =A0 =A0 =A0/* Ne= w pid namespace */ > | =A0#define CLONE_NEWNET =A0 =A0 =A0 =A0 0x40000000 =A0 =A0 =A0/* Ne= w network namespace */ > | =A0#define CLONE_IO =A0 =A0 =A0 =A0 =A0 =A0 0x80000000 =A0 =A0 =A0/= * Clone io context */ > | +#define CLONE_WITH_PID =A0 =A0 =A0 =A0 =A0 =A0 =A0 0x00001000 =A0 = =A0 =A0/* Clone with pre-select PID */ > | > | =A0/* > | =A0 * Scheduling policies > | diff --git a/kernel/exit.c b/kernel/exit.c > | index 2d8be7e..4baf651 100644 > | --- a/kernel/exit.c > | +++ b/kernel/exit.c > | @@ -3,7 +3,7 @@ > | =A0 * > | =A0 * =A0Copyright (C) 1991, 1992 =A0Linus Torvalds > | =A0 */ > | - > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | @@ -1676,6 +1676,7 @@ static long do_wait(enum pid_type type, struc= t pid *pid, > | =A0 =A0 =A0 DECLARE_WAITQUEUE(wait, current); > | =A0 =A0 =A0 struct task_struct *tsk; > | =A0 =A0 =A0 int retval; > | + =A0 =A0 int level; > > and this (level is not used). > | > | =A0 =A0 =A0 trace_sched_process_wait(pid); > | > | @@ -1708,7 +1709,6 @@ repeat: > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 retval =3D tsk_result; > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto end; > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 } > | - > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (options & __WNOTHREAD) > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 break; > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 tsk =3D next_thread(tsk); > | @@ -1817,7 +1817,6 @@ asmlinkage long sys_wait4(pid_t upid, int __u= ser *stat_a > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 type =3D PIDTYPE_PID; > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 pid =3D find_get_pid(upid); > | =A0 =A0 =A0 } > | - > | =A0 =A0 =A0 ret =3D do_wait(type, pid, options | WEXITED, NULL, sta= t_addr, ru); > | =A0 =A0 =A0 put_pid(pid); > | > | diff --git a/kernel/fork.c b/kernel/fork.c > | index 085ce56..262ae1e 100644 > | --- a/kernel/fork.c > | +++ b/kernel/fork.c > | @@ -10,7 +10,7 @@ > | =A0 * Fork is rather simple, once you get the hang of it, but the m= emory > | =A0 * management can be a bitch. See 'mm/memory.c': 'copy_page_rang= e()' > | =A0 */ > | - > | +#define DEBUG > | =A0#include > | =A0#include > | =A0#include > | @@ -959,10 +959,19 @@ static struct task_struct *copy_process(unsig= ned long cl > | =A0 =A0 =A0 int retval; > | =A0 =A0 =A0 struct task_struct *p; > | =A0 =A0 =A0 int cgroup_callbacks_done =3D 0; > | + =A0 =A0 pid_t clone_pid =3D stack_size; > | > | =A0 =A0 =A0 if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) =3D=3D (CLON= E_NEWNS|CLONE_FS)) > | =A0 =A0 =A0 =A0 =A0 =A0 =A0 return ERR_PTR(-EINVAL); > | > | + =A0 =A0 /* We only allow the clone_with_pid when a new pid namesp= ace is > | + =A0 =A0 =A0* created. FIXME: how to restrict it. > > Not sure why CLONE_NEWPID is required to set pid_nr. In fact with CLO= NE_NEWPID, > by definition, pid_nr should be 1. Also, what happens if a container = has > more than one process - where the second process has a pid_nr > 2 ? > -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html