[RFC][v5][PATCH 7/8]: Define do_fork_with_pids()

Sukadev Bhattiprolu
2009-09-07T21:11:55Z

Subject: [RFC][v5][PATCH 7/8]: Define do_fork_with_pids()

do_fork_with_pids() is same as do_fork(), except that it takes an
additional, 'pid_set', parameter. This parameter, currently unused,
specifies the set of target pids of the process in each of its pid
namespaces.

Changelog[v4]:
- Rename 'struct target_pid_set' to 'struct pid_set' since it may
be useful in other contexts.
Changelog[v3]:
- Fix "long-line" warning from checkpatch.pl

Changelog[v2]:
- To facilitate moving architecture-inpdendent code to kernel/fork.c
pass in 'struct target_pid_set __user *' to do_fork_with_pids()
rather than 'pid_t *' (next patch moves the arch-independent
code to kernel/fork.c)

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Reviewed-by: Oren Laadan <orenl@cs.columbia.edu>
---
include/linux/sched.h | 3 +++
include/linux/types.h | 5 +++++
kernel/fork.c | 16 ++++++++++++++--
3 files changed, 22 insertions(+), 2 deletions(-)

Index: linux-2.6/include/linux/sched.h
===================================================================
--- linux-2.6.orig/include/linux/sched.h 2009-09-07 13:10:39.000000000 -0700
+++ linux-2.6/include/linux/sched.h 2009-09-07 13:13:33.000000000 -0700
@@ -2054,6 +2054,9 @@

extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
+extern long do_fork_with_pids(unsigned long, unsigned long, struct pt_regs *,
+ unsigned long, int __user *, int __user *,
+ struct pid_set __user *pid_set);
struct task_struct *fork_idle(int);

extern void set_task_comm(struct task_struct *tsk, char *from);
Index: linux-2.6/include/linux/types.h
===================================================================
--- linux-2.6.orig/include/linux/types.h 2009-09-05 19:16:37.000000000 -0700
+++ linux-2.6/include/linux/types.h 2009-09-07 13:13:33.000000000 -0700
@@ -204,6 +204,11 @@
char f_fpack[6];
};

+struct pid_set {
+ int num_pids;
+ pid_t *pids;
+};
+
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
#endif /* _LINUX_TYPES_H */
Index: linux-2.6/kernel/fork.c
===================================================================
--- linux-2.6.orig/kernel/fork.c 2009-09-07 13:13:33.000000000 -0700
+++ linux-2.6/kernel/fork.c 2009-09-07 13:13:33.000000000 -0700
@@ -1332,12 +1332,13 @@
* It copies the process, and if successful kick-starts
* it and waits for it to finish using the VM if required.
*/
-long do_fork(unsigned long clone_flags,
+long do_fork_with_pids(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size,
int __user *parent_tidptr,
- int __user *child_tidptr)
+ int __user *child_tidptr,
+ struct pid_set __user *pid_setp)
{
struct task_struct *p;
int trace = 0;
@@ -1440,6 +1441,17 @@
return nr;
}

+long do_fork(unsigned long clone_flags,
+ unsigned long stack_start,
+ struct pt_regs *regs,
+ unsigned long stack_size,
+ int __user *parent_tidptr,
+ int __user *child_tidptr)
+{
+ return do_fork_with_pids(clone_flags, stack_start, regs, stack_size,
+ parent_tidptr, child_tidptr, NULL);
+}
+
#ifndef ARCH_MIN_MMSTRUCT_ALIGN
#define ARCH_MIN_MMSTRUCT_ALIGN 0
#endif