[v11][PATCH 7/9] Define do_fork_with_pids()

Sukadev Bhattiprolu
2009-11-05T05:39:45Z

Subject: [v11][PATCH 7/9] 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[v7]:
- Drop 'struct pid_set' object and pass in 'pid_t *target_pids'
instead of 'struct pid_set *'.

Changelog[v6]:
- (Nathan Lynch, Arnd Bergmann, H. Peter Anvin, Linus Torvalds)
Change 'pid_set.pids' to a 'pid_t pids[]' so size of 'struct pid_set'
is constant across architectures.
- (Nathan Lynch) Change 'pid_set.num_pids' to 'unsigned int'.

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@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Reviewed-by: Oren Laadan <orenl@cs.columbia.edu>
---
include/linux/sched.h | 3 +++
kernel/fork.c | 17 +++++++++++++++--
2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6b319a0..265efe5 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2153,6 +2153,9 @@ extern int disallow_signal(int);

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 *,
+ unsigned int, pid_t __user *);
struct task_struct *fork_idle(int);

extern void set_task_comm(struct task_struct *tsk, char *from);
diff --git a/kernel/fork.c b/kernel/fork.c
index 11f77ed..210e841 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1377,12 +1377,14 @@ struct task_struct * __cpuinit fork_idle(int cpu)
* 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,
+ unsigned int num_pids,
+ pid_t __user *upids)
{
struct task_struct *p;
int trace = 0;
@@ -1485,6 +1487,17 @@ long do_fork(unsigned long clone_flags,
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, 0, NULL);
+}
+
#ifndef ARCH_MIN_MMSTRUCT_ALIGN
#define ARCH_MIN_MMSTRUCT_ALIGN 0
#endif
--
1.6.0.4