From f400e198b2ed26ce55b22a1412ded0896e7516ac Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Fri, 29 Sep 2006 02:00:07 -0700 Subject: [PATCH] pidspace: is_init() This is an updated version of Eric Biederman's is_init() patch. (http://lkml.org/lkml/2006/2/6/280). It applies cleanly to 2.6.18-rc3 and replaces a few more instances of ->pid == 1 with is_init(). Further, is_init() checks pid and thus removes dependency on Eric's other patches for now. Eric's original description: There are a lot of places in the kernel where we test for init because we give it special properties. Most significantly init must not die. This results in code all over the kernel test ->pid == 1. Introduce is_init to capture this case. With multiple pid spaces for all of the cases affected we are looking for only the first process on the system, not some other process that has pid == 1. Signed-off-by: Eric W. Biederman Signed-off-by: Sukadev Bhattiprolu Cc: Dave Hansen Cc: Serge Hallyn Cc: Cedric Le Goater Cc: Acked-by: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/capability.c | 2 +- kernel/cpuset.c | 2 +- kernel/exit.c | 2 +- kernel/kexec.c | 2 +- kernel/ptrace.c | 1 + kernel/sysctl.c | 2 +- 6 files changed, 6 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/capability.c b/kernel/capability.c index c7685ad00a97..edb845a6e84a 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -133,7 +133,7 @@ static inline int cap_set_all(kernel_cap_t *effective, int found = 0; do_each_thread(g, target) { - if (target == current || target->pid == 1) + if (target == current || is_init(target)) continue; found = 1; if (security_capset_check(target, effective, inheritable, diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 1b32c2c04c15..584bb4e6c042 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -240,7 +240,7 @@ static struct super_block *cpuset_sb; * A cpuset can only be deleted if both its 'count' of using tasks * is zero, and its list of 'children' cpusets is empty. Since all * tasks in the system use _some_ cpuset, and since there is always at - * least one task in the system (init, pid == 1), therefore, top_cpuset + * least one task in the system (init), therefore, top_cpuset * always has either children cpusets and/or using tasks. So we don't * need a special hack to ensure that top_cpuset cannot be deleted. * diff --git a/kernel/exit.c b/kernel/exit.c index 4b6fb054b25d..9961192d6055 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -219,7 +219,7 @@ static int will_become_orphaned_pgrp(int pgrp, struct task_struct *ignored_task) do_each_task_pid(pgrp, PIDTYPE_PGID, p) { if (p == ignored_task || p->exit_state - || p->real_parent->pid == 1) + || is_init(p->real_parent)) continue; if (process_group(p->real_parent) != pgrp && p->real_parent->signal->session == p->signal->session) { diff --git a/kernel/kexec.c b/kernel/kexec.c index 50087ecf337e..37cad75cf494 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -40,7 +40,7 @@ struct resource crashk_res = { int kexec_should_crash(struct task_struct *p) { - if (in_interrupt() || !p->pid || p->pid == 1 || panic_on_oops) + if (in_interrupt() || !p->pid || is_init(p) || panic_on_oops) return 1; return 0; } diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 8aad0331d82e..4d50e06fd745 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -440,6 +440,7 @@ struct task_struct *ptrace_get_task_struct(pid_t pid) child = find_task_by_pid(pid); if (child) get_task_struct(child); + read_unlock(&tasklist_lock); if (!child) return ERR_PTR(-ESRCH); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8bfa7d117c54..9535a3839930 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1915,7 +1915,7 @@ int proc_dointvec_bset(ctl_table *table, int write, struct file *filp, return -EPERM; } - op = (current->pid == 1) ? OP_SET : OP_AND; + op = is_init(current) ? OP_SET : OP_AND; return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, do_proc_dointvec_bset_conv,&op); } -- cgit v1.2.3