On Mon, 2 Sep 2024 19:49:20 +0800 Yun Zhou <[email protected]> wrote:
-ENOCHANGELOG What? Why? Why should I care about this? A change log *must* have all the information to say why this change is necessary. It's OK for the subject to state what it is doing, but there most definitely needs a "why?" in the change log. -- Steve > Signed-off-by: Yun Zhou <[email protected]> > --- > include/linux/pid_namespace.h | 1 + > kernel/pid.c | 12 ++++++------ > kernel/pid_namespace.c | 33 ++++++++++++++++++++++++++++----- > kernel/sysctl.c | 9 --------- > kernel/trace/pid_list.c | 2 +- > kernel/trace/trace.c | 2 +- > kernel/trace/trace.h | 2 -- > 7 files changed, 37 insertions(+), 24 deletions(-) > > diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h > index f9f9931e02d6..0e3c18f3cac5 100644 > --- a/include/linux/pid_namespace.h > +++ b/include/linux/pid_namespace.h > @@ -27,6 +27,7 @@ struct pid_namespace { > struct idr idr; > struct rcu_head rcu; > unsigned int pid_allocated; > + int pid_max; > struct task_struct *child_reaper; > struct kmem_cache *pid_cachep; > unsigned int level; > diff --git a/kernel/pid.c b/kernel/pid.c > index 6500ef956f2f..14da3f68ceed 100644 > --- a/kernel/pid.c > +++ b/kernel/pid.c > @@ -59,8 +59,6 @@ struct pid init_struct_pid = { > }, } > }; > > -int pid_max = PID_MAX_DEFAULT; > - > #define RESERVED_PIDS 300 > > int pid_max_min = RESERVED_PIDS + 1; > @@ -74,6 +72,7 @@ int pid_max_max = PID_MAX_LIMIT; > */ > struct pid_namespace init_pid_ns = { > .ns.count = REFCOUNT_INIT(2), > + .pid_max = PID_MAX_DEFAULT, > .idr = IDR_INIT(init_pid_ns.idr), > .pid_allocated = PIDNS_ADDING, > .level = 0, > @@ -194,7 +193,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t > *set_tid, > tid = set_tid[ns->level - i]; > > retval = -EINVAL; > - if (tid < 1 || tid >= pid_max) > + if (tid < 1 || tid >= tmp->pid_max) > goto out_free; > /* > * Also fail if a PID != 1 is requested and > @@ -234,7 +233,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t > *set_tid, > * a partially initialized PID (see below). > */ > nr = idr_alloc_cyclic(&tmp->idr, NULL, pid_min, > - pid_max, GFP_ATOMIC); > + tmp->pid_max, GFP_ATOMIC); > } > spin_unlock_irq(&pidmap_lock); > idr_preload_end(); > @@ -651,11 +650,12 @@ void __init pid_idr_init(void) > BUILD_BUG_ON(PID_MAX_LIMIT >= PIDNS_ADDING); > > /* bump default and minimum pid_max based on number of cpus */ > - pid_max = min(pid_max_max, max_t(int, pid_max, > + init_pid_ns.pid_max = min(pid_max_max, max_t(int, init_pid_ns.pid_max, > PIDS_PER_CPU_DEFAULT * num_possible_cpus())); > pid_max_min = max_t(int, pid_max_min, > PIDS_PER_CPU_MIN * num_possible_cpus()); > - pr_info("pid_max: default: %u minimum: %u\n", pid_max, pid_max_min); > + pr_info("pid_max: default: %u minimum: %u\n", init_pid_ns.pid_max, > + pid_max_min); > > idr_init(&init_pid_ns.idr); > > diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c > index 3028b2218aa4..d6b3f34ecb25 100644 > --- a/kernel/pid_namespace.c > +++ b/kernel/pid_namespace.c > @@ -110,6 +110,7 @@ static struct pid_namespace *create_pid_namespace(struct > user_namespace *user_ns > ns->user_ns = get_user_ns(user_ns); > ns->ucounts = ucounts; > ns->pid_allocated = PIDNS_ADDING; > + ns->pid_max = parent_pid_ns->pid_max; > #if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE) > ns->memfd_noexec_scope = pidns_memfd_noexec_scope(parent_pid_ns); > #endif > @@ -295,20 +296,44 @@ static int pid_ns_ctl_handler(struct ctl_table *table, > int write, > > return ret; > } > +#endif /* CONFIG_CHECKPOINT_RESTORE */ > + > +static int pid_max_ns_ctl_handler(struct ctl_table *table, int write, > + void *buffer, size_t *lenp, loff_t *ppos) > +{ > + struct pid_namespace *pid_ns = task_active_pid_ns(current); > + > + if (write && !checkpoint_restore_ns_capable(pid_ns->user_ns)) > + return -EPERM; > + > + table->data = &pid_ns->pid_max; > + if (pid_ns->parent) > + table->extra2 = &pid_ns->parent->pid_max; > + > + return proc_dointvec_minmax(table, write, buffer, lenp, ppos); > +} > > -extern int pid_max; > static struct ctl_table pid_ns_ctl_table[] = { > +#ifdef CONFIG_CHECKPOINT_RESTORE > { > .procname = "ns_last_pid", > .maxlen = sizeof(int), > .mode = 0666, /* permissions are checked in the handler */ > .proc_handler = pid_ns_ctl_handler, > .extra1 = SYSCTL_ZERO, > - .extra2 = &pid_max, > + .extra2 = &init_pid_ns.pid_max, > + }, > +#endif /* CONFIG_CHECKPOINT_RESTORE */ > + { > + .procname = "pid_max", > + .maxlen = sizeof(int), > + .mode = 0644, > + .proc_handler = pid_max_ns_ctl_handler, > + .extra1 = &pid_max_min, > + .extra2 = &pid_max_max, > }, > { } > }; > -#endif /* CONFIG_CHECKPOINT_RESTORE */ > > int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd) > { > @@ -465,9 +490,7 @@ static __init int pid_namespaces_init(void) > { > pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC | SLAB_ACCOUNT); > > -#ifdef CONFIG_CHECKPOINT_RESTORE > register_sysctl_init("kernel", pid_ns_ctl_table); > -#endif > > register_pid_ns_sysctl_table_vm(); > return 0; > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index 157f7ce2942d..857bfdb39b15 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -1809,15 +1809,6 @@ static struct ctl_table kern_table[] = { > .proc_handler = proc_dointvec, > }, > #endif > - { > - .procname = "pid_max", > - .data = &pid_max, > - .maxlen = sizeof (int), > - .mode = 0644, > - .proc_handler = proc_dointvec_minmax, > - .extra1 = &pid_max_min, > - .extra2 = &pid_max_max, > - }, > { > .procname = "panic_on_oops", > .data = &panic_on_oops, > diff --git a/kernel/trace/pid_list.c b/kernel/trace/pid_list.c > index 95106d02b32d..ef52820e6719 100644 > --- a/kernel/trace/pid_list.c > +++ b/kernel/trace/pid_list.c > @@ -414,7 +414,7 @@ struct trace_pid_list *trace_pid_list_alloc(void) > int i; > > /* According to linux/thread.h, pids can be no bigger that 30 bits */ > - WARN_ON_ONCE(pid_max > (1 << 30)); > + WARN_ON_ONCE(init_pid_ns.pid_max > (1 << 30)); > > pid_list = kzalloc(sizeof(*pid_list), GFP_KERNEL); > if (!pid_list) > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index fbcd3bafb93e..6295679ce16c 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5415,7 +5415,7 @@ int set_tracer_flag(struct trace_array *tr, unsigned > int mask, int enabled) > > if (mask == TRACE_ITER_RECORD_TGID) { > if (!tgid_map) { > - tgid_map_max = pid_max; > + tgid_map_max = init_pid_ns.pid_max; > map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map), > GFP_KERNEL); > > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h > index b7f4ea25a194..df61b1db86a2 100644 > --- a/kernel/trace/trace.h > +++ b/kernel/trace/trace.h > @@ -700,8 +700,6 @@ extern unsigned long tracing_thresh; > > /* PID filtering */ > > -extern int pid_max; > - > bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids, > pid_t search_pid); > bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
