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Mon, 02 Sep 2024 11:49:25 +0000 (GMT) Received: from ala-exchng01.corp.ad.wrs.com (147.11.82.252) by ala-exchng01.corp.ad.wrs.com (147.11.82.252) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 2 Sep 2024 04:49:23 -0700 Received: from pek-lpd-ccm5.wrs.com (147.11.136.210) by ala-exchng01.corp.ad.wrs.com (147.11.82.252) with Microsoft SMTP Server id 15.1.2507.39 via Frontend Transport; Mon, 2 Sep 2024 04:49:21 -0700 From: Yun Zhou To: , , , , , , CC: , , Subject: [PATCH] kernel: add pid_max to pid_namespace Date: Mon, 2 Sep 2024 19:49:20 +0800 Message-ID: <20240902114920.1534699-1-yun.zhou@windriver.com> X-Mailer: git-send-email 2.27.0 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Proofpoint-ORIG-GUID: pBk3oJjMTpTfqvgKEfVvYDrt0PlWpOZ0 X-Authority-Analysis: v=2.4 cv=DN/d4DNb c=1 sm=1 tr=0 ts=66d5a645 cx=c_pps a=/ZJR302f846pc/tyiSlYyQ==:117 a=/ZJR302f846pc/tyiSlYyQ==:17 a=EaEq8P2WXUwA:10 a=t7CeM3EgAAAA:8 a=Xi3v-mgWfji5ICalIy4A:9 a=FdTzh2GWekK77mhwV6Dw:22 X-Proofpoint-GUID: pBk3oJjMTpTfqvgKEfVvYDrt0PlWpOZ0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-09-02_02,2024-09-02_01,2024-05-17_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1011 suspectscore=0 spamscore=0 phishscore=0 adultscore=0 mlxscore=0 impostorscore=0 lowpriorityscore=0 bulkscore=0 mlxlogscore=999 malwarescore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.21.0-2407110000 definitions=main-2409020095 Signed-off-by: Yun Zhou --- 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,