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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c69
1 files changed, 57 insertions, 12 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 6c463c80e93d..e53770d2bf95 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -87,6 +87,7 @@
#include <linux/compiler.h>
#include <linux/sysctl.h>
#include <linux/kcov.h>
+#include <linux/livepatch.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -178,6 +179,24 @@ void __weak arch_release_thread_stack(unsigned long *stack)
*/
#define NR_CACHED_STACKS 2
static DEFINE_PER_CPU(struct vm_struct *, cached_stacks[NR_CACHED_STACKS]);
+
+static int free_vm_stack_cache(unsigned int cpu)
+{
+ struct vm_struct **cached_vm_stacks = per_cpu_ptr(cached_stacks, cpu);
+ int i;
+
+ for (i = 0; i < NR_CACHED_STACKS; i++) {
+ struct vm_struct *vm_stack = cached_vm_stacks[i];
+
+ if (!vm_stack)
+ continue;
+
+ vfree(vm_stack->addr);
+ cached_vm_stacks[i] = NULL;
+ }
+
+ return 0;
+}
#endif
static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node)
@@ -202,7 +221,7 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node)
stack = __vmalloc_node_range(THREAD_SIZE, THREAD_SIZE,
VMALLOC_START, VMALLOC_END,
- THREADINFO_GFP | __GFP_HIGHMEM,
+ THREADINFO_GFP,
PAGE_KERNEL,
0, node, __builtin_return_address(0));
@@ -466,6 +485,11 @@ void __init fork_init(void)
for (i = 0; i < UCOUNT_COUNTS; i++) {
init_user_ns.ucount_max[i] = max_threads/2;
}
+
+#ifdef CONFIG_VMAP_STACK
+ cpuhp_setup_state(CPUHP_BP_PREPARE_DYN, "fork:vm_stack_cache",
+ NULL, free_vm_stack_cache);
+#endif
}
int __weak arch_dup_task_struct(struct task_struct *dst,
@@ -536,7 +560,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
set_task_stack_end_magic(tsk);
#ifdef CONFIG_CC_STACKPROTECTOR
- tsk->stack_canary = get_random_int();
+ tsk->stack_canary = get_random_long();
#endif
/*
@@ -1313,7 +1337,7 @@ void __cleanup_sighand(struct sighand_struct *sighand)
if (atomic_dec_and_test(&sighand->count)) {
signalfd_cleanup(sighand);
/*
- * sighand_cachep is SLAB_DESTROY_BY_RCU so we can free it
+ * sighand_cachep is SLAB_TYPESAFE_BY_RCU so we can free it
* without an RCU grace period, see __lock_task_sighand().
*/
kmem_cache_free(sighand_cachep, sighand);
@@ -1438,6 +1462,7 @@ static void rt_mutex_init_task(struct task_struct *p)
#ifdef CONFIG_RT_MUTEXES
p->pi_waiters = RB_ROOT;
p->pi_waiters_leftmost = NULL;
+ p->pi_top_task = NULL;
p->pi_blocked_on = NULL;
#endif
}
@@ -1552,6 +1577,18 @@ static __latent_entropy struct task_struct *copy_process(
if (!p)
goto fork_out;
+ /*
+ * This _must_ happen before we call free_task(), i.e. before we jump
+ * to any of the bad_fork_* labels. This is to avoid freeing
+ * p->set_child_tid which is (ab)used as a kthread's data pointer for
+ * kernel threads (PF_KTHREAD).
+ */
+ p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
+ /*
+ * Clear TID on mm_release()?
+ */
+ p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
+
ftrace_graph_init_task(p);
rt_mutex_init_task(p);
@@ -1679,9 +1716,12 @@ static __latent_entropy struct task_struct *copy_process(
goto bad_fork_cleanup_perf;
/* copy all the process information */
shm_init_task(p);
- retval = copy_semundo(clone_flags, p);
+ retval = security_task_alloc(p, clone_flags);
if (retval)
goto bad_fork_cleanup_audit;
+ retval = copy_semundo(clone_flags, p);
+ if (retval)
+ goto bad_fork_cleanup_security;
retval = copy_files(clone_flags, p);
if (retval)
goto bad_fork_cleanup_semundo;
@@ -1715,11 +1755,6 @@ static __latent_entropy struct task_struct *copy_process(
}
}
- p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
- /*
- * Clear TID on mm_release()?
- */
- p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
#ifdef CONFIG_BLOCK
p->plug = NULL;
#endif
@@ -1797,6 +1832,8 @@ static __latent_entropy struct task_struct *copy_process(
p->parent_exec_id = current->self_exec_id;
}
+ klp_copy_process(p);
+
spin_lock(&current->sighand->siglock);
/*
@@ -1815,11 +1852,13 @@ static __latent_entropy struct task_struct *copy_process(
*/
recalc_sigpending();
if (signal_pending(current)) {
- spin_unlock(&current->sighand->siglock);
- write_unlock_irq(&tasklist_lock);
retval = -ERESTARTNOINTR;
goto bad_fork_cancel_cgroup;
}
+ if (unlikely(!(ns_of_pid(pid)->nr_hashed & PIDNS_HASH_ADDING))) {
+ retval = -ENOMEM;
+ goto bad_fork_cancel_cgroup;
+ }
if (likely(p->pid)) {
ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
@@ -1877,6 +1916,8 @@ static __latent_entropy struct task_struct *copy_process(
return p;
bad_fork_cancel_cgroup:
+ spin_unlock(&current->sighand->siglock);
+ write_unlock_irq(&tasklist_lock);
cgroup_cancel_fork(p);
bad_fork_free_pid:
cgroup_threadgroup_change_end(current);
@@ -1903,6 +1944,8 @@ bad_fork_cleanup_files:
exit_files(p); /* blocking */
bad_fork_cleanup_semundo:
exit_sem(p);
+bad_fork_cleanup_security:
+ security_task_free(p);
bad_fork_cleanup_audit:
audit_free(p);
bad_fork_cleanup_perf:
@@ -2144,7 +2187,7 @@ void __init proc_caches_init(void)
{
sighand_cachep = kmem_cache_create("sighand_cache",
sizeof(struct sighand_struct), 0,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_DESTROY_BY_RCU|
+ SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_TYPESAFE_BY_RCU|
SLAB_NOTRACK|SLAB_ACCOUNT, sighand_ctor);
signal_cachep = kmem_cache_create("signal_cache",
sizeof(struct signal_struct), 0,
@@ -2352,6 +2395,8 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
}
}
+ perf_event_namespaces(current);
+
bad_unshare_cleanup_cred:
if (new_cred)
put_cred(new_cred);
generated by cgit (git 2.34.1) at 2024-05-26 23:16:35 +0000