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Message-Id: <20170629190211.16927-10-tkjos@google.com>
Date: Thu, 29 Jun 2017 12:01:43 -0700
From: Todd Kjos <tkjos@...roid.com>
To: gregkh@...uxfoundation.org, arve@...roid.com,
devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org,
maco@...gle.com, tkjos@...gle.com
Subject: [PATCH 09/37] binder: add protection for non-perf cases
Add binder_dead_nodes_lock, binder_procs_lock, and
binder_context_mgr_node_lock to protect the associated global lists
Signed-off-by: Todd Kjos <tkjos@...gle.com>
---
drivers/android/binder.c | 81 +++++++++++++++++++++++++++++++++++++-----------
1 file changed, 63 insertions(+), 18 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 10fda7ab9fa5..fb484c6acd3e 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -46,12 +46,16 @@
#include "binder_trace.h"
static DEFINE_MUTEX(binder_main_lock);
+
+static HLIST_HEAD(binder_deferred_list);
static DEFINE_MUTEX(binder_deferred_lock);
static HLIST_HEAD(binder_devices);
static HLIST_HEAD(binder_procs);
-static HLIST_HEAD(binder_deferred_list);
+static DEFINE_MUTEX(binder_procs_lock);
+
static HLIST_HEAD(binder_dead_nodes);
+static DEFINE_SPINLOCK(binder_dead_nodes_lock);
static struct dentry *binder_debugfs_dir_entry_root;
static struct dentry *binder_debugfs_dir_entry_proc;
@@ -219,6 +223,8 @@ static struct binder_transaction_log_entry *binder_transaction_log_add(
struct binder_context {
struct binder_node *binder_context_mgr_node;
+ struct mutex context_mgr_node_lock;
+
kuid_t binder_context_mgr_uid;
const char *name;
};
@@ -570,7 +576,9 @@ static int binder_dec_node(struct binder_node *node, int strong, int internal)
"refless node %d deleted\n",
node->debug_id);
} else {
+ spin_lock(&binder_dead_nodes_lock);
hlist_del(&node->dead_node);
+ spin_unlock(&binder_dead_nodes_lock);
binder_debug(BINDER_DEBUG_INTERNAL_REFS,
"dead node %d deleted\n",
node->debug_id);
@@ -1454,11 +1462,14 @@ static void binder_transaction(struct binder_proc *proc,
}
target_node = ref->node;
} else {
+ mutex_lock(&context->context_mgr_node_lock);
target_node = context->binder_context_mgr_node;
if (target_node == NULL) {
return_error = BR_DEAD_REPLY;
+ mutex_unlock(&context->context_mgr_node_lock);
goto err_no_context_mgr_node;
}
+ mutex_unlock(&context->context_mgr_node_lock);
}
e->to_node = target_node->debug_id;
target_proc = target_node->proc;
@@ -1824,22 +1835,31 @@ static int binder_thread_write(struct binder_proc *proc,
case BC_RELEASE:
case BC_DECREFS: {
uint32_t target;
- struct binder_ref *ref;
+ struct binder_ref *ref = NULL;
const char *debug_string;
if (get_user(target, (uint32_t __user *)ptr))
return -EFAULT;
+
ptr += sizeof(uint32_t);
- if (target == 0 && context->binder_context_mgr_node &&
+ if (target == 0 &&
(cmd == BC_INCREFS || cmd == BC_ACQUIRE)) {
- ref = binder_get_ref_for_node(proc,
- context->binder_context_mgr_node);
- if (ref->desc != target) {
- binder_user_error("%d:%d tried to acquire reference to desc 0, got %d instead\n",
- proc->pid, thread->pid,
- ref->desc);
+ struct binder_node *ctx_mgr_node;
+
+ mutex_lock(&context->context_mgr_node_lock);
+ ctx_mgr_node = context->binder_context_mgr_node;
+ if (ctx_mgr_node) {
+ ref = binder_get_ref_for_node(proc,
+ ctx_mgr_node);
+ if (ref && ref->desc != target) {
+ binder_user_error("%d:%d tried to acquire reference to desc 0, got %d instead\n",
+ proc->pid, thread->pid,
+ ref->desc);
+ }
}
- } else
+ mutex_unlock(&context->context_mgr_node_lock);
+ }
+ if (ref == NULL)
ref = binder_get_ref(proc, target,
cmd == BC_ACQUIRE ||
cmd == BC_RELEASE);
@@ -2753,9 +2773,10 @@ static int binder_ioctl_set_ctx_mgr(struct file *filp)
int ret = 0;
struct binder_proc *proc = filp->private_data;
struct binder_context *context = proc->context;
-
+ struct binder_node *new_node;
kuid_t curr_euid = current_euid();
+ mutex_lock(&context->context_mgr_node_lock);
if (context->binder_context_mgr_node) {
pr_err("BINDER_SET_CONTEXT_MGR already set\n");
ret = -EBUSY;
@@ -2776,16 +2797,18 @@ static int binder_ioctl_set_ctx_mgr(struct file *filp)
} else {
context->binder_context_mgr_uid = curr_euid;
}
- context->binder_context_mgr_node = binder_new_node(proc, 0, 0);
- if (!context->binder_context_mgr_node) {
+ new_node = binder_new_node(proc, 0, 0);
+ if (!new_node) {
ret = -ENOMEM;
goto out;
}
- context->binder_context_mgr_node->local_weak_refs++;
- context->binder_context_mgr_node->local_strong_refs++;
- context->binder_context_mgr_node->has_strong_ref = 1;
- context->binder_context_mgr_node->has_weak_ref = 1;
+ new_node->local_weak_refs++;
+ new_node->local_strong_refs++;
+ new_node->has_strong_ref = 1;
+ new_node->has_weak_ref = 1;
+ context->binder_context_mgr_node = new_node;
out:
+ mutex_unlock(&context->context_mgr_node_lock);
return ret;
}
@@ -2965,13 +2988,16 @@ static int binder_open(struct inode *nodp, struct file *filp)
binder_lock(__func__);
binder_stats_created(BINDER_STAT_PROC);
- hlist_add_head(&proc->proc_node, &binder_procs);
proc->pid = current->group_leader->pid;
INIT_LIST_HEAD(&proc->delivered_death);
filp->private_data = proc;
binder_unlock(__func__);
+ mutex_lock(&binder_procs_lock);
+ hlist_add_head(&proc->proc_node, &binder_procs);
+ mutex_unlock(&binder_procs_lock);
+
if (binder_debugfs_dir_entry_proc) {
char strbuf[11];
@@ -3050,7 +3076,10 @@ static int binder_node_release(struct binder_node *node, int refs)
node->proc = NULL;
node->local_strong_refs = 0;
node->local_weak_refs = 0;
+
+ spin_lock(&binder_dead_nodes_lock);
hlist_add_head(&node->dead_node, &binder_dead_nodes);
+ spin_unlock(&binder_dead_nodes_lock);
hlist_for_each_entry(ref, &node->refs, node_entry) {
refs++;
@@ -3084,8 +3113,11 @@ static void binder_deferred_release(struct binder_proc *proc)
BUG_ON(proc->files);
+ mutex_lock(&binder_procs_lock);
hlist_del(&proc->proc_node);
+ mutex_unlock(&binder_procs_lock);
+ mutex_lock(&context->context_mgr_node_lock);
if (context->binder_context_mgr_node &&
context->binder_context_mgr_node->proc == proc) {
binder_debug(BINDER_DEBUG_DEAD_BINDER,
@@ -3093,6 +3125,7 @@ static void binder_deferred_release(struct binder_proc *proc)
__func__, proc->pid);
context->binder_context_mgr_node = NULL;
}
+ mutex_unlock(&context->context_mgr_node_lock);
threads = 0;
active_transactions = 0;
@@ -3509,13 +3542,17 @@ static int binder_state_show(struct seq_file *m, void *unused)
seq_puts(m, "binder state:\n");
+ spin_lock(&binder_dead_nodes_lock);
if (!hlist_empty(&binder_dead_nodes))
seq_puts(m, "dead nodes:\n");
hlist_for_each_entry(node, &binder_dead_nodes, dead_node)
print_binder_node(m, node);
+ spin_unlock(&binder_dead_nodes_lock);
+ mutex_lock(&binder_procs_lock);
hlist_for_each_entry(proc, &binder_procs, proc_node)
print_binder_proc(m, proc, 1);
+ mutex_unlock(&binder_procs_lock);
binder_unlock(__func__);
return 0;
}
@@ -3530,8 +3567,10 @@ static int binder_stats_show(struct seq_file *m, void *unused)
print_binder_stats(m, "", &binder_stats);
+ mutex_lock(&binder_procs_lock);
hlist_for_each_entry(proc, &binder_procs, proc_node)
print_binder_proc_stats(m, proc);
+ mutex_unlock(&binder_procs_lock);
binder_unlock(__func__);
return 0;
}
@@ -3543,8 +3582,10 @@ static int binder_transactions_show(struct seq_file *m, void *unused)
binder_lock(__func__);
seq_puts(m, "binder transactions:\n");
+ mutex_lock(&binder_procs_lock);
hlist_for_each_entry(proc, &binder_procs, proc_node)
print_binder_proc(m, proc, 0);
+ mutex_unlock(&binder_procs_lock);
binder_unlock(__func__);
return 0;
}
@@ -3556,12 +3597,15 @@ static int binder_proc_show(struct seq_file *m, void *unused)
binder_lock(__func__);
+ mutex_lock(&binder_procs_lock);
hlist_for_each_entry(itr, &binder_procs, proc_node) {
if (itr->pid == pid) {
seq_puts(m, "binder proc state:\n");
print_binder_proc(m, itr, 1);
}
}
+ mutex_unlock(&binder_procs_lock);
+
binder_unlock(__func__);
return 0;
}
@@ -3622,6 +3666,7 @@ static int __init init_binder_device(const char *name)
binder_device->context.binder_context_mgr_uid = INVALID_UID;
binder_device->context.name = name;
+ mutex_init(&binder_device->context.context_mgr_node_lock);
ret = misc_register(&binder_device->miscdev);
if (ret < 0) {
--
2.13.2.725.g09c95d1e9-goog
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