VisionFive2 Linux kernel

StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)

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author: Hang Lu <hangl@codeaurora.org> 2021-04-09 17:40:46 +0800 committer: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2021-04-10 10:52:04 +0200 commit: a7dc1e6f99df59799ab0128d9c4e47bbeceb934d parent: 005169157448ca41eff8716d79dc1b8f158229d2
Commit Summary:
binder: tell userspace to dump current backtrace when detected oneway spamming
Diffstat:
4 files changed, 47 insertions, 8 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index be34da3dd077..63d2c4339689 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3020,7 +3020,10 @@ static void binder_transaction(struct binder_proc *proc,
 			goto err_bad_object_type;
 		}
 	}
-	tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;
+	if (t->buffer->oneway_spam_suspect)
+		tcomplete->type = BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT;
+	else
+		tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;
 	t->work.type = BINDER_WORK_TRANSACTION;
 
 	if (reply) {
@@ -3893,9 +3896,14 @@ retry:
 
 			binder_stat_br(proc, thread, cmd);
 		} break;
-		case BINDER_WORK_TRANSACTION_COMPLETE: {
+		case BINDER_WORK_TRANSACTION_COMPLETE:
+		case BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT: {
+			if (proc->oneway_spam_detection_enabled &&
+				   w->type == BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT)
+				cmd = BR_ONEWAY_SPAM_SUSPECT;
+			else
+				cmd = BR_TRANSACTION_COMPLETE;
 			binder_inner_proc_unlock(proc);
-			cmd = BR_TRANSACTION_COMPLETE;
 			kfree(w);
 			binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
 			if (put_user(cmd, (uint32_t __user *)ptr))
@@ -4897,6 +4905,18 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		}
 		break;
 	}
+	case BINDER_ENABLE_ONEWAY_SPAM_DETECTION: {
+		uint32_t enable;
+
+		if (copy_from_user(&enable, ubuf, sizeof(enable))) {
+			ret = -EINVAL;
+			goto err;
+		}
+		binder_inner_proc_lock(proc);
+		proc->oneway_spam_detection_enabled = (bool)enable;
+		binder_inner_proc_unlock(proc);
+		break;
+	}
 	default:
 		ret = -EINVAL;
 		goto err;
@@ -5561,6 +5581,7 @@ static const char * const binder_return_strings[] = {
 	"BR_CLEAR_DEATH_NOTIFICATION_DONE",
 	"BR_FAILED_REPLY",
 	"BR_FROZEN_REPLY",
+	"BR_ONEWAY_SPAM_SUSPECT",
 };
 
 static const char * const binder_command_strings[] = {
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 7caf74ad2405..340515f54498 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -338,7 +338,7 @@ static inline struct vm_area_struct *binder_alloc_get_vma(
 	return vma;
 }
 
-static void debug_low_async_space_locked(struct binder_alloc *alloc, int pid)
+static bool debug_low_async_space_locked(struct binder_alloc *alloc, int pid)
 {
 	/*
 	 * Find the amount and size of buffers allocated by the current caller;
@@ -366,13 +366,19 @@ static void debug_low_async_space_locked(struct binder_alloc *alloc, int pid)
 
 	/*
 	 * Warn if this pid has more than 50 transactions, or more than 50% of
-	 * async space (which is 25% of total buffer size).
+	 * async space (which is 25% of total buffer size). Oneway spam is only
+	 * detected when the threshold is exceeded.
 	 */
 	if (num_buffers > 50 || total_alloc_size > alloc->buffer_size / 4) {
 		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
 			     "%d: pid %d spamming oneway? %zd buffers allocated for a total size of %zd\n",
 			      alloc->pid, pid, num_buffers, total_alloc_size);
+		if (!alloc->oneway_spam_detected) {
+			alloc->oneway_spam_detected = true;
+			return true;
+		}
 	}
+	return false;
 }
 
 static struct binder_buffer *binder_alloc_new_buf_locked(
@@ -525,6 +531,7 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
 	buffer->async_transaction = is_async;
 	buffer->extra_buffers_size = extra_buffers_size;
 	buffer->pid = pid;
+	buffer->oneway_spam_suspect = false;
 	if (is_async) {
 		alloc->free_async_space -= size + sizeof(struct binder_buffer);
 		binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
@@ -536,7 +543,9 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
 			 * of async space left (which is less than 10% of total
 			 * buffer size).
 			 */
-			debug_low_async_space_locked(alloc, pid);
+			buffer->oneway_spam_suspect = debug_low_async_space_locked(alloc, pid);
+		} else {
+			alloc->oneway_spam_detected = false;
 		}
 	}
 	return buffer;
diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h
index 6e8e001381af..7dea57a84c79 100644
--- a/drivers/android/binder_alloc.h
+++ b/drivers/android/binder_alloc.h
@@ -26,6 +26,8 @@ struct binder_transaction;
  * @clear_on_free:      %true if buffer must be zeroed after use
  * @allow_user_free:    %true if user is allowed to free buffer
  * @async_transaction:  %true if buffer is in use for an async txn
+ * @oneway_spam_suspect: %true if total async allocate size just exceed
+ * spamming detect threshold
  * @debug_id:           unique ID for debugging
  * @transaction:        pointer to associated struct binder_transaction
  * @target_node:        struct binder_node associated with this buffer
@@ -45,7 +47,8 @@ struct binder_buffer {
 	unsigned clear_on_free:1;
 	unsigned allow_user_free:1;
 	unsigned async_transaction:1;
-	unsigned debug_id:28;
+	unsigned oneway_spam_suspect:1;
+	unsigned debug_id:27;
 
 	struct binder_transaction *transaction;
 
@@ -87,6 +90,8 @@ struct binder_lru_page {
  * @buffer_size:        size of address space specified via mmap
  * @pid:                pid for associated binder_proc (invariant after init)
  * @pages_high:         high watermark of offset in @pages
+ * @oneway_spam_detected: %true if oneway spam detection fired, clear that
+ * flag once the async buffer has returned to a healthy state
  *
  * Bookkeeping structure for per-proc address space management for binder
  * buffers. It is normally initialized during binder_init() and binder_mmap()
@@ -107,6 +112,7 @@ struct binder_alloc {
 	uint32_t buffer_free;
 	int pid;
 	size_t pages_high;
+	bool oneway_spam_detected;
 };
 
 #ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
index a50716696fad..810c0b84d3f8 100644
--- a/drivers/android/binder_internal.h
+++ b/drivers/android/binder_internal.h
@@ -155,7 +155,7 @@ enum binder_stat_types {
 };
 
 struct binder_stats {
-	atomic_t br[_IOC_NR(BR_FROZEN_REPLY) + 1];
+	atomic_t br[_IOC_NR(BR_ONEWAY_SPAM_SUSPECT) + 1];
 	atomic_t bc[_IOC_NR(BC_REPLY_SG) + 1];
 	atomic_t obj_created[BINDER_STAT_COUNT];
 	atomic_t obj_deleted[BINDER_STAT_COUNT];
@@ -174,6 +174,7 @@ struct binder_work {
 	enum binder_work_type {
 		BINDER_WORK_TRANSACTION = 1,
 		BINDER_WORK_TRANSACTION_COMPLETE,
+		BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT,
 		BINDER_WORK_RETURN_ERROR,
 		BINDER_WORK_NODE,
 		BINDER_WORK_DEAD_BINDER,
@@ -409,6 +410,8 @@ struct binder_ref {
  * @outer_lock:           no nesting under innor or node lock
  *                        Lock order: 1) outer, 2) node, 3) inner
  * @binderfs_entry:       process-specific binderfs log file
+ * @oneway_spam_detection_enabled: process enabled oneway spam detection
+ *                        or not
  *
  * Bookkeeping structure for binder processes
  */
@@ -444,6 +447,7 @@ struct binder_proc {
 	spinlock_t inner_lock;
 	spinlock_t outer_lock;
 	struct dentry *binderfs_entry;
+	bool oneway_spam_detection_enabled;
 };
 
 /**