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From:   Sherry Yang <sherryy@android.com>
To:     linux-kernel@vger.kernel.org
Cc:     tkjos@google.com, maco@google.com,
        Sherry Yang <sherryy@android.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= <arve@android.com>,
        Todd Kjos <tkjos@android.com>,
        Martijn Coenen <maco@android.com>,
        devel@driverdev.osuosl.org (open list:ANDROID DRIVERS)
Subject: [PATCH 2/2] android: binder: Rate-limit debug and userspace triggered err msgs
Date:   Thu, 26 Jul 2018 17:17:18 -0700
Message-Id: <20180727001718.242587-3-sherryy@android.com>
In-Reply-To: <20180727001718.242587-1-sherryy@android.com>
References: <20180727001718.242587-1-sherryy@android.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Use rate-limited debug messages where userspace can trigger
excessive log spams.

Acked-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Sherry Yang <sherryy@android.com>
---
 drivers/android/binder.c       |  5 +++--
 drivers/android/binder_alloc.c | 41 +++++++++++++++++++++-------------
 2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 95283f3bb51c..78cc1190282c 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -71,6 +71,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/security.h>
 #include <linux/spinlock.h>
+#include <linux/ratelimit.h>
 
 #include <uapi/linux/android/binder.h>
 #include "binder_alloc.h"
@@ -161,13 +162,13 @@ module_param_call(stop_on_user_error, binder_set_stop_on_user_error,
 #define binder_debug(mask, x...) \
 	do { \
 		if (binder_debug_mask & mask) \
-			pr_info(x); \
+			pr_info_ratelimited(x); \
 	} while (0)
 
 #define binder_user_error(x...) \
 	do { \
 		if (binder_debug_mask & BINDER_DEBUG_USER_ERROR) \
-			pr_info(x); \
+			pr_info_ratelimited(x); \
 		if (binder_stop_on_user_error) \
 			binder_stop_on_user_error = 2; \
 	} while (0)
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 2628806c64a2..e16116e9ad1f 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -28,6 +28,7 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/list_lru.h>
+#include <linux/ratelimit.h>
 #include "binder_alloc.h"
 #include "binder_trace.h"
 
@@ -36,11 +37,12 @@ struct list_lru binder_alloc_lru;
 static DEFINE_MUTEX(binder_alloc_mmap_lock);
 
 enum {
+	BINDER_DEBUG_USER_ERROR             = 1U << 0,
 	BINDER_DEBUG_OPEN_CLOSE             = 1U << 1,
 	BINDER_DEBUG_BUFFER_ALLOC           = 1U << 2,
 	BINDER_DEBUG_BUFFER_ALLOC_ASYNC     = 1U << 3,
 };
-static uint32_t binder_alloc_debug_mask;
+static uint32_t binder_alloc_debug_mask = BINDER_DEBUG_USER_ERROR;
 
 module_param_named(debug_mask, binder_alloc_debug_mask,
 		   uint, 0644);
@@ -48,7 +50,7 @@ module_param_named(debug_mask, binder_alloc_debug_mask,
 #define binder_alloc_debug(mask, x...) \
 	do { \
 		if (binder_alloc_debug_mask & mask) \
-			pr_info(x); \
+			pr_info_ratelimited(x); \
 	} while (0)
 
 static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer)
@@ -152,8 +154,10 @@ static struct binder_buffer *binder_alloc_prepare_to_free_locked(
 			 * free the buffer twice
 			 */
 			if (buffer->free_in_progress) {
-				pr_err("%d:%d FREE_BUFFER u%016llx user freed buffer twice\n",
-				       alloc->pid, current->pid, (u64)user_ptr);
+				binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+						   "%d:%d FREE_BUFFER u%016llx user freed buffer twice\n",
+						   alloc->pid, current->pid,
+						   (u64)user_ptr);
 				return NULL;
 			}
 			buffer->free_in_progress = 1;
@@ -224,8 +228,9 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 	}
 
 	if (!vma && need_mm) {
-		pr_err("%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
-			alloc->pid);
+		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+				   "%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
+				   alloc->pid);
 		goto err_no_vma;
 	}
 
@@ -344,8 +349,9 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
 	int ret;
 
 	if (alloc->vma == NULL) {
-		pr_err("%d: binder_alloc_buf, no vma\n",
-		       alloc->pid);
+		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+				   "%d: binder_alloc_buf, no vma\n",
+				   alloc->pid);
 		return ERR_PTR(-ESRCH);
 	}
 
@@ -417,11 +423,14 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
 			if (buffer_size > largest_free_size)
 				largest_free_size = buffer_size;
 		}
-		pr_err("%d: binder_alloc_buf size %zd failed, no address space\n",
-			alloc->pid, size);
-		pr_err("allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
-		       total_alloc_size, allocated_buffers, largest_alloc_size,
-		       total_free_size, free_buffers, largest_free_size);
+		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+				   "%d: binder_alloc_buf size %zd failed, no address space\n",
+				   alloc->pid, size);
+		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+				   "allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
+				   total_alloc_size, allocated_buffers,
+				   largest_alloc_size, total_free_size,
+				   free_buffers, largest_free_size);
 		return ERR_PTR(-ENOSPC);
 	}
 	if (n == NULL) {
@@ -731,8 +740,10 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 err_get_vm_area_failed:
 err_already_mapped:
 	mutex_unlock(&binder_alloc_mmap_lock);
-	pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
-	       alloc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
+	binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+			   "%s: %d %lx-%lx %s failed %d\n", __func__,
+			   alloc->pid, vma->vm_start, vma->vm_end,
+			   failure_string, ret);
 	return ret;
 }
 
-- 
2.18.0.345.g5c9ce644c3-goog