xnu-2422.115.4.tar.gz

[apple/xnu.git] / osfmk / kern / telemetry.c

diff --git a/osfmk/kern/telemetry.c b/osfmk/kern/telemetry.c
index 724f8a2af6e036ba87cd4b1fa4bf67d60bcc4682..15b0254183921213a1ed86f0f07f31af7dedef4c 100644 (file)
--- a/osfmk/kern/telemetry.c
+++ b/osfmk/kern/telemetry.c
@@ -73,6 +73,7 @@ void telemetry_take_sample(thread_t thread, uint8_t microsnapshot_flags);
 #define TELEMETRY_MAX_BUFFER_SIZE (64*1024)
 
 #define        TELEMETRY_DEFAULT_NOTIFY_LEEWAY (4*1024) // Userland gets 4k of leeway to collect data after notification
+#define        TELEMETRY_MAX_UUID_COUNT (128) // Max of 128 non-shared-cache UUIDs to log for symbolication
 
 uint32_t                       telemetry_sample_rate = 0;
 volatile boolean_t     telemetry_needs_record = FALSE;
@@ -421,6 +422,14 @@ void telemetry_take_sample(thread_t thread, uint8_t microsnapshot_flags)
                uuid_info_count = 0;
        }
 
+       /*
+        * Don't copy in an unbounded amount of memory. The main binary and interesting
+        * non-shared-cache libraries should be in the first few images.
+        */
+       if (uuid_info_count > TELEMETRY_MAX_UUID_COUNT) {
+               uuid_info_count = TELEMETRY_MAX_UUID_COUNT;
+       }
+
        uint32_t uuid_info_size = (uint32_t)(task_has_64BitAddr(thread->task) ? sizeof(struct user64_dyld_uuid_info) : sizeof(struct user32_dyld_uuid_info));
        uint32_t uuid_info_array_size = uuid_info_count * uuid_info_size;
        char     *uuid_info_array = NULL;
@@ -483,6 +492,10 @@ copytobuffer:
                 */
                telemetry_buffer_end_point = current_record_start;
                telemetry_buffer_current_position = 0;
+               if (current_record_start == 0) {
+                       /* This sample is too large to fit in the buffer even when we started at 0, so skip it */
+                       goto cancel_sample;
+               }
                goto copytobuffer;
        }
 
@@ -499,6 +512,10 @@ copytobuffer:
        if ((telemetry_buffer_size - telemetry_buffer_current_position) < sizeof(struct task_snapshot)) {
                telemetry_buffer_end_point = current_record_start;
                telemetry_buffer_current_position = 0;
+               if (current_record_start == 0) {
+                       /* This sample is too large to fit in the buffer even when we started at 0, so skip it */
+                       goto cancel_sample;
+               }
                goto copytobuffer;
        }
 
@@ -567,6 +584,10 @@ copytobuffer:
        if ((telemetry_buffer_size - telemetry_buffer_current_position) < uuid_info_array_size) {
                telemetry_buffer_end_point = current_record_start;
                telemetry_buffer_current_position = 0;
+               if (current_record_start == 0) {
+                       /* This sample is too large to fit in the buffer even when we started at 0, so skip it */
+                       goto cancel_sample;
+               }
                goto copytobuffer;
        }
 
@@ -588,6 +609,10 @@ copytobuffer:
                /* wrap and overwrite */
                telemetry_buffer_end_point = current_record_start;              
                telemetry_buffer_current_position = 0;
+               if (current_record_start == 0) {
+                       /* This sample is too large to fit in the buffer even when we started at 0, so skip it */
+                       goto cancel_sample;
+               }
                goto copytobuffer;
        }
 
@@ -627,6 +652,10 @@ copytobuffer:
                        /* wrap and overwrite */
                        telemetry_buffer_end_point = current_record_start;              
                        telemetry_buffer_current_position = 0;
+                       if (current_record_start == 0) {
+                               /* This sample is too large to fit in the buffer even when we started at 0, so skip it */
+                               goto cancel_sample;
+                       }
                        goto copytobuffer;
                }
 
@@ -651,6 +680,10 @@ copytobuffer:
        if ((telemetry_buffer_size - telemetry_buffer_current_position)/framesize < btcount) {
                telemetry_buffer_end_point = current_record_start;
                telemetry_buffer_current_position = 0;
+               if (current_record_start == 0) {
+                       /* This sample is too large to fit in the buffer even when we started at 0, so skip it */
+                       goto cancel_sample;
+               }
                goto copytobuffer;
        }
 
@@ -679,6 +712,8 @@ copytobuffer:
                notify = TRUE;
        }
 
+cancel_sample:
+
        TELEMETRY_UNLOCK();
 
        KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_STACKSHOT, MICROSTACKSHOT_RECORD) | DBG_FUNC_END, notify, telemetry_bytes_since_last_mark, telemetry_buffer_current_position, telemetry_buffer_end_point, 0);