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Author: noahsmartin

CHANGELOG.md

@@ -23,6 +23,7 @@
 - Properties on SentryOptions that had no effect on the WithoutUIKit variant are now removed from the API (#6644)
 - Removes the SentryOptions.inAppExclude property because it had no effect (#6646)
 - Removes segment property on SentryUser, SentryBaggage, and SentryTraceContext (#5638)
+- Removes local symbolication when `debug=True` which fixes various deadlocks (#6562)
 - Removes deprecated TraceContext initializers (#6348)
 - Removes deprecated user feedback API, this is replaced with the new feedback API (#5591)
 - Removes `enablePerformanceV2` option and makes this the default. The app start duration will now finish when the first frame is drawn instead of when the OS posts the UIWindowDidBecomeVisibleNotification. (#6008)

Sources/Sentry/SentryCrashReportConverter.m

@@ -307,8 +307,6 @@ - (SentryFrame *)stackFrameAtIndex:(NSInteger)frameIndex inThreadIndex:(NSIntege
         = (uintptr_t)[frameDictionary[@"instruction_addr"] unsignedLongLongValue];
     NSDictionary *binaryImage = [self binaryImageForAddress:instructionAddress];
     SentryFrame *frame = [[SentryFrame alloc] init];
-    // The symbol address is not known, so it defaults to 0
-    frame.symbolAddress = @"0x0000000000000000";
     frame.instructionAddress = sentry_formatHexAddress(frameDictionary[@"instruction_addr"]);
     frame.imageAddress = sentry_formatHexAddress(binaryImage[@"image_addr"]);
     frame.package = binaryImage[@"name"];

Sources/Sentry/SentryStacktrace.m

@@ -29,12 +29,9 @@ - (void)fixDuplicateFrames
         return;
     }
 
-    SentryFrame *lastFrame = self.frames.lastObject;
     SentryFrame *beforeLastFrame = [self.frames objectAtIndex:self.frames.count - 2];
 
-    if ([lastFrame.symbolAddress
-            isEqualToString:SENTRY_UNWRAP_NULLABLE(NSString, beforeLastFrame.symbolAddress)]
-        && [self.registers[@"lr"]
+    if ([self.registers[@"lr"]
             isEqualToString:SENTRY_UNWRAP_NULLABLE(NSString, beforeLastFrame.instructionAddress)]) {
         NSMutableArray *copyFrames = self.frames.mutableCopy;
         [copyFrames removeObjectAtIndex:self.frames.count - 2];

Sources/Sentry/SentryUseNSExceptionCallstackWrapper.m

@@ -43,6 +43,10 @@ - (instancetype)initWithName:(NSExceptionName)aName
         enumerateObjectsUsingBlock:^(NSNumber *_Nonnull obj, NSUInteger idx, BOOL *_Nonnull stop) {
             SentryCrashStackCursor stackCursor;
             stackCursor.stackEntry.address = [obj unsignedLongValue];
+            stackCursor.stackEntry.imageName = nil;
+            stackCursor.stackEntry.imageAddress = 0;
+            stackCursor.stackEntry.symbolAddress = 0;
+            stackCursor.stackEntry.symbolName = nil;
 
             [frames addObject:[crashStackToEntryMapper
                                   sentryCrashStackEntryToSentryFrame:stackCursor.stackEntry]];

Sources/SentryCrash/Recording/SentryCrashDoctor.m

@@ -262,30 +262,6 @@ - (NSDictionary *)basicRegistersFromThreadReport:(NSDictionary *)threadReport
     return basic;
 }
 
-- (NSDictionary *)lastInAppStackEntry:(NSDictionary *)report
-{
-    NSString *executableName = [self mainExecutableNameForReport:report];
-    NSDictionary *crashedThread = [self crashedThreadReport:report];
-    NSArray *backtrace = [self backtraceFromThreadReport:crashedThread];
-    for (NSDictionary *entry in backtrace) {
-        NSString *objectName = [entry objectForKey:@SentryCrashField_ObjectName];
-        if ([objectName isEqualToString:executableName]) {
-            return entry;
-        }
-    }
-    return nil;
-}
-
-- (NSDictionary *)lastStackEntry:(NSDictionary *)report
-{
-    NSDictionary *crashedThread = [self crashedThreadReport:report];
-    NSArray *backtrace = [self backtraceFromThreadReport:crashedThread];
-    if ([backtrace count] > 0) {
-        return [backtrace objectAtIndex:0];
-    }
-    return nil;
-}
-
 - (BOOL)isInvalidAddress:(NSDictionary *)errorReport
 {
     NSDictionary *machError = [errorReport objectForKey:@SentryCrashField_Mach];
@@ -329,25 +305,6 @@ - (BOOL)isMemoryCorruption:(NSDictionary *)report
         }
     }
 
-    NSArray *backtrace = [self backtraceFromThreadReport:crashedThread];
-    for (NSDictionary *entry in backtrace) {
-        NSString *objectName = [entry objectForKey:@SentryCrashField_ObjectName];
-        NSString *symbolName = [entry objectForKey:@SentryCrashField_SymbolName];
-        if ([symbolName isEqualToString:@"objc_autoreleasePoolPush"]) {
-            return YES;
-        }
-        if ([symbolName isEqualToString:@"free_list_checksum_botch"]) {
-            return YES;
-        }
-        if ([symbolName isEqualToString:@"szone_malloc_should_clear"]) {
-            return YES;
-        }
-        if ([symbolName isEqualToString:@"lookUpMethod"] &&
-            [objectName isEqualToString:@"libobjc.A.dylib"]) {
-            return YES;
-        }
-    }
-
     return NO;
 }
 
@@ -359,8 +316,6 @@ - (BOOL)wasProgramTerminationRequested:(NSDictionary *)errorReport
 - (SentryCrashDoctorFunctionCall *)lastFunctionCall:(NSDictionary *)report
 {
     SentryCrashDoctorFunctionCall *function = [[SentryCrashDoctorFunctionCall alloc] init];
-    NSDictionary *lastStackEntry = [self lastStackEntry:report];
-    function.name = [lastStackEntry objectForKey:@SentryCrashField_SymbolName];
 
     NSDictionary *crashedThread = [self crashedThreadReport:report];
     NSDictionary *notableAddresses =
@@ -425,13 +380,11 @@ - (BOOL)isStackOverflow:(NSDictionary *)crashedThreadReport
 - (NSString *)diagnoseCrash:(NSDictionary *)report
 {
     @try {
-        NSString *lastFunctionName =
-            [[self lastInAppStackEntry:report] objectForKey:@SentryCrashField_SymbolName];
         NSDictionary *crashedThreadReport = [self crashedThreadReport:report];
         NSDictionary *errorReport = [self errorReport:report];
 
         if ([self isStackOverflow:crashedThreadReport]) {
-            return [NSString stringWithFormat:@"Stack overflow in %@", lastFunctionName];
+            return [NSString stringWithFormat:@"Stack overflow"];
         }
 
         NSString *crashType = [errorReport objectForKey:@SentryCrashField_Type];

Sources/SentryCrash/Recording/SentryCrashReportFields.h

@@ -77,11 +77,6 @@
 #pragma mark - Backtrace -
 
 #define SentryCrashField_InstructionAddr "instruction_addr"
-#define SentryCrashField_LineOfCode "line_of_code"
-#define SentryCrashField_ObjectAddr "object_addr"
-#define SentryCrashField_ObjectName "object_name"
-#define SentryCrashField_SymbolAddr "symbol_addr"
-#define SentryCrashField_SymbolName "symbol_name"
 
 #pragma mark - Stack Dump -
 

Sources/SentryCrash/Recording/Tools/SentryCrashStackCursor.h

@@ -46,7 +46,7 @@ extern "C" {
 typedef struct {
     /** Current address in the stack trace. */
     uintptr_t address;
-    
+
     /** The name (if any) of the binary image the current address falls
      * inside. */
     const char *imageName;

Tests/SentryTests/SentryCrashReportConverterTests.m

@@ -55,8 +55,6 @@ - (void)testConvertReport
     XCTAssertEqualObjects(firstDebugImage.imageSize, @(65536));
 
     SentryException *exception = event.exceptions.firstObject;
-    XCTAssertEqualObjects(
-        exception.stacktrace.frames.lastObject.symbolAddress, @"0x0000000000000000");
     XCTAssertEqualObjects(
         exception.stacktrace.frames.lastObject.instructionAddress, @"0x000000010014caa4");
     XCTAssertEqualObjects(

develop-docs/DECISIONS.md

@@ -1,5 +1,13 @@
 # Decision Log
 
+## No local symbolication of crashes
+
+Date: Nov 7th, 2025
+Contributors: @noahsmartin, @philipphofmann
+
+We decided to remove local symbolication. The existing local symbolication was not signal-safe and caused deadlocks (https://github.com/getsentry/sentry-cocoa/issues/6560).
+It is possible to implement local symbolication that does not cause deadlocks; however, it would be a debug-only feature, since in production apps should have their symbols stripped and only available in the dSYM. Therefore, to quickly fix the issue, we decided to remove all unsafe local symbolication in v9. The addition of signal-safe symbolication for binaries with symbols can always be added in a future minor version.
+
 ## Not capturing screenshots for crashes
 
 Date: April 21st 2022