fix(native): Omit outermost nullish frames

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - Temp files are now always created in the configured cache directory. ([#2028](https://github.com/getsentry/symbolicator/pull/2028))
 - Filter bogus entry point frames after `__clone` and `__clone3` frames. ([#2040](https://github.com/getsentry/symbolicator/pull/2040))
+- Filter nullish outermost frames from stack traces. ([#2041](https://github.com/getsentry/symbolicator/pull/2041))
 
 ## 26.8.0
 

crates/symbolicator-native/src/symbolication/symbolicate.rs

@@ -14,8 +14,8 @@ use crate::caches::il2cpp::Il2cppService;
 use crate::caches::ppdb_caches::PortablePdbCacheActor;
 use crate::caches::symcaches::SymCacheActor;
 use crate::interface::{
-    AdjustInstructionAddr, CompleteStacktrace, CompletedSymbolicationResponse, FrameStatus,
-    FrameTrust, RawFrame, RawStacktrace, Registers, Signal, SymbolicateStacktraces,
+    AddrMode, AdjustInstructionAddr, CompleteStacktrace, CompletedSymbolicationResponse,
+    FrameStatus, FrameTrust, RawFrame, RawStacktrace, Registers, Signal, SymbolicateStacktraces,
     SymbolicatedFrame,
 };
 use crate::memory::MemoryAccess;
@@ -239,6 +239,9 @@ fn symbolicate_stacktrace(
                     continue;
                 }
 
+                // Whether this frame is the last (outermost) frame.
+                let is_outermost_frame = unsymbolicated_frames_iter.peek().is_none();
+
                 // Glibc inserts an explicit `DW_CFA_undefined: RIP` DWARF rule to say that frames like
                 // `_start` have no return address.
                 // See https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/x86_64/start.S;h=1b3e36826b8a477474cee24d1c931429fbdf6d8f;hb=HEAD#l59
@@ -250,14 +253,30 @@ fn symbolicate_stacktrace(
                 // * this is the last frame to symbolicate (via peek)
                 // * the previous symbolicated frame is a well known frame like `_start`
                 if status == FrameStatus::UnknownImage
-                    && unsymbolicated_frames_iter.peek().is_none()
+                    && is_outermost_frame
                     && symbolicated_frames
                         .last()
                         .is_some_and(is_likely_glibc_undefined_rip_frame)
                 {
                     continue;
                 }
 
+                // Stack traces unwound from a minidump already consider an address from the first page
+                // practically null and use it as a marker to indicate that stack unwinding is complete.
+                //
+                // Stack traces which are unwound on the client side, may still have a frame at the
+                // end of the stack trace which is null-ish -> remove it here.
+                let is_nullish =
+                    frame.addr_mode == AddrMode::Abs && frame.instruction_addr.0 < 4096;
+                if status == FrameStatus::UnknownImage
+                    && is_outermost_frame
+                    && is_nullish
+                    // Check for any frames to avoid completely empty stack traces
+                    && !symbolicated_frames.is_empty()
+                {
+                    continue;
+                }
+
                 metrics.unsymbolicated_frames += 1;
                 match frame.trust {
                     FrameTrust::Scan => {