chore(sentry): pin sentry-native 0.16.5, and the crash daemon walks ARM32 frame chains

[GLinnik21]

The pin moves 0.13.9 → 0.16.5. Two things this repo hand-wrote against 0.13.9 are
upstream now and leave the patch: the non-regular-file guard when reading
/proc//maps entries as ELF (sentry__elf_open), and the ptrace snapshot of
the other threads — #1747's per-thread remote libunwind unwinding replaces it
with DWARF frames and symbol names. Also gone: previous-handler chaining and the
flush_scope fields (release, dist, environment, sdk, event_id), which upstream
fills. The patch shrinks from 600 lines to what upstream does not do.

What it still does, and why:

• process_vm_readv wrapper for glibc 2.12 (also needed by the daemon now).
• ARM32 registers in the event, and a frame-pointer walk that reads BOTH
  ARM32 frame records. GCC's push {..,fp,lr}; add fp,sp,#N leaves fp on the
  LR slot ([fp-4] saved fp, [fp] return); rustc/LLVM leaves it on the saved-fp
  slot ([fp] saved fp, [fp+4] return). The old patch hard-coded the GCC shape,
  so a crash in Rust — nearly every crash — walked one frame and reported a
  saved fp as a return address. Candidates are judged against the crashed
  process's mappings, recorded with permission bits while maps is parsed:
  return address in an executable, non-writable mapping; saved fp above the
  current frame in a writable one. Fail closed when the mapping snapshot is
  incomplete or differs on a second read after the stack copy. Both halves
  are upstream PRs (fix(native): read frame records at pointer width in the crash daemon's FP walk getsentry/sentry-native#2052, #2053) and drop out of the
  patch once a pinned release contains them.
• Pointer-width stack reads with a subtraction range check.
• 32-frame cap for non-crashed threads (the 256 KiB record ceiling), the 30 s
  handler budget, and the two webOS-only signal-handler escapes.

libsentry and our C are built with -funwind-tables so the remote unwinder gets
through them (it stopped at threadpool_thread before).

Device-verified on the debug install: SIGSEGV and SIGABRT → envelope → import
(queued=1 rejected=0, native_wins=1) → flushed → visible in the Sentry project
with sdk.version 0.16.5; crashed thread crash_on_purpose ← plex_run ← __libc_start_main; a GCC-built noinline chain leaf ← f2 ← f1 ← __libc_start_main. fwcompat matrix unchanged (OK 4.4.2→11.2.0); both binaries
still need only GLIBC_2.12.

🤖 Generated with Claude Code

[Copilot]

🟢 Approval recommended

The version pin, patch adjustments, build flags, and accompanying docs/tests are consistent and appear internally coherent for the intended webOS ARM32 crash-walk behavior.

Pull request overview

This PR updates the vendored Sentry Native crash handler integration to a pinned sentry-native 0.16.5 release, reducing the downstream webOS/ARM32 patch surface by dropping functionality that has moved upstream and keeping only the remaining webOS/ARM32-specific crash-walk requirements (notably ARM32 frame-chain correctness and glibc 2.12 compatibility).

Changes:

• Pin sentry-native to 0.16.5 in the build script and update the downstream webos-arm32.patch accordingly.
• Improve ARM32 crash-walk reliability: pointer-width stack reads, dual frame-record shape support, mapping-snapshot verification, and a longer handler wait budget for cold crashes.
• Align build flags and documentation/examples with the new pinned version and unwinding requirements.

File summaries

File	Description
vendor/sentry-native/webos-arm32.patch	Updates the downstream webOS/ARM32 patch for sentry-native 0.16.5, keeping only non-upstreamed webOS/ARM32 crash-walk behavior and compatibility shims.
rust-modules/src/telemetry/native.rs	Updates the representative native event/schema preview and tests to report sdk.version 0.16.5.
Makefile	Adds -funwind-tables to C compilation flags to support remote DWARF unwinding paths.
docs/agent-reference.md	Updates the crash-forensics architecture notes to reflect the new upstream/unpatched behavior and the 0.16.5 pin.
ci/build-sentry-native.sh	Pins the build to 0.16.5, updates SHA256, and sets explicit C flags for unwind tables + frame pointers in the cross build.
.agents/skills/crash-triage/SKILL.md	Updates the crash triage skill text to match the new crash-daemon unwinding behavior and limits.

Review details

• Files reviewed: 5/6 changed files
• Comments generated: 0
• Review effort level: Lite

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.