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fix(native): int32 size and endians on mac #1651

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3a65dff
fix(native): int32 size and endians on mac
mujacica Apr 15, 2026
7642051
Fix changelog and stlye
mujacica Apr 15, 2026
934ec10
extract utility, remoove duplicated code, double -> int64
mujacica Apr 16, 2026
693574e
Fix windows builds
mujacica Apr 16, 2026
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1 change: 1 addition & 0 deletions CHANGELOG.md
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Expand Up @@ -12,6 +12,7 @@
- macOS: cache VM regions for FP validation in the new unwinder. ([#1634](https://github.com/getsentry/sentry-native/pull/1634))
- Linux: remove dependency on `stdio` in the unwinder pointer validation code to reduce exposure to async-signal-unsafe functions. ([#1637](https://github.com/getsentry/sentry-native/pull/1637))
- macOS: replace sandbox-incompatible IPC primitives (`sem_open`, `shm_open`, `fork`) with sandbox-safe alternatives (`pthread_mutex`, file-backed `mmap`, `posix_spawn`) so the native backend works inside App Sandbox. ([#1644](https://github.com/getsentry/sentry-native/pull/1644))
- Fix minidump UUID byte order (swap GUID fields to match RSDS format) and use `int64` for image sizes to support modules larger than 2 GB. ([#1651](https://github.com/getsentry/sentry-native/pull/1651))

## 0.13.6

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6 changes: 5 additions & 1 deletion src/backends/native/minidump/sentry_minidump_macos.c
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@@ -1,4 +1,5 @@
#include "sentry_boot.h"
#include "sentry_utils.h"

#if defined(SENTRY_PLATFORM_MACOS)

Expand Down Expand Up @@ -243,8 +244,11 @@ write_cv_record(
cv_record->cv_signature = CV_SIGNATURE_RSDS;
cv_record->age = 0; // Not used for Mach-O

// Copy UUID
// Copy UUID with byte-swap for GUID format.
// Mach-O LC_UUID is big-endian (RFC 4122), but the RSDS CV record uses
// Windows GUID layout where the first 3 fields are little-endian.
memcpy(cv_record->signature, uuid, 16);
sentry__uuid_swap_guid_bytes(cv_record->signature);

// Copy module path
memcpy(cv_record->pdb_file_name, module_path, path_len + 1);
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12 changes: 2 additions & 10 deletions src/backends/native/sentry_crash_daemon.c
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Expand Up @@ -29,7 +29,6 @@
#include <time.h>

#if defined(SENTRY_PLATFORM_UNIX)
# include <arpa/inet.h>
# include <dirent.h>
# include <dlfcn.h>
# include <errno.h>
Expand Down Expand Up @@ -1171,13 +1170,7 @@ capture_modules_from_proc_maps(sentry_crash_context_t *ctx)
mod->name, mod->uuid, sizeof(mod->uuid));

// Convert to little-endian GUID format for Sentry debug_id
// (same byte swapping as sentry_modulefinder_linux.c)
uint32_t *a = (uint32_t *)mod->uuid;
*a = htonl(*a);
uint16_t *b = (uint16_t *)(mod->uuid + 4);
*b = htons(*b);
uint16_t *c = (uint16_t *)(mod->uuid + 6);
*c = htons(*c);
sentry__uuid_swap_guid_bytes(mod->uuid);

SENTRY_DEBUGF("Captured module: %s base=0x%llx size=0x%llx", mod->name,
(unsigned long long)mod->base_address,
Expand Down Expand Up @@ -2092,9 +2085,8 @@ build_native_crash_event(
sentry_value_set_by_key(
image, "image_addr", sentry_value_new_string(addr_buf));

// Set image_size as int32 (modules > 2GB are extremely rare)
sentry_value_set_by_key(image, "image_size",
sentry_value_new_int32((int32_t)mod->size));
sentry_value_new_int64((int64_t)mod->size));

#if defined(SENTRY_PLATFORM_WINDOWS)
// Set code_id for PE modules (TimeDateStamp + SizeOfImage)
Comment on lines 2085 to 2092
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@sentry sentry bot Apr 16, 2026

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Bug: On macOS, the native crash handler fails to byte-swap the module UUID, creating an incorrect debug_id in big-endian format, which will break symbolication.
Severity: HIGH

Suggested Fix

In build_native_crash_event() within sentry_crash_daemon.c, before creating the debug_id from the module's UUID, apply the same byte-swapping logic used for Linux and minidumps. Specifically, call sentry__uuid_swap_guid_bytes() on the mod->uuid to convert it from big-endian RFC 4122 format to the little-endian format expected by the symbolicator.

Prompt for AI Agent 
Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: src/backends/native/sentry_crash_daemon.c#L2085-L2092

Potential issue: On macOS, the native crash handler reads the module UUID from the
Mach-O `LC_UUID` load command, which is in big-endian format. This UUID is then used
directly in `build_native_crash_event()` to create the `debug_id` for the crash event.
However, the Sentry symbolicator expects the `debug_id` to be in the little-endian
Windows GUID format. Unlike the Linux path, which correctly byte-swaps the ID, the macOS
native crash path is missing this conversion. This will cause symbolication to fail for
native macOS crash reports, as the `debug_id` will not match the one stored for the
debug symbols.

Also affects:

  • src/backends/native/minidump/sentry_minidump_macos.c:247~251

Did we get this right? 👍 / 👎 to inform future reviews.

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9 changes: 1 addition & 8 deletions src/modulefinder/sentry_modulefinder_linux.c
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Expand Up @@ -10,7 +10,6 @@
#include "sentry_utils.h"
#include "sentry_value.h"

#include <arpa/inet.h>
#include <elf.h>
#include <fcntl.h>
#include <string.h>
Expand Down Expand Up @@ -493,13 +492,7 @@ sentry__procmaps_read_ids_from_elf(
// https://getsentry.github.io/symbolicator/advanced/symbol-server-compatibility/#identifiers
// in particular, the debug_id is a `little-endian GUID`, so we have
// to do appropriate byte-flipping
char *uuid_bytes = uuid.bytes;
uint32_t *a = (uint32_t *)uuid_bytes;
*a = htonl(*a);
uint16_t *b = (uint16_t *)(uuid_bytes + 4);
*b = htons(*b);
uint16_t *c = (uint16_t *)(uuid_bytes + 6);
*c = htons(*c);
sentry__uuid_swap_guid_bytes(uuid.bytes);

sentry_value_set_by_key(value, "debug_id", sentry__value_new_uuid(&uuid));
return true;
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29 changes: 29 additions & 0 deletions src/sentry_utils.h
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Expand Up @@ -15,6 +15,12 @@
# include <time.h>
#endif

#ifdef SENTRY_PLATFORM_WINDOWS
# include <stdlib.h>
#else
# include <arpa/inet.h>
#endif

#ifdef SENTRY_PLATFORM_PS
# undef MIN
# undef MAX
Expand All @@ -24,6 +30,29 @@
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define MAX(a, b) ((a) > (b) ? (a) : (b))

/**
* Byte-swap the first three GUID fields (Data1, Data2, Data3) of a 16-byte
* UUID in place. This converts between RFC 4122 (big-endian) and Windows
* mixed-endian GUID layout, which is used by RSDS CodeView records and Sentry
* debug-id strings.
*/
static inline void
sentry__uuid_swap_guid_bytes(void *uuid)
{
uint32_t *a = (uint32_t *)uuid;
uint16_t *b = (uint16_t *)((char *)uuid + 4);
uint16_t *c = (uint16_t *)((char *)uuid + 6);
#ifdef SENTRY_PLATFORM_WINDOWS
*a = _byteswap_ulong(*a);
*b = _byteswap_ushort(*b);
*c = _byteswap_ushort(*c);
#else
*a = htonl(*a);
*b = htons(*b);
*c = htons(*c);
#endif
}

#if defined(_MSC_VER) && !defined(__clang__)
# define UNREACHABLE(reason) assert(!reason)
#else
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