commit 551b9388af9174d2279860d26e5326a2356bffa6
author Francois Rousseau <frousseau@google.com> Thu May 13 16:31:10 2021 -0700
committer Copybara-Service <copybara-worker@google.com> Thu May 13 17:22:39 2021 -0700
tree 178cd7347c4603d186fe19ef0b6392471586690a
parent c7c08590ac9d7ed6390e0c7bb7f7e7dc8eae0154

fuchsia: clarify stack capture in case of stack overflow

Bug: fuchsia:74897
Change-Id: If3ba11aa2eacf0e139d89eb7b47fc0c961bcb2b9
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/2895346
Reviewed-by: Scott Graham <scottmg@chromium.org>
Commit-Queue: Francois Rousseau <frousseau@google.com>
GitOrigin-RevId: e841b92e18e85f0d943441f949062b74b2a544b6

snapshot/fuchsia/process_reader_fuchsia.cc

diff --git a/snapshot/fuchsia/process_reader_fuchsia.cc b/snapshot/fuchsia/process_reader_fuchsia.cc
index 4522e51..1c037d7 100644
--- a/snapshot/fuchsia/process_reader_fuchsia.cc
+++ b/snapshot/fuchsia/process_reader_fuchsia.cc
@@ -46,6 +46,12 @@
 #error Port
 #endif
 
+  // TODO(fxbug.dev/74897): make this work for stack overflows, e.g., by looking
+  // up using the initial stack pointer (sp) when the thread was created. Right
+  // now, it gets the stack by getting the mapping that contains the current sp.
+  // But in the case of stack overflows, the current sp is by definition outside
+  // of the stack so the mapping returned is not the stack and fails the type
+  // check, at least on arm64.
   zx_info_maps_t range_with_sp;
   if (!memory_map.FindMappingForAddress(sp, &range_with_sp)) {
     LOG(ERROR) << "stack pointer not found in mapping";
@@ -54,7 +60,7 @@
 
   if (range_with_sp.type != ZX_INFO_MAPS_TYPE_MAPPING) {
     LOG(ERROR) << "stack range has unexpected type " << range_with_sp.type
-               << ", aborting";
+               << ", stack overflow? Aborting";
     return;
   }