[llvm] 8131eeb - [scudo] document allocation_ring_buffer_size (#71812)

[via llvm-commits]

Author: Florian Mayer
Date: 2023-11-09T07:59:47-08:00
New Revision: 8131eeb9e1ee9d61a84c053f6449044afbe40266

URL: https://github.com/llvm/llvm-project/commit/8131eeb9e1ee9d61a84c053f6449044afbe40266
DIFF: https://github.com/llvm/llvm-project/commit/8131eeb9e1ee9d61a84c053f6449044afbe40266.diff

LOG: [scudo] document allocation_ring_buffer_size (#71812)

Added: 
    

Modified: 
    llvm/docs/ScudoHardenedAllocator.rst

Removed: 
    


################################################################################
diff  --git a/llvm/docs/ScudoHardenedAllocator.rst b/llvm/docs/ScudoHardenedAllocator.rst
index 3862415111960ff..9a85f7bed9c4d41 100644
--- a/llvm/docs/ScudoHardenedAllocator.rst
+++ b/llvm/docs/ScudoHardenedAllocator.rst
@@ -250,6 +250,22 @@ The following "string" options are available:
 |                                 |                |                | can be attempted (a negative value disables     |
 |                                 |                |                | reclaiming).                                    |
 +---------------------------------+----------------+----------------+-------------------------------------------------+
+| allocation_ring_buffer_size     | 32768          | n/a            | If stack trace collection is requested, how     |
+|                                 |                |                | many previous allocations to keep in the        |
+|                                 |                |                | allocation ring buffer.                         |
+|                                 |                |                |                                                 |
+|                                 |                |                | This buffer is used to provide allocation and   |
+|                                 |                |                | deallocation stack traces for MTE fault         |
+|                                 |                |                | reports. The larger the buffer, the more        |
+|                                 |                |                | unrelated allocations can happen between        |
+|                                 |                |                | (de)allocation and the fault.                   |
+|                                 |                |                | If your sync-mode MTE faults do not have        |
+|                                 |                |                | (de)allocation stack traces, try increasing the |
+|                                 |                |                | buffer size.                                    |
+|                                 |                |                |                                                 |
+|                                 |                |                | Stack trace collection can be requested using   |
+|                                 |                |                | scudo_malloc_set_track_allocation_stacks        |
++---------------------------------+----------------+----------------+-------------------------------------------------+
 
 Additional flags can be specified, for example if Scudo if compiled with
 `GWP-ASan <https://llvm.org/docs/GwpAsan.html>`_ support.