CVS commit: src/sys/lib/libunwind

[Joerg Sonnenberger]

Module Name:    src
Committed By:   joerg
Date:           Sun Feb 28 23:12:37 UTC 2021

Modified Files:
        src/sys/lib/libunwind: AddressSpace.hpp

Log Message:
Defer acquiring the FDE lock until after the allocation. This can avoid
nesting issues between malloc and backtrace when using LSan.


To generate a diff of this commit:
cvs rdiff -u -r1.9 -r1.10 src/sys/lib/libunwind/AddressSpace.hpp

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/lib/libunwind/AddressSpace.hpp
diff -u src/sys/lib/libunwind/AddressSpace.hpp:1.9 src/sys/lib/libunwind/AddressSpace.hpp:1.10
--- src/sys/lib/libunwind/AddressSpace.hpp:1.9	Thu Nov  2 16:09:33 2017
+++ src/sys/lib/libunwind/AddressSpace.hpp	Sun Feb 28 23:12:37 2021
@@ -283,7 +283,6 @@ public:
   }
 
   bool addFDE(pint_t pcStart, pint_t pcEnd, pint_t fde) {
-    pthread_rwlock_wrlock(&fdeTreeLock);
     Range *n = (Range *)malloc(sizeof(*n));
     n->hdr_base = fde;
     n->hdr_start = 0;
@@ -292,6 +291,7 @@ public:
     n->last_pc = pcEnd;
     n->data_base = 0;
     n->ehframe_base = 0;
+    pthread_rwlock_wrlock(&fdeTreeLock);
     if (static_cast<Range *>(rb_tree_insert_node(&segmentTree, n)) == n) {
       pthread_rwlock_unlock(&fdeTreeLock);
       return true;