https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81021
--- Comment #19 from Avi Kivity <a...@cloudius-systems.com> --- (In reply to Martin Liška from comment #18) > I can confirm I can reproduce it. Now with just AddressSanitizer I see: > > ==5488==ERROR: AddressSanitizer: unknown-crash on address 0x7fa04c0092e0 at > pc 0x000005ee3108 bp 0x7fa04c0091b0 sp 0x7fa04c0091a0 > WRITE of size 32 at 0x7fa04c0092e0 thread T1 > > ... > > SUMMARY: AddressSanitizer: unknown-crash tests/cql_test_env.cc:247 in > single_node_cql_env::create_keyspace(seastar::basic_sstring<char, unsigned > int, 15u>) > Shadow bytes around the buggy address: > 0x0ff4897f9200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 0x0ff4897f9210: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 0x0ff4897f9220: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 0x0ff4897f9230: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 0x0ff4897f9240: f1 f1 f1 f1 00 f2 f2 f2 f2 f2 f2 f2 00 00 f2 f2 > =>0x0ff4897f9250: f2 f2 f2 f2 00 00 00 00 f2 f2 f2 f2[00]00 f8 f8 > 0x0ff4897f9260: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 > > And I realized there's one interesting function in back-trace: > > 0x7fa04c0092e0 is located 119520 bytes inside of 131072-byte region > [0x7fa04bfec000,0x7fa04c00c000) > allocated by thread T1 here: > #0 0x7fa060d984a0 in posix_memalign (/lib64/libasan.so.4+0xdf4a0) > #1 0x7cef31 in operator new[](unsigned long, seastar::with_alignment) > core/memory.cc:1754 > #2 0x8a0704 in seastar::thread_context::make_stack() core/thread.cc:169 > #3 0x89ff7d in > seastar::thread_context::thread_context(seastar::thread_attributes, > std::function<void ()>) core/thread.cc:153 > > Where in #2 there's a call of make_stack. Maybe that does some magic which > breaks a shadow stack? Can you please investigate that? The code uses user-level threads (makecontext/setcontext etc). It annotates the new stack during the switch, see for example https://github.com/scylladb/seastar/blob/master/core/thread.cc#L66. Supposedly it's correct, but perhaps something is missing.
