https://bugs.openldap.org/show_bug.cgi?id=9306

Issue ID: 9306 Summary: clang UndefinedBehaviorSanitizer report Product: LMDB Version: 0.9.24 Hardware: x86_64 OS: Mac OS Status: UNCONFIRMED Severity: normal Priority: --- Component: liblmdb Assignee: bugs@openldap.org Reporter: AskAlexSharov@gmail.com Target Milestone: ---

Hello.

We using LMDB from Golang application. Clang compiler with flag "-fsanitize=undefined" shows next report:

mdb.c:7544:26: runtime error: member access within misaligned address 0x00d24759d53a for type 'MDB_page' (aka 'struct MDB_page'), which requires 8 byte alignment 0x00d24759d53a: note: pointer points here 00 00 00 01 c4 49 00 01 00 00 00 00 00 00 52 00 20 00 20 00 6a 01 2e 01 f2 00 4a 00 9e 00 74 00 ^ SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior mdb.c:7544:26 in mdb.c:7544:26: runtime error: member access within misaligned address 0x00d24759d546 for type 'union (anonymous union at mdb.c:826:2)', which requires 4 byte alignment 0x00d24759d546: note: pointer points here 00 00 52 00 20 00 20 00 6a 01 2e 01 f2 00 4a 00 9e 00 74 00 c8 00 20 00 00 00 00 00 00 00 21 00 ^ SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior mdb.c:7544:26 in mdb.c:7544:26: runtime error: member access within misaligned address 0x00d24759d546 for type 'struct (anonymous struct at mdb.c:827:3)', which requires 4 byte alignment 0x00d24759d546: note: pointer points here 00 00 52 00 20 00 20 00 6a 01 2e 01 f2 00 4a 00 9e 00 74 00 c8 00 20 00 00 00 00 00 00 00 21 00 ^ SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior mdb.c:7544:26 in mdb.c:7544:26: runtime error: load of misaligned address 0x00d24759d546 for type 'indx_t' (aka 'unsigned short'), which requires 4 byte alignment 0x00d24759d546: note: pointer points here 00 00 52 00 20 00 20 00 6a 01 2e 01 f2 00 4a 00 9e 00 74 00 c8 00 20 00 00 00 00 00 00 00 21 00 ^ SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior mdb.c:7544:26 in mdb.c:7545:3: runtime error: member access within misaligned address 0x00d24759d53a for type 'MDB_page' (aka 'struct MDB_page'), which requires 8 byte alignment 0x00d24759d53a: note: pointer points here 00 00 00 01 c4 49 00 01 00 00 00 00 00 00 52 00 20 00 20 00 6a 01 2e 01 f2 00 4a 00 9e 00 74 00 ^ SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior mdb.c:7545:3 in mdb.c:7545:3: runtime error: member access within misaligned address 0x00d24759d53a for type 'union (anonymous union at mdb.c:802:2)', which requires 8 byte alignment 0x00d24759d53a: note: pointer points here 00 00 00 01 c4 49 00 01 00 00 00 00 00 00 52 00 20 00 20 00 6a 01 2e 01 f2 00 4a 00 9e 00 74 00 ^ SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior mdb.c:7545:3 in mdb.c:7545:3: runtime error: load of misaligned address 0x00d24759d53a for type 'pgno_t' (aka 'unsigned long'), which requires 8 byte alignment 0x00d24759d53a: note: pointer points here 00 00 00 01 c4 49 00 01 00 00 00 00 00 00 52 00 20 00 20 00 6a 01 2e 01 f2 00 4a 00 9e 00 74 00 ^