Fix crash with wal_debug in EXEC_BACKEND child processes Converting xlog.c to the new shared memory allocation API left the creation of the memory context used by wal_debug in the XLOGShmemInit() callback, which now only runs in the postmaster or in a standalone backend. Previously, XLOGShmemInit() ran in every child. As a result, walDebugCtx was left uninitialized in child processes in EXEC_BACKEND mode, and with wal_debug turned on, the backend crashed on first WAL insertion.
Fix by moving the walDebugCtx initialization to a separate function that is called in each backend that wishes to create WAL records. (It cannot be created lazily on first WAL insertion, because it's done in a critical section, and you cannot create a new memory context in a critical section.) Oversight in 9b5acad3f40f. Co-authored-by:: Bharath Rupireddy <[email protected]> Reviewed-by: Ashutosh Bapat <[email protected]> Discussion: https://www.postgresql.org/message-id/calj2acunl4xn3abzvm4dtpdr_l0-afl2agsghmrry_ztikh...@mail.gmail.com Backpatch-through: 19 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/6873a138f782cf816e6019bbe922857050df96c9 Modified Files -------------- src/backend/access/transam/xlog.c | 40 ++++++++++++++++++++------------- src/backend/access/transam/xloginsert.c | 5 +++++ src/include/access/xlog.h | 3 +++ 3 files changed, 32 insertions(+), 16 deletions(-)
