c159b0383f
The WAIT_USE_EPOLL and WAIT_USE_KQUEUE implementations of WaitEventSetWaitBlock() confused the size of their internal buffer with the size of the caller's output buffer, and could ask the kernel for too many events. In fact the set of events retrieved from the kernel needs to be able to fit in both buffers, so take the smaller of the two. The WAIT_USE_POLL and WAIT_USE WIN32 implementations didn't have this confusion. This probably didn't come up before because we always used the same number in both places, but commit 7389aad6 calculates a dynamic size at construction time, while using MAXLISTEN for its output event buffer on the stack. That seems like a reasonable thing to want to do, so consider this to be a pre-existing bug worth fixing. As discovered by valgrind on skink. Back-patch to all supported releases for epoll, and to release 13 for the kqueue part, which copied the incorrect epoll code. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/901504.1673504836%40sss.pgh.pa.us
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.