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30 hoursFix compilation warning with SerializeClientConnectionInfo()Michael Paquier
This function uses an argument named "maxsize" that is only used in assertions, being set once outside the assertion area. Recent gcc versions with -Wunused-but-set-parameter complain about a warning when building without assertions enabled, because of that. In order to fix this issue, PG_USED_FOR_ASSERTS_ONLY is added to the function argument of SerializeClientConnectionInfo(), which is the first time we are doing so in the tree. The CI is fine with the change, but let's see what the buildfarm has to say on the matter. Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Jacob Champion <jchampion@postgresql.org> Discussion: https://postgr.es/m/pevajesswhxafjkivoq3yvwxga77tbncghlf3gq5fvchsvfuda@6uivg25sb3nx Backpatch-through: 16
12 daysSilence Valgrind leakage complaints in more-or-less-hackish ways.Tom Lane
These changes don't actually fix any leaks. They just make sure that Valgrind will find pointers to data structures that remain allocated at process exit, and thus not falsely complain about leaks. In particular, we are trying to avoid situations where there is no pointer to the beginning of an allocated block (except possibly within the block itself, which Valgrind won't count). * Because dynahash.c never frees hashtable storage except by deleting the whole hashtable context, it doesn't bother to track the individual blocks of elements allocated by element_alloc(). This results in "possibly lost" complaints from Valgrind except when the first element of each block is actively in use. (Otherwise it'll be on a freelist, but very likely only reachable via "interior pointers" within element blocks, which doesn't satisfy Valgrind.) To fix, if we're building with USE_VALGRIND, expend an extra pointer's worth of space in each element block so that we can chain them all together from the HTAB header. Skip this in shared hashtables though: Valgrind doesn't track those, and we'd need additional locking to make it safe to manipulate a shared chain. While here, update a comment obsoleted by 9c911ec06. * Put the dlist_node fields of catctup and catclist structs first. This ensures that the dlist pointers point to the starts of these palloc blocks, and thus that Valgrind won't consider them "possibly lost". * The postmaster's PMChild structs and the autovac launcher's avl_dbase structs also have the dlist_node-is-not-first problem, but putting it first still wouldn't silence the warning because we bulk-allocate those structs in an array, so that Valgrind sees a single allocation. Commonly the first array element will be pointed to only from some later element, so that the reference would be an interior pointer even if it pointed to the array start. (This is the same issue as for dynahash elements.) Since these are pretty simple data structures, I don't feel too bad about faking out Valgrind by just keeping a static pointer to the array start. (This is all quite hacky, and it's not hard to imagine usages where we'd need some other idea in order to have reasonable leak tracking of structures that are only accessible via dlist_node lists. But these changes seem to be enough to silence this class of leakage complaints for the moment.) * Free a couple of data structures manually near the end of an autovacuum worker's run when USE_VALGRIND, and ensure that the final vac_update_datfrozenxid() call is done in a non-permanent context. This doesn't have any real effect on the process's total memory consumption, since we're going to exit as soon as that last transaction is done. But it does pacify Valgrind. * Valgrind complains about the postmaster's socket-files and lock-files lists being leaked, which we can silence by just not nulling out the static pointers to them. * Valgrind seems not to consider the global "environ" variable as a valid root pointer; so when we allocate a new environment array, it claims that data is leaked. To fix that, keep our own statically-allocated copy of the pointer, similarly to the previous item. Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/285483.1746756246@sss.pgh.pa.us
2025-03-18aio: Infrastructure for io_method=workerAndres Freund
This commit contains the basic, system-wide, infrastructure for io_method=worker. It does not yet actually execute IO, this commit just provides the infrastructure for running IO workers, kept separate for easier review. The number of IO workers can be adjusted with a PGC_SIGHUP GUC. Eventually we'd like to make the number of workers dynamically scale up/down based on the current "IO load". To allow the number of IO workers to be increased without a restart, we need to reserve PGPROC entries for the workers unconditionally. This has been judged to be worth the cost. If it turns out to be problematic, we can introduce a PGC_POSTMASTER GUC to control the maximum number. As io workers might be needed during shutdown, e.g. for AIO during the shutdown checkpoint, a new PMState phase is added. IO workers are shut down after the shutdown checkpoint has been performed and walsender/archiver have shut down, but before the checkpointer itself shuts down. See also 87a6690cc69. Updates PGSTAT_FILE_FORMAT_ID due to the addition of a new BackendType. Reviewed-by: Noah Misch <noah@leadboat.com> Co-authored-by: Thomas Munro <thomas.munro@gmail.com> Co-authored-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt Discussion: https://postgr.es/m/20210223100344.llw5an2aklengrmn@alap3.anarazel.de Discussion: https://postgr.es/m/stj36ea6yyhoxtqkhpieia2z4krnam7qyetc57rfezgk4zgapf@gcnactj4z56m
2025-03-06Split WaitEventSet functions to separate source fileHeikki Linnakangas
latch.c now only contains the Latch related functions, which build on the WaitEventSet abstraction. Most of the platform-dependent stuff is now in waiteventset.c. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/8a507fb6-df28-49d3-81a5-ede180d7f0fb@iki.fi
2025-01-01Update copyright for 2025Bruce Momjian
Backpatch-through: 13
2024-12-28Exclude parallel workers from connection privilege/limit checks.Tom Lane
Cause parallel workers to not check datallowconn, rolcanlogin, and ACL_CONNECT privileges. The leader already checked these things (except for rolcanlogin which might have been checked for a different role). Re-checking can accomplish little except to induce unexpected failures in applications that might not even be aware that their query has been parallelized. We already had the principle that parallel workers rely on their leader to pass a valid set of authorization information, so this change just extends that a bit further. Also, modify the ReservedConnections, datconnlimit and rolconnlimit logic so that these limits are only enforced against regular backends, and only regular backends are counted while checking if the limits were already reached. Previously, background processes that had an assigned database or role were subject to these limits (with rather random exclusions for autovac workers and walsenders), and the set of existing processes that counted against each limit was quite haphazard as well. The point of these limits, AFAICS, is to ensure the availability of PGPROC slots for regular backends. Since all other types of processes have their own separate pools of PGPROC slots, it makes no sense either to enforce these limits against them or to count them while enforcing the limit. While edge-case failures of these sorts have been possible for a long time, the problem got a good deal worse with commit 5a2fed911 (CVE-2024-10978), which caused parallel workers to make some of these checks using the leader's current role where before we had used its AuthenticatedUserId, thus allowing parallel queries to fail after SET ROLE. The previous behavior was fairly accidental and I have no desire to return to it. This patch includes reverting 73c9f91a1, which was an emergency hack to suppress these same checks in some cases. It wasn't complete, as shown by a recent bug report from Laurenz Albe. We can also revert fd4d93d26 and 492217301, which hacked around the same problems in one regression test. In passing, remove the special case for autovac workers in CheckMyDatabase; it seems cleaner to have AutoVacWorkerMain pass the INIT_PG_OVERRIDE_ALLOW_CONNS flag, now that that does what's needed. Like 5a2fed911, back-patch to supported branches (which sadly no longer includes v12). Discussion: https://postgr.es/m/1808397.1735156190@sss.pgh.pa.us
2024-12-17Set the stack_base_ptr in main(), not in random other places.Tom Lane
Previously we did this in PostmasterMain() and InitPostmasterChild(), which meant that stack depth checking was disabled in non-postmaster server processes, for instance in single-user mode. That seems like a fairly bad idea, since there's no a-priori restriction on the complexity of queries we will run in single-user mode. Moreover, this led to not having quite the same stack depth limit in all processes, which likely has no real-world effect but it offends my inner neatnik. Setting the depth in main() guarantees that check_stack_depth() is armed and has a consistent interpretation of stack depth in all forms of server processes. While at it, move the code associated with checking the stack depth out of tcop/postgres.c (which was never a great home for it) into a new file src/backend/utils/misc/stack_depth.c. Discussion: https://postgr.es/m/2081982.1734393311@sss.pgh.pa.us
2024-11-15Fix per-session activation of ALTER {ROLE|DATABASE} SET role.Noah Misch
After commit 5a2fed911a85ed6d8a015a6bafe3a0d9a69334ae, the catalog state resulting from these commands ceased to affect sessions. Restore the longstanding behavior, which is like beginning the session with a SET ROLE command. If cherry-picking the CVE-2024-10978 fixes, default to including this, too. (This fixes an unintended side effect of fixing CVE-2024-10978.) Back-patch to v12, like that commit. The release team decided to include v12, despite the original intent to halt v12 commits earlier this week. Tom Lane and Noah Misch. Reported by Etienne LAFARGE. Discussion: https://postgr.es/m/CADOZwSb0UsEr4_UTFXC5k7=fyyK8uKXekucd+-uuGjJsGBfxgw@mail.gmail.com
2024-11-14Replace postmaster.c's own backend type codes with BackendTypeHeikki Linnakangas
Introduce a separate BackendType for dead-end children, so that we don't need a separate dead_end flag. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/a102f15f-eac4-4ff2-af02-f9ff209ec66f@iki.fi
2024-11-11Fix improper interactions between session_authorization and role.Tom Lane
The SQL spec mandates that SET SESSION AUTHORIZATION implies SET ROLE NONE. We tried to implement that within the lowest-level functions that manipulate these settings, but that was a bad idea. In particular, guc.c assumes that it doesn't matter in what order it applies GUC variable updates, but that was not the case for these two variables. This problem, compounded by some hackish attempts to work around it, led to some security-grade issues: * Rolling back a transaction that had done SET SESSION AUTHORIZATION would revert to SET ROLE NONE, even if that had not been the previous state, so that the effective user ID might now be different from what it had been. * The same for SET SESSION AUTHORIZATION in a function SET clause. * If a parallel worker inspected current_setting('role'), it saw "none" even when it should see something else. Also, although the parallel worker startup code intended to cope with the current role's pg_authid row having disappeared, its implementation of that was incomplete so it would still fail. Fix by fully separating the miscinit.c functions that assign session_authorization from those that assign role. To implement the spec's requirement, teach set_config_option itself to perform "SET ROLE NONE" when it sets session_authorization. (This is undoubtedly ugly, but the alternatives seem worse. In particular, there's no way to do it within assign_session_authorization without incompatible changes in the API for GUC assign hooks.) Also, improve ParallelWorkerMain to directly set all the relevant user-ID variables instead of relying on some of them to get set indirectly. That allows us to survive not finding the pg_authid row during worker startup. In v16 and earlier, this includes back-patching 9987a7bf3 which fixed a violation of GUC coding rules: SetSessionAuthorization is not an appropriate place to be throwing errors from. Security: CVE-2024-10978
2024-10-07Fix Y2038 issues with MyStartTime.Nathan Bossart
Several places treat MyStartTime as a "long", which is only 32 bits wide on some platforms. In reality, MyStartTime is a pg_time_t, i.e., a signed 64-bit integer. This will lead to interesting bugs on the aforementioned systems in 2038 when signed 32-bit integers are no longer sufficient to store Unix time (e.g., "pg_ctl start" hanging). To fix, ensure that MyStartTime is handled as a 64-bit value everywhere. (Of course, users will need to ensure that time_t is 64 bits wide on their system, too.) Co-authored-by: Max Johnson Discussion: https://postgr.es/m/CO1PR07MB905262E8AC270FAAACED66008D682%40CO1PR07MB9052.namprd07.prod.outlook.com Backpatch-through: 12
2024-03-04Remove unused #include's from backend .c filesPeter Eisentraut
as determined by include-what-you-use (IWYU) While IWYU also suggests to *add* a bunch of #include's (which is its main purpose), this patch does not do that. In some cases, a more specific #include replaces another less specific one. Some manual adjustments of the automatic result: - IWYU currently doesn't know about includes that provide global variable declarations (like -Wmissing-variable-declarations), so those includes are being kept manually. - All includes for port(ability) headers are being kept for now, to play it safe. - No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the patch from exploding in size. Note that this patch touches just *.c files, so nothing declared in header files changes in hidden ways. As a small example, in src/backend/access/transam/rmgr.c, some IWYU pragma annotations are added to handle a special case there. Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org
2024-03-04Use MyBackendType in more places to check what process this isHeikki Linnakangas
Remove IsBackgroundWorker, IsAutoVacuumLauncherProcess(), IsAutoVacuumWorkerProcess(), and IsLogicalSlotSyncWorker() in favor of new Am*Process() macros that use MyBackendType. For consistency with the existing Am*Process() macros. Reviewed-by: Andres Freund Discussion: https://www.postgresql.org/message-id/f3ecd4cb-85ee-4e54-8278-5fabfb3a4ed0@iki.fi
2024-02-22Add a new slot sync worker to synchronize logical slots.Amit Kapila
By enabling slot synchronization, all the failover logical replication slots on the primary (assuming configurations are appropriate) are automatically created on the physical standbys and are synced periodically. The slot sync worker on the standby server pings the primary server at regular intervals to get the necessary failover logical slots information and create/update the slots locally. The slots that no longer require synchronization are automatically dropped by the worker. The nap time of the worker is tuned according to the activity on the primary. The slot sync worker waits for some time before the next synchronization, with the duration varying based on whether any slots were updated during the last cycle. A new parameter sync_replication_slots enables or disables this new process. On promotion, the slot sync worker is shut down by the startup process to drop any temporary slots acquired by the slot sync worker and to prevent the worker from trying to fetch the failover slots. A functionality to allow logical walsenders to wait for the physical will be done in a subsequent commit. Author: Shveta Malik, Hou Zhijie based on design inputs by Masahiko Sawada and Amit Kapila Reviewed-by: Masahiko Sawada, Bertrand Drouvot, Peter Smith, Dilip Kumar, Ajin Cherian, Nisha Moond, Kuroda Hayato, Amit Kapila Discussion: https://postgr.es/m/514f6f2f-6833-4539-39f1-96cd1e011f23@enterprisedb.com
2024-01-03Update copyright for 2024Bruce Momjian
Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
2023-12-20Add a new WAL summarizer process.Robert Haas
When active, this process writes WAL summary files to $PGDATA/pg_wal/summaries. Each summary file contains information for a certain range of LSNs on a certain TLI. For each relation, it stores a "limit block" which is 0 if a relation is created or destroyed within a certain range of WAL records, or otherwise the shortest length to which the relation was truncated during that range of WAL records, or otherwise InvalidBlockNumber. In addition, it stores a list of blocks which have been modified during that range of WAL records, but excluding blocks which were removed by truncation after they were modified and never subsequently modified again. In other words, it tells us which blocks need to copied in case of an incremental backup covering that range of WAL records. But this doesn't yet add the capability to actually perform an incremental backup; the next patch will do that. A new parameter summarize_wal enables or disables this new background process. The background process also automatically deletes summary files that are older than wal_summarize_keep_time, if that parameter has a non-zero value and the summarizer is configured to run. Patch by me, with some design help from Dilip Kumar and Andres Freund. Reviewed by Matthias van de Meent, Dilip Kumar, Jakub Wartak, Peter Eisentraut, and Álvaro Herrera. Discussion: http://postgr.es/m/CA+TgmoYOYZfMCyOXFyC-P+-mdrZqm5pP2N7S-r0z3_402h9rsA@mail.gmail.com
2023-12-01Adjust obsolete comment explaining set_stack_base().Thomas Munro
Commit 7389aad6 removed the notion of backends started from inside a signal handler. A stray comment still referred to them, while explaining the need for a call to set_stack_base(). That leads to the question of whether we still need the call in !EXEC_BACKEND builds. There doesn't seem to be much point in suppressing it now, as it doesn't hurt and probably helps to measure the stack base from the exact same place in EXEC_BACKEND and !EXEC_BACKEND builds. Back-patch to 16. Reported-by: Heikki Linnakangas <hlinnaka@iki.fi> Reported-by: Tristan Partin <tristan@neon.tech> Reported-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA%2BhUKG%2BEJHcevNGNOxVWxTNFbuB%3Dvjf4U68%2B85rAC_Sxvy2zEQ%40mail.gmail.com
2023-11-06Set GUC "is_superuser" in all processes that set AuthenticatedUserId.Noah Misch
It was always false in single-user mode, in autovacuum workers, and in background workers. This had no specifically-identified security consequences, but non-core code or future work might make it security-relevant. Back-patch to v11 (all supported versions). Jelte Fennema-Nio. Reported by Jelte Fennema-Nio.
2023-10-12Add option to bgworkers to allow the bypass of role login checkMichael Paquier
This adds a new option called BGWORKER_BYPASS_ROLELOGINCHECK to the flags available to BackgroundWorkerInitializeConnection() and BackgroundWorkerInitializeConnectionByOid(). This gives the possibility to bgworkers to bypass the role login check, making possible the use of a role that has no login rights while not being a superuser. PostgresInit() gains a new flag called INIT_PG_OVERRIDE_ROLE_LOGIN, taking advantage of the refactoring done in 4800a5dfb4c4. Regression tests are added to worker_spi to check the behavior of this new option with bgworkers. Author: Bertrand Drouvot Reviewed-by: Nathan Bossart, Michael Paquier, Bharath Rupireddy Discussion: https://postgr.es/m/bcc36259-7850-4882-97ef-d6b905d2fc51@gmail.com
2023-07-13Fix privilege check for SET SESSION AUTHORIZATION.Nathan Bossart
Presently, the privilege check for SET SESSION AUTHORIZATION checks whether the original authenticated role was a superuser at connection start time. Even if the role loses the superuser attribute, its existing sessions are permitted to change session authorization to any role. This commit modifies this privilege check to verify the original authenticated role currently has superuser. In the event that the authenticated role loses superuser within a session authorization change, the authorization change will remain in effect, which means the user can still take advantage of the target role's privileges. However, [RE]SET SESSION AUTHORIZATION will only permit switching to the original authenticated role. Author: Joseph Koshakow Discussion: https://postgr.es/m/CAAvxfHc-HHzONQ2oXdvhFF9ayRnidPwK%2BfVBhRzaBWYYLVQL-g%40mail.gmail.com
2023-07-13Move privilege check for SET SESSION AUTHORIZATION.Nathan Bossart
Presently, the privilege check for SET SESSION AUTHORIZATION is performed in session_authorization's assign_hook. A relevant comment states, "It's OK because the check does not require catalog access and can't fail during an end-of-transaction GUC reversion..." However, we plan to add a catalog lookup to this privilege check in a follow-up commit. This commit moves this privilege check to the check_hook for session_authorization. Like check_role(), we do not throw a hard error for insufficient privileges when the source is PGC_S_TEST. Author: Joseph Koshakow Discussion: https://postgr.es/m/CAAvxfHc-HHzONQ2oXdvhFF9ayRnidPwK%2BfVBhRzaBWYYLVQL-g%40mail.gmail.com
2023-03-16Integrate superuser check into has_rolreplication()Peter Eisentraut
This makes it consistent with similar functions like has_createrole_privilege() and allows removing some explicit superuser checks. Author: Nathan Bossart <nathandbossart@gmail.com> Discussion: https://www.postgresql.org/message-id/20230310000313.GA3992372%40nathanxps13
2023-03-03Don't leak descriptors into subprograms.Thomas Munro
Open long-lived data and WAL file descriptors with O_CLOEXEC. This flag was introduced by SUSv4 (POSIX.1-2008), and by now all of our target Unix systems have it. Our open() implementation for Windows already had that behavior, so provide a dummy O_CLOEXEC flag on that platform. For now, callers of open() and the "thin" wrappers in fd.c that deal in raw descriptors need to pass in O_CLOEXEC explicitly if desired. This commit does that for WAL files, and automatically for everything accessed via VFDs including SMgrRelation and BufFile. (With more discussion we might decide to turn it on automatically for the thin open()-wrappers too to avoid risk of missing places that need it, but these are typically used for short-lived descriptors where we don't expect to fork/exec, and it's remotely possible that extensions could be using these APIs and passing descriptors to subprograms deliberately, so that hasn't been done here.) Do the same for sockets and the postmaster pipe with FD_CLOEXEC. (Later commits might use modern interfaces to remove these extra fcntl() calls and more where possible, but we'll need them as a fallback for a couple of systems, so do it that way in this initial commit.) With this change, subprograms executed for archiving, copying etc will no longer have access to the server's descriptors, other than the ones that we decide to pass down. Reviewed-by: Andres Freund <andres@anarazel.de> (earlier version) Discussion: https://postgr.es/m/CA%2BhUKGKb6FsAdQWcRL35KJsftv%2B9zXqQbzwkfRf1i0J2e57%2BhQ%40mail.gmail.com
2023-02-03Retire PG_SETMASK() macro.Thomas Munro
In the 90s we needed to deal with computers that still had the pre-standard signal masking APIs. That hasn't been relevant for a very long time on Unix systems, and c94ae9d8 got rid of a remaining dependency in our Windows porting code. PG_SETMASK didn't expose save/restore functionality, so we'd already started using sigprocmask() directly in places, creating the visual distraction of having two ways to spell it. It's not part of the API that extensions are expected to be using (but if they are, the change will be trivial). It seems like a good time to drop the old macro and just call the standard POSIX function. Reviewed-by: Nathan Bossart <nathandbossart@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKG%2BKfQgrhHP2DLTohX1WwubaCBHmTzGnAEDPZ-Gug-Xskg%40mail.gmail.com
2023-01-12Use WaitEventSet API for postmaster's event loop.Thomas Munro
Switch to a design similar to regular backends, instead of the previous arrangement where signal handlers did non-trivial state management and called fork(). The main changes are: * The postmaster now has its own local latch to wait on. (For now, we don't want other backends setting its latch directly, but that could probably be made to work with more research on robustness.) * The existing signal handlers are cut in two: a handle_pm_XXX() part that just sets pending_pm_XXX flags and the latch, and a process_pm_XXX() part that runs later when the latch is seen. * Signal handlers are now installed with the regular pqsignal() function rather than the special pqsignal_pm() function; historical portability concerns about the effect of SA_RESTART on select() are no longer relevant, and we don't need to block signals anymore. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA%2BhUKG%2BZ-HpOj1JsO9eWUP%2Bar7npSVinsC_npxSy%2BjdOMsx%3DGg%40mail.gmail.com
2023-01-02Update copyright for 2023Bruce Momjian
Backpatch-through: 11
2022-10-28Remove AssertArg and AssertStatePeter Eisentraut
These don't offer anything over plain Assert, and their usage had already been declared obsolescent. Author: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/20221009210148.GA900071@nathanxps13
2022-09-29Introduce SYSTEM_USERMichael Paquier
SYSTEM_USER is a reserved keyword of the SQL specification that, roughly described, is aimed at reporting some information about the system user who has connected to the database server. It may include implementation-specific information about the means by the user connected, like an authentication method. This commit implements SYSTEM_USER as of auth_method:identity, where "auth_method" is a keyword about the authentication method used to log into the server (like peer, md5, scram-sha-256, gss, etc.) and "identity" is the authentication identity as introduced by 9afffcb (peer sets authn to the OS user name, gss to the user principal, etc.). This format has been suggested by Tom Lane. Note that thanks to d951052, SYSTEM_USER is available to parallel workers. Bump catalog version. Author: Bertrand Drouvot Reviewed-by: Jacob Champion, Joe Conway, Álvaro Herrera, Michael Paquier Discussion: https://postgr.es/m/7e692b8c-0b11-45db-1cad-3afc5b57409f@amazon.com
2022-09-29Restore pg_pread and friends.Thomas Munro
Commits cf112c12 and a0dc8271 were a little too hasty in getting rid of the pg_ prefixes where we use pread(), pwrite() and vectored variants. We dropped support for ancient Unixes where we needed to use lseek() to implement replacements for those, but it turns out that Windows also changes the current position even when you pass in an offset to ReadFile() and WriteFile() if the file handle is synchronous, despite its documentation saying otherwise. Switching to asynchronous file handles would fix that, but have other complications. For now let's just put back the pg_ prefix and add some comments to highlight the non-standard side-effect, which we can now describe as Windows-only. Reported-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Discussion: https://postgr.es/m/20220923202439.GA1156054%40nathanxps13
2022-08-24Allow parallel workers to retrieve some data from PortMichael Paquier
This commit moves authn_id into a new global structure called ClientConnectionInfo (mapping to a MyClientConnectionInfo for each backend) which is intended to hold all the client information that should be shared between the backend and any of its parallel workers, access for extensions and triggers being the primary use case. There is no need to push all the data of Port to the workers, and authn_id is quite a generic concept so using a separate structure provides the best balance (the name of the structure has been suggested by Robert Haas). While on it, and per discussion as this would be useful for a potential SYSTEM_USER that can be accessed through parallel workers, a second field is added for the authentication method, copied directly from Port. ClientConnectionInfo is serialized and restored using a new parallel key and a structure tracks the length of the authn_id, making the addition of more fields straight-forward. Author: Jacob Champion Reviewed-by: Bertrand Drouvot, Stephen Frost, Robert Haas, Tom Lane, Michael Paquier, Julien Rouhaud Discussion: https://postgr.es/m/793d990837ae5c06a558d58d62de9378ab525d83.camel@vmware.com
2022-08-22Add BackendType for standalone backendsAndres Freund
All backends should have a BackendType to enable statistics reporting per BackendType. Add a new BackendType for standalone backends, B_STANDALONE_BACKEND (and alphabetize the BackendTypes). Both the bootstrap backend and single user mode backends will have BackendType B_STANDALONE_BACKEND. Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/CAAKRu_aaq33UnG4TXq3S-OSXGWj1QGf0sU%2BECH4tNwGFNERkZA%40mail.gmail.com
2022-08-05Remove dead pread and pwrite replacement code.Thomas Munro
pread() and pwrite() are in SUSv2, and all targeted Unix systems have them. Previously, we defined pg_pread and pg_pwrite to emulate these function with lseek() on old Unixen. The names with a pg_ prefix were a reminder of a portability hazard: they might change the current file position. That hazard is gone, so we can drop the prefixes. Since the remaining replacement code is Windows-only, move it into src/port/win32p{read,write}.c, and move the declarations into src/include/port/win32_port.h. No need for vestigial HAVE_PREAD, HAVE_PWRITE macros as they were only used for declarations in port.h which have now moved into win32_port.h. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Greg Stark <stark@mit.edu> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA+hUKGJ3LHeP9w5Fgzdr4G8AnEtJ=z=p6hGDEm4qYGEUX5B6fQ@mail.gmail.com
2022-07-03Remove redundant null pointer checks before free()Peter Eisentraut
Per applicable standards, free() with a null pointer is a no-op. Systems that don't observe that are ancient and no longer relevant. Some PostgreSQL code already required this behavior, so this change does not introduce any new requirements, just makes the code more consistent. Discussion: https://www.postgresql.org/message-id/flat/dac5d2d0-98f5-94d9-8e69-46da2413593d%40enterprisedb.com
2022-06-08Be more careful about GucSource for internally-driven GUC settings.Tom Lane
The original advice for hard-wired SetConfigOption calls was to use PGC_S_OVERRIDE, particularly for PGC_INTERNAL GUCs. However, that's really overkill for PGC_INTERNAL GUCs, since there is no possibility that we need to override a user-provided setting. Instead use PGC_S_DYNAMIC_DEFAULT in most places, so that the value will appear with source = 'default' in pg_settings and thereby not be shown by psql's new \dconfig command. The one exception is that when changing in_hot_standby in a hot-standby session, we still use PGC_S_OVERRIDE, because people felt that seeing that in \dconfig would be a good thing. Similarly use PGC_S_DYNAMIC_DEFAULT for the auto-tune value of wal_buffers (if possible, that is if wal_buffers wasn't explicitly set to -1), and for the typical 2MB value of max_stack_depth. In combination these changes remove four not-very-interesting entries from the typical output of \dconfig, all of which people fingered as "why is that showing up?" in the discussion thread. Discussion: https://postgr.es/m/3118455.1649267333@sss.pgh.pa.us
2022-05-13Add a new shmem_request_hook hook.Robert Haas
Currently, preloaded libraries are expected to request additional shared memory and LWLocks in _PG_init(). However, it is not unusal for such requests to depend on MaxBackends, which won't be initialized at that time. Such requests could also depend on GUCs that other modules might change. This introduces a new hook where modules can safely use MaxBackends and GUCs to request additional shared memory and LWLocks. Furthermore, this change restricts requests for shared memory and LWLocks to this hook. Previously, libraries could make requests until the size of the main shared memory segment was calculated. Unlike before, we no longer silently ignore requests received at invalid times. Instead, we FATAL if someone tries to request additional shared memory or LWLocks outside of the hook. Nathan Bossart and Julien Rouhaud Discussion: https://postgr.es/m/20220412210112.GA2065815%40nathanxps13 Discussion: https://postgr.es/m/Yn2jE/lmDhKtkUdr@paquier.xyz
2022-05-09Make relation-enumerating operations be security-restricted operations.Noah Misch
When a feature enumerates relations and runs functions associated with all found relations, the feature's user shall not need to trust every user having permission to create objects. BRIN-specific functionality in autovacuum neglected to account for this, as did pg_amcheck and CLUSTER. An attacker having permission to create non-temp objects in at least one schema could execute arbitrary SQL functions under the identity of the bootstrap superuser. CREATE INDEX (not a relation-enumerating operation) and REINDEX protected themselves too late. This change extends to the non-enumerating amcheck interface. Back-patch to v10 (all supported versions). Sergey Shinderuk, reviewed (in earlier versions) by Alexander Lakhin. Reported by Alexander Lakhin. Security: CVE-2022-1552
2022-04-06Custom WAL Resource Managers.Jeff Davis
Allow extensions to specify a new custom resource manager (rmgr), which allows specialized WAL. This is meant to be used by a Table Access Method or Index Access Method. Prior to this commit, only Generic WAL was available, which offers support for recovery and physical replication but not logical replication. Reviewed-by: Julien Rouhaud, Bharath Rupireddy, Andres Freund Discussion: https://postgr.es/m/ed1fb2e22d15d3563ae0eb610f7b61bb15999c0a.camel%40j-davis.com
2022-04-06pgstat: store statistics in shared memory.Andres Freund
Previously the statistics collector received statistics updates via UDP and shared statistics data by writing them out to temporary files regularly. These files can reach tens of megabytes and are written out up to twice a second. This has repeatedly prevented us from adding additional useful statistics. Now statistics are stored in shared memory. Statistics for variable-numbered objects are stored in a dshash hashtable (backed by dynamic shared memory). Fixed-numbered stats are stored in plain shared memory. The header for pgstat.c contains an overview of the architecture. The stats collector is not needed anymore, remove it. By utilizing the transactional statistics drop infrastructure introduced in a prior commit statistics entries cannot "leak" anymore. Previously leaked statistics were dropped by pgstat_vacuum_stat(), called from [auto-]vacuum. On systems with many small relations pgstat_vacuum_stat() could be quite expensive. Now that replicas drop statistics entries for dropped objects, it is not necessary anymore to reset stats when starting from a cleanly shut down replica. Subsequent commits will perform some further code cleanup, adapt docs and add tests. Bumps PGSTAT_FILE_FORMAT_ID. Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Author: Andres Freund <andres@anarazel.de> Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-By: Andres Freund <andres@anarazel.de> Reviewed-By: Thomas Munro <thomas.munro@gmail.com> Reviewed-By: Justin Pryzby <pryzby@telsasoft.com> Reviewed-By: "David G. Johnston" <david.g.johnston@gmail.com> Reviewed-By: Tomas Vondra <tomas.vondra@2ndquadrant.com> (in a much earlier version) Reviewed-By: Arthur Zakirov <a.zakirov@postgrespro.ru> (in a much earlier version) Reviewed-By: Antonin Houska <ah@cybertec.at> (in a much earlier version) Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de Discussion: https://postgr.es/m/20210319235115.y3wz7hpnnrshdyv6@alap3.anarazel.de
2022-02-17Suppress warning about stack_base_ptr with late-model GCC.Tom Lane
GCC 12 complains that set_stack_base is storing the address of a local variable in a long-lived pointer. This is an entirely reasonable warning (indeed, it just helped us find a bug); but that behavior is intentional here. We can work around it by using __builtin_frame_address(0) instead of a specific local variable; that produces an address a dozen or so bytes different, in my testing, but we don't care about such a small difference. Maybe someday a compiler lacking that function will start to issue a similar warning, but we'll worry about that when it happens. Patch by me, per a suggestion from Andres Freund. Back-patch to v12, which is as far back as the patch will go without some pain. (Recently-established project policy would permit a back-patch as far as 9.2, but I'm disinclined to expend the work until GCC 12 is much more widespread.) Discussion: https://postgr.es/m/3773792.1645141467@sss.pgh.pa.us
2022-02-03Allow archiving via loadable modules.Robert Haas
Running a shell command for each file to be archived has a lot of overhead and may not offer as much error checking as you want, or the exact semantics that you want. So, offer the option to call a loadable module for each file to be archived, rather than running a shell command. Also, add a 'basic_archive' contrib module as an example implementation that archives to a local directory. Nathan Bossart, with a little bit of kibitzing by me. Discussion: http://postgr.es/m/20220202224433.GA1036711@nathanxps13
2022-01-07Update copyright for 2022Bruce Momjian
Backpatch-through: 10
2021-08-05process startup: Centralize pgwin32_signal_initialize() calls.Andres Freund
For one, the existing location lead to somewhat awkward code in main(). For another, the new location is easier to understand anyway. Author: Andres Freund <andres@anarazel.de> Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-By: Robert Haas <robertmhaas@gmail.com> Discussion: https://postgr.es/m/20210802164124.ufo5buo4apl6yuvs@alap3.anarazel.de
2021-03-01Introduce symbolic names for FeBeWaitSet positions.Thomas Munro
Previously we used 0 and 1 to refer to the socket and latch in far flung parts of the tree, without any explanation. Also use PGINVALID_SOCKET rather than -1 in a couple of places that didn't already do that. Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKGJAC4Oqao%3DqforhNey20J8CiG2R%3DoBPqvfR0vOJrFysGw%40mail.gmail.com
2021-03-01Use signalfd(2) for epoll latches.Thomas Munro
Cut down on system calls and other overheads by reading from a signalfd instead of using a signal handler and self-pipe. Affects Linux sytems, and possibly others including illumos that implement the Linux epoll and signalfd interfaces. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA+hUKGJjxPDpzBE0a3hyUywBvaZuC89yx3jK9RFZgfv_KHU7gg@mail.gmail.com
2021-02-17Use errmsg_internal for debug messagesPeter Eisentraut
An inconsistent set of debug-level messages was not using errmsg_internal(), thus uselessly exposing the messages to translation work. Fix those.
2021-01-02Update copyright for 2021Bruce Momjian
Backpatch-through: 9.5
2020-09-16Centralize setup of SIGQUIT handling for postmaster child processes.Tom Lane
We decided that the policy established in commit 7634bd4f6 for the bgwriter, checkpointer, walwriter, and walreceiver processes, namely that they should accept SIGQUIT at all times, really ought to apply uniformly to all postmaster children. Therefore, get rid of the duplicative and inconsistent per-process code for establishing that signal handler and removing SIGQUIT from BlockSig. Instead, make InitPostmasterChild do it. The handler set up by InitPostmasterChild is SignalHandlerForCrashExit, which just summarily does _exit(2). In interactive backends, we almost immediately replace that with quickdie, since we would prefer to try to tell the client that we're dying. However, this patch is changing the behavior of autovacuum (both launcher and workers), as well as walsenders. Those processes formerly also used quickdie, but AFAICS that was just mindless copy-and-paste: they don't have any interactive client that's likely to benefit from being told this. The stats collector continues to be an outlier, in that it thinks SIGQUIT means normal exit. That should probably be changed for consistency, but there's another patch set where that's being dealt with, so I didn't do so here. Discussion: https://postgr.es/m/644875.1599933441@sss.pgh.pa.us
2020-07-30Use a long lived WaitEventSet for WaitLatch().Thomas Munro
Create LatchWaitSet at backend startup time, and use it to implement WaitLatch(). This avoids repeated epoll/kqueue setup and teardown system calls. Reorder SubPostmasterMain() slightly so that we restore the postmaster pipe and Windows signal emulation before we reach InitPostmasterChild(), to make this work in EXEC_BACKEND builds. Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKGJAC4Oqao%3DqforhNey20J8CiG2R%3DoBPqvfR0vOJrFysGw%40mail.gmail.com
2020-05-14Initial pgindent and pgperltidy run for v13.Tom Lane
Includes some manual cleanup of places that pgindent messed up, most of which weren't per project style anyway. Notably, it seems some people didn't absorb the style rules of commit c9d297751, because there were a bunch of new occurrences of function calls with a newline just after the left paren, all with faulty expectations about how the rest of the call would get indented.
2020-04-05Recompute stack base in forked postmaster children.Andres Freund
This is for the benefit of running postgres under the rr debugger. When using rr signal handlers running while a syscall is active use an alternative stack. As e.g. bgworkers are started from within signal handlers, the forked backend then has a different stack base than postmaster. Previously that subsequently lead to those processes triggering spurious "stack depth limit exceeded" errors. Discussion: https://postgr.es/m/20200327182217.ubrrl32lyfhxfwk5@alap3.anarazel.de