Commit Graph

10033 Commits

Author SHA1 Message Date
Tom Lane edc0a8d82a Detect integer overflow while computing new array dimensions.
array_set_element() and related functions allow an array to be
enlarged by assigning to subscripts outside the current array bounds.
While these places were careful to check that the new bounds are
allowable, they neglected to consider the risk of integer overflow
in computing the new bounds.  In edge cases, we could compute new
bounds that are invalid but get past the subsequent checks,
allowing bad things to happen.  Memory stomps that are potentially
exploitable for arbitrary code execution are possible, and so is
disclosure of server memory.

To fix, perform the hazardous computations using overflow-detecting
arithmetic routines, which fortunately exist in all still-supported
branches.

The test cases added for this generate (after patching) errors that
mention the value of MaxArraySize, which is platform-dependent.
Rather than introduce multiple expected-files, use psql's VERBOSITY
parameter to suppress the printing of the message text.  v11 psql
lacks that parameter, so omit the tests in that branch.

Our thanks to Pedro Gallegos for reporting this problem.

Security: CVE-2023-5869
2023-11-06 10:56:43 -05:00
Tom Lane 47c0f00cf9 Be more wary about NULL values for GUC string variables.
get_explain_guc_options() crashed if a string GUC marked GUC_EXPLAIN
has a NULL boot_val.  Nosing around found a couple of other places
that seemed insufficiently cautious about NULL string values, although
those are likely unreachable in practice.  Add some commentary
defining the expectations for NULL values of string variables,
in hopes of forestalling future additions of more such bugs.

Xing Guo, Aleksander Alekseev, Tom Lane

Discussion: https://postgr.es/m/CACpMh+AyDx5YUpPaAgzVwC1d8zfOL4JoD-uyFDnNSa1z0EsDQQ@mail.gmail.com
2023-11-02 11:47:33 -04:00
Tom Lane 8f4a6b9e4f Fix problems when a plain-inheritance parent table is excluded.
When an UPDATE/DELETE/MERGE's target table is an old-style
inheritance tree, it's possible for the parent to get excluded
from the plan while some children are not.  (I believe this is
only possible if we can prove that a CHECK ... NO INHERIT
constraint on the parent contradicts the query WHERE clause,
so it's a very unusual case.)  In such a case, ExecInitModifyTable
mistakenly concluded that the first surviving child is the target
table, leading to at least two bugs:

1. The wrong table's statement-level triggers would get fired.

2. In v16 and up, it was possible to fail with "invalid perminfoindex
0 in RTE with relid nnnn" due to the child RTE not having permissions
data included in the query plan.  This was hard to reproduce reliably
because it did not occur unless the update triggered some non-HOT
index updates.

In v14 and up, this is easy to fix by defining ModifyTable.rootRelation
to be the parent RTE in plain inheritance as well as partitioned cases.

While the wrong-triggers bug also appears in older branches, the
relevant code in both the planner and executor is quite a bit
different, so it would take a good deal of effort to develop and
test a suitable patch.  Given the lack of field complaints about the
trigger issue, I'll desist for now.  (Patching v11 for this seems
unwise anyway, given that it will have no more releases after next
month.)

Per bug #18147 from Hans Buschmann.

Amit Langote and Tom Lane

Discussion: https://postgr.es/m/18147-6fc796538913ee88@postgresql.org
2023-10-24 14:48:34 -04:00
Thomas Munro ee3e4c41f3 jit: Supply LLVMGlobalGetValueType() for LLVM < 8.
Commit 37d5babb used this C API function while adding support for LLVM
16 and opaque pointers, but it's not available in LLVM 7 and older.
Provide it in our own llvmjit_wrap.cpp.  It just calls a C++ function
that pre-dates LLVM 3.9, our minimum target.

Back-patch to 12, like 37d5babb.

Discussion: https://postgr.es/m/CA%2BhUKGKnLnJnWrkr%3D4mSGhE5FuTK55FY15uULR7%3Dzzc%3DwX4Nqw%40mail.gmail.com
2023-10-19 03:03:46 +13:00
Thomas Munro 82d9a782a2 jit: Support opaque pointers in LLVM 16.
Remove use of LLVMGetElementType() and provide the type of all pointers
to LLVMBuildXXX() functions when emitting IR, as required by modern LLVM
versions[1].

 * For LLVM <= 14, we'll still use the old LLVMBuildXXX() functions.
 * For LLVM == 15, we'll continue to do the same, explicitly opting
   out of opaque pointer mode.
 * For LLVM >= 16, we'll use the new LLVMBuildXXX2() functions that take
   the extra type argument.

The difference is hidden behind some new IR emitting wrapper functions
l_load(), l_gep(), l_call() etc.  The change is mostly mechanical,
except that at each site the correct type had to be provided.

In some places we needed to do some extra work to get functions types,
including some new wrappers for C++ APIs that are not yet exposed by in
LLVM's C API, and some new "example" functions in llvmjit_types.c
because it's no longer possible to start from the function pointer type
and ask for the function type.

Back-patch to 12, because it's a little tricker in 11 and we agreed not
to put the latest LLVM support into the upcoming final release of 11.

[1] https://llvm.org/docs/OpaquePointers.html

Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Ronan Dunklau <ronan.dunklau@aiven.io>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKGKNX_%3Df%2B1C4r06WETKTq0G4Z_7q4L4Fxn5WWpMycDj9Fw%40mail.gmail.com
2023-10-18 23:04:09 +13:00
Nathan Bossart 555bc89c90 windows: msvc: Define STDIN/OUT/ERR_FILENO.
This commit (c290e79cf0) was originally back-patched to v15.
Commit 97550c0711 added a new use of STDERR_FILENO, and it was
back-patched all the way to v11, thus breaking MSVC builds for v11
through v14.  Since STDERR_FILENO is now needed on older versions,
let's back-patch c290e79cf0 down to v11, too.

Here follows the original commit message describing the change:

Because they are not available we've used _fileno(stdin) in some places, but
that doesn't reliably work, because stdin might be closed. This is the
prerequisite of the subsequent commit, fixing a failure introduced in
76e38b37a5.

Author: Andres Freund <andres@anarazel.de>
Reported-By: Sandeep Thakkar <sandeep.thakkar@enterprisedb.com>
Message-Id: 20220520164558.ozb7lm6unakqzezi@alap3.anarazel.de (on pgsql-packagers)
Discussion: https://postgr.es/m/20231017164517.GA613565%40nathanxps13
Backpatch-through: 11
2023-10-17 16:11:03 -05:00
Nathan Bossart 54fc9dca5b Avoid calling proc_exit() in processes forked by system().
The SIGTERM handler for the startup process immediately calls
proc_exit() for the duration of the restore_command, i.e., a call
to system().  This system() call forks a new process to execute the
shell command, and this child process inherits the parent's signal
handlers.  If both the parent and child processes receive SIGTERM,
both will attempt to call proc_exit().  This can end badly.  For
example, both processes will try to remove themselves from the
PGPROC shared array.

To fix this problem, this commit adds a check in
StartupProcShutdownHandler() to see whether MyProcPid == getpid().
If they match, this is the parent process, and we can proc_exit()
like before.  If they do not match, this is a child process, and we
just emit a message to STDERR (in a signal safe manner) and
_exit(), thereby skipping any problematic exit callbacks.

This commit also adds checks in proc_exit(), ProcKill(), and
AuxiliaryProcKill() that verify they are not being called within
such child processes.

Suggested-by: Andres Freund
Reviewed-by: Thomas Munro, Andres Freund
Discussion: https://postgr.es/m/Y9nGDSgIm83FHcad%40paquier.xyz
Discussion: https://postgr.es/m/20230223231503.GA743455%40nathanxps13
Backpatch-through: 11
2023-10-17 10:42:12 -05:00
Noah Misch 0834df9094 Dissociate btequalimage() from interval_ops, ending its deduplication.
Under interval_ops, some equal values are distinguishable.  One such
pair is '24:00:00' and '1 day'.  With that being so, btequalimage()
breaches the documented contract for the "equalimage" btree support
function.  This can cause incorrect results from index-only scans.
Users should REINDEX any btree indexes having interval-type columns.
After updating, pg_amcheck will report an error for almost all such
indexes.  This fix makes interval_ops simply omit the support function,
like numeric_ops does.  Back-pack to v13, where btequalimage() first
appeared.  In back branches, for the benefit of old catalog content,
btequalimage() code will return false for type "interval".  Going
forward, back-branch initdb will include the catalog change.

Reviewed by Peter Geoghegan.

Discussion: https://postgr.es/m/20231011013317.22.nmisch@google.com
2023-10-14 16:33:54 -07:00
Peter Geoghegan 41486c4aae Fix btmarkpos/btrestrpos array key wraparound bug.
nbtree's mark/restore processing failed to correctly handle an edge case
involving array key advancement and related search-type scan key state.
Scans with ScalarArrayScalarArrayOpExpr quals requiring mark/restore
processing (for a merge join) could incorrectly conclude that an
affected array/scan key must not have advanced during the time between
marking and restoring the scan's position.

As a result of all this, array key handling within btrestrpos could skip
a required call to _bt_preprocess_keys().  This confusion allowed later
primitive index scans to overlook tuples matching the true current array
keys.  The scan's search-type scan keys would still have spurious values
corresponding to the final array element(s) -- not values matching the
first/now-current array element(s).

To fix, remember that "array key wraparound" has taken place during the
ongoing btrescan in a flag variable stored in the scan's state, and use
that information at the point where btrestrpos decides if another call
to _bt_preprocess_keys is required.

Oversight in commit 70bc5833, which taught nbtree to handle array keys
during mark/restore processing, but missed this subtlety.  That commit
was itself a bug fix for an issue in commit 9e8da0f7, which taught
nbtree to handle ScalarArrayOpExpr quals natively.

Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WzkgP3DDRJxw6DgjCxo-cu-DKrvjEv_ArkP2ctBJatDCYg@mail.gmail.com
Backpatch: 11- (all supported branches).
2023-09-28 16:29:29 -07:00
Tom Lane 9b2a41db1c Avoid unnecessary plancache revalidation of utility statements.
Revalidation of a plancache entry (after a cache invalidation event)
requires acquiring a snapshot.  Normally that is harmless, but not
if the cached statement is one that needs to run without acquiring a
snapshot.  We were already aware of that for TransactionStmts,
but for some reason hadn't extrapolated to the other statements that
PlannedStmtRequiresSnapshot() knows mustn't set a snapshot.  This can
lead to unexpected failures of commands such as SET TRANSACTION
ISOLATION LEVEL.  We can fix it in the same way, by excluding those
command types from revalidation.

However, we can do even better than that: there is no need to
revalidate for any statement type for which parse analysis, rewrite,
and plan steps do nothing interesting, which is nearly all utility
commands.  To mechanize this, invent a parser function
stmt_requires_parse_analysis() that tells whether parse analysis does
anything beyond wrapping a CMD_UTILITY Query around the raw parse
tree.  If that's what it does, then rewrite and plan will just
skip the Query, so that it is not possible for the same raw parse
tree to produce a different plan tree after cache invalidation.

stmt_requires_parse_analysis() is basically equivalent to the
existing function analyze_requires_snapshot(), except that for
obscure reasons that function omits ReturnStmt and CallStmt.
It is unclear whether those were oversights or intentional.
I have not been able to demonstrate a bug from not acquiring a
snapshot while analyzing these commands, but at best it seems mighty
fragile.  It seems safer to acquire a snapshot for parse analysis of
these commands too, which allows making stmt_requires_parse_analysis
and analyze_requires_snapshot equivalent.

In passing this fixes a second bug, which is that ResetPlanCache
would exclude ReturnStmts and CallStmts from revalidation.
That's surely *not* safe, since they contain parsable expressions.

Per bug #18059 from Pavel Kulakov.  Back-patch to all supported
branches.

Discussion: https://postgr.es/m/18059-79c692f036b25346@postgresql.org
2023-08-24 12:02:40 -04:00
Etsuro Fujita 1ea0424a5b Update comments on CustomPath struct.
Commit e7cb7ee14 allowed custom scan providers to create CustomPath
paths for join relations as well, but missed updating the comments.

Back-patch to all supported branches.

Discussion: https://postgr.es/m/CAPmGK15ODkN%2B%3DhkBCufj1HBW0x5OTb65Xuy7ryXchMdiCMpx_g%40mail.gmail.com
2023-08-03 17:15:04 +09:00
Etsuro Fujita b0e390e6d1 Disallow replacing joins with scans in problematic cases.
Commit e7cb7ee14, which introduced the infrastructure for FDWs and
custom scan providers to replace joins with scans, failed to add support
handling of pseudoconstant quals assigned to replaced joins in
createplan.c, leading to an incorrect plan without a gating Result node
when postgres_fdw replaced a join with such a qual.

To fix, we could add the support by 1) modifying the ForeignPath and
CustomPath structs to store the list of RestrictInfo nodes to apply to
the join, as in JoinPaths, if they represent foreign and custom scans
replacing a join with a scan, and by 2) modifying create_scan_plan() in
createplan.c to use that list in that case, instead of the
baserestrictinfo list, to get pseudoconstant quals assigned to the join;
but #1 would cause an ABI break.  So fix by modifying the infrastructure
to just disallow replacing joins with such quals.

Back-patch to all supported branches.

Reported by Nishant Sharma.  Patch by me, reviewed by Nishant Sharma and
Richard Guo.

Discussion: https://postgr.es/m/CADrsxdbcN1vejBaf8a%2BQhrZY5PXL-04mCd4GDu6qm6FigDZd6Q%40mail.gmail.com
2023-07-28 15:45:04 +09:00
Andres Freund d11efe8303 Handle DROP DATABASE getting interrupted
Until now, when DROP DATABASE got interrupted in the wrong moment, the removal
of the pg_database row would also roll back, even though some irreversible
steps have already been taken. E.g. DropDatabaseBuffers() might have thrown
out dirty buffers, or files could have been unlinked. But we continued to
allow connections to such a corrupted database.

To fix this, mark databases invalid with an in-place update, just before
starting to perform irreversible steps. As we can't add a new column in the
back branches, we use pg_database.datconnlimit = -2 for this purpose.

An invalid database cannot be connected to anymore, but can still be
dropped.

Unfortunately we can't easily add output to psql's \l to indicate that some
database is invalid, it doesn't fit in any of the existing columns.

Add tests verifying that a interrupted DROP DATABASE is handled correctly in
the backend and in various tools.

Reported-by: Evgeny Morozov <postgresql3@realityexists.net>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20230509004637.cgvmfwrbht7xm7p6@awork3.anarazel.de
Discussion: https://postgr.es/m/20230314174521.74jl6ffqsee5mtug@awork3.anarazel.de
Backpatch: 11-, bug present in all supported versions
2023-07-13 13:03:33 -07:00
Andres Freund 1508b57d4b Fix type of iterator variable in SH_START_ITERATE
Also add comment to make the reasoning behind the Assert() more explicit (per
Tom).

Reported-by: Ranier Vilela
Discussion: https://postgr.es/m/CAEudQAocXNJ6s1VLz+hMamLAQAiewRoW17OJ6-+9GACKfj6iPQ@mail.gmail.com
Backpatch: 11-
2023-07-06 09:57:32 -07:00
Tom Lane f8320cc72d Fix misbehavior of EvalPlanQual checks with multiple result relations.
The idea of EvalPlanQual is that we replace the query's scan of the
result relation with a single injected tuple, and see if we get a
tuple out, thereby implying that the injected tuple still passes the
query quals.  (In join cases, other relations in the query are still
scanned normally.)  This logic was not updated when commit 86dc90056
made it possible for a single DML query plan to have multiple result
relations, when the query target relation has inheritance or partition
children.  We replaced the output for the current result relation
successfully, but other result relations were still scanned normally;
thus, if any other result relation contained a tuple satisfying the
quals, we'd think the EPQ check passed, even if it did not pass for
the injected tuple itself.  This would lead to update or delete
actions getting performed when they should have been skipped due to
a conflicting concurrent update in READ COMMITTED isolation mode.

Fix by blocking all sibling result relations from emitting tuples
during an EvalPlanQual recheck.  In the back branches, the fix is
complicated a bit by the need to not change the size of struct
EPQState (else we'd have ABI-breaking changes in offsets in
struct ModifyTableState).  Like the back-patches of 3f7836ff6
and 4b3e37993, add a separately palloc'd struct to avoid that.
The logic is the same as in HEAD otherwise.

This is only a live bug back to v14 where 86dc90056 came in.
However, I chose to back-patch the test cases further, on the
grounds that this whole area is none too well tested.  I skipped
doing so in v11 though because none of the test applied cleanly,
and it didn't quite seem worth extra work for a branch with only
six months to live.

Per report from Ante Krešić (via Aleksander Alekseev)

Discussion: https://postgr.es/m/CAJ7c6TMBTN3rcz4=AjYhLPD_w3FFT0Wq_C15jxCDn8U4tZnH1g@mail.gmail.com
2023-05-19 14:26:34 -04:00
Michael Paquier e72580232c pageinspect: Fix gist_page_items() with included columns
Non-leaf pages of GiST indexes contain key attributes, leaf pages
contain both key and non-key attributes, and gist_page_items() ignored
the handling of non-key attributes.  This caused a few problems when
using gist_page_items() on a GiST index with INCLUDE:
- On a non-leaf page, the function would crash.
- On a leaf page, the function would work, but miss to display all the
values for included attributes.

This commit fixes gist_page_items() to handle such cases in a more
appropriate way, and now displays the values of key and non-key
attributes for each item separately in a style consistent with what
ruleutils.c would generate for the attribute list, depending on the page
type dealt with.  In a way similar to how a record is displayed, values
would be double-quoted for key or non-key attributes if required.

ruleutils.c did not provide a routine able to control if non-key
attributes should be displayed, so an extended() routine for index
definitions is added to work around the leaf and non-leaf page
differences.

While on it, this commit fixes a third problem related to the amount of
data reported for key attributes.  The code originally relied on
BuildIndexValueDescription() (used for error reports on constraints)
that would not print all the data stored in the index but the index
opclass's input type, so this limited the amount of information
available.  This switch makes gist_page_items() much cheaper as there is
no need to run ACL checks for each item printed, which is not an issue
anyway as superuser rights are required to execute the functions of
pageinspect.  Opclasses whose data cannot be displayed can rely on
gist_page_items_bytea().

The documentation of this function was slightly incorrect for the
output results generated on HEAD and v15, so adjust it on these
branches.

Author: Alexander Lakhin, Michael Paquier
Discussion: https://postgr.es/m/17884-cb8c326522977acb@postgresql.org
Backpatch-through: 14
2023-05-19 12:38:18 +09:00
Tomas Vondra 40d465cafc Fix handling of empty ranges and NULLs in BRIN
BRIN indexes did not properly distinguish between summaries for empty
(no rows) and all-NULL ranges, treating them as essentially the same
thing. Summaries were initialized with allnulls=true, and opclasses
simply reset allnulls to false when processing the first non-NULL value.
This however produces incorrect results if the range starts with a NULL
value (or a sequence of NULL values), in which case we forget the range
contains NULL values when adding the first non-NULL value.

This happens because the allnulls flag is used for two separate
purposes - to mark empty ranges (not representing any rows yet) and
ranges containing only NULL values.

Opclasses don't know which of these cases it is, and so don't know
whether to set hasnulls=true. Setting the flag in both cases would make
it correct, but it would also make BRIN indexes useless for queries with
IS NULL clauses. All ranges start empty (and thus allnulls=true), so all
ranges would end up with either allnulls=true or hasnulls=true.

The severity of the issue is somewhat reduced by the fact that it only
happens when adding values to an existing summary with allnulls=true.
This can happen e.g. for small tables (because a summary for the first
range exists for all BRIN indexes), or for tables with large fraction of
NULL values in the indexed columns.

Bulk summarization (e.g. during CREATE INDEX or automatic summarization)
that processes all values at once is not affected by this issue. In this
case the flags were updated in a slightly different way, not forgetting
the NULL values.

To identify empty ranges we use a new flag, stored in an unused bit in
the BRIN tuple header so the on-disk format remains the same. A matching
flag is added to BrinMemTuple, into a 3B gap after bt_placeholder.
That means there's no risk of ABI breakage, although we don't actually
pass the BrinMemTuple to any public API.

We could also skip storing index tuples for empty summaries, but then
we'd have to always process such ranges - even if there are no rows in
large parts of the table (e.g. after a bulk DELETE), it would still
require reading the pages etc. So we store them, but ignore them when
building the bitmap.

Backpatch to 11. The issue exists since BRIN indexes were introduced in
9.5, but older releases are already EOL.

Backpatch-through: 11
Reviewed-by: Justin Pryzby, Matthias van de Meent, Alvaro Herrera
Discussion: https://postgr.es/m/402430e4-7d9d-6cf1-09ef-464d80afff3b@enterprisedb.com
2023-05-19 00:15:00 +02:00
Michael Paquier d29eba1987 Fix crashes with CREATE SCHEMA AUTHORIZATION and schema elements
CREATE SCHEMA AUTHORIZATION with appended schema elements can lead to
crashes when comparing the schema name of the query with the schemas
used in the qualification of some clauses in the elements' queries.

The origin of the problem is that the transformation routine for the
elements listed in a CREATE SCHEMA query uses as new, expected, schema
name the one listed in CreateSchemaStmt itself.  However, depending on
the query, CreateSchemaStmt.schemaname may be NULL, being computed
instead from the role specification of the query given by the
AUTHORIZATION clause, that could be either:
- A user name string, with the new schema name being set to the same
value as the role given.
- Guessed from CURRENT_ROLE, SESSION_ROLE or CURRENT_ROLE, with a new
schema name computed from the security context where CREATE SCHEMA is
running.

Regression tests are added for CREATE SCHEMA with some appended elements
(some of them with schema qualifications), covering also some role
specification patterns.

While on it, this simplifies the context structure used during the
transformation of the elements listed in a CREATE SCHEMA query by
removing the fields for the role specification and the role type.  They
were not used, and for the role specification this could be confusing as
the schema name may by extracted from that at the beginning of
CreateSchemaCommand().

This issue exists for a long time, so backpatch down to all the versions
supported.

Reported-by: Song Hongyu
Author: Michael Paquier
Reviewed-by: Richard Guo
Discussion: https://postgr.es/m/17909-f65c12dfc5f0451d@postgresql.org
Backpatch-through: 11
2023-04-28 19:29:38 +09:00
Michael Paquier 34105eea62 Fix detection of unseekable files for fseek() and ftello() with MSVC
Calling fseek() or ftello() on a handle to a non-seeking device such as
a pipe or a communications device is not supported.  Unfortunately,
MSVC's flavor of these routines, _fseeki64() and _ftelli64(), do not
return an error when given a pipe as handle.  Some of the logic of
pg_dump and restore relies on these routines to check if a handle is
seekable, causing failures when passing the contents of pg_dump to
pg_restore through a pipe, for example.

This commit introduces wrappers for fseeko() and ftello() on MSVC so as
any callers are able to properly detect the cases of non-seekable
handles.  This relies mainly on GetFileType(), sharing a bit of code
with the MSVC port for fstat().  The code in charge of getting a file
type is refactored into a new file called win32common.c, shared by
win32stat.c and the new win32fseek.c.  It includes the MSVC ports for
fseeko() and ftello().

Like 765f5df, this is backpatched down to 14, where the fstat()
implementation for MSVC is able to understand about files larger than
4GB in size.  Using a TAP test for that is proving to be tricky as
IPC::Run handles the pipes by itself, still I have been able to check
the fix manually.

Reported-by: Daniel Watzinger
Author: Juan José Santamaría Flecha, Michael Paquier
Discussion: https://postgr.es/m/CAC+AXB26a4EmxM2suXxPpJaGrqAdxracd7hskLg-zxtPB50h7A@mail.gmail.com
Backpatch-through: 14
2023-04-12 09:09:58 +09:00
Thomas Munro 1b9e42e82a Fix race in parallel hash join batch cleanup, take II.
With unlucky timing and parallel_leader_participation=off (not the
default), PHJ could attempt to access per-batch shared state just as it
was being freed.  There was code intended to prevent that by checking
for a cleared pointer, but it was racy.  Fix, by introducing an extra
barrier phase.  The new phase PHJ_BUILD_RUNNING means that it's safe to
access the per-batch state to find a batch to help with, and
PHJ_BUILD_DONE means that it is too late.  The last to detach will free
the array of per-batch state as before, but now it will also atomically
advance the phase, so that late attachers can avoid the hazard.  This
mirrors the way per-batch hash tables are freed (see phases
PHJ_BATCH_PROBING and PHJ_BATCH_DONE).

An earlier attempt to fix this (commit 3b8981b6, later reverted) missed
one special case.  When the inner side is empty (the "empty inner
optimization), the build barrier would only make it to
PHJ_BUILD_HASHING_INNER phase before workers attempted to detach from
the hashtable.  In that case, fast-forward the build barrier to
PHJ_BUILD_RUNNING before proceeding, so that our later assertions hold
and we can still negotiate who is cleaning up.

Revealed by build farm failures, where BarrierAttach() failed a sanity
check assertion, because the memory had been clobbered by dsa_free().
In non-assert builds, the result could be a segmentation fault.

Back-patch to all supported releases.

Author: Thomas Munro <thomas.munro@gmail.com>
Author: Melanie Plageman <melanieplageman@gmail.com>
Reported-by: Michael Paquier <michael@paquier.xyz>
Reported-by: David Geier <geidav.pg@gmail.com>
Tested-by: David Geier <geidav.pg@gmail.com>
Discussion: https://postgr.es/m/20200929061142.GA29096%40paquier.xyz
2023-03-21 14:37:33 +13:00
Tom Lane 9eaba06027 Fix MULTIEXPR_SUBLINK with partitioned target tables, yet again.
We already tried to fix this in commits 3f7323cbb et al (and follow-on
fixes), but now it emerges that there are still unfixed cases;
moreover, these cases affect all branches not only pre-v14.  I thought
we had eliminated all cases of making multiple clones of an UPDATE's
target list when we nuked inheritance_planner.  But it turns out we
still do that in some partitioned-UPDATE cases, notably including
INSERT ... ON CONFLICT UPDATE, because ExecInitPartitionInfo thinks
it's okay to clone and modify the parent's targetlist.

This fix is based on a suggestion from Andres Freund: let's stop
abusing the ParamExecData.execPlan mechanism, which was only ever
meant to handle initplans, and instead solve the execution timing
problem by having the expression compiler move MULTIEXPR_SUBLINK steps
to the front of their expression step lists.  This is feasible because
(a) all branches still in support compile the entire targetlist of
an UPDATE into a single ExprState, and (b) we know that all
MULTIEXPR_SUBLINKs do need to be evaluated --- none could be buried
inside a CASE, for example.  There is a minor semantics change
concerning the order of execution of the MULTIEXPR's subquery versus
other parts of the parent targetlist, but that seems like something
we can get away with.  By doing that, we no longer need to worry
about whether different clones of a MULTIEXPR_SUBLINK share output
Params; their usage of that data structure won't overlap.

Per bug #17800 from Alexander Lakhin.  Back-patch to all supported
branches.  In v13 and earlier, we can revert 3f7323cbb and follow-on
fixes; however, I chose to keep the SubPlan.subLinkId field added
in ccbb54c72.  We don't need that anymore in the core code, but it's
cheap enough to fill, and removing a plan node field in a minor
release seems like it'd be asking for trouble.

Andres Freund and Tom Lane

Discussion: https://postgr.es/m/17800-ff90866b3906c964@postgresql.org
2023-02-25 14:44:14 -05:00
Michael Paquier 864f80fead Fix handling of SCRAM-SHA-256's channel binding with RSA-PSS certificates
OpenSSL 1.1.1 and newer versions have added support for RSA-PSS
certificates, which requires the use of a specific routine in OpenSSL to
determine which hash function to use when compiling it when using
channel binding in SCRAM-SHA-256.  X509_get_signature_nid(), that is the
original routine the channel binding code has relied on, is not able to
determine which hash algorithm to use for such certificates.  However,
X509_get_signature_info(), new to OpenSSL 1.1.1, is able to do it.  This
commit switches the channel binding logic to rely on
X509_get_signature_info() over X509_get_signature_nid(), which would be
the choice when building with 1.1.1 or newer.

The error could have been triggered on the client or the server, hence
libpq and the backend need to have their related code paths patched.
Note that attempting to load an RSA-PSS certificate with OpenSSL 1.1.0
or older leads to a failure due to an unsupported algorithm.

The discovery of relying on X509_get_signature_info() comes from Jacob,
the tests have been written by Heikki (with few tweaks from me), while I
have bundled the whole together while adding the bits needed for MSVC
and meson.

This issue exists since channel binding exists, so backpatch all the way
down.  Some tests are added in 15~, triggered if compiling with OpenSSL
1.1.1 or newer, where the certificate and key files can easily be
generated for RSA-PSS.

Reported-by: Gunnar "Nick" Bluth
Author: Jacob Champion, Heikki Linnakangas
Discussion: https://postgr.es/m/17760-b6c61e752ec07060@postgresql.org
Backpatch-through: 11
2023-02-15 10:12:33 +09:00
Michael Paquier 0801345758 Make EXEC_BACKEND more convenient on Linux and FreeBSD.
Try to disable ASLR when building in EXEC_BACKEND mode, to avoid random
memory mapping failures while testing.  For developer use only, no
effect on regular builds.

This has been originally applied as of f3e7806 for v15~, but
recently-added buildfarm member gokiburi tests this configuration on
older branches as well, causing it to fail randomly as ASLR would be
enabled.

Suggested-by: Andres Freund <andres@anarazel.de>
Tested-by: Bossart, Nathan <bossartn@amazon.com>
Discussion: https://postgr.es/m/20210806032944.m4tz7j2w47mant26%40alap3.anarazel.de
Backpatch-through: 12
2023-02-08 13:09:27 +09:00
Tom Lane 21c058648e Make our back branches build under -fkeep-inline-functions.
Add "#ifndef FRONTEND" where necessary to make pg_waldump build
on compilers that don't elide unused static-inline functions.

This back-patches relevant parts of commit 3e9ca5260, fixing build
breakage from dc7420c2c and back-patching of f10f0ae42.

Per recently-resurrected buildfarm member castoroides.  We aren't
expecting castoroides to build anything newer than v11, but we
might as well clean up the intermediate branches while at it.
2023-01-20 11:58:12 -05:00
Tom Lane a8b88c26f7 Make new GENERATED-expressions code more bulletproof.
In commit 8bf6ec3ba I assumed that no code path could reach
ExecGetExtraUpdatedCols without having gone through
ExecInitStoredGenerated.  That turns out not to be the case in
logical replication: if there's an ON UPDATE trigger on the target
table, trigger.c will call this code before anybody has set up its
generated columns.  Having seen that, I don't have a lot of faith in
there not being other such paths.  ExecGetExtraUpdatedCols can call
ExecInitStoredGenerated for itself, as long as we are willing to
assume that it is only called in CMD_UPDATE operations, which on
the whole seems like a safer leap of faith.

Per report from Vitaly Davydov.

Discussion: https://postgr.es/m/d259d69652b8c2ff50e14cda3c236c7f@postgrespro.ru
2023-01-15 14:06:46 -05:00
Tom Lane 8cd190e13a Fix calculation of which GENERATED columns need to be updated.
We were identifying the updatable generated columns of inheritance
children by transposing the calculation made for their parent.
However, there's nothing that says a traditional-inheritance child
can't have generated columns that aren't there in its parent, or that
have different dependencies than are in the parent's expression.
(At present it seems that we don't enforce that for partitioning
either, which is likely wrong to some degree or other; but the case
clearly needs to be handled with traditional inheritance.)

Hence, drop the very-klugy-anyway "extraUpdatedCols" RTE field
in favor of identifying which generated columns depend on updated
columns during executor startup.  In HEAD we can remove
extraUpdatedCols altogether; in back branches, it's still there but
always empty.  Another difference between the HEAD and back-branch
versions of this patch is that in HEAD we can add the new bitmap field
to ResultRelInfo, but that would cause an ABI break in back branches.
Like 4b3e37993, add a List field at the end of struct EState instead.

Back-patch to v13.  The bogus calculation is also being made in v12,
but it doesn't have the same visible effect because we don't use it
to decide which generated columns to recalculate; as a consequence of
which the patch doesn't apply easily.  I think that there might still
be a demonstrable bug associated with trigger firing conditions, but
that's such a weird corner-case usage that I'm content to leave it
unfixed in v12.

Amit Langote and Tom Lane

Discussion: https://postgr.es/m/CA+HiwqFshLKNvQUd1DgwJ-7tsTp=dwv7KZqXC4j2wYBV1aCDUA@mail.gmail.com
Discussion: https://postgr.es/m/2793383.1672944799@sss.pgh.pa.us
2023-01-05 14:12:17 -05:00
Andres Freund 7b5dec760f perl: Hide warnings inside perl.h when using gcc compatible compiler
New versions of perl trigger warnings within perl.h with our compiler
flags. At least -Wdeclaration-after-statement, -Wshadow=compatible-local are
known to be problematic.

To avoid these warnings, conditionally use #pragma GCC system_header before
including plperl.h.

Alternatively, we could add the include paths for problematic headers with
-isystem, but that is a larger hammer and is harder to search for.

A more granular alternative would be to use #pragma GCC diagnostic
push/ignored/pop, but gcc warns about unknown warnings being ignored, so every
to-be-ignored-temporarily compiler warning would require its own pg_config.h
symbol and #ifdef.

As the warnings are voluminous, it makes sense to backpatch this change. But
don't do so yet, we first want gather buildfarm coverage - it's e.g. possible
that some compiler claiming to be gcc compatible has issues with the pragma.

Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: Discussion: https://postgr.es/m/20221228182455.hfdwd22zztvkojy2@awork3.anarazel.de
2023-01-02 15:50:00 -08:00
Tom Lane ae47f8a966 Rethink handling of [Prevent|Is]InTransactionBlock in pipeline mode.
Commits f92944137 et al. made IsInTransactionBlock() set the
XACT_FLAGS_NEEDIMMEDIATECOMMIT flag before returning "false",
on the grounds that that kept its API promises equivalent to those of
PreventInTransactionBlock().  This turns out to be a bad idea though,
because it allows an ANALYZE in a pipelined series of commands to
cause an immediate commit, which is unexpected.

Furthermore, if we return "false" then we have another issue,
which is that ANALYZE will decide it's allowed to do internal
commit-and-start-transaction sequences, thus possibly unexpectedly
committing the effects of previous commands in the pipeline.

To fix the latter situation, invent another transaction state flag
XACT_FLAGS_PIPELINING, which explicitly records the fact that we
have executed some extended-protocol command and not yet seen a
commit for it.  Then, require that flag to not be set before allowing
InTransactionBlock() to return "false".

Having done that, we can remove its setting of NEEDIMMEDIATECOMMIT
without fear of causing problems.  This means that the API guarantees
of IsInTransactionBlock now diverge from PreventInTransactionBlock,
which is mildly annoying, but it seems OK given the very limited usage
of IsInTransactionBlock.  (In any case, a caller preferring the old
behavior could always set NEEDIMMEDIATECOMMIT for itself.)

For consistency also require XACT_FLAGS_PIPELINING to not be set
in PreventInTransactionBlock.  This too is meant to prevent commands
such as CREATE DATABASE from silently committing previous commands
in a pipeline.

Per report from Peter Eisentraut.  As before, back-patch to all
supported branches (which sadly no longer includes v10).

Discussion: https://postgr.es/m/65a899dd-aebc-f667-1d0a-abb89ff3abf8@enterprisedb.com
2022-12-13 14:23:59 -05:00
Etsuro Fujita d43a97ef49 Remove new structure member from ResultRelInfo.
In commit ffbb7e65a, I added a ModifyTableState member to ResultRelInfo
to save the owning ModifyTableState for use by nodeModifyTable.c when
performing batch inserts, but as pointed out by Tom Lane, that changed
the array stride of es_result_relations, and that would break any
previously-compiled extension code that accesses that array.  Fix by
removing that member from ResultRelInfo and instead adding a List member
at the end of EState to save such ModifyTableStates.

Per report from Tom Lane.  Back-patch to v14, like the previous commit;
I chose to apply the patch to HEAD as well, to make back-patching easy.

Discussion: http://postgr.es/m/4065383.1669395453%40sss.pgh.pa.us
2022-12-08 16:15:03 +09:00
Tom Lane dc3648f65b Fix Memoize to work with partitionwise joining.
A couple of places weren't up to speed for this.  By sheer good
luck, we didn't fail but just selected a non-memoized join plan,
at least in the test case we have.  Nonetheless, it's a bug,
and I'm not quite sure that it couldn't have worse consequences
in other examples.  So back-patch to v14 where Memoize came in.

Richard Guo

Discussion: https://postgr.es/m/CAMbWs48GkNom272sfp0-WeD6_0HSR19BJ4H1c9ZKSfbVnJsvRg@mail.gmail.com
2022-12-05 12:36:41 -05:00
Tom Lane 06998eab16 Improve heuristics for compressing the KnownAssignedXids array.
Previously, we'd compress only when the active range of array entries
reached Max(4 * PROCARRAY_MAXPROCS, 2 * pArray->numKnownAssignedXids).
If max_connections is large, the first term could result in not
compressing for a long time, resulting in much wastage of cycles in
hot-standby backends scanning the array to take snapshots.  Get rid
of that term, and just bound it to 2 * pArray->numKnownAssignedXids.

That however creates the opposite risk, that we might spend too much
effort compressing.  Hence, consider compressing only once every 128
commit records.  (This frequency was chosen by benchmarking.  While
we only tried one benchmark scenario, the results seem stable over
a fairly wide range of frequencies.)

Also, force compression when processing RecoveryInfo WAL records
(which should be infrequent); the old code could perform compression
then, but would do so only after the same array-range check as for
the transaction-commit path.

Also, opportunistically run compression if the startup process is about
to wait for WAL, though not oftener than once a second.  This should
prevent cases where we waste lots of time by leaving the array
not-compressed for long intervals due to low WAL traffic.

Lastly, add a simple check to keep us from uselessly compressing
when the array storage is already compact.

Back-patch, as the performance problem is worse in pre-v14 branches
than in HEAD.

Simon Riggs and Michail Nikolaev, with help from Tom Lane and
Andres Freund.

Discussion: https://postgr.es/m/CALdSSPgahNUD_=pB_j=1zSnDBaiOtqVfzo8Ejt5J_k7qZiU1Tw@mail.gmail.com
2022-11-29 15:43:17 -05:00
Etsuro Fujita e52245228e Fix handling of pending inserts in nodeModifyTable.c.
Commit b663a4136, which allowed FDWs to INSERT rows in bulk, added to
nodeModifyTable.c code to flush pending inserts to the foreign-table
result relation(s) before completing processing of the ModifyTable node,
but the code failed to take into account the case where the INSERT query
has modifying CTEs, leading to incorrect results.

Also, that commit failed to flush pending inserts before firing BEFORE
ROW triggers so that rows are visible to such triggers.

In that commit we scanned through EState's
es_tuple_routing_result_relations or es_opened_result_relations list to
find the foreign-table result relations to which pending inserts are
flushed, but that would be inefficient in some cases.  So to fix, 1) add
a List member to EState to record the insert-pending result relations,
and 2) modify nodeModifyTable.c so that it adds the foreign-table result
relation to the list in ExecInsert() if appropriate, and flushes pending
inserts properly using the list where needed.

While here, fix a copy-and-pasteo in a comment in ExecBatchInsert(),
which was added by that commit.

Back-patch to v14 where that commit appeared.

Discussion: https://postgr.es/m/CAPmGK16qutyCmyJJzgQOhfBq%3DNoGDqTB6O0QBZTihrbqre%2BoxA%40mail.gmail.com
2022-11-25 17:45:03 +09:00
Tom Lane 1b9c04b138 Add comments and a missing CHECK_FOR_INTERRUPTS in ts_headline.
I just spent an annoying amount of time reverse-engineering the
100%-undocumented API between ts_headline and the text search
parser's prsheadline function.  Add some commentary about that
while it's fresh in mind.  Also remove some unused macros in
wparser_def.c.

While at it, I noticed that when commit 78e73e875 added a
CHECK_FOR_INTERRUPTS call in TS_execute_recurse, it missed
doing so in the parallel function TS_phrase_execute, which
surely needs one just as much.

Back-patch because of the missing CHECK_FOR_INTERRUPTS.
Might as well back-patch the rest of this too.
2022-11-21 17:07:07 -05:00
Tom Lane 32d5a4974c Replace RelationOpenSmgr() with RelationGetSmgr().
This is a back-patch of the v15-era commit f10f0ae42 into older
supported branches.  The idea is to design out bugs in which an
ill-timed relcache flush clears rel->rd_smgr partway through
some code sequence that wasn't expecting that.  We had another
report today of a corner case that reliably crashes v14 under
debug_discard_caches (nee CLOBBER_CACHE_ALWAYS), and therefore
would crash once in a blue moon in the field.  We're unlikely
to get rid of all such code paths unless we adopt the more
rigorous coding rules instituted by f10f0ae42.  Therefore,
even though this is a bit invasive, it's time to back-patch.
Some comfort can be taken in the fact that f10f0ae42 has been
in v15 for 16 months without problems.

I left the RelationOpenSmgr macro present in the back branches,
even though no core code should use it anymore, in order to not break
third-party extensions in minor releases.  Such extensions might opt
to start using RelationGetSmgr instead, to reduce their code
differential between v15 and earlier branches.  This carries a hazard
of failing to compile against headers from existing minor releases.
However, once compiled the extension should work fine even with such
releases, because RelationGetSmgr is a "static inline" function so
it creates no link-time dependency.  So depending on distribution
practices, that might be an OK tradeoff.

Per report from Spyridon Dimitrios Agathos.  Original patch
by Amul Sul.

Discussion: https://postgr.es/m/CAFM5RaqdgyusQvmWkyPYaWMwoK5gigdtW-7HcgHgOeAw7mqJ_Q@mail.gmail.com
Discussion: https://postgr.es/m/CANiYTQsU7yMFpQYnv=BrcRVqK_3U3mtAzAsJCaqtzsDHfsUbdQ@mail.gmail.com
2022-11-17 16:54:30 -05:00
Tom Lane eeb5461e76 Add casts to simplehash.h to silence C++ warnings.
Casting the result of palloc etc. to the intended type is more per
project style anyway.

(The fact that cpluspluscheck doesn't notice these problems is
because it doesn't expand any macros, which seems like a troubling
shortcoming.  Don't have a good idea about improving that.)

Back-patch to v13, which is as far as the patch applies cleanly;
doesn't seem worth working harder.

David Geier

Discussion: https://postgr.es/m/aa5d88a3-71f4-3455-11cf-82de0372c941@gmail.com
2022-11-03 10:47:31 -04:00
Tom Lane 058c7b5dd4 Allow use of __sync_lock_test_and_set for spinlocks on any machine.
If we have no special-case code in s_lock.h for the current platform,
but the compiler has __sync_lock_test_and_set, use that instead of
failing.  It's unlikely that anybody's __sync_lock_test_and_set
would be so awful as to be worse than our semaphore-based fallback,
but if it is, they can (continue to) use --disable-spinlocks.

This allows removal of the RISC-V special case installed by commit
c32fcac56, which generated exactly the same code but only on that
platform.  Usefully, the RISC-V buildfarm animals should now test
at least the int variant of this patch.

I've manually tested both variants on ARM by dint of removing the
ARM-specific stanza.  We don't want to drop that, because it already
has some special knowledge and is likely to grow more over time.
Likewise, this is not meant to preclude installing special cases
for other arches if that proves worthwhile.

Per discussion of a request to install the same code for loongarch64.
Like the previous patch, we might as well back-patch to supported
branches.

Discussion: https://postgr.es/m/761ac43d44b84d679ba803c2bd947cc0@HSMAILSVR04.hs.handsome.com.cn
2022-11-02 17:37:26 -04:00
Robert Haas aaad8adb02 pg_basebackup: Fix cross-platform tablespace relocation.
Specifically, when pg_basebackup is invoked with -Tx=y, don't error
out if x could plausibly be an absolute path either on Windows or on
non-Windows systems. We don't know whether the remote system is
running the same OS as the local system, so it's not appropriate to
assume that our local rule about absolute pathnames is the same as
the rule on the remote system.

Patch by me, reviewed by Tom Lane, Andrew Dunstan, and
Davinder Singh.

Discussion: http://postgr.es/m/CA+TgmoY+jC3YiskomvYKDPK3FbrmsDU7_8+wMHt02HOdJeRb0g@mail.gmail.com
2022-10-21 08:39:48 -04:00
Tom Lane 18e60712dd Rename parser token REF to REF_P to avoid a symbol conflict.
In the latest version of Apple's macOS SDK, <sys/socket.h>
fails to compile if "REF" is #define'd as something.
Apple may or may not agree that this is a bug, and even if
they do accept the bug report I filed, they probably won't
fix it very quickly.  In the meantime, our back branches will all
fail to compile gram.y.  v15 and HEAD currently escape the problem
thanks to the refactoring done in 98e93a1fc, but that's purely
accidental.  Moreover, since that patch removed a widely-visible
inclusion of <netdb.h>, back-patching it seems too likely to break
third-party code.

Instead, change the token's code name to REF_P, following our usual
convention for naming parser tokens that are likely to have symbol
conflicts.  The effects of that should be localized to the grammar
and immediately surrounding files, so it seems like a safer answer.

Per project policy that we want to keep recently-out-of-support
branches buildable on modern systems, back-patch all the way to 9.2.

Discussion: https://postgr.es/m/1803927.1665938411@sss.pgh.pa.us
2022-10-16 15:27:04 -04:00
Peter Geoghegan 44933010ce Make check_usermap() parameter names consistent.
The function has a bool argument named "case_insensitive", but that was
spelled "case_sensitive" in the declaration.  Make them consistent now
to avoid confusion in the future.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Michael Paquiër <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAH2-WznJt9CMM9KJTMjJh_zbL5hD9oX44qdJ4aqZtjFi-zA3Tg@mail.gmail.com
Backpatch: 10-
2022-09-17 16:54:14 -07:00
Peter Eisentraut b7f37af7c1 Expand palloc/pg_malloc API for more type safety
This adds additional variants of palloc, pg_malloc, etc. that
encapsulate common usage patterns and provide more type safety.

Specifically, this adds palloc_object(), palloc_array(), and
repalloc_array(), which take the type name of the object to be
allocated as its first argument and cast the return as a pointer to
that type.  There are also palloc0_object() and palloc0_array()
variants for initializing with zero, and pg_malloc_*() variants of all
of the above.

Inspired by the talloc library.

This is backpatched from master so that future backpatchable code can
make use of these APIs.  This patch by itself does not contain any
users of these APIs.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/bb755632-2a43-d523-36f8-a1e7a389a907@enterprisedb.com
2022-09-14 06:08:34 +02:00
Amit Kapila 68dcce247f Fix catalog lookup with the wrong snapshot during logical decoding.
Previously, we relied on HEAP2_NEW_CID records and XACT_INVALIDATION
records to know if the transaction has modified the catalog, and that
information is not serialized to snapshot. Therefore, after the restart,
if the logical decoding decodes only the commit record of the transaction
that has actually modified a catalog, we will miss adding its XID to the
snapshot. Thus, we will end up looking at catalogs with the wrong
snapshot.

To fix this problem, this changes the snapshot builder so that it
remembers the last-running-xacts list of the decoded RUNNING_XACTS record
after restoring the previously serialized snapshot. Then, we mark the
transaction as containing catalog changes if it's in the list of initial
running transactions and its commit record has XACT_XINFO_HAS_INVALS. To
avoid ABI breakage, we store the array of the initial running transactions
in the static variables InitialRunningXacts and NInitialRunningXacts,
instead of storing those in SnapBuild or ReorderBuffer.

This approach has a false positive; we could end up adding the transaction
that didn't change catalog to the snapshot since we cannot distinguish
whether the transaction has catalog changes only by checking the COMMIT
record. It doesn't have the information on which (sub) transaction has
catalog changes, and XACT_XINFO_HAS_INVALS doesn't necessarily indicate
that the transaction has catalog change. But that won't be a problem since
we use snapshot built during decoding only to read system catalogs.

On the master branch, we took a more future-proof approach by writing
catalog modifying transactions to the serialized snapshot which avoids the
above false positive. But we cannot backpatch it because of a change in
the SnapBuild.

Reported-by: Mike Oh
Author: Masahiko Sawada
Reviewed-by: Amit Kapila, Shi yu, Takamichi Osumi, Kyotaro Horiguchi, Bertrand Drouvot, Ahsan Hadi
Backpatch-through: 10
Discussion: https://postgr.es/m/81D0D8B0-E7C4-4999-B616-1E5004DBDCD2%40amazon.com
2022-08-11 09:45:04 +05:30
Tom Lane 5721da7e41 In extensions, don't replace objects not belonging to the extension.
Previously, if an extension script did CREATE OR REPLACE and there was
an existing object not belonging to the extension, it would overwrite
the object and adopt it into the extension.  This is problematic, first
because the overwrite is probably unintentional, and second because we
didn't change the object's ownership.  Thus a hostile user could create
an object in advance of an expected CREATE EXTENSION command, and would
then have ownership rights on an extension object, which could be
modified for trojan-horse-type attacks.

Hence, forbid CREATE OR REPLACE of an existing object unless it already
belongs to the extension.  (Note that we've always forbidden replacing
an object that belongs to some other extension; only the behavior for
previously-free-standing objects changes here.)

For the same reason, also fail CREATE IF NOT EXISTS when there is
an existing object that doesn't belong to the extension.

Our thanks to Sven Klemm for reporting this problem.

Security: CVE-2022-2625
2022-08-08 11:12:31 -04:00
Alvaro Herrera 731d514ae5
Fix ENABLE/DISABLE TRIGGER to handle recursion correctly
Using ATSimpleRecursion() in ATPrepCmd() to do so as bbb927b4db did is
not correct, because ATPrepCmd() can't distinguish between triggers that
may be cloned and those that may not, so would wrongly try to recurse
for the latter category of triggers.

So this commit restores the code in EnableDisableTrigger() that
86f575948c had added to do the recursion, which would do it only for
triggers that may be cloned, that is, row-level triggers.  This also
changes tablecmds.c such that ATExecCmd() is able to pass the value of
ONLY flag down to EnableDisableTrigger() using its new 'recurse'
parameter.

This also fixes what seems like an oversight of 86f575948c that the
recursion to partition triggers would only occur if EnableDisableTrigger()
had actually changed the trigger.  It is more apt to recurse to inspect
partition triggers even if the parent's trigger didn't need to be
changed: only then can we be certain that all descendants share the same
state afterwards.

Backpatch all the way back to 11, like bbb927b4db.  Care is taken not
to break ABI compatibility (and that no catversion bump is needed.)

Co-authored-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Dmitry Koval <d.koval@postgrespro.ru>
Discussion: https://postgr.es/m/CA+HiwqG-cZT3XzGAnEgZQLoQbyfJApVwOTQaCaas1mhpf+4V5A@mail.gmail.com
2022-08-05 09:47:11 +02:00
Tom Lane 445b9020c9 Fix incorrect tests for SRFs in relation_can_be_sorted_early().
Commit fac1b470a thought we could check for set-returning functions
by testing only the top-level node in an expression tree.  This is
wrong in itself, and to make matters worse it encouraged others
to make the same mistake, by exporting tlist.c's special-purpose
IS_SRF_CALL() as a widely-visible macro.  I can't find any evidence
that anyone's taken the bait, but it was only a matter of time.

Use expression_returns_set() instead, and stuff the IS_SRF_CALL()
genie back in its bottle, this time with a warning label.  I also
added a couple of cross-reference comments.

After a fair amount of fooling around, I've despaired of making
a robust test case that exposes the bug reliably, so no test case
here.  (Note that the test case added by fac1b470a is itself
broken, in that it doesn't notice if you remove the code change.
The repro given by the bug submitter currently doesn't fail either
in v15 or HEAD, though I suspect that may indicate an unrelated bug.)

Per bug #17564 from Martijn van Oosterhout.  Back-patch to v13,
as the faulty patch was.

Discussion: https://postgr.es/m/17564-c7472c2f90ef2da3@postgresql.org
2022-08-03 17:33:42 -04:00
Alvaro Herrera 961cab0a5a
Allow "in place" tablespaces.
This is a backpatch to branches 10-14 of the following commits:

7170f2159f Allow "in place" tablespaces.
c6f2f01611 Fix pg_basebackup with in-place tablespaces.
f6f0db4d62 Fix pg_tablespace_location() with in-place tablespaces
7a7cd84893 doc: Remove mention to in-place tablespaces for pg_tablespace_location()
5344723755 Remove unnecessary Windows-specific basebackup code.

In-place tablespaces were introduced as a testing helper mechanism, but
they are going to be used for a bugfix in WAL replay to be backpatched
to all stable branches.

I (Álvaro) had to adjust some code to account for lack of
get_dirent_type() in branches prior to 14.

Author: Thomas Munro <thomas.munro@gmail.com>
Author: Michaël Paquier <michael@paquier.xyz>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20220722081858.omhn2in5zt3g4nek@alvherre.pgsql
2022-07-27 07:55:13 +02:00
Tom Lane 3e1297a63f Force immediate commit after CREATE DATABASE etc in extended protocol.
We have a few commands that "can't run in a transaction block",
meaning that if they complete their processing but then we fail
to COMMIT, we'll be left with inconsistent on-disk state.
However, the existing defenses for this are only watertight for
simple query protocol.  In extended protocol, we didn't commit
until receiving a Sync message.  Since the client is allowed to
issue another command instead of Sync, we're in trouble if that
command fails or is an explicit ROLLBACK.  In any case, sitting
in an inconsistent state while waiting for a client message
that might not come seems pretty risky.

This case wasn't reachable via libpq before we introduced pipeline
mode, but it's always been an intended aspect of extended query
protocol, and likely there are other clients that could reach it
before.

To fix, set a flag in PreventInTransactionBlock that tells
exec_execute_message to force an immediate commit.  This seems
to be the approach that does least damage to existing working
cases while still preventing the undesirable outcomes.

While here, add some documentation to protocol.sgml that explicitly
says how to use pipelining.  That's latent in the existing docs if
you know what to look for, but it's better to spell it out; and it
provides a place to document this new behavior.

Per bug #17434 from Yugo Nagata.  It's been wrong for ages,
so back-patch to all supported branches.

Discussion: https://postgr.es/m/17434-d9f7a064ce2a88a3@postgresql.org
2022-07-26 13:07:03 -04:00
Peter Eisentraut 8657946d37 Re-add SPICleanup for ABI compatibility in stable branch
This fixes an ABI break introduced by
604651880c.

Author: Markus Wanner <markus.wanner@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/defd749a-8410-841d-1126-21398686d63d@enterprisedb.com
2022-07-18 16:23:48 +02:00
Tom Lane af72b08894 Invent qsort_interruptible().
Justin Pryzby reported that some scenarios could cause gathering
of extended statistics to spend many seconds in an un-cancelable
qsort() operation.  To fix, invent qsort_interruptible(), which is
just like qsort_arg() except that it will also do CHECK_FOR_INTERRUPTS
every so often.  This bloats the backend by a couple of kB, which
seems like a good investment.  (We considered just enabling
CHECK_FOR_INTERRUPTS in the existing qsort and qsort_arg functions,
but there are some callers for which that'd demonstrably be unsafe.
Opt-in seems like a better way.)

For now, just apply qsort_interruptible() in statistics collection.
There's probably more places where it could be useful, but we can
always change other call sites as we find problems.

Back-patch to v14.  Before that we didn't have extended stats on
expressions, so that the problem was less severe.  Also, this patch
depends on the sort_template infrastructure introduced in v14.

Tom Lane and Justin Pryzby

Discussion: https://postgr.es/m/20220509000108.GQ28830@telsasoft.com
2022-07-12 16:30:36 -04:00
Thomas Munro 5e7608e81e Fix lock assertions in dshash.c.
dshash.c previously maintained flags to be able to assert that you
didn't hold any partition lock.  These flags could get out of sync with
reality in error scenarios.

Get rid of all that, and make assertions about the locks themselves
instead.  Since LWLockHeldByMe() loops internally, we don't want to put
that inside another loop over all partition locks.  Introduce a new
debugging-only interface LWLockAnyHeldByMe() to avoid that.

This problem was noted by Tom and Andres while reviewing changes to
support the new shared memory stats system, and later showed up in
reality while working on commit 389869af.

Back-patch to 11, where dshash.c arrived.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220311012712.botrpsikaufzteyt@alap3.anarazel.de
Discussion: https://postgr.es/m/CA%2BhUKGJ31Wce6HJ7xnVTKWjFUWQZPBngxfJVx4q0E98pDr3kAw%40mail.gmail.com
2022-07-11 15:47:12 +12:00
Thomas Munro 99504ff826 Fix relptr's encoding of the base address.
Previously, we encoded both NULL and the first byte at the base address
as 0.  That confusion led to the assertion in commit e07d4ddc, which
failed when min_dynamic_shared_memory was used.  Give them distinct
encodings, by switching to 1-based offsets for non-NULL pointers.  Also
improve macro hygiene in passing (missing/misplaced parentheses), and
remove open-coded access to the raw offset value from freepage.c/h.

Although e07d4ddc was back-patched to 10, the only code that actually
makes use of relptr at the base address arrived in 84b1c63a, so no need
to back-patch further than 14 for now.

Reported-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/20220519193839.GT19626%40telsasoft.com
2022-06-27 11:45:03 +12:00