DefineQueryRewrite() has long required that ON SELECT rules be named
"_RETURN". But we overlooked the converse case: we should forbid
non-ON-SELECT rules that are named "_RETURN". In particular this
prevents using CREATE OR REPLACE RULE to overwrite a view's _RETURN
rule with some other kind of rule, thereby breaking the view.
Per bug #17646 from Kui Liu. Back-patch to all supported branches.
Discussion: https://postgr.es/m/17646-70c93cfa40365776@postgresql.org
The executor will dump core if it's asked to execute a seqscan on
a relation having no table AM, such as a view. While that shouldn't
really happen, it's possible to get there via catalog corruption,
such as a missing ON SELECT rule. It seems worth installing a defense
against that. There are multiple plausible places for such a defense,
but I picked the planner's get_relation_info().
Per discussion of bug #17646 from Kui Liu. Back-patch to v12 where
the tableam APIs were introduced; in older versions you won't get a
SIGSEGV, so it seems less pressing.
Discussion: https://postgr.es/m/17646-70c93cfa40365776@postgresql.org
If the non-recursive term of a SEARCH BREADTH FIRST recursive
query has only constants in its target list, the planner will
fold the starting RowExpr added by rewrite into a simple Const
of type RECORD. The executor doesn't have any problem with
that --- but EXPLAIN VERBOSE will encounter the Const as the
ultimate source of truth about what the field names of the
SET column are, and it didn't know what to do with that.
Fortunately, we can pull the identifying typmod out of the
Const, in much the same way that record_out would.
For reasons that remain a bit obscure to me, this only fails
with SEARCH BREADTH FIRST, not SEARCH DEPTH FIRST or CYCLE.
But I added regression test cases for both of those options
too, just to make sure we don't break it in future.
Per bug #17644 from Matthijs van der Vleuten. Back-patch
to v14 where these constructs were added.
Discussion: https://postgr.es/m/17644-3bd1f3036d6d7a16@postgresql.org
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
snprintf.c has always fallen back on libc's *printf implementation
when printing pointers (%p) and floats. When this code originated,
we were still supporting some platforms that lacked native snprintf,
so we used sprintf for that. That's not actually unsafe in our usage,
but nonetheless builds on macOS are starting to complain about sprintf
being unconditionally deprecated; and I wouldn't be surprised if other
platforms follow suit. There seems little reason to believe that any
platform supporting C99 wouldn't have standards-compliant snprintf,
so let's just use that instead to suppress such warnings.
Back-patch to v12, which is where we started to require C99. It's
also where we started to use our snprintf.c everywhere, so this
wouldn't be enough to suppress the warning in older branches anyway
--- that is, in older branches these aren't necessarily all our
usages of libc's sprintf. It is enough in v12+ because any
deprecation annotation attached to libc's sprintf won't apply to
pg_sprintf. (Whether all our usages of pg_sprintf are adequately
safe is not a matter I intend to address here, but perhaps it could
do with some review.)
Per report from Andres Freund and local testing.
Discussion: https://postgr.es/m/20221015211955.q4cwbsfkyk3c4ty3@awork3.anarazel.de
When a query whose results were requested in single-row mode is the last
in the queue by the time those results are being read, the single-row
flag was not being reset, because we were returning early from
pqPipelineProcessQueue. Move that stanza up so that the flag is always
reset at the end of sending that query's results.
Add a test for the situation.
Backpatch to 14.
Author: Denis Laxalde <denis.laxalde@dalibo.com>
Discussion: https://postgr.es/m/01af18c5-dacc-a8c8-07ee-aecc7650c3e8@dalibo.com
The postmaster is not supposed to do anything that depends
fundamentally on shared memory contents, because that creates
the risk that a backend crash that trashes shared memory will
take the postmaster down with it, preventing automatic recovery.
In commit 969d7cd43 I lost sight of this principle and coded
AssignPostmasterChildSlot() in such a way that it could fail
or even crash if the shared PMSignalState structure became
corrupted. Remarkably, we've not seen field reports of such
crashes; but I managed to induce one while testing the recent
changes around palloc chunk headers.
To fix, make a semi-duplicative state array inside the postmaster
so that we need consult only local state while choosing a "child
slot" for a new backend. Ensure that other postmaster-executed
routines in pmsignal.c don't have critical dependencies on the
shared state, either. Corruption of PMSignalState might now
lead ReleasePostmasterChildSlot() to conclude that backend X
failed, when actually backend Y was the one that trashed things.
But that doesn't matter, because we'll force a cluster-wide reset
regardless.
Back-patch to all supported branches, since this is an old bug.
Discussion: https://postgr.es/m/3436789.1665187055@sss.pgh.pa.us
DEFAULT markers appearing in an INSERT on an updatable view
could be mis-processed if they were in a multi-row VALUES clause.
This would lead to strange errors such as "cache lookup failed
for type NNNN", or in older branches even to crashes.
The cause is that commit 41531e42d tried to re-use rewriteValuesRTE()
to remove any SetToDefault nodes (that hadn't previously been replaced
by the view's own default values) appearing in "product" queries,
that is DO ALSO queries. That's fundamentally wrong because the
DO ALSO queries might not even be INSERTs; and even if they are,
their targetlists don't necessarily match the view's column list,
so that almost all the logic in rewriteValuesRTE() is inapplicable.
What we want is a narrow focus on replacing any such nodes with NULL
constants. (That is, in this context we are interpreting the defaults
as being strictly those of the view itself; and we already replaced
any that aren't NULL.) We could add still more !force_nulls tests
to further lobotomize rewriteValuesRTE(); but it seems cleaner to
split out this case to a new function, restoring rewriteValuesRTE()
to the charter it had before.
Per bug #17633 from jiye_sw. Patch by me, but thanks to
Richard Guo and Japin Li for initial investigation.
Back-patch to all supported branches, as the previous fix was.
Discussion: https://postgr.es/m/17633-98cc85e1fa91e905@postgresql.org
PostgreSQL::Test::Cluster and ::Utils were not being installed. This is
very hard to notice, as it only seems to affect external modules that
want to run tests from 15 back in earlier versions. Oversight in
b235d41d96.
This applies only to branches 14 and back, because 15 had already been
made correct in commit b3b4d8e68a.
Discussion: https://postgr.es/m/20221010093415.poplkyn7pjeiv2y7@alvherre.pgsql
There are a number of bugs in this area. Two of them are fixed here,
namely:
1. get_relation_idx_constraint_oid does not restrict the type of
constraint that's returned, so with sufficient bad luck it can
return the OID of a foreign key constraint. This has the effect that
a primary key in a partition can end up as a child of a foreign key,
which makes no sense (it needs to be the child of the equivalent
primary key.)
Change the API contract so that only index-backed constraints are
returned, mimicking get_constraint_index().
2. Both CloneFkReferenced and CloneFkReferencing clone a
self-referencing foreign key, so the partition ends up with
a duplicate foreign key. Change the former function to ignore such
constraints.
Add some tests to verify that things are better now. (However, these
new tests show some additional misbehavior that will be fixed later --
namely that there's a constraint marked NOT VALID.)
Backpatch to 12, where these constraints are possible at all.
Author: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Discussion: https://postgr.es/m/20220603154232.1715b14c@karst
Commit 34f581c39 intended to ensure that RelationGetBufferForTuple
would acquire a visibility-map page pin in case the otherBuffer's
all-visible bit had become set since we last had lock on that page.
But I missed a case: when we're extending the relation, VM concerns
were dealt with only in the relatively-less-likely case that we
fail to conditionally lock the otherBuffer. I think I'd believed
that we couldn't need to worry about it if the conditional lock
succeeds, which is true for the target buffer; but the otherBuffer
was unlocked for awhile so its bit might be set anyway. So we need
to do the GetVisibilityMapPins dance, and then also recheck the
page's free space, in both cases.
Per report from Jaime Casanova. Back-patch to v12 as the previous
patch was (although there's still no evidence that the bug is
reachable pre-v14).
Discussion: https://postgr.es/m/E1lWLjP-00006Y-Ml@gemulon.postgresql.org
This prevents marking the argument string for translation for gettext,
and it also prevents the given string (which is already translated) from
being translated at runtime.
Also, mark the strings used as arguments to check_rolespec_name for
translation.
Backpatch all the way back as appropriate. None of this is caught by
any tests (necessarily so), so I verified it manually.
Commit 25936fd46 adjusted things so that the "storeslot" we use
for remapping trigger tuples would have adequate lifespan, but it
neglected to consider the lifespan of the tuple descriptor that
the slot depends on. It turns out that in at least some cases, the
tupdesc we are passing is a refcounted tupdesc, and the refcount for
the slot's reference can get assigned to a resource owner having
different lifespan than the slot does. That leads to an error like
"tupdesc reference 0x7fdef236a1b8 is not owned by resource owner
SubTransaction". Worse, because of a second oversight in the same
commit, we'd try to free the same tupdesc refcount again while
cleaning up after that error, leading to recursive errors and an
"ERRORDATA_STACK_SIZE exceeded" PANIC.
To fix the initial problem, let's just make a non-refcounted copy
of the tupdesc we're supposed to use. That seems likely to guard
against additional problems, since there's no strong reason for
this code to assume that what it's given is a refcounted tupdesc;
in which case there's an independent hazard of the tupdesc having
shorter lifespan than the slot does. (I didn't bother trying to
free said copy, since it should go away anyway when the (sub)
transaction context is cleaned up.)
The other issue can be fixed by making the code added to
AfterTriggerFreeQuery work like the rest of that function, ie be
sure that it doesn't try to free the same slot twice in the event
of recursive error cleanup.
While here, also clean up minor stylistic issues in the test case
added by 25936fd46: don't use "create or replace function", as any
name collision within the tests is likely to have ill effects
that that won't mask; and don't use function names as generic as
trigger_function1, especially if you're not going to drop them
at the end of the test stanza.
Per bug #17607 from Thomas Mc Kay. Back-patch to v12, as the
previous fix was.
Discussion: https://postgr.es/m/17607-bd8ccc81226f7f80@postgresql.org
The "emulation" I wrote for PQsendQuery in pipeline mode to use extended
query protocol, in commit acb7e4eb6b, is problematic. Due to numerous
bugs we'll soon remove it. As a first step and for all branches back to
14, stop using PQsendQuery in libpq_pipeline. Also remove a few test
lines that will no longer be relevant.
Backpatch to 14.
Discussion: https://postgr.es/m/CA+mi_8ZGSQNmW6-mk_iSR4JZB_LJ4ww3suOF+1vGNs3MrLsv4g@mail.gmail.com
Mop up assorted set-but-not-used warnings in the back branches.
This includes back-patching relevant fixes from commit 152c9f7b8
the rest of the way, but there are also several cases that did not
appear in HEAD. Some of those we'd fixed in a retail way but not
back-patched, and others I think just got rewritten out of existence
during nearby refactoring.
While here, also back-patch b1980f6d0 (PL/Tcl: Fix compiler warnings
with Tcl 8.6) into 9.2, so that that branch compiles warning-free
with modern Tcl.
Per project policy, this is a candidate for back-patching into
out-of-support branches: it suppresses annoying compiler warnings
but changes no behavior. Hence, back-patch all the way to 9.2.
Discussion: https://postgr.es/m/514615.1663615243@sss.pgh.pa.us
clang 15+ will issue a set-but-not-used warning when the only
use of a variable is in autoincrements (e.g., "foo++;").
That's perfectly sensible, but it detects a few more cases that
we'd not noticed before. Silence the warnings with our usual
methods, such as PG_USED_FOR_ASSERTS_ONLY, or in one case by
actually removing a useless variable.
One thing that we can't nicely get rid of is that with %pure-parser,
Bison emits "yynerrs" as a local variable that falls foul of this
warning. To silence those, I inserted "(void) yynerrs;" in the
top-level productions of affected grammars.
Per recently-established project policy, this is a candidate
for back-patching into out-of-support branches: it suppresses
annoying compiler warnings but changes no behavior. Hence,
back-patch to 9.5, which is as far as these patches go without
issues. (A preliminary check shows that the prior branches
need some other set-but-not-used cleanups too, so I'll leave
them for another day.)
Discussion: https://postgr.es/m/514615.1663615243@sss.pgh.pa.us
The API contract for planstate_tree_walker() callbacks is that they
take a PlanState pointer and a context pointer. Somebody figured
they could save a couple lines of code by ignoring that, and passing
ExecShutdownNode itself as the walker even though it has but one
argument. Somewhat remarkably, we've gotten away with that so far.
However, it seems clear that the upcoming C2x standard means to
forbid such cases, and compilers that actively break such code
likely won't be far behind. So spend the extra few lines of code
to do it honestly with a separate walker function.
In HEAD, we might as well go further and remove ExecShutdownNode's
useless return value. I left that as-is in back branches though,
to forestall complaints about ABI breakage.
Back-patch, with the thought that this might become of practical
importance before our stable branches are all out of service.
It doesn't seem to be fixing any live bug on any currently known
platform, however.
Discussion: https://postgr.es/m/208054.1663534665@sss.pgh.pa.us
Treat arguments declared as RECORD as if that were a polymorphic type
(which it is, sort of), in that we substitute the actual argument type
while forming the function cache lookup key. This allows the specific
composite type to be known in some cases where it was not before,
at the cost of making a separate function cache entry for each named
composite type that's passed to the function during a session. The
particular symptom discussed in bug #17610 could be solved in other
more-efficient ways, but only at the cost of considerable development
work, and there are other cases where we'd still fail without this.
Per bug #17610 from Martin Jurča. Back-patch to v11 where we first
allowed plpgsql functions to be declared as taking type RECORD.
Discussion: https://postgr.es/m/17610-fb1eef75bf6c2364@postgresql.org
I happened to notice that libpq_pipeline's private implementation
of pg_fatal lacked any pg_attribute_printf decoration. Indeed,
adding that turned up a mistake! We'd likely never have noticed
because the error exits in this code are unlikely to get hit,
but still, it's a bug.
We're so used to having the compiler check this stuff for us that
a printf-like function without pg_attribute_printf is a land mine.
I wonder if there is a way to detect such omissions.
Back-patch to v14 where this code came in.
The zlib documentation mentions the values supported for the compression
strategy, but this code has been using a hardcoded value of 0 rather
than Z_DEFAULT_STRATEGY. This commit adjusts the code to use
Z_DEFAULT_STRATEGY.
Backpatch down to where this code has been added to ease the backport of
any future patch touching this area.
Reported-by: Tom Lane
Discussion: https://postgr.es/m/1400032.1662217889@sss.pgh.pa.us
Backpatch-through: 10
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
The primary fix here is to fix has_matching_range() so it does not
reference ranges->values[-1] when nranges == 0. Similar problems existed
in AssertCheckRanges() too. It does not look like any of these problems
could lead to a crash as the array in question is at the end of the Ranges
struct, and values[-1] is memory that belongs to other fields in the
struct. However, let's get rid of these rather unsafe coding practices.
In passing, I (David) adjusted some comments to try to make it more clear
what some of the fields are for in the Ranges struct. I had to study the
code to find out what nsorted was for as I couldn't tell from the
comments.
Author: Ranier Vilela
Discussion: https://postgr.es/m/CAEudQAqJQzPitufX-jR=YUbJafpCDAKUnwgdbX_MzSc93wuvdw@mail.gmail.com
Backpatch-through: 14, where multi-range brin was added.
Commit c4c340088 changed geometric operators to use float4 and float8
functions, and handle NaN's in a better way. The circle sameness test
had a typo in the code which resulted in all comparisons with the left
circle having a NaN radius considered same.
postgres=# select '<(0,0),NaN>'::circle ~= '<(0,0),1>'::circle;
?column?
----------
t
(1 row)
This fixes the sameness test to consider the radius of both the left
and right circle.
Backpatch to v12 where this was introduced.
Author: Ranier Vilela <ranier.vf@gmail.com>
Discussion: https://postgr.es/m/CAEudQAo8dK=yctg2ZzjJuzV4zgOPBxRU5+Kb+yatFiddtQk6Rw@mail.gmail.com
Backpatch-through: v12
The ECPG preprocessor converted code such as
static varchar str1[10], str2[20], str3[30];
into
static struct varchar_1 { int len; char arr[ 10 ]; } str1 ;
struct varchar_2 { int len; char arr[ 20 ]; } str2 ;
struct varchar_3 { int len; char arr[ 30 ]; } str3 ;
thus losing the storage attribute for the later variables.
Repeat the declaration for each such variable.
(Note that this occurred only for variables declared "varchar"
or "bytea", which may help explain how it escaped detection
for so long.)
Andrey Sokolov
Discussion: https://postgr.es/m/942241662288242@mail.yandex.ru
During ALTER TABLE ATTACH PARTITION, if the name of a parent's foreign
key constraint is already used on the partition, the code tries to
choose another one before the FK attributes list has been populated,
so the resulting constraint name was "<relname>__fkey" instead of
"<relname>_<attrs>_fkey". Repair, and add a test case.
Backpatch to 12. In 11, the code to attach a partition was not smart
enough to cope with conflicting constraint names, so the problem doesn't
exist there.
Author: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Discussion: https://postgr.es/m/20220901184156.738ebee5@karst
Primarily, this fixes an incorrect calculation in SlabCheck which was
looking in the wrong byte for the sentinel check. The reason that we've
never noticed this before in the form of a failing sentinel check is
because the pre-check to this always fails because all current core users
of slab contexts have a chunk size which is already MAXALIGNed, therefore
there's never any space for the sentinel byte. It is possible that an
extension needs to use a slab context and if they do with a chunk size
that's not MAXALIGNed, then they'll likely get errors about overwritten
sentinel bytes.
Additionally, this patch changes various calculations which are being done
based on the sizeof(SlabBlock). Currently, sizeof(SlabBlock) is a
multiple of 8, therefore sizeof(SlabBlock) is the same as
MAXALIGN(sizeof(SlabBlock)), however, if we were to ever have to add any
fields to that struct as part of a bug fix, then SlabAlloc could end up
returning a non-MAXALIGNed pointer. To be safe, let's ensure we always
MAXALIGN sizeof(SlabBlock) before using it in any calculations.
This patch has already been applied to master in d5ee4db0e.
Diagnosed-by: Tomas Vondra, Tom Lane
Author: Tomas Vondra, David Rowley
Discussion: https://postgr.es/m/CAA4eK1%2B1JyW5TiL%3DyV-3Uq1CrfnTyn0Xrk5uArt31Z%3D8rgPhXQ%40mail.gmail.com
Backpatch-through: 10
get_database_list() failed to restore the caller's memory context,
instead leaving current context set to TopMemoryContext which is
how CommitTransactionCommand() leaves it. The callers both think
they are using short-lived contexts, for the express purpose of
not having to worry about cleaning up individual allocations.
The net effect therefore is that supposedly short-lived allocations
could accumulate indefinitely in the launcher's TopMemoryContext.
Although this has been broken for a long time, it seems we didn't
have any obvious memory leak here until v15's rearrangement of the
stats logic. I (tgl) am not entirely convinced that there's no
other leak at all, though, and we're surely at risk of adding one
in future back-patched fixes. So back-patch to all supported
branches, even though this may be only a latent bug in pre-v15.
Reid Thompson
Discussion: https://postgr.es/m/972a4e12b68b0f96db514777a150ceef7dcd2e0f.camel@crunchydata.com
If the input word exceeds 1000 bytes, don't pass it to the stemmer;
just return it as-is after case folding. Such an input is surely
not a word in any human language, so whatever the stemmer might
do to it would be pretty dubious in the first place. Adding this
restriction protects us against a known recursion-to-stack-overflow
problem in the Turkish stemmer, and it seems like good insurance
against any other safety or performance issues that may exist in
the Snowball stemmers. (I note, for example, that they contain no
CHECK_FOR_INTERRUPTS calls, so we really don't want them running
for a long time.) The threshold of 1000 bytes is arbitrary.
An alternative definition could have been to treat such words as
stopwords, but that seems like a bigger break from the old behavior.
Per report from Egor Chindyaskin and Alexander Lakhin.
Thanks to Olly Betts for the recommendation to fix it this way.
Discussion: https://postgr.es/m/1661334672.728714027@f473.i.mail.ru
The default of lazy symbol resolution means that when the postmaster
first reaches the select() call in ServerLoop, it'll need to resolve
the link to that libc entry point. NetBSD's dynamic loader takes
an internal lock while doing that, and if a signal interrupts the
operation then there is a risk of self-deadlock should the signal
handler do anything that requires that lock, as several of the
postmaster signal handlers do. The window for this is pretty narrow,
and timing considerations make it unlikely that a signal would arrive
right then anyway. But it's semi-repeatable on slow single-CPU
machines, and in principle the race could happen with any hardware.
The least messy solution to this is to force binding of dynamic
symbols at postmaster start, using the "-z now" linker option.
While we're at it, also use "-z relro" so as to provide a small
security gain.
It's not entirely clear whether any other platforms share this
issue, but for now we'll assume it's NetBSD-specific. (We might
later try to use "-z now" on more platforms for performance
reasons, but that would not likely be something to back-patch.)
Report and patch by me; the idea to fix it this way is from
Andres Freund.
Discussion: https://postgr.es/m/3384826.1661802235@sss.pgh.pa.us
When a PostgreSQL instance performing archive recovery but not using
standby mode is promoted, and the last WAL segment that it attempted
to read ended in a partial record, the previous code would create
invalid WAL on the new timeline. The WAL from the previously timeline
would be copied to the new timeline up until the end of the last valid
record, but instead of beginning to write WAL at immediately
afterwards, the promoted server would write an overwrite contrecord at
the beginning of the next segment. The end of the previous segment
would be left as all-zeroes, resulting in failures if anything tried
to read WAL from that file.
The root of the issue is that ReadRecord() decides whether to set
abortedRecPtr and missingContrecPtr based on the value of StandbyMode,
but ReadRecord() switches to a new timeline based on the value of
ArchiveRecoveryRequested. We shouldn't try to write an overwrite
contrecord if we're switching to a new timeline, so change the test in
ReadRecod() to check ArchiveRecoveryRequested instead.
Code fix by Dilip Kumar. Comments by me incorporating suggested
language from Álvaro Herrera. Further review from Kyotaro Horiguchi
and Sami Imseih.
Discussion: http://postgr.es/m/CAFiTN-t7umki=PK8dT1tcPV=mOUe2vNhHML6b3T7W7qqvvajjg@mail.gmail.com
Discussion: http://postgr.es/m/FB0DEA0B-E14E-43A0-811F-C1AE93D00FF3%40amazon.com
While waiting for slots to become available in wait_on_slots() in
parallel_slot.c, the cancellation always relied on the first connection
in the set to do the job. This could cause problems when this slot's
socket is gone as PQgetCancel() would return NULL in this case. Rather
than always using the first connection, this changes the logic to use
the first valid connection for the cancellation.
Author: Ranier Vilela
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/CAEudQAokk1h_pUwGXsYS4oVOuf35s1O2o3TXGHpV8=AWikvgHA@mail.gmail.com
Backpatch-through: 14
SplitToVariants() in the ispell code, lseg_inside_poly() in geo_ops.c,
and regex_selectivity_sub() in selectivity estimation could recurse
until stack overflow; fix by adding check_stack_depth() calls.
So could next() in the regex compiler, but that case is better fixed by
converting its tail recursion to a loop. (We probably get better code
that way too, since next() can now be inlined into its sole caller.)
There remains a reachable stack overrun in the Turkish stemmer, but
we'll need some advice from the Snowball people about how to fix that.
Per report from Egor Chindyaskin and Alexander Lakhin. These mistakes
are old, so back-patch to all supported branches.
Richard Guo and Tom Lane
Discussion: https://postgr.es/m/1661334672.728714027@f473.i.mail.ru
sysctl is more portable than Linux's /proc/sys file tree, and
often easier to use too. That's why most of our docs refer to
sysctl when talking about how to adjust kernel parameters.
Bring the few stragglers into line.
Discussion: https://postgr.es/m/361175.1661187463@sss.pgh.pa.us
When creating a partitioned index, DefineIndex tries to identify
any existing indexes on the partitions that match the partitioned
index, so that it can absorb those as child indexes instead of
building new ones. Part of the matching is to compare IndexInfo
structs --- but that wasn't done quite right. We're comparing
the IndexInfo built within DefineIndex itself to one made from
existing catalog contents by BuildIndexInfo. Notably, while
BuildIndexInfo will run index expressions and predicates through
expression preprocessing, that has not happened to DefineIndex's
struct. The result is failure to match and subsequent creation
of duplicate indexes.
The easiest and most bulletproof fix is to build a new IndexInfo
using BuildIndexInfo, thereby guaranteeing that the processing done
is identical.
While here, let's also extract the opfamily and collation data
from the new partitioned index, removing ad-hoc logic that
duplicated knowledge about how those are constructed.
Per report from Christophe Pettus. Back-patch to v11 where
we invented partitioned indexes.
Richard Guo and Tom Lane
Discussion: https://postgr.es/m/8864BFAA-81FD-4BF9-8E06-7DEB8D4164ED@thebuild.com
The assert, introduced by 9f1cf97bb5, is intended to check if the prefix
is terminated by a \0 byte, but it has two flaws. Firstly, prefix_size
includes the \0 byte, so prefix[prefix_size] points to the byte after
the null byte. Secondly, the check ensures the byte is not equal \0,
while it should be checking the opposite.
Backpatch-through: 14
Discussion: https://postgr.es/m/b99b6101-2f14-3796-3dfa-4a6cd7d4326d@enterprisedb.com
The current publisher code checks if UPDATE or DELETE can be executed with
the replica identity of the table even if it's a partitioned table. We can
skip checking the replica identity for partitioned tables because the
operations are actually performed on the leaf partitions (not the
partitioned table).
Reported-by: Brad Nicholson
Author: Hou Zhijie
Reviewed-by: Peter Smith, Amit Kapila
Backpatch-through: 13
Discussion: https://postgr.es/m/CAMMnM%3D8i5DohH%3DYKzV0_wYuYSYvuOJoL9F5nzXTc%2ByzsG1f6rg%40mail.gmail.com
There's a convention that externally-visible libpq functions should
check for a NULL PGconn pointer, and fail gracefully instead of
crashing. PQflush() and PQisnonblocking() didn't get that memo
though. Also add a similar check to PQdefaultSSLKeyPassHook_OpenSSL;
while it's not clear that ordinary usage could reach that with a
null conn pointer, it's cheap enough to check, so let's be consistent.
Daniele Varrazzo and Tom Lane
Discussion: https://postgr.es/m/CA+mi_8Zm_mVVyW1iNFgyMd9Oh0Nv8-F+7Y3-BqwMgTMHuo_h2Q@mail.gmail.com
When enlarging the work buffers of a VarStringSortSupport object,
varstrfastcmp_locale was careful to keep them in the ssup_cxt
memory context; but varstr_abbrev_convert just used palloc().
The latter creates a hazard that the buffers could be freed out
from under the VarStringSortSupport object, resulting in stomping
on whatever gets allocated in that memory later.
In practice, because we only use this code for ICU collations
(cf. 3df9c374e), the problem is confined to use of ICU collations.
I believe it may have been unreachable before the introduction
of incremental sort, too, as traditional sorting usually just
uses one context for the duration of the sort.
We could fix this by making the broken stanzas in varstr_abbrev_convert
match the non-broken ones in varstrfastcmp_locale. However, it seems
like a better idea to dodge the issue altogether by replacing the
pfree-and-allocate-anew coding with repalloc, which automatically
preserves the chunk's memory context. This fix does add a few cycles
because repalloc will copy the chunk's content, which the existing
coding assumes is useless. However, we don't expect that these buffer
enlargement operations are performance-critical. Besides that, it's
far from obvious that copying the buffer contents isn't required, since
these stanzas make no effort to mark the buffers invalid by resetting
last_returned, cache_blob, etc. That seems to be safe upon examination,
but it's fragile and could easily get broken in future, which wouldn't
get revealed in testing with short-to-moderate-size strings.
Per bug #17584 from James Inform. Whether or not the issue is
reachable in the older branches, this code has been broken on its
own terms from its introduction, so patch all the way back.
Discussion: https://postgr.es/m/17584-95c79b4a7d771f44@postgresql.org
It's possible to reach this case when work_mem is very small and tupsize
is (relatively) very large. In that case ExecChooseHashTableSize would
get an assertion failure, or with asserts off it'd compute nbuckets = 0,
which'd likely cause misbehavior later (I've not checked). To fix,
clamp the number of buckets to be at least 1.
This is due to faulty conversion of old my_log2() coding in 28d936031.
Back-patch to v13, as that was.
Zhang Mingli
Discussion: https://postgr.es/m/beb64ca0-91e2-44ac-bf4a-7ea36275ec02@Spark
Most parts of the parser can expect that the stack overflow check
in transformExprRecurse() will trigger before things get desperate.
However, transformFromClauseItem() can recurse directly to self
without having analyzed any expressions, so it's possible to drive
it to a stack-overrun crash. Add a check to prevent that.
Per bug #17583 from Egor Chindyaskin. Back-patch to all supported
branches.
Richard Guo
Discussion: https://postgr.es/m/17583-33be55b9f981f75c@postgresql.org
