When reading a line from a pipe failed on no data being read, the
errorhandling was erroneously logging with %m even thoug no error
description is available for %m to print. This flaw accidentally
introduced in 5c7038d70b.
Reported-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/baa34329-f431-46af-bf74-1a78fdc90e4f@eisentraut.org
perror() is not used in postgres anymore out of policy, this replaces
the final callsites with the custom postgres logging framework.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/89B00F63-40F7-4D82-8353-DC9CABBAC1D1@yesql.se
Commit 5b2f4afffe refactored find_other_exec() and in the process
created pipe_read_line() into a static routine for reading a single
line of output, aimed at reading version numbers. Commit a7e8ece41
later exposed it externally in order to read a postgresql.conf GUC
using "postgres -C ..". Further, f06b1c598 also made use of it for
reading a version string much like find_other_exec(). The internal
variable remained "pgver", even when used for other purposes.
Since the function requires passing a buffer and its size, and at
most size - 1 bytes will be read via fgets(), there is a truncation
risk when using this for reading GUCs (like how pg_rewind does,
though the risk in this case is marginal).
To keep this as generic functionality for reading a line from a pipe,
this refactors pipe_read_line() into returning an allocated buffer
containing all of the line to remove the risk of silent truncation.
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Discussion: https://postgr.es/m/DEDF73CE-D528-49A3-9089-B3592FD671A9@yesql.se
Replace the symlink-chasing logic in find_my_exec with realpath(3),
which has been required by POSIX since SUSv2. (Windows lacks
realpath(), but there we can use _fullpath() which is functionally
equivalent.) The main benefit of this is that -- on all modern
platforms at least -- realpath() avoids the chdir() shenanigans
we used to perform while interpreting symlinks. That had various
corner-case failure modes so it's good to get rid of it.
There is still ongoing discussion about whether we could skip the
replacement of symlinks in some cases, but that's really matter
for a separate patch. Meanwhile I want to push this before we get
too close to feature freeze, so that we can find out if there are
showstopper portability issues.
Discussion: https://postgr.es/m/797232.1662075573@sss.pgh.pa.us
More than twenty years ago (79fcde48b), we hacked the postmaster
to avoid a core-dump on systems that didn't support fflush(NULL).
We've mostly, though not completely, hewed to that rule ever since.
But such systems are surely gone in the wild, so in the spirit of
cleaning out no-longer-needed portability hacks let's get rid of
multiple per-file fflush() calls in favor of using fflush(NULL).
Also, we were fairly inconsistent about whether to fflush() before
popen() and system() calls. While we've received no bug reports
about that, it seems likely that at least some of these call sites
are at risk of odd behavior, such as error messages appearing in
an unexpected order. Rather than expend a lot of brain cells
figuring out which places are at hazard, let's just establish a
uniform coding rule that we should fflush(NULL) before these calls.
A no-op fflush() is surely of trivial cost compared to launching
a sub-process via a shell; while if it's not a no-op then we likely
need it.
Discussion: https://postgr.es/m/2923412.1661722825@sss.pgh.pa.us
symlink() and readlink() are in SUSv2 and all targeted Unix systems have
them. We have partial emulation on Windows. Code that raised runtime
errors on systems without it has been dead for years, so we can remove
that and also references to such systems in the documentation.
Define HAVE_READLINK and HAVE_SYMLINK macros on Unix. Our Windows
replacement functions based on junction points can't be used for
relative paths or for non-directories, so the macros can be used to
check for full symlink support. The places that deal with tablespaces
can just use symlink functions without checking the macros. (If they
did check the macros, they'd need to provide an #else branch with a
runtime or compile time error, and it'd be dead code.)
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA+hUKGJ3LHeP9w5Fgzdr4G8AnEtJ=z=p6hGDEm4qYGEUX5B6fQ@mail.gmail.com
validate_exec() didn't guarantee to set errno to something appropriate
after a failure, leading to callers not being able to print an on-point
message. Improve that.
Noted by Kyotaro Horiguchi, though this isn't exactly his proposal.
Discussion: https://postgr.es/m/20220615.131403.1791191615590453058.horikyota.ntt@gmail.com
For some reason by default the mingw C Runtime takes it upon itself to
expand program arguments that look like shell globbing characters. That
has caused much scratching of heads and mis-attribution of the causes of
some TAP test failures, so stop doing that.
This removes an inconsistency with Windows binaries built with MSVC,
which have no such behaviour.
Per suggestion from Noah Misch.
Backpatch to all live branches.
Discussion: https://postgr.es/m/20220423025927.GA1274057@rfd.leadboat.com
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.
Suggested-by: Andres Freund <andres@anarazel.de>
Tested-by: Bossart, Nathan <bossartn@amazon.com>
Discussion: https://postgr.es/m/20210806032944.m4tz7j2w47mant26%40alap3.anarazel.de
Instead, put them in via a format placeholder. This reduces the
number of distinct translatable messages and also reduces the chances
of typos during translation. We already did this for the system call
arguments in a number of cases, so this is just the same thing taken a
bit further.
Discussion: https://www.postgresql.org/message-id/flat/92d6f545-5102-65d8-3c87-489f71ea0a37%40enterprisedb.com
This expands the binary validation in pg_upgrade with a version
check per binary to ensure that the target cluster installation
only contains binaries from the target version.
In order to reduce duplication, validate_exec is exported from
port.h and the local copy in pg_upgrade is removed.
Author: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://www.postgresql.org/message-id/flat/9328.1552952117@sss.pgh.pa.us
Since at least 2001 we've used putenv() and avoided setenv(), on the
grounds that the latter was unportable and not in POSIX. However,
POSIX added it that same year, and by now the situation has reversed:
setenv() is probably more portable than putenv(), since POSIX now
treats the latter as not being a core function. And setenv() has
cleaner semantics too. So, let's reverse that old policy.
This commit adds a simple src/port/ implementation of setenv() for
any stragglers (we have one in the buildfarm, but I'd not be surprised
if that code is never used in the field). More importantly, extend
win32env.c to also support setenv(). Then, replace usages of putenv()
with setenv(), and get rid of some ad-hoc implementations of setenv()
wannabees.
Also, adjust our src/port/ implementation of unsetenv() to follow the
POSIX spec that it returns an error indicator, rather than returning
void as per the ancient BSD convention. I don't feel a need to make
all the call sites check for errors, but the portability stub ought
to match real-world practice.
Discussion: https://postgr.es/m/2065122.1609212051@sss.pgh.pa.us
They are equivalent, except that StrNCpy() zero-fills the entire
destination buffer instead of providing just one trailing zero. For
all but a tiny number of callers, that's just overhead rather than
being desirable.
Remove StrNCpy() as it is now unused.
In some cases, namestrcpy() is the more appropriate function to use.
While we're here, simplify the API of namestrcpy(): Remove the return
value, don't check for NULL input. Nothing was using that anyway.
Also, remove a few unused name-related functions.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/44f5e198-36f6-6cdb-7fa9-60e34784daae%402ndquadrant.com
pg_rewind needs to copy from the source cluster to the target cluster a
set of relation blocks changed from the previous checkpoint where WAL
forked up to the end of WAL on the target. Building this list of
relation blocks requires a range of WAL segments that may not be present
anymore on the target's pg_wal, causing pg_rewind to fail. It is
possible to work around this issue by copying manually the WAL segments
needed but this may lead to some extra and actually useless work.
This commit introduces a new option allowing pg_rewind to use a
restore_command while doing the rewind by grabbing the parameter value
of restore_command from the target cluster configuration. This allows
the rewind operation to be more reliable, so as only the WAL segments
needed by the rewind are restored from the archives.
In order to be able to do that, a new routine is added to src/common/ to
allow frontend tools to restore files from archives using an
already-built restore command. This version is more simple than the
backend equivalent as there is no need to handle the non-recovery case.
Author: Alexey Kondratov
Reviewed-by: Andrey Borodin, Andres Freund, Alvaro Herrera, Alexander
Korotkov, Michael Paquier
Discussion: https://postgr.es/m/a3acff50-5a0d-9a2c-b3b2-ee36168955c1@postgrespro.ru
This fixes and updates a couple of comments related to outdated Windows
versions. Particularly, src/common/exec.c had a fallback implementation
to read a file's line from a pipe because stdin/stdout/stderr does not
exist in Windows 2000 that is removed to simplify src/common/ as there
are unlikely versions of Postgres running on such platforms.
Author: Michael Paquier
Reviewed-by: Kyotaro Horiguchi, Juan José Santamaría Flecha
Discussion: https://postgr.es/m/20191219021526.GC4202@paquier.xyz
This code used elog where it really ought to use ereport, mainly so that
it can report a SQLSTATE different from ERRCODE_INTERNAL_ERROR. There
were some other random deviations from typical error report practice too.
In addition, we can make some cleanups that were impractical six months
ago:
* Use one variadic macro, instead of several with different numbers
of arguments, reducing the temptation to force-fit messages into
particular numbers of arguments;
* Use %m, even in the frontend case, simplifying the code.
Discussion: https://postgr.es/m/6025.1527351693@sss.pgh.pa.us
It's often unsafe to reference errno within an elog/ereport call, because
there are a lot of sub-functions involved and they might not all preserve
errno. (This is why we support the %m format spec: it works off a value
of errno captured before we execute any potentially-unsafe functions in
the arguments.) Therefore, we have a project policy not to use errno
there.
This patch adds a hack to cause an (admittedly obscure) compiler error
for such unsafe usages. With the current code, the error will only be seen
on Linux, macOS, and FreeBSD, but that should certainly be enough to catch
mistakes in the buildfarm if they somehow get missed earlier.
In addition, fix some places in src/common/exec.c that trip the error.
I think these places are actually all safe, but it's simple enough to
avoid the error by capturing errno manually, and doing so is good
future-proofing in case these call sites get any more complicated.
Thomas Munro (exec.c fixes by me)
Discussion: https://postgr.es/m/2975.1526862605@sss.pgh.pa.us
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4d wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
The new indent version includes numerous fixes thanks to Piotr Stefaniak.
The main changes visible in this commit are:
* Nicer formatting of function-pointer declarations.
* No longer unexpectedly removes spaces in expressions using casts,
sizeof, or offsetof.
* No longer wants to add a space in "struct structname *varname", as
well as some similar cases for const- or volatile-qualified pointers.
* Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely.
* Fixes bug where comments following declarations were sometimes placed
with no space separating them from the code.
* Fixes some odd decisions for comments following case labels.
* Fixes some cases where comments following code were indented to less
than the expected column 33.
On the less good side, it now tends to put more whitespace around typedef
names that are not listed in typedefs.list. This might encourage us to
put more effort into typedef name collection; it's not really a bug in
indent itself.
There are more changes coming after this round, having to do with comment
indentation and alignment of lines appearing within parentheses. I wanted
to limit the size of the diffs to something that could be reviewed without
one's eyes completely glazing over, so it seemed better to split up the
changes as much as practical.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
This used to mean "Visual C++ except in those parts where Borland C++
was supported where it meant one of those". Now that we don't support
Borland C++ anymore, simplify by using _MSC_VER which is the normal way
to detect Visual C++.
Where possible, use palloc or pg_malloc instead; otherwise, insert
explicit NULL checks.
Generally speaking, these are places where an actual OOM is quite
unlikely, either because they're in client programs that don't
allocate all that much, or they're very early in process startup
so that we'd likely have had a fork() failure instead. Hence,
no back-patch, even though this is nominally a bug fix.
Michael Paquier, with some adjustments by me
Discussion: <CAB7nPqRu07Ot6iht9i9KRfYLpDaF2ZuUv5y_+72uP23ZAGysRg@mail.gmail.com>
GetTokenUser() will have reported an adequate error message. These
error conditions almost can't happen, so users are unlikely to observe
this change.
Reviewed by Tom Lane and Stephen Frost.
Darwin --enable-nls builds use a substitute setlocale() that may start a
thread. Buildfarm member orangutan experienced BackendList corruption
on account of different postmaster threads executing signal handlers
simultaneously. Furthermore, a multithreaded postmaster risks undefined
behavior from sigprocmask() and fork(). Emit LOG messages about the
problem and its workaround. Back-patch to 9.0 (all supported versions).
Coverity identified a number of places in which it couldn't prove that a
string being copied into a fixed-size buffer would fit. We believe that
most, perhaps all of these are in fact safe, or are copying data that is
coming from a trusted source so that any overrun is not really a security
issue. Nonetheless it seems prudent to forestall any risk by using
strlcpy() and similar functions.
Fixes by Peter Eisentraut and Jozef Mlich based on Coverity reports.
In addition, fix a potential null-pointer-dereference crash in
contrib/chkpass. The crypt(3) function is defined to return NULL on
failure, but chkpass.c didn't check for that before using the result.
The main practical case in which this could be an issue is if libc is
configured to refuse to execute unapproved hashing algorithms (e.g.,
"FIPS mode"). This ideally should've been a separate commit, but
since it touches code adjacent to one of the buffer overrun changes,
I included it in this commit to avoid last-minute merge issues.
This issue was reported by Honza Horak.
Security: CVE-2014-0065 for buffer overruns, CVE-2014-0066 for crypt()
Continuing 63f32f3416, libpgcommon should
depend on libpgport, but not vice versa. But wait_result_to_str() in
wait_error.c depends on pstrdup() in libpgcommon. So move exec.c and
wait_error.c from libpgport to libpgcommon. Also switch the link order
in the place that's actually used by the failing ecpg builds.
The function declarations have been left in port.h for now. That should
perhaps be separated sometime.
Daniel Gustafsson
Bruce Momjian
Tom Lane
Thomas Munro
Andrew Dunstan
Peter Eisentraut
Michael Paquier
Alvaro Herrera
Magnus Hagander
Noah Misch
Peter Eisentraut