I was able to crash postgres 6.5.3 when I did an 'alter user' command.
After I started a debugger I found the problem in the timezone handling
of
datetime (my Linux box lost its timezone information, that's how the
problem occurred).
Only 7 bytes are reserved for the timezone, without checking for
boundaries.
Attached is a patch that fixes this problem and emits a NOTICE if a
timezone is encountered that is longer than MAXTZLEN bytes, like this:
Jeroen van Vianen
Ok. I made patches replacing all of "#if FALSE" or "#if 0" to "#ifdef
NOT_USED" for current. I have tested these patches in that the
postgres binaries are identical.
to give HAVE_TM_ZONE priority. This fixes glibc2 machines and any other
machine which passes both tests in configure.
Repair HAVE_TM_ZONE code which stuffs tm structure with date type values.
Same problems as were originally there before v6.1, but never noticed.
Thanks to Oleg for nagging :)
where you state a format and arguments. the old behavior required
each appendStringInfo to have to have a sprintf() before it if any
formatting was required.
Also shortened several instances where there were multiple appendStringInfo()
calls in a row, doing nothing more then adding one more word to the String,
instead of doing them all in one call.
over HAVE_INT_TIMEZONE. This may help out linux/glibc2 and Dec Alpha.
Included #error precompiler macros to catch cases where neither is defined
but USE_POSIX_TIME is (shouldn't happen). Hopefully this isn't just
a gcc-ism.
Add type conversion functions for floating point numbers.
Check for zero in unary minus floating point code (IEEE allows an
explicit negative zero which looks ugly in a query result!).
Ensure circle type has non-negative radius.
Here are patches which should help fix timezone problems in the
datetime and abstime code. Also, I repatched varlena.c to add in
some comments and a little error checking on top of Vadim's earlier
repairs. There are slight mods to the circle data type to have the
distance operator between circles measure the distance between
closest points rather than between centers.
Subject: [PATCHES] date/time timezone patches (mail bounced?)
Here are some hacks to get timezone behavior for the various time
data types to be compatible with v6.0. Although we have some hooks
already installed to get timezone info from the client to the
server, it still isn't clear if that can correctly transfer enough
timezone info to make the behavior the same as if timezone info
were derived from the server as is now the case. We certainly
won't resolve it in a day, so I think we are stuck with server-only
timezones for v6.1.
Subject: [HACKERS] More date time functions
Here are some additional patches mostly related to the date and time
data types. It includes some type conversion routines to move between
the different date types and some other date manipulation routines such
as date_part(units,datetime).
I noticed Edmund Mergl et al's neat trick for getting function overloading
for builtin functions, so started to use that for the date and time stuff.
Later, if someone figures out how to get function overloading directly
for internal C code, then we can move to that technique.
These patches include documentation updates (don't faint!) for the built-in
man page. Doesn't yet include mention of timestamp, since I don't know
much about it and since it may change a bit to become a _real_ ANSI timestamp
which would include parser support for the declaration syntax (what do you
think, Dan?).
The patches were developed on the 970330 release, but have been rebuilt
off of the 970402 release. The first patch below is to get libpq to compile,
on my Linux box, but is not related to the rest of the patches and you can
choose not to apply that one at this time. Thanks in advance, scrappy!
Subject: Re: [HACKERS] abstime "now" broken
Yes, I broke 'now' :( with an attempt at a bug fix involving
servers running in the UTC/GMT timezone. These patches fix
the problem, and have been tested in GMT (+00 hours),
PST (-08), and NZT (+12) timezones which exercized the code for
various cases including across day boundaries. btw, this code
fixes the same type of problem for 'today', 'yesterday', 'tomorrow',
for DATETIME, ABSTIME, DATE and TIME types.
The bugfix itself is quite small, but I have accumulated other
changes in the datetime data type and include them here also.
One set of changes involves printing ISO-formatted dates and
is in response to the helpful information from Kurt Lidl regarding
ANSI SQL dates. I'll send another e-mail sometime soon discussing
more issues he has raised...
Subject: [HACKERS] More patches for date/time
I have accumulated several patches to add functionality to the datetime
and timespan data types as well as to fix reported porting bugs on non-BSD
machines. These patches are:
dt.c.patch - add datetime_part(), fix bugs
dt.h.patch - add quarter and timezone support, add prototypes
globals.c.patch - add time and timezone variables
miscadmin.h.patch - add time and timezone variables
nabstime.c.patch - add datetime conversion routine
nabstime.h.patch - add prototypes
pg_operator.h.patch - add datetime operators, clean up formatting
pg_proc.h.patch - add datetime functions, reassign conflicting date OIDs
pg_type.h.patch - add datetime and timespan data types
The dt.c and pg_proc.h patches are fairly large; the latter mostly because I tried
to get some columns for existing entries to line up.
Subject: [HACKERS] backend/utils/adt/nabstime.c
There is a problem with some of the calls to strftime. The second arg is
missing. In all cases the buffer is CTZName which, according to the
file init/globals.c, is char CTZName[8] so I have added this value.
I know there should be a #define set up for this but I wasn't sure
which header to put it in.