mirror/postgresql
2
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2025-02-23 19:39:53 +08:00
Code Issues Packages Projects Releases Wiki Activity

Don't use %s-with-precision format spec to truncate data being displayed

Browse Source 
in a COPY error message.  It seems that glibc gets indigestion if it is
asked to truncate strings that contain invalid UTF-8 encoding sequences.
vsnprintf will return -1 in such cases, leading to looping and eventual
memory overflow in elog.c.  Instead use our own, more robust pg_mbcliplen
routine.  I believe this problem accounts for several recent reports of
unexpected 'out of memory' errors during COPY IN.
This commit is contained in:
Tom Lane 2004-01-18 02:15:57 +00:00
parent 9933ba3f67
commit ab189aaad9
1 changed files with 48 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
src/backend/commands/copy.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.213 2003/10/06 02:38:53 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.213.2.1 2004/01/18 02:15:57 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -139,6 +139,7 @@ static Datum CopyReadBinaryAttribute(int column_no, FmgrInfo *flinfo,
Oid typelem, bool *isnull);
static void CopyAttributeOut(char *string, char *delim);
static List *CopyGetAttnums(Relation rel, List *attnamelist);
static void limit_printout_length(StringInfo buf);
/* Internal communications functions */
static void SendCopyBegin(bool binary, int natts);
@ -1140,8 +1141,6 @@ CopyTo(Relation rel, List *attnumlist, bool binary, bool oids,
static void
copy_in_error_callback(void *arg)
{
#define MAX_COPY_DATA_DISPLAY 100
if (copy_binary)
{
/* can't usefully display the data */
@ -1156,10 +1155,10 @@ copy_in_error_callback(void *arg)
if (copy_attname)
{
/* error is relevant to a particular column */
errcontext("COPY %s, line %d, column %s: \"%.*s%s\"",
limit_printout_length(&attribute_buf);
errcontext("COPY %s, line %d, column %s: \"%s\"",
copy_relname, copy_lineno, copy_attname,
MAX_COPY_DATA_DISPLAY, attribute_buf.data,
(attribute_buf.len > MAX_COPY_DATA_DISPLAY) ? "..." : "");
attribute_buf.data);
}
else
{
@ -1167,6 +1166,7 @@ copy_in_error_callback(void *arg)
if (!line_buf_converted)
{
/* didn't convert the encoding yet... */
line_buf_converted = true;
if (client_encoding != server_encoding)
{
char *cvt;
@ -1181,16 +1181,46 @@ copy_in_error_callback(void *arg)
appendBinaryStringInfo(&line_buf, cvt, strlen(cvt));
}
}
line_buf_converted = true;
}
errcontext("COPY %s, line %d: \"%.*s%s\"",
limit_printout_length(&line_buf);
errcontext("COPY %s, line %d: \"%s\"",
copy_relname, copy_lineno,
MAX_COPY_DATA_DISPLAY, line_buf.data,
(line_buf.len > MAX_COPY_DATA_DISPLAY) ? "..." : "");
line_buf.data);
}
}
}
/*
* Make sure we don't print an unreasonable amount of COPY data in a message.
*
* It would seem a lot easier to just use the sprintf "precision" limit to
* truncate the string. However, some versions of glibc have a bug/misfeature
* that vsnprintf will always fail (return -1) if it is asked to truncate
* a string that contains invalid byte sequences for the current encoding.
* So, do our own truncation. We assume we can alter the StringInfo buffer
* holding the input data.
*/
static void
limit_printout_length(StringInfo buf)
{
#define MAX_COPY_DATA_DISPLAY 100
int len;
/* Fast path if definitely okay */
if (buf->len <= MAX_COPY_DATA_DISPLAY)
return;
/* Apply encoding-dependent truncation */
len = pg_mbcliplen(buf->data, buf->len, MAX_COPY_DATA_DISPLAY);
if (buf->len <= len)
return; /* no need to truncate */
buf->len = len;
buf->data[len] = '\0';
/* Add "..." to show we truncated the input */
appendStringInfoString(buf, "...");
}
/*
* Copy FROM file to relation.
@ -1875,7 +1905,15 @@ CopyReadLine(void)
/*
* Done reading the line. Convert it to server encoding.
*
* Note: set line_buf_converted to true *before* attempting conversion;
* this prevents infinite recursion during error reporting should
* pg_client_to_server() issue an error, due to copy_in_error_callback
* again attempting the same conversion. We'll end up issuing the message
* without conversion, which is bad but better than nothing ...
*/
line_buf_converted = true;
if (change_encoding)
{
cvt = (char *) pg_client_to_server((unsigned char *) line_buf.data,
@ -1889,8 +1927,6 @@ CopyReadLine(void)
}
}
line_buf_converted = true;
return result;
}