postgrespro.git / summary / log / commit / refs
commit 8eb4a9312c95be56cdb31f5411eddc2cb2ba89be
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon Jan 21 17:07:02 2019 +0000
Avoid thread-safety problem in ecpglib.
ecpglib attempts to force the LC_NUMERIC locale to "C" while reading
server output, to avoid problems with strtod() and related functions.
Historically it's just issued setlocale() calls to do that, but that
has major problems if we're in a threaded application. setlocale()
itself is not required by POSIX to be thread-safe (and indeed is not,
on recent OpenBSD). Moreover, its effects are process-wide, so that
we could cause unexpected results in other threads, or another thread
could change our setting.
On platforms having uselocale(), which is required by POSIX:2008,
we can avoid these problems by using uselocale() instead. Windows
goes its own way as usual, but we can make it safe by using
_configthreadlocale(). Platforms having neither continue to use the
old code, but that should be pretty much nobody among current systems.
This should get back-patched, but let's see what the buildfarm
thinks of it first.
Michael Meskes and Tom Lane; thanks also to Takayuki Tsunakawa.
Discussion: https://postgr.es/m/31420.1547783697@sss.pgh.pa.us
configure | 2 +-
configure.in | 1 +
src/include/pg_config.h.in | 3 ++
src/include/pg_config.h.win32 | 3 ++
src/interfaces/ecpg/ecpglib/descriptor.c | 37 +++++++++++++++++++-----
src/interfaces/ecpg/ecpglib/ecpglib_extern.h | 11 ++++++++
src/interfaces/ecpg/ecpglib/execute.c | 42 +++++++++++++++++++++++++++-
7 files changed, 90 insertions(+), 9 deletions(-)
diff --git a/configure b/configure
index 7602e65416..1e69edacde 100755
--- a/configure
+++ b/configure
@@ -15209,7 +15209,7 @@ fi
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
-for ac_func in cbrt clock_gettime copyfile fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate ppoll pstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open strchrnul strsignal symlink sync_file_range utime utimes wcstombs_l
+for ac_func in cbrt clock_gettime copyfile fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate ppoll pstat pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open strchrnul strsignal symlink sync_file_range uselocale utime utimes wcstombs_l
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.in b/configure.in
index d599ad85cc..556186cf2d 100644
--- a/configure.in
+++ b/configure.in
@@ -1618,6 +1618,7 @@ AC_CHECK_FUNCS(m4_normalize([
strsignal
symlink
sync_file_range
+ uselocale
utime
utimes
wcstombs_l
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 9d99816eae..2c899a1569 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -691,6 +691,9 @@
/* Define to 1 if the system has the type `unsigned long long int'. */
#undef HAVE_UNSIGNED_LONG_LONG_INT
+/* Define to 1 if you have the `uselocale' function. */
+#undef HAVE_USELOCALE
+
/* Define to 1 if you have the `utime' function. */
#undef HAVE_UTIME
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 8a560ef0f3..396443386a 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -545,6 +545,9 @@
/* Define to 1 if you have the `unsetenv' function. */
/* #undef HAVE_UNSETENV */
+/* Define to 1 if you have the `uselocale' function. */
+/* #undef HAVE_USELOCALE */
+
/* Define to 1 if you have the `utime' function. */
#define HAVE_UTIME 1
diff --git a/src/interfaces/ecpg/ecpglib/descriptor.c b/src/interfaces/ecpg/ecpglib/descriptor.c
index 186f92cc3e..71cef15172 100644
--- a/src/interfaces/ecpg/ecpglib/descriptor.c
+++ b/src/interfaces/ecpg/ecpglib/descriptor.c
@@ -483,22 +483,45 @@ ECPGget_desc(int lineno, const char *desc_name, int index,...)
if (data_var.type != ECPGt_EORT)
{
struct statement stmt;
- char *oldlocale;
+
+ memset(&stmt, 0, sizeof stmt);
+ stmt.lineno = lineno;
/* Make sure we do NOT honor the locale for numeric input */
/* since the database gives the standard decimal point */
- oldlocale = ecpg_strdup(setlocale(LC_NUMERIC, NULL), lineno);
+ /* (see comments in execute.c) */
+#ifdef HAVE_USELOCALE
+ stmt.clocale = newlocale(LC_NUMERIC_MASK, "C", (locale_t) 0);
+ if (stmt.clocale != (locale_t) 0)
+ stmt.oldlocale = uselocale(stmt.clocale);
+#else
+#ifdef WIN32
+ stmt.oldthreadlocale = _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
+#endif
+ stmt.oldlocale = ecpg_strdup(setlocale(LC_NUMERIC, NULL), lineno);
setlocale(LC_NUMERIC, "C");
-
- memset(&stmt, 0, sizeof stmt);
- stmt.lineno = lineno;
+#endif
/* desperate try to guess something sensible */
stmt.connection = ecpg_get_connection(NULL);
ecpg_store_result(ECPGresult, index, &stmt, &data_var);
- setlocale(LC_NUMERIC, oldlocale);
- ecpg_free(oldlocale);
+#ifdef HAVE_USELOCALE
+ if (stmt.oldlocale != (locale_t) 0)
+ uselocale(stmt.oldlocale);
+ if (stmt.clocale)
+ freelocale(stmt.clocale);
+#else
+ if (stmt.oldlocale)
+ {
+ setlocale(LC_NUMERIC, stmt.oldlocale);
+ ecpg_free(stmt.oldlocale);
+ }
+#ifdef WIN32
+ if (stmt.oldthreadlocale != -1)
+ _configthreadlocale(stmt.oldthreadlocale);
+#endif
+#endif
}
else if (data_var.ind_type != ECPGt_NO_INDICATOR && data_var.ind_pointer != NULL)
diff --git a/src/interfaces/ecpg/ecpglib/ecpglib_extern.h b/src/interfaces/ecpg/ecpglib/ecpglib_extern.h
index 1c9bce1456..41851d5900 100644
--- a/src/interfaces/ecpg/ecpglib/ecpglib_extern.h
+++ b/src/interfaces/ecpg/ecpglib/ecpglib_extern.h
@@ -12,6 +12,9 @@
#ifndef CHAR_BIT
#include <limits.h>
#endif
+#ifdef LOCALE_T_IN_XLOCALE
+#include <xlocale.h>
+#endif
enum COMPAT_MODE
{
@@ -61,7 +64,15 @@ struct statement
bool questionmarks;
struct variable *inlist;
struct variable *outlist;
+#ifdef HAVE_USELOCALE
+ locale_t clocale;
+ locale_t oldlocale;
+#else
char *oldlocale;
+#ifdef WIN32
+ int oldthreadlocale;
+#endif
+#endif
int nparams;
char **paramvalues;
PGresult *results;
diff --git a/src/interfaces/ecpg/ecpglib/execute.c b/src/interfaces/ecpg/ecpglib/execute.c
index 3f5034e792..81aaf10f08 100644
--- a/src/interfaces/ecpg/ecpglib/execute.c
+++ b/src/interfaces/ecpg/ecpglib/execute.c
@@ -102,7 +102,12 @@ free_statement(struct statement *stmt)
free_variable(stmt->outlist);
ecpg_free(stmt->command);
ecpg_free(stmt->name);
+#ifdef HAVE_USELOCALE
+ if (stmt->clocale)
+ freelocale(stmt->clocale);
+#else
ecpg_free(stmt->oldlocale);
+#endif
ecpg_free(stmt);
}
@@ -1771,8 +1776,32 @@ ecpg_do_prologue(int lineno, const int compat, const int force_indicator,
/*
* Make sure we do NOT honor the locale for numeric input/output since the
- * database wants the standard decimal point
+ * database wants the standard decimal point. If available, use
+ * uselocale() for this because it's thread-safe. Windows doesn't have
+ * that, but it does have _configthreadlocale().
*/
+#ifdef HAVE_USELOCALE
+ stmt->clocale = newlocale(LC_NUMERIC_MASK, "C", (locale_t) 0);
+ if (stmt->clocale == (locale_t) 0)
+ {
+ ecpg_do_epilogue(stmt);
+ return false;
+ }
+ stmt->oldlocale = uselocale(stmt->clocale);
+ if (stmt->oldlocale == (locale_t) 0)
+ {
+ ecpg_do_epilogue(stmt);
+ return false;
+ }
+#else
+#ifdef WIN32
+ stmt->oldthreadlocale = _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
+ if (stmt->oldthreadlocale == -1)
+ {
+ ecpg_do_epilogue(stmt);
+ return false;
+ }
+#endif
stmt->oldlocale = ecpg_strdup(setlocale(LC_NUMERIC, NULL), lineno);
if (stmt->oldlocale == NULL)
{
@@ -1780,6 +1809,7 @@ ecpg_do_prologue(int lineno, const int compat, const int force_indicator,
return false;
}
setlocale(LC_NUMERIC, "C");
+#endif
#ifdef ENABLE_THREAD_SAFETY
ecpg_pthreads_init();
@@ -1982,8 +2012,18 @@ ecpg_do_epilogue(struct statement *stmt)
if (stmt == NULL)
return;
+#ifdef HAVE_USELOCALE
+ if (stmt->oldlocale != (locale_t) 0)
+ uselocale(stmt->oldlocale);
+#else
if (stmt->oldlocale)
+ {
setlocale(LC_NUMERIC, stmt->oldlocale);
+#ifdef WIN32
+ _configthreadlocale(stmt->oldthreadlocale);
+#endif
+ }
+#endif
free_statement(stmt);
}
[parent: f4593bd2ff03]