From 0140dec18019e10c7df9f25dc19cab8e93a430c2 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 15 Jul 2020 22:05:12 -0400 Subject: [PATCH] Replace use of sys_siglist[] with strsignal(). This commit back-patches the v12-era commits a73d08319, cc92cca43, and 7570df0f3 into supported pre-v12 branches. The net effect is to eliminate our former dependency on the never-standard sys_siglist[] array, instead using POSIX-standard strsignal(3). What motivates doing this now is that glibc just removed sys_siglist[] from the set of symbols available to newly-built programs. While our code can survive without sys_siglist[], it then fails to print any description of the signal that killed a child process, which is a non-negligible loss of friendliness. We can expect that people will be wanting to build the back branches on platforms that include this change, so we need to do something. Since strsignal(3) has existed for quite a long time, and we've not had any trouble with these patches so far in v12, it seems safe to back-patch into older branches. Discussion: https://postgr.es/m/3179114.1594853308@sss.pgh.pa.us --- configure | 20 +-------- configure.in | 9 +--- src/backend/postmaster/pgarch.c | 11 +---- src/backend/postmaster/postmaster.c | 16 ++----- src/bin/pg_basebackup/pg_basebackup.c | 18 +++----- src/common/wait_error.c | 16 ++----- src/include/pg_config.h.in | 7 ++- src/include/pg_config.h.win32 | 3 ++ src/include/port.h | 3 ++ src/port/Makefile | 2 +- src/port/pgstrsignal.c | 64 +++++++++++++++++++++++++++ src/test/regress/pg_regress.c | 9 +--- 12 files changed, 94 insertions(+), 84 deletions(-) create mode 100644 src/port/pgstrsignal.c diff --git a/configure b/configure index e69106c86e3..986d3906a95 100755 --- a/configure +++ b/configure @@ -13256,7 +13256,7 @@ fi LIBS_including_readline="$LIBS" LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'` -for ac_func in cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower uselocale utime utimes wcstombs wcstombs_l +for ac_func in cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate pstat pthread_is_threaded_np readlink setproctitle setsid shm_open strsignal symlink sync_file_range towlower uselocale utime utimes wcstombs 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" @@ -14122,24 +14122,6 @@ esac fi -ac_fn_c_check_decl "$LINENO" "sys_siglist" "ac_cv_have_decl_sys_siglist" "#include -/* NetBSD declares sys_siglist in unistd.h. */ -#ifdef HAVE_UNISTD_H -# include -#endif - -" -if test "x$ac_cv_have_decl_sys_siglist" = xyes; then : - ac_have_decl=1 -else - ac_have_decl=0 -fi - -cat >>confdefs.h <<_ACEOF -#define HAVE_DECL_SYS_SIGLIST $ac_have_decl -_ACEOF - - ac_fn_c_check_func "$LINENO" "syslog" "ac_cv_func_syslog" if test "x$ac_cv_func_syslog" = xyes; then : ac_fn_c_check_header_mongrel "$LINENO" "syslog.h" "ac_cv_header_syslog_h" "$ac_includes_default" diff --git a/configure.in b/configure.in index 95580ae7ee3..22dfc3b7a4f 100644 --- a/configure.in +++ b/configure.in @@ -1516,6 +1516,7 @@ AC_CHECK_FUNCS(m4_normalize([ setproctitle setsid shm_open + strsignal symlink sync_file_range towlower @@ -1717,14 +1718,6 @@ if test "$PORTNAME" = "cygwin"; then AC_LIBOBJ(dirmod) fi -AC_CHECK_DECLS([sys_siglist], [], [], -[#include -/* NetBSD declares sys_siglist in unistd.h. */ -#ifdef HAVE_UNISTD_H -# include -#endif -]) - AC_CHECK_FUNC(syslog, [AC_CHECK_HEADER(syslog.h, [AC_DEFINE(HAVE_SYSLOG, 1, [Define to 1 if you have the syslog interface.])])]) diff --git a/src/backend/postmaster/pgarch.c b/src/backend/postmaster/pgarch.c index dc2739bf36d..1d2bedf8bee 100644 --- a/src/backend/postmaster/pgarch.c +++ b/src/backend/postmaster/pgarch.c @@ -596,17 +596,10 @@ pgarch_archiveXlog(char *xlog) errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value."), errdetail("The failed archive command was: %s", xlogarchcmd))); -#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST - ereport(lev, - (errmsg("archive command was terminated by signal %d: %s", - WTERMSIG(rc), - WTERMSIG(rc) < NSIG ? sys_siglist[WTERMSIG(rc)] : "(unknown)"), - errdetail("The failed archive command was: %s", - xlogarchcmd))); #else ereport(lev, - (errmsg("archive command was terminated by signal %d", - WTERMSIG(rc)), + (errmsg("archive command was terminated by signal %d: %s", + WTERMSIG(rc), pg_strsignal(WTERMSIG(rc))), errdetail("The failed archive command was: %s", xlogarchcmd))); #endif diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 5c1215b0a12..9edf412d96a 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -3611,6 +3611,7 @@ LogChildExit(int lev, const char *procname, int pid, int exitstatus) procname, pid, WEXITSTATUS(exitstatus)), activity ? errdetail("Failed process was running: %s", activity) : 0)); else if (WIFSIGNALED(exitstatus)) + { #if defined(WIN32) ereport(lev, @@ -3621,7 +3622,7 @@ LogChildExit(int lev, const char *procname, int pid, int exitstatus) procname, pid, WTERMSIG(exitstatus)), errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value."), activity ? errdetail("Failed process was running: %s", activity) : 0)); -#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST +#else ereport(lev, /*------ @@ -3629,19 +3630,10 @@ LogChildExit(int lev, const char *procname, int pid, int exitstatus) "server process" */ (errmsg("%s (PID %d) was terminated by signal %d: %s", procname, pid, WTERMSIG(exitstatus), - WTERMSIG(exitstatus) < NSIG ? - sys_siglist[WTERMSIG(exitstatus)] : "(unknown)"), - activity ? errdetail("Failed process was running: %s", activity) : 0)); -#else - ereport(lev, - - /*------ - translator: %s is a noun phrase describing a child process, such as - "server process" */ - (errmsg("%s (PID %d) was terminated by signal %d", - procname, pid, WTERMSIG(exitstatus)), + pg_strsignal(WTERMSIG(exitstatus))), activity ? errdetail("Failed process was running: %s", activity) : 0)); #endif + } else ereport(lev, diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c index 2a3e33eb08e..9793a08cc0c 100644 --- a/src/bin/pg_basebackup/pg_basebackup.c +++ b/src/bin/pg_basebackup/pg_basebackup.c @@ -1965,7 +1965,7 @@ BaseBackup(void) { #ifndef WIN32 int status; - int r; + pid_t r; #else DWORD status; @@ -1993,7 +1993,7 @@ BaseBackup(void) /* Just wait for the background process to exit */ r = waitpid(bgchild, &status, 0); - if (r == -1) + if (r == (pid_t) -1) { fprintf(stderr, _("%s: could not wait for child process: %s\n"), progname, strerror(errno)); @@ -2002,19 +2002,13 @@ BaseBackup(void) if (r != bgchild) { fprintf(stderr, _("%s: child %d died, expected %d\n"), - progname, r, (int) bgchild); + progname, (int) r, (int) bgchild); disconnect_and_exit(1); } - if (!WIFEXITED(status)) + if (status != 0) { - fprintf(stderr, _("%s: child process did not exit normally\n"), - progname); - disconnect_and_exit(1); - } - if (WEXITSTATUS(status) != 0) - { - fprintf(stderr, _("%s: child process exited with error %d\n"), - progname, WEXITSTATUS(status)); + fprintf(stderr, "%s: %s\n", + progname, wait_result_to_str(status)); disconnect_and_exit(1); } /* Exited normally, we're happy! */ diff --git a/src/common/wait_error.c b/src/common/wait_error.c index 4fb5276961d..cb5df8c89eb 100644 --- a/src/common/wait_error.c +++ b/src/common/wait_error.c @@ -56,25 +56,17 @@ wait_result_to_str(int exitstatus) } } else if (WIFSIGNALED(exitstatus)) + { #if defined(WIN32) snprintf(str, sizeof(str), _("child process was terminated by exception 0x%X"), WTERMSIG(exitstatus)); -#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST - { - char str2[256]; - - snprintf(str2, sizeof(str2), "%d: %s", WTERMSIG(exitstatus), - WTERMSIG(exitstatus) < NSIG ? - sys_siglist[WTERMSIG(exitstatus)] : "(unknown)"); - snprintf(str, sizeof(str), - _("child process was terminated by signal %s"), str2); - } #else snprintf(str, sizeof(str), - _("child process was terminated by signal %d"), - WTERMSIG(exitstatus)); + _("child process was terminated by signal %d: %s"), + WTERMSIG(exitstatus), pg_strsignal(WTERMSIG(exitstatus))); #endif + } else snprintf(str, sizeof(str), _("child process exited with unrecognized status %d"), diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in index 3c82718bf99..a27eb57048c 100644 --- a/src/include/pg_config.h.in +++ b/src/include/pg_config.h.in @@ -158,10 +158,6 @@ don't. */ #undef HAVE_DECL_STRTOULL -/* Define to 1 if you have the declaration of `sys_siglist', and to 0 if you - don't. */ -#undef HAVE_DECL_SYS_SIGLIST - /* Define to 1 if you have the declaration of `vsnprintf', and to 0 if you don't. */ #undef HAVE_DECL_VSNPRINTF @@ -511,6 +507,9 @@ /* Define to use have a strong random number source */ #undef HAVE_STRONG_RANDOM +/* Define to 1 if you have the `strsignal' function. */ +#undef HAVE_STRSIGNAL + /* Define to 1 if you have the `strtoll' function. */ #undef HAVE_STRTOLL diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32 index f84077afa03..720653d5881 100644 --- a/src/include/pg_config.h.win32 +++ b/src/include/pg_config.h.win32 @@ -364,6 +364,9 @@ /* Define to use have a strong random number source */ #define HAVE_STRONG_RANDOM 1 +/* Define to 1 if you have the `strsignal' function. */ +/* #undef HAVE_STRSIGNAL */ + /* Define to 1 if you have the `strtoll' function. */ #ifdef HAVE_LONG_LONG_INT_64 #define HAVE_STRTOLL 1 diff --git a/src/include/port.h b/src/include/port.h index 80a3556889d..f2b966fdca5 100644 --- a/src/include/port.h +++ b/src/include/port.h @@ -205,6 +205,9 @@ extern char *pgwin32_setlocale(int category, const char *locale); #define setlocale(a,b) pgwin32_setlocale(a,b) #endif /* WIN32 */ +/* Wrap strsignal(), or provide our own version if necessary */ +extern const char *pg_strsignal(int signum); + /* Portable prompt handling */ extern void simple_prompt(const char *prompt, char *destination, size_t destlen, bool echo); diff --git a/src/port/Makefile b/src/port/Makefile index 81f01b25bbc..d20999a0b5f 100644 --- a/src/port/Makefile +++ b/src/port/Makefile @@ -32,7 +32,7 @@ LIBS += $(PTHREAD_LIBS) OBJS = $(LIBOBJS) $(PG_CRC32C_OBJS) chklocale.o erand48.o inet_net_ntop.o \ noblock.o path.o pgcheckdir.o pgmkdirp.o pgsleep.o \ - pgstrcasecmp.o pqsignal.o \ + pgstrcasecmp.o pgstrsignal.o pqsignal.o \ qsort.o qsort_arg.o quotes.o sprompt.o tar.o thread.o ifeq ($(enable_strong_random), yes) diff --git a/src/port/pgstrsignal.c b/src/port/pgstrsignal.c new file mode 100644 index 00000000000..7724edf56e1 --- /dev/null +++ b/src/port/pgstrsignal.c @@ -0,0 +1,64 @@ +/*------------------------------------------------------------------------- + * + * pgstrsignal.c + * Identify a Unix signal number + * + * On platforms compliant with modern POSIX, this just wraps strsignal(3). + * Elsewhere, we do the best we can. + * + * This file is not currently built in MSVC builds, since it's useless + * on non-Unix platforms. + * + * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/port/pgstrsignal.c + * + *------------------------------------------------------------------------- + */ + +#include "c.h" + + +/* + * pg_strsignal + * + * Return a string identifying the given Unix signal number. + * + * The result is declared "const char *" because callers should not + * modify the string. Note, however, that POSIX does not promise that + * the string will remain valid across later calls to strsignal(). + * + * This version guarantees to return a non-NULL pointer, although + * some platforms' versions of strsignal() reputedly do not. + * + * Note that the fallback cases just return constant strings such as + * "unrecognized signal". Project style is for callers to print the + * numeric signal value along with the result of this function, so + * there's no need to work harder than that. + */ +const char * +pg_strsignal(int signum) +{ + const char *result; + + /* + * If we have strsignal(3), use that --- but check its result for NULL. + */ +#ifdef HAVE_STRSIGNAL + result = strsignal(signum); + if (result == NULL) + result = "unrecognized signal"; +#else + + /* + * We used to have code here to try to use sys_siglist[] if available. + * However, it seems that all platforms with sys_siglist[] have also had + * strsignal() for many years now, so that was just a waste of code. + */ + result = "(signal names not available on this platform)"; +#endif + + return result; +} diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c index 5d08d1e12e5..38b53d2aa3e 100644 --- a/src/test/regress/pg_regress.c +++ b/src/test/regress/pg_regress.c @@ -1559,14 +1559,9 @@ log_child_failure(int exitstatus) #if defined(WIN32) status(_(" (test process was terminated by exception 0x%X)"), WTERMSIG(exitstatus)); -#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST - status(_(" (test process was terminated by signal %d: %s)"), - WTERMSIG(exitstatus), - WTERMSIG(exitstatus) < NSIG ? - sys_siglist[WTERMSIG(exitstatus)] : "(unknown))"); #else - status(_(" (test process was terminated by signal %d)"), - WTERMSIG(exitstatus)); + status(_(" (test process was terminated by signal %d: %s)"), + WTERMSIG(exitstatus), pg_strsignal(WTERMSIG(exitstatus))); #endif } else