[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <ZFPeVxdqNroBcFeB@voyager>
Date: Thu, 4 May 2023 18:33:27 +0200
From: Markus Wichmann <nullplan@....net>
To: musl@...ts.openwall.com
Subject: Namespace violation in system()?
Hi all,
I stumbled upon the source code of system() today. It is this at the
moment:
|int system(const char *cmd)
|{
| pid_t pid;
| sigset_t old, reset;
| struct sigaction sa = { .sa_handler = SIG_IGN }, oldint, oldquit;
| int status = -1, ret;
| posix_spawnattr_t attr;
|
| pthread_testcancel();
|
| if (!cmd) return 1;
|
| sigaction(SIGINT, &sa, &oldint);
| sigaction(SIGQUIT, &sa, &oldquit);
| sigaddset(&sa.sa_mask, SIGCHLD);
| sigprocmask(SIG_BLOCK, &sa.sa_mask, &old);
|
| sigemptyset(&reset);
| if (oldint.sa_handler != SIG_IGN) sigaddset(&reset, SIGINT);
| if (oldquit.sa_handler != SIG_IGN) sigaddset(&reset, SIGQUIT);
| posix_spawnattr_init(&attr);
| posix_spawnattr_setsigmask(&attr, &old);
| posix_spawnattr_setsigdefault(&attr, &reset);
| posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGDEF|POSIX_SPAWN_SETSIGMASK);
| ret = posix_spawn(&pid, "/bin/sh", 0, &attr,
| (char *[]){"sh", "-c", (char *)cmd, 0}, __environ);
| posix_spawnattr_destroy(&attr);
|
| if (!ret) while (waitpid(pid, &status, 0)<0 && errno == EINTR);
| sigaction(SIGINT, &oldint, NULL);
| sigaction(SIGQUIT, &oldquit, NULL);
| sigprocmask(SIG_SETMASK, &old, NULL);
|
| if (ret) errno = ret;
| return status;
|}
Aren't all of those calls namespace violations? system() is an ISO-C
function, so the only symbols it is allowed to pull into the link are
other ISO-C functions or hidden double-underscore symbols, right? But
all the functions called here POSIX functions. And while POSIX contains
the rule that posix_* functions are reserved, that is in POSIX, not
ISO-C. And even with that rule, there are all the other calls.
Does someone need to pour out a bucket of underscores over this
function?
Ciao,
Markus
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
