Bug 470713

I'm not handling a NULL for returned_path

https://man.freebsd.org/cgi/man.cgi?query=realpath&sektion=3&format=html

Though I thought libc was supost to allocate memory if it's NULL.

Ah but it's not using realpath.

https://github.com/YosysHQ/yosys/blob/5813809ad9afbe1c38f65c6aae7c3441d7614d0b/kernel/yosys.cc#L890

#elif defined(__FreeBSD__)
std::string proc_self_dirname()
{
	int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
	size_t buflen;
	char *buffer;
	std::string path;
	if (sysctl(mib, 4, NULL, &buflen, NULL, 0) != 0)
		log_error("sysctl failed: %s\n", strerror(errno));
	buffer = (char*)malloc(buflen);
	if (buffer == NULL)
		log_error("malloc failed: %s\n", strerror(errno));
	if (sysctl(mib, 4, buffer, &buflen, NULL, 0) != 0)
		log_error("sysctl failed: %s\n", strerror(errno));
	while (buflen > 0 && buffer[buflen-1] != '/')
		buflen--;
	path.assign(buffer, buflen);
	free(buffer);
	return path;
}

There are two calls to sysctl kern.proc.pathname, one to get the buffer size and one to get the pathname.

commit 840ccb9915c675fd7db527107e6b38343fafdf86 (HEAD -> master, origin/master, origin/HEAD)
Author: Paul Floyd <pjfloyd@wanadoo.fr>
Date:   Wed Jun 7 22:27:08 2023 +0200

    Bug 470713 -  Failure on the Yosys project: valgrind: m_libcfile.c:1802 (Bool vgPlain_realpath(const HChar *, HChar *)): Assertion 'resolved' failed
    
        When using sysctl kern proc pathname with the pid of the guest or -1
        we need to intercept the call otherwise the syscall will return the path
        of the memcheck tool and not the path of the guest.
    
        This uses VG_(realpath), which asserts if it doesn't get valid
        input pointers.
    
        sysctl kern proc pathname can use a NULL pointer in order to
        determine the length of the path (so users can allocate the minumum
        necessary). The NULL pointer was being passed on to VG_(realpath)
        without being checked, resulting in an assert.

Should be fixed with the above change. Can you build Valgrind from source and test it?

Otherwise I'll do a test with Yosys.

Rather try this as I made one mistake

commit 8bc3a55d50570ef3e3077a7bdfb6354895a56878 (HEAD -> master, origin/master, origin/HEAD)
Author: Paul Floyd <pjfloyd@wanadoo.fr>
Date:   Wed Jun 7 22:54:22 2023 +0200

    Merge error, missing continuation in Makefile.am

I tried with the yosys port, and it now gets to the command prompt.