On Tue, 25 Jun 2002, Carsten Langgaard wrote: > > Linux platforms do it this way, e.g. Alpha and IA-64. A SIGSEGV is a > > valid response for an invalid address. Remember you test pipe(3) and not > > pipe(2). > > I'm not sure that you mean by pipe(2) and pipe(3), but according to my man > page, pipe should return with EFAULT in this case. pipe(2) is a syscall, while pipe(3) is a library call (see `man 2 intro' and `man 3 intro', respectively). You rarely access syscalls directly -- the system library usually does this for you. Depending on a system certain library functions may be trivial syscall wrappers, invoke a number of syscalls (see e.g. the stat() family) or be implemented entirely in the userland. > ERRORS > EMFILE Too many file descriptors are in use by the pro > cess. > ENFILE The system file table is full. > EFAULT filedes is not valid. Yep, this denotes such an error is possible and under what conditions. I don't think it actually mandates it, at least it's not expressed explicitly. Anyway, it's valid for i386 and possibly nothing else. Look at the system version it refers to -- my version is: "Linux 0.99.11 23 July 1993". A brief search of the web for "EFAULT pipe" reveals confirms others agree with me -- the error is not mandatory (the EFAULT vs SIGSEGV issue was discussed a few times at least in various contexts -- go search the web). I believe a SIGSEGV is saner, too -- this way it's harder for an error resulting from passing an invalid pointer to remain unnoticed (consider some code that passes a pointer to read-only memory and fails to check a result of pipe()). If still in doubt, you may try to discuss the LTP result at <linux-kernel@vger.kernel.org>. I don't think anybody wants to rewrite pipe(2) for all the platforms that handle it our way. Maciej -- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available +
