* Re: posix_spawn_file_actions_add* functions on musl libc
[not found] <17480807.kbxdrRNLtY@omega>
@ 2019-03-24 14:16 ` Rich Felker
2019-03-24 18:23 ` Bruno Haible
0 siblings, 1 reply; 3+ messages in thread
From: Rich Felker @ 2019-03-24 14:16 UTC (permalink / raw)
To: Bruno Haible; +Cc: bug-gnulib, musl
On Sat, Mar 23, 2019 at 09:46:28PM +0100, Bruno Haible wrote:
> The gnulib configure test in m4/posix_spawn.m4, when run on Alpine Linux 3.7,
> determines that the posix_spawn_file_actions_add* functions do not fail as
> expected for an out-of-range file descriptor.
The POSIX "shall fail" requirement is for >=OPEN_MAX, which is not
defined (variable limit). It's not clear to me whether it's supposed
to apply if the fd number is >= the current dynamic limit reported by
sysconf(_SC_OPEN_MAX), but it seems like doing so would be undesirable
-- it would preclude advance creation of a file actions object which
will open or dup onto high fd numbers at a later time after the rlimit
has been increased.
Rich
> Let me document this in gnulib and update the cross-compilation guess
> accordingly.
>
> Rich, FYI: These are the test programs:
>
> #include <spawn.h>
> int main ()
> {
> posix_spawn_file_actions_t actions;
> if (posix_spawn_file_actions_init (&actions) != 0)
> return 1;
> if (posix_spawn_file_actions_addclose (&actions, 10000000) == 0)
> return 2;
> return 0;
> }
>
> #include <spawn.h>
> int main ()
> {
> posix_spawn_file_actions_t actions;
> if (posix_spawn_file_actions_init (&actions) != 0)
> return 1;
> if (posix_spawn_file_actions_adddup2 (&actions, 10000000, 2) == 0)
> return 2;
> return 0;
> }
>
> #include <spawn.h>
> #include <fcntl.h>
> int main ()
> {
> posix_spawn_file_actions_t actions;
> if (posix_spawn_file_actions_init (&actions) != 0)
> return 1;
> if (posix_spawn_file_actions_addopen (&actions, 10000000, "foo", 0, O_RDONLY)
> == 0)
> return 2;
> return 0;
> }
>
>
> 2019-03-23 Bruno Haible <bruno@clisp.org>
>
> posix_spawn_file_actions_*: Document musl libc bugs.
> * doc/posix-functions/posix_spawn_file_actions_addclose.texi: Mention
> the bug.
> * doc/posix-functions/posix_spawn_file_actions_adddup2.texi: Likewise.
> * doc/posix-functions/posix_spawn_file_actions_addopen.texi: Likewise.
> * m4/posix_spawn.m4 (gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE): When
> cross-compiling to a musl system, guess no.
> (gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2): Likewise.
> (gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN): Likewise.
>
> diff --git a/doc/posix-functions/posix_spawn_file_actions_addclose.texi b/doc/posix-functions/posix_spawn_file_actions_addclose.texi
> index 199daa1..80418db 100644
> --- a/doc/posix-functions/posix_spawn_file_actions_addclose.texi
> +++ b/doc/posix-functions/posix_spawn_file_actions_addclose.texi
> @@ -13,7 +13,7 @@ This function is missing on some platforms:
> Mac OS X 10.4, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 9, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 8.1.
> @item
> This function does not reject a too large file descriptor on some platforms:
> -Solaris 11.4.
> +musl libc, Solaris 11.4.
> @end itemize
>
> Portability problems not fixed by Gnulib:
> diff --git a/doc/posix-functions/posix_spawn_file_actions_adddup2.texi b/doc/posix-functions/posix_spawn_file_actions_adddup2.texi
> index e515715..985d6bc 100644
> --- a/doc/posix-functions/posix_spawn_file_actions_adddup2.texi
> +++ b/doc/posix-functions/posix_spawn_file_actions_adddup2.texi
> @@ -13,7 +13,7 @@ This function is missing on some platforms:
> Mac OS X 10.4, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 9, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 8.1.
> @item
> This function does not reject a too large file descriptor on some platforms:
> -Solaris 11.4.
> +musl libc, Solaris 11.4.
> @end itemize
>
> Portability problems not fixed by Gnulib:
> diff --git a/doc/posix-functions/posix_spawn_file_actions_addopen.texi b/doc/posix-functions/posix_spawn_file_actions_addopen.texi
> index a7809cf..eea56e3 100644
> --- a/doc/posix-functions/posix_spawn_file_actions_addopen.texi
> +++ b/doc/posix-functions/posix_spawn_file_actions_addopen.texi
> @@ -13,7 +13,7 @@ This function is missing on some platforms:
> Mac OS X 10.4, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 9, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 8.1.
> @item
> This function does not reject a too large file descriptor on some platforms:
> -Solaris 11.4.
> +musl libc, Solaris 11.4.
> @end itemize
>
> Portability problems not fixed by Gnulib:
> diff --git a/m4/posix_spawn.m4 b/m4/posix_spawn.m4
> index 1e2533c..d50dcc9 100644
> --- a/m4/posix_spawn.m4
> +++ b/m4/posix_spawn.m4
> @@ -1,4 +1,4 @@
> -# posix_spawn.m4 serial 15
> +# posix_spawn.m4 serial 16
> dnl Copyright (C) 2008-2019 Free Software Foundation, Inc.
> dnl This file is free software; the Free Software Foundation
> dnl gives unlimited permission to copy and/or distribute it,
> @@ -422,8 +422,8 @@ AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE],
> if test $REPLACE_POSIX_SPAWN = 1; then
> REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE=1
> else
> - dnl On Solaris 11.0, posix_spawn_file_actions_addclose succeeds even
> - dnl if the fd argument is out of range.
> + dnl On musl libc and Solaris 11.0, posix_spawn_file_actions_addclose
> + dnl succeeds even if the fd argument is out of range.
> AC_CACHE_CHECK([whether posix_spawn_file_actions_addclose works],
> [gl_cv_func_posix_spawn_file_actions_addclose_works],
> [AC_RUN_IFELSE(
> @@ -440,8 +440,9 @@ int main ()
> }]])],
> [gl_cv_func_posix_spawn_file_actions_addclose_works=yes],
> [gl_cv_func_posix_spawn_file_actions_addclose_works=no],
> - [# Guess no on Solaris, yes otherwise.
> + [# Guess no on musl libc and Solaris, yes otherwise.
> case "$host_os" in
> + *-musl*) gl_cv_func_posix_spawn_file_actions_addclose_works="guessing no" ;;
> solaris*) gl_cv_func_posix_spawn_file_actions_addclose_works="guessing no" ;;
> # Guess no on native Windows.
> mingw*) gl_cv_func_posix_spawn_file_actions_addclose_works="guessing no" ;;
> @@ -465,8 +466,8 @@ AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2],
> if test $REPLACE_POSIX_SPAWN = 1; then
> REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2=1
> else
> - dnl On Solaris 11.0, posix_spawn_file_actions_adddup2 succeeds even
> - dnl if the fd argument is out of range.
> + dnl On musl libc and Solaris 11.0, posix_spawn_file_actions_adddup2
> + dnl succeeds even if the fd argument is out of range.
> AC_CACHE_CHECK([whether posix_spawn_file_actions_adddup2 works],
> [gl_cv_func_posix_spawn_file_actions_adddup2_works],
> [AC_RUN_IFELSE(
> @@ -483,8 +484,9 @@ int main ()
> }]])],
> [gl_cv_func_posix_spawn_file_actions_adddup2_works=yes],
> [gl_cv_func_posix_spawn_file_actions_adddup2_works=no],
> - [# Guess no on Solaris, yes otherwise.
> + [# Guess no on musl libc and Solaris, yes otherwise.
> case "$host_os" in
> + *-musl*) gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing no";;
> solaris*) gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing no";;
> # Guess no on native Windows.
> mingw*) gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing no" ;;
> @@ -508,8 +510,8 @@ AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN],
> if test $REPLACE_POSIX_SPAWN = 1; then
> REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN=1
> else
> - dnl On Solaris 11.0, posix_spawn_file_actions_addopen succeeds even
> - dnl if the fd argument is out of range.
> + dnl On musl libc and Solaris 11.0, posix_spawn_file_actions_addopen
> + dnl succeeds even if the fd argument is out of range.
> AC_CACHE_CHECK([whether posix_spawn_file_actions_addopen works],
> [gl_cv_func_posix_spawn_file_actions_addopen_works],
> [AC_RUN_IFELSE(
> @@ -528,8 +530,9 @@ int main ()
> }]])],
> [gl_cv_func_posix_spawn_file_actions_addopen_works=yes],
> [gl_cv_func_posix_spawn_file_actions_addopen_works=no],
> - [# Guess no on Solaris, yes otherwise.
> + [# Guess no on musl libc and Solaris, yes otherwise.
> case "$host_os" in
> + *-musl*) gl_cv_func_posix_spawn_file_actions_addopen_works="guessing no";;
> solaris*) gl_cv_func_posix_spawn_file_actions_addopen_works="guessing no";;
> # Guess no on native Windows.
> mingw*) gl_cv_func_posix_spawn_file_actions_addopen_works="guessing no" ;;
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