# HG changeset patch # User Bruno Haible # Date 1316819242 -7200 # Node ID a27be0e3ac062791e53fd6e084652e21ffaeba5b # Parent 6efe9315fa039015207f8df9a3b1085d736b0c8c sigprocmask: Avoid crashes through signal() on MSVC 9. * lib/sigprocmask.c: Include msvc-inval.h. (signal_nothrow): New function. (signal): Redefine it. * m4/signalblocking.m4 (gl_PREREQ_SIGPROCMASK): Require AC_C_INLINE. * modules/sigprocmask (Depends-on): Add msvc-inval. * doc/posix-functions/signal.texi: Mention the problem on MSVC. diff --git a/ChangeLog b/ChangeLog --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2011-09-23 Bruno Haible + + sigprocmask: Avoid crashes through signal() on MSVC 9. + * lib/sigprocmask.c: Include msvc-inval.h. + (signal_nothrow): New function. + (signal): Redefine it. + * m4/signalblocking.m4 (gl_PREREQ_SIGPROCMASK): Require AC_C_INLINE. + * modules/sigprocmask (Depends-on): Add msvc-inval. + * doc/posix-functions/signal.texi: Mention the problem on MSVC. + 2011-09-23 Bruno Haible Tests for module 'raise'. diff --git a/doc/posix-functions/signal.texi b/doc/posix-functions/signal.texi --- a/doc/posix-functions/signal.texi +++ b/doc/posix-functions/signal.texi @@ -13,6 +13,9 @@ Portability problems not fixed by Gnulib: @itemize @item +This function crashes when invoked with invalid arguments on some platforms: +MSVC 9. +@item On System V platforms, when the signal is triggered, the kernel uninstalls the handler (i.e.@: resets the signal's action to SIG_DFL) before invoking the handler. This opens the door to race conditions: undesired things happen diff --git a/lib/sigprocmask.c b/lib/sigprocmask.c --- a/lib/sigprocmask.c +++ b/lib/sigprocmask.c @@ -24,6 +24,8 @@ #include #include +#include "msvc-inval.h" + /* We assume that a platform without POSIX signal blocking functions also does not have the POSIX sigaction() function, only the signal() function. We also assume signal() has SysV semantics, @@ -58,6 +60,28 @@ typedef void (*handler_t) (int); +#if HAVE_MSVC_INVALID_PARAMETER_HANDLER +static inline handler_t +signal_nothrow (int sig, handler_t handler) +{ + handler_t result; + + TRY_MSVC_INVAL + { + result = signal (sig, handler); + } + CATCH_MSVC_INVAL + { + result = SIG_ERR; + errno = EINVAL; + } + DONE_MSVC_INVAL; + + return result; +} +# define signal signal_nothrow +#endif + /* Handling of gnulib defined signals. */ #if GNULIB_defined_SIGPIPE @@ -80,6 +104,7 @@ return signal (sig, handler); } } +# undef signal # define signal ext_signal #endif diff --git a/m4/signalblocking.m4 b/m4/signalblocking.m4 --- a/m4/signalblocking.m4 +++ b/m4/signalblocking.m4 @@ -1,4 +1,4 @@ -# signalblocking.m4 serial 12 +# signalblocking.m4 serial 13 dnl Copyright (C) 2001-2002, 2006-2011 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -22,4 +22,6 @@ ]) # Prerequisites of lib/sigprocmask.c. -AC_DEFUN([gl_PREREQ_SIGPROCMASK], [:]) +AC_DEFUN([gl_PREREQ_SIGPROCMASK], [ + AC_REQUIRE([AC_C_INLINE]) +]) diff --git a/modules/sigprocmask b/modules/sigprocmask --- a/modules/sigprocmask +++ b/modules/sigprocmask @@ -9,6 +9,7 @@ signal stdint [test $HAVE_POSIX_SIGNALBLOCKING = 0] raise [test $HAVE_POSIX_SIGNALBLOCKING = 0] +msvc-inval [test $HAVE_POSIX_SIGNALBLOCKING = 0] configure.ac: gl_SIGNALBLOCKING