diff options
author | Brooks Davis <brooks@FreeBSD.org> | 2020-03-17 16:56:50 +0000 |
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committer | Brooks Davis <brooks@FreeBSD.org> | 2020-03-17 16:56:50 +0000 |
commit | 08334c51dbb99d9ecd2bb86a2d94ed06da9e167a (patch) | |
tree | c43eb24d59bd5c963583a5190caef80fc8387322 /utils/signals/misc.cpp |
Notes
Diffstat (limited to 'utils/signals/misc.cpp')
-rw-r--r-- | utils/signals/misc.cpp | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/utils/signals/misc.cpp b/utils/signals/misc.cpp new file mode 100644 index 0000000000000..b9eb1c402a28c --- /dev/null +++ b/utils/signals/misc.cpp @@ -0,0 +1,106 @@ +// Copyright 2010 The Kyua Authors. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// * Neither the name of Google Inc. nor the names of its contributors +// may be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "utils/signals/misc.hpp" + +#if defined(HAVE_CONFIG_H) +# include "config.h" +#endif + +extern "C" { +#include <signal.h> +} + +#include <cerrno> +#include <cstddef> + +#include "utils/format/macros.hpp" +#include "utils/logging/macros.hpp" +#include "utils/signals/exceptions.hpp" + +namespace signals = utils::signals; + + +/// Number of the last valid signal. +const int utils::signals::last_signo = LAST_SIGNO; + + +/// Resets a signal handler to its default behavior. +/// +/// \param signo The number of the signal handler to reset. +/// +/// \throw signals::system_error If there is a problem trying to reset the +/// signal handler to its default behavior. +void +signals::reset(const int signo) +{ + struct ::sigaction sa; + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + + if (::sigaction(signo, &sa, NULL) == -1) { + const int original_errno = errno; + throw system_error(F("Failed to reset signal %s") % signo, + original_errno); + } +} + + +/// Resets all signals to their default handlers. +/// +/// \return True if all signals could be reset properly; false otherwise. +bool +signals::reset_all(void) +{ + bool ok = true; + + for (int signo = 1; signo <= signals::last_signo; ++signo) { + if (signo == SIGKILL || signo == SIGSTOP) { + // Don't attempt to reset immutable signals. + } else { + try { + signals::reset(signo); + } catch (const signals::error& e) { +#if defined(SIGTHR) + if (signo == SIGTHR) { + // If FreeBSD's libthr is loaded, it prevents us from + // modifying SIGTHR (at least in 11.0-CURRENT as of + // 2015-01-28). Skip failures for this signal if they + // happen to avoid this corner case. + continue; + } +#endif + LW(e.what()); + ok = false; + } + } + } + + return ok; +} |