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| author | Heinz Mauelshagen <heinzm@redhat.com> | 2017-04-07 17:07:45 +0200 |
|---|---|---|
| committer | Heinz Mauelshagen <heinzm@redhat.com> | 2017-04-07 17:07:45 +0200 |
| commit | 53b62d950a4a82ff65bb7775d3ea1cb7ad84bf04 (patch) | |
| tree | 6db03d131e74207bc730656929e06c0fb5857327 | |
| parent | ef3e1013aa8d7797fa432e2da219255178b8ede3 (diff) | |
| download | lvm2-dev-lvmguy-sigint-flaw.tar.gz | |
signal: workaround sigint handler flawdev-lvmguy-sigint-flaw
| -rw-r--r-- | lib/misc/lvm-signal.c | 33 |
1 files changed, 21 insertions, 12 deletions
diff --git a/lib/misc/lvm-signal.c b/lib/misc/lvm-signal.c index 7e78407bf..fa830bebb 100644 --- a/lib/misc/lvm-signal.c +++ b/lib/misc/lvm-signal.c @@ -22,7 +22,7 @@ static sigset_t _oldset; static int _signals_blocked = 0; static volatile sig_atomic_t _sigint_caught = 0; -static volatile sig_atomic_t _handler_installed; +static volatile sig_atomic_t _handler_installed = 0; /* Support 3 level nesting, increase if needed more */ #define MAX_SIGINTS 3 @@ -34,7 +34,26 @@ static void _catch_sigint(int unused __attribute__((unused))) _sigint_caught = 1; } +static void _register_sigint_caught(struct sigaction *old_handler) +{ + struct sigaction handler; + + /* Grab old sigaction for SIGINT: shall not fail. */ + if (sigaction(SIGINT, NULL, &handler)) + log_sys_debug("sigaction", "SIGINT"); + + handler.sa_flags &= ~SA_RESTART; /* Clear restart flag */ + handler.sa_handler = _catch_sigint; + + /* Override the signal handler: shall not fail. */ + if (sigaction(SIGINT, &handler, old_handler)) + log_sys_debug("sigaction", "SIGINT"); +} + int sigint_caught(void) { +printf("%s[%u] CALLED\n", __func__, __LINE__); + _register_sigint_caught(NULL); + if (_sigint_caught) log_error("Interrupted..."); @@ -58,7 +77,6 @@ void sigint_clear(void) void sigint_allow(void) { - struct sigaction handler; sigset_t sigs; if (memlock_count_daemon()) @@ -70,16 +88,7 @@ void sigint_allow(void) if (++_handler_installed >= MAX_SIGINTS) return; - /* Grab old sigaction for SIGINT: shall not fail. */ - if (sigaction(SIGINT, NULL, &handler)) - log_sys_debug("sigaction", "SIGINT"); - - handler.sa_flags &= ~SA_RESTART; /* Clear restart flag */ - handler.sa_handler = _catch_sigint; - - /* Override the signal handler: shall not fail. */ - if (sigaction(SIGINT, &handler, &_oldhandler[_handler_installed - 1])) - log_sys_debug("sigaction", "SIGINT"); + _register_sigint_caught(&_oldhandler[_handler_installed - 1]); /* Unmask SIGINT. Remember to mask it again on restore. */ if (sigprocmask(0, NULL, &sigs)) |