Prep v221: Update and clean up build system to sync with upstream

[elogind.git] / src / shared / sigbus.c

diff --git a/src/shared/sigbus.c b/src/shared/sigbus.c
deleted file mode 100644 (file)
index 0108603..0000000
--- a/src/shared/sigbus.c
+++ /dev/null
@@ -1,152 +0,0 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
-  This file is part of systemd.
-
-  Copyright 2014 Lennart Poettering
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <signal.h>
-#include <sys/mman.h>
-
-#include "macro.h"
-#include "util.h"
-#include "sigbus.h"
-
-#define SIGBUS_QUEUE_MAX 64
-
-static struct sigaction old_sigaction;
-static unsigned n_installed = 0;
-
-/* We maintain a fixed size list of page addresses that triggered a
-   SIGBUS. We access with list with atomic operations, so that we
-   don't have to deal with locks between signal handler and main
-   programs in possibly multiple threads. */
-
-static void* volatile sigbus_queue[SIGBUS_QUEUE_MAX];
-static volatile sig_atomic_t n_sigbus_queue = 0;
-
-static void sigbus_push(void *addr) {
-        unsigned u;
-
-        assert(addr);
-
-        /* Find a free place, increase the number of entries and leave, if we can */
-        for (u = 0; u < SIGBUS_QUEUE_MAX; u++)
-                if (__sync_bool_compare_and_swap(&sigbus_queue[u], NULL, addr)) {
-                        __sync_fetch_and_add(&n_sigbus_queue, 1);
-                        return;
-                }
-
-        /* If we can't, make sure the queue size is out of bounds, to
-         * mark it as overflow */
-        for (;;) {
-                unsigned c;
-
-                __sync_synchronize();
-                c = n_sigbus_queue;
-
-                if (c > SIGBUS_QUEUE_MAX) /* already overflow */
-                        return;
-
-                if (__sync_bool_compare_and_swap(&n_sigbus_queue, c, c + SIGBUS_QUEUE_MAX))
-                        return;
-        }
-}
-
-int sigbus_pop(void **ret) {
-        assert(ret);
-
-        for (;;) {
-                unsigned u, c;
-
-                __sync_synchronize();
-                c = n_sigbus_queue;
-
-                if (_likely_(c == 0))
-                        return 0;
-
-                if (_unlikely_(c >= SIGBUS_QUEUE_MAX))
-                        return -EOVERFLOW;
-
-                for (u = 0; u < SIGBUS_QUEUE_MAX; u++) {
-                        void *addr;
-
-                        addr = sigbus_queue[u];
-                        if (!addr)
-                                continue;
-
-                        if (__sync_bool_compare_and_swap(&sigbus_queue[u], addr, NULL)) {
-                                __sync_fetch_and_sub(&n_sigbus_queue, 1);
-                                *ret = addr;
-                                return 1;
-                        }
-                }
-        }
-}
-
-static void sigbus_handler(int sn, siginfo_t *si, void *data) {
-        unsigned long ul;
-        void *aligned;
-
-        assert(sn == SIGBUS);
-        assert(si);
-
-        if (si->si_code != BUS_ADRERR || !si->si_addr) {
-                assert_se(sigaction(SIGBUS, &old_sigaction, NULL) == 0);
-                raise(SIGBUS);
-                return;
-        }
-
-        ul = (unsigned long) si->si_addr;
-        ul = ul / page_size();
-        ul = ul * page_size();
-        aligned = (void*) ul;
-
-        /* Let's remember which address failed */
-        sigbus_push(aligned);
-
-        /* Replace mapping with an anonymous page, so that the
-         * execution can continue, however with a zeroed out page */
-        assert_se(mmap(aligned, page_size(), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0) == aligned);
-}
-
-void sigbus_install(void) {
-        struct sigaction sa = {
-                .sa_sigaction = sigbus_handler,
-                .sa_flags = SA_SIGINFO,
-        };
-
-        n_installed++;
-
-        if (n_installed == 1)
-                assert_se(sigaction(SIGBUS, &sa, &old_sigaction) == 0);
-
-        return;
-}
-
-void sigbus_reset(void) {
-
-        if (n_installed <= 0)
-                return;
-
-        n_installed--;
-
-        if (n_installed == 0)
-                assert_se(sigaction(SIGBUS, &old_sigaction, NULL) == 0);
-
-        return;
-}