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author | 2017-04-25 03:31:15 -0700 | |
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committer | 2017-05-22 06:48:08 +0000 | |
commit | bb756eebdac6fd24e8919e2c43f7d2c8c4091f59 (patch) | |
tree | ca11e03542edf2d8f631efeca5e1626d211107e3 /qemu/util/coroutine-sigaltstack.c | |
parent | a14b48d18a9ed03ec191cf16b162206998a895ce (diff) |
Adding qemu as a submodule of KVMFORNFV
This Patch includes the changes to add qemu as a submodule to
kvmfornfv repo and make use of the updated latest qemu for the
execution of all testcase
Change-Id: I1280af507a857675c7f81d30c95255635667bdd7
Signed-off-by:RajithaY<rajithax.yerrumsetty@intel.com>
Diffstat (limited to 'qemu/util/coroutine-sigaltstack.c')
-rw-r--r-- | qemu/util/coroutine-sigaltstack.c | 290 |
1 files changed, 0 insertions, 290 deletions
diff --git a/qemu/util/coroutine-sigaltstack.c b/qemu/util/coroutine-sigaltstack.c deleted file mode 100644 index a7c336655..000000000 --- a/qemu/util/coroutine-sigaltstack.c +++ /dev/null @@ -1,290 +0,0 @@ -/* - * sigaltstack coroutine initialization code - * - * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws> - * Copyright (C) 2011 Kevin Wolf <kwolf@redhat.com> - * Copyright (C) 2012 Alex Barcelo <abarcelo@ac.upc.edu> -** This file is partly based on pth_mctx.c, from the GNU Portable Threads -** Copyright (c) 1999-2006 Ralf S. Engelschall <rse@engelschall.com> - * - * This library 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. - * - * This library 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 this library; if not, see <http://www.gnu.org/licenses/>. - */ - -/* XXX Is there a nicer way to disable glibc's stack check for longjmp? */ -#ifdef _FORTIFY_SOURCE -#undef _FORTIFY_SOURCE -#endif -#include "qemu/osdep.h" -#include <pthread.h> -#include "qemu-common.h" -#include "qemu/coroutine_int.h" - -typedef struct { - Coroutine base; - void *stack; - sigjmp_buf env; -} CoroutineUContext; - -/** - * Per-thread coroutine bookkeeping - */ -typedef struct { - /** Currently executing coroutine */ - Coroutine *current; - - /** The default coroutine */ - CoroutineUContext leader; - - /** Information for the signal handler (trampoline) */ - sigjmp_buf tr_reenter; - volatile sig_atomic_t tr_called; - void *tr_handler; -} CoroutineThreadState; - -static pthread_key_t thread_state_key; - -static CoroutineThreadState *coroutine_get_thread_state(void) -{ - CoroutineThreadState *s = pthread_getspecific(thread_state_key); - - if (!s) { - s = g_malloc0(sizeof(*s)); - s->current = &s->leader.base; - pthread_setspecific(thread_state_key, s); - } - return s; -} - -static void qemu_coroutine_thread_cleanup(void *opaque) -{ - CoroutineThreadState *s = opaque; - - g_free(s); -} - -static void __attribute__((constructor)) coroutine_init(void) -{ - int ret; - - ret = pthread_key_create(&thread_state_key, qemu_coroutine_thread_cleanup); - if (ret != 0) { - fprintf(stderr, "unable to create leader key: %s\n", strerror(errno)); - abort(); - } -} - -/* "boot" function - * This is what starts the coroutine, is called from the trampoline - * (from the signal handler when it is not signal handling, read ahead - * for more information). - */ -static void coroutine_bootstrap(CoroutineUContext *self, Coroutine *co) -{ - /* Initialize longjmp environment and switch back the caller */ - if (!sigsetjmp(self->env, 0)) { - siglongjmp(*(sigjmp_buf *)co->entry_arg, 1); - } - - while (true) { - co->entry(co->entry_arg); - qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE); - } -} - -/* - * This is used as the signal handler. This is called with the brand new stack - * (thanks to sigaltstack). We have to return, given that this is a signal - * handler and the sigmask and some other things are changed. - */ -static void coroutine_trampoline(int signal) -{ - CoroutineUContext *self; - Coroutine *co; - CoroutineThreadState *coTS; - - /* Get the thread specific information */ - coTS = coroutine_get_thread_state(); - self = coTS->tr_handler; - coTS->tr_called = 1; - co = &self->base; - - /* - * Here we have to do a bit of a ping pong between the caller, given that - * this is a signal handler and we have to do a return "soon". Then the - * caller can reestablish everything and do a siglongjmp here again. - */ - if (!sigsetjmp(coTS->tr_reenter, 0)) { - return; - } - - /* - * Ok, the caller has siglongjmp'ed back to us, so now prepare - * us for the real machine state switching. We have to jump - * into another function here to get a new stack context for - * the auto variables (which have to be auto-variables - * because the start of the thread happens later). Else with - * PIC (i.e. Position Independent Code which is used when PTH - * is built as a shared library) most platforms would - * horrible core dump as experience showed. - */ - coroutine_bootstrap(self, co); -} - -Coroutine *qemu_coroutine_new(void) -{ - const size_t stack_size = 1 << 20; - CoroutineUContext *co; - CoroutineThreadState *coTS; - struct sigaction sa; - struct sigaction osa; - stack_t ss; - stack_t oss; - sigset_t sigs; - sigset_t osigs; - sigjmp_buf old_env; - - /* The way to manipulate stack is with the sigaltstack function. We - * prepare a stack, with it delivering a signal to ourselves and then - * put sigsetjmp/siglongjmp where needed. - * This has been done keeping coroutine-ucontext as a model and with the - * pth ideas (GNU Portable Threads). See coroutine-ucontext for the basics - * of the coroutines and see pth_mctx.c (from the pth project) for the - * sigaltstack way of manipulating stacks. - */ - - co = g_malloc0(sizeof(*co)); - co->stack = g_malloc(stack_size); - co->base.entry_arg = &old_env; /* stash away our jmp_buf */ - - coTS = coroutine_get_thread_state(); - coTS->tr_handler = co; - - /* - * Preserve the SIGUSR2 signal state, block SIGUSR2, - * and establish our signal handler. The signal will - * later transfer control onto the signal stack. - */ - sigemptyset(&sigs); - sigaddset(&sigs, SIGUSR2); - pthread_sigmask(SIG_BLOCK, &sigs, &osigs); - sa.sa_handler = coroutine_trampoline; - sigfillset(&sa.sa_mask); - sa.sa_flags = SA_ONSTACK; - if (sigaction(SIGUSR2, &sa, &osa) != 0) { - abort(); - } - - /* - * Set the new stack. - */ - ss.ss_sp = co->stack; - ss.ss_size = stack_size; - ss.ss_flags = 0; - if (sigaltstack(&ss, &oss) < 0) { - abort(); - } - - /* - * Now transfer control onto the signal stack and set it up. - * It will return immediately via "return" after the sigsetjmp() - * was performed. Be careful here with race conditions. The - * signal can be delivered the first time sigsuspend() is - * called. - */ - coTS->tr_called = 0; - pthread_kill(pthread_self(), SIGUSR2); - sigfillset(&sigs); - sigdelset(&sigs, SIGUSR2); - while (!coTS->tr_called) { - sigsuspend(&sigs); - } - - /* - * Inform the system that we are back off the signal stack by - * removing the alternative signal stack. Be careful here: It - * first has to be disabled, before it can be removed. - */ - sigaltstack(NULL, &ss); - ss.ss_flags = SS_DISABLE; - if (sigaltstack(&ss, NULL) < 0) { - abort(); - } - sigaltstack(NULL, &ss); - if (!(oss.ss_flags & SS_DISABLE)) { - sigaltstack(&oss, NULL); - } - - /* - * Restore the old SIGUSR2 signal handler and mask - */ - sigaction(SIGUSR2, &osa, NULL); - pthread_sigmask(SIG_SETMASK, &osigs, NULL); - - /* - * Now enter the trampoline again, but this time not as a signal - * handler. Instead we jump into it directly. The functionally - * redundant ping-pong pointer arithmetic is necessary to avoid - * type-conversion warnings related to the `volatile' qualifier and - * the fact that `jmp_buf' usually is an array type. - */ - if (!sigsetjmp(old_env, 0)) { - siglongjmp(coTS->tr_reenter, 1); - } - - /* - * Ok, we returned again, so now we're finished - */ - - return &co->base; -} - -void qemu_coroutine_delete(Coroutine *co_) -{ - CoroutineUContext *co = DO_UPCAST(CoroutineUContext, base, co_); - - g_free(co->stack); - g_free(co); -} - -CoroutineAction qemu_coroutine_switch(Coroutine *from_, Coroutine *to_, - CoroutineAction action) -{ - CoroutineUContext *from = DO_UPCAST(CoroutineUContext, base, from_); - CoroutineUContext *to = DO_UPCAST(CoroutineUContext, base, to_); - CoroutineThreadState *s = coroutine_get_thread_state(); - int ret; - - s->current = to_; - - ret = sigsetjmp(from->env, 0); - if (ret == 0) { - siglongjmp(to->env, action); - } - return ret; -} - -Coroutine *qemu_coroutine_self(void) -{ - CoroutineThreadState *s = coroutine_get_thread_state(); - - return s->current; -} - -bool qemu_in_coroutine(void) -{ - CoroutineThreadState *s = pthread_getspecific(thread_state_key); - - return s && s->current->caller; -} - |