* THE SOFTWARE.
*/
-/* The following block of code temporarily renames the daemon() function so the
- compiler does not see the warning associated with it in stdlib.h on OSX */
-#ifdef __APPLE__
-#define daemon qemu_fake_daemon_function
-#include <stdlib.h>
-#undef daemon
-extern int daemon(int, int);
-#endif
-
-#if defined(__linux__) && (defined(__x86_64__) || defined(__arm__))
- /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
- Valgrind does not support alignments larger than 1 MiB,
- therefore we need special code which handles running on Valgrind. */
-# define QEMU_VMALLOC_ALIGN (512 * 4096)
-#elif defined(__linux__) && defined(__s390x__)
- /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
-# define QEMU_VMALLOC_ALIGN (256 * 4096)
-#else
-# define QEMU_VMALLOC_ALIGN getpagesize()
-#endif
-#define HUGETLBFS_MAGIC 0x958458f6
-
+#include "qemu/osdep.h"
#include <termios.h>
-#include <unistd.h>
#include <glib/gprintf.h>
-#include "config-host.h"
#include "sysemu/sysemu.h"
#include "trace.h"
+#include "qapi/error.h"
#include "qemu/sockets.h"
-#include <sys/mman.h>
#include <libgen.h>
-#include <setjmp.h>
#include <sys/signal.h>
+#include "qemu/cutils.h"
#ifdef CONFIG_LINUX
#include <sys/syscall.h>
-#include <sys/vfs.h>
#endif
#ifdef __FreeBSD__
#include <sys/sysctl.h>
+#include <sys/user.h>
+#include <libutil.h>
+#endif
+
+#include "qemu/mmap-alloc.h"
+
+#ifdef CONFIG_DEBUG_STACK_USAGE
+#include "qemu/error-report.h"
#endif
+#define MAX_MEM_PREALLOC_THREAD_COUNT 16
+
+struct MemsetThread {
+ char *addr;
+ uint64_t numpages;
+ uint64_t hpagesize;
+ QemuThread pgthread;
+ sigjmp_buf env;
+};
+typedef struct MemsetThread MemsetThread;
+
+static MemsetThread *memset_thread;
+static int memset_num_threads;
+static bool memset_thread_failed;
+
int qemu_get_thread_id(void)
{
#if defined(__linux__)
void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
{
size_t align = QEMU_VMALLOC_ALIGN;
- size_t total = size + align - getpagesize();
- void *ptr = mmap(0, total, PROT_READ | PROT_WRITE,
- MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
- size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
+ void *ptr = qemu_ram_mmap(-1, size, align, false);
if (ptr == MAP_FAILED) {
return NULL;
if (alignment) {
*alignment = align;
}
- ptr += offset;
- total -= offset;
-
- if (offset > 0) {
- munmap(ptr - offset, offset);
- }
- if (total > size) {
- munmap(ptr + size, total - size);
- }
trace_qemu_anon_ram_alloc(size, ptr);
return ptr;
void qemu_anon_ram_free(void *ptr, size_t size)
{
trace_qemu_anon_ram_free(ptr, size);
- if (ptr) {
- munmap(ptr, size);
- }
+ qemu_ram_munmap(ptr, size);
}
void qemu_set_block(int fd)
return;
}
}
- dir = dirname(p);
+ dir = g_path_get_dirname(p);
pstrcpy(exec_dir, sizeof(exec_dir), dir);
+
+ g_free(dir);
}
char *qemu_get_exec_dir(void)
return g_strdup(exec_dir);
}
-static sigjmp_buf sigjump;
-
static void sigbus_handler(int signal)
{
- siglongjmp(sigjump, 1);
+ int i;
+ if (memset_thread) {
+ for (i = 0; i < memset_num_threads; i++) {
+ if (qemu_thread_is_self(&memset_thread[i].pgthread)) {
+ siglongjmp(memset_thread[i].env, 1);
+ }
+ }
+ }
}
-static size_t fd_getpagesize(int fd)
+static void *do_touch_pages(void *arg)
{
-#ifdef CONFIG_LINUX
- struct statfs fs;
- int ret;
+ MemsetThread *memset_args = (MemsetThread *)arg;
+ char *addr = memset_args->addr;
+ uint64_t numpages = memset_args->numpages;
+ uint64_t hpagesize = memset_args->hpagesize;
+ sigset_t set, oldset;
+ int i = 0;
- if (fd != -1) {
- do {
- ret = fstatfs(fd, &fs);
- } while (ret != 0 && errno == EINTR);
+ /* unblock SIGBUS */
+ sigemptyset(&set);
+ sigaddset(&set, SIGBUS);
+ pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
- if (ret == 0 && fs.f_type == HUGETLBFS_MAGIC) {
- return fs.f_bsize;
+ if (sigsetjmp(memset_args->env, 1)) {
+ memset_thread_failed = true;
+ } else {
+ for (i = 0; i < numpages; i++) {
+ /*
+ * Read & write back the same value, so we don't
+ * corrupt existing user/app data that might be
+ * stored.
+ *
+ * 'volatile' to stop compiler optimizing this away
+ * to a no-op
+ *
+ * TODO: get a better solution from kernel so we
+ * don't need to write at all so we don't cause
+ * wear on the storage backing the region...
+ */
+ *(volatile char *)addr = *addr;
+ addr += hpagesize;
}
}
-#endif
+ pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+ return NULL;
+}
- return getpagesize();
+static inline int get_memset_num_threads(int smp_cpus)
+{
+ long host_procs = sysconf(_SC_NPROCESSORS_ONLN);
+ int ret = 1;
+
+ if (host_procs > 0) {
+ ret = MIN(MIN(host_procs, MAX_MEM_PREALLOC_THREAD_COUNT), smp_cpus);
+ }
+ /* In case sysconf() fails, we fall back to single threaded */
+ return ret;
}
-void os_mem_prealloc(int fd, char *area, size_t memory)
+static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
+ int smp_cpus)
+{
+ uint64_t numpages_per_thread, size_per_thread;
+ char *addr = area;
+ int i = 0;
+
+ memset_thread_failed = false;
+ memset_num_threads = get_memset_num_threads(smp_cpus);
+ memset_thread = g_new0(MemsetThread, memset_num_threads);
+ numpages_per_thread = (numpages / memset_num_threads);
+ size_per_thread = (hpagesize * numpages_per_thread);
+ for (i = 0; i < memset_num_threads; i++) {
+ memset_thread[i].addr = addr;
+ memset_thread[i].numpages = (i == (memset_num_threads - 1)) ?
+ numpages : numpages_per_thread;
+ memset_thread[i].hpagesize = hpagesize;
+ qemu_thread_create(&memset_thread[i].pgthread, "touch_pages",
+ do_touch_pages, &memset_thread[i],
+ QEMU_THREAD_JOINABLE);
+ addr += size_per_thread;
+ numpages -= numpages_per_thread;
+ }
+ for (i = 0; i < memset_num_threads; i++) {
+ qemu_thread_join(&memset_thread[i].pgthread);
+ }
+ g_free(memset_thread);
+ memset_thread = NULL;
+
+ return memset_thread_failed;
+}
+
+void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus,
+ Error **errp)
{
int ret;
struct sigaction act, oldact;
- sigset_t set, oldset;
+ size_t hpagesize = qemu_fd_getpagesize(fd);
+ size_t numpages = DIV_ROUND_UP(memory, hpagesize);
memset(&act, 0, sizeof(act));
act.sa_handler = &sigbus_handler;
ret = sigaction(SIGBUS, &act, &oldact);
if (ret) {
- perror("os_mem_prealloc: failed to install signal handler");
- exit(1);
+ error_setg_errno(errp, errno,
+ "os_mem_prealloc: failed to install signal handler");
+ return;
}
- /* unblock SIGBUS */
- sigemptyset(&set);
- sigaddset(&set, SIGBUS);
- pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
+ /* touch pages simultaneously */
+ if (touch_all_pages(area, hpagesize, numpages, smp_cpus)) {
+ error_setg(errp, "os_mem_prealloc: Insufficient free host memory "
+ "pages available to allocate guest RAM\n");
+ }
- if (sigsetjmp(sigjump, 1)) {
- fprintf(stderr, "os_mem_prealloc: Insufficient free host memory "
- "pages available to allocate guest RAM\n");
+ ret = sigaction(SIGBUS, &oldact, NULL);
+ if (ret) {
+ /* Terminate QEMU since it can't recover from error */
+ perror("os_mem_prealloc: failed to reinstall signal handler");
exit(1);
+ }
+}
+
+
+static struct termios oldtty;
+
+static void term_exit(void)
+{
+ tcsetattr(0, TCSANOW, &oldtty);
+}
+
+static void term_init(void)
+{
+ struct termios tty;
+
+ tcgetattr(0, &tty);
+ oldtty = tty;
+
+ tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
+ |INLCR|IGNCR|ICRNL|IXON);
+ tty.c_oflag |= OPOST;
+ tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
+ tty.c_cflag &= ~(CSIZE|PARENB);
+ tty.c_cflag |= CS8;
+ tty.c_cc[VMIN] = 1;
+ tty.c_cc[VTIME] = 0;
+
+ tcsetattr(0, TCSANOW, &tty);
+
+ atexit(term_exit);
+}
+
+int qemu_read_password(char *buf, int buf_size)
+{
+ uint8_t ch;
+ int i, ret;
+
+ printf("password: ");
+ fflush(stdout);
+ term_init();
+ i = 0;
+ for (;;) {
+ ret = read(0, &ch, 1);
+ if (ret == -1) {
+ if (errno == EAGAIN || errno == EINTR) {
+ continue;
+ } else {
+ break;
+ }
+ } else if (ret == 0) {
+ ret = -1;
+ break;
+ } else {
+ if (ch == '\r' ||
+ ch == '\n') {
+ ret = 0;
+ break;
+ }
+ if (i < (buf_size - 1)) {
+ buf[i++] = ch;
+ }
+ }
+ }
+ term_exit();
+ buf[i] = '\0';
+ printf("\n");
+ return ret;
+}
+
+
+char *qemu_get_pid_name(pid_t pid)
+{
+ char *name = NULL;
+
+#if defined(__FreeBSD__)
+ /* BSDs don't have /proc, but they provide a nice substitute */
+ struct kinfo_proc *proc = kinfo_getproc(pid);
+
+ if (proc) {
+ name = g_strdup(proc->ki_comm);
+ free(proc);
+ }
+#else
+ /* Assume a system with reasonable procfs */
+ char *pid_path;
+ size_t len;
+
+ pid_path = g_strdup_printf("/proc/%d/cmdline", pid);
+ g_file_get_contents(pid_path, &name, &len, NULL);
+ g_free(pid_path);
+#endif
+
+ return name;
+}
+
+
+pid_t qemu_fork(Error **errp)
+{
+ sigset_t oldmask, newmask;
+ struct sigaction sig_action;
+ int saved_errno;
+ pid_t pid;
+
+ /*
+ * Need to block signals now, so that child process can safely
+ * kill off caller's signal handlers without a race.
+ */
+ sigfillset(&newmask);
+ if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
+ error_setg_errno(errp, errno,
+ "cannot block signals");
+ return -1;
+ }
+
+ pid = fork();
+ saved_errno = errno;
+
+ if (pid < 0) {
+ /* attempt to restore signal mask, but ignore failure, to
+ * avoid obscuring the fork failure */
+ (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+ error_setg_errno(errp, saved_errno,
+ "cannot fork child process");
+ errno = saved_errno;
+ return -1;
+ } else if (pid) {
+ /* parent process */
+
+ /* Restore our original signal mask now that the child is
+ * safely running. Only documented failures are EFAULT (not
+ * possible, since we are using just-grabbed mask) or EINVAL
+ * (not possible, since we are using correct arguments). */
+ (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
} else {
- int i;
- size_t hpagesize = fd_getpagesize(fd);
- size_t numpages = DIV_ROUND_UP(memory, hpagesize);
+ /* child process */
+ size_t i;
+
+ /* Clear out all signal handlers from parent so nothing
+ * unexpected can happen in our child once we unblock
+ * signals */
+ sig_action.sa_handler = SIG_DFL;
+ sig_action.sa_flags = 0;
+ sigemptyset(&sig_action.sa_mask);
+
+ for (i = 1; i < NSIG; i++) {
+ /* Only possible errors are EFAULT or EINVAL The former
+ * won't happen, the latter we expect, so no need to check
+ * return value */
+ (void)sigaction(i, &sig_action, NULL);
+ }
- /* MAP_POPULATE silently ignores failures */
- for (i = 0; i < numpages; i++) {
- memset(area + (hpagesize * i), 0, 1);
+ /* Unmask all signals in child, since we've no idea what the
+ * caller's done with their signal mask and don't want to
+ * propagate that to children */
+ sigemptyset(&newmask);
+ if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
+ Error *local_err = NULL;
+ error_setg_errno(&local_err, errno,
+ "cannot unblock signals");
+ error_report_err(local_err);
+ _exit(1);
}
+ }
+ return pid;
+}
- ret = sigaction(SIGBUS, &oldact, NULL);
- if (ret) {
- perror("os_mem_prealloc: failed to reinstall signal handler");
- exit(1);
+void *qemu_alloc_stack(size_t *sz)
+{
+ void *ptr, *guardpage;
+#ifdef CONFIG_DEBUG_STACK_USAGE
+ void *ptr2;
+#endif
+ size_t pagesz = getpagesize();
+#ifdef _SC_THREAD_STACK_MIN
+ /* avoid stacks smaller than _SC_THREAD_STACK_MIN */
+ long min_stack_sz = sysconf(_SC_THREAD_STACK_MIN);
+ *sz = MAX(MAX(min_stack_sz, 0), *sz);
+#endif
+ /* adjust stack size to a multiple of the page size */
+ *sz = ROUND_UP(*sz, pagesz);
+ /* allocate one extra page for the guard page */
+ *sz += pagesz;
+
+ ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (ptr == MAP_FAILED) {
+ abort();
+ }
+
+#if defined(HOST_IA64)
+ /* separate register stack */
+ guardpage = ptr + (((*sz - pagesz) / 2) & ~pagesz);
+#elif defined(HOST_HPPA)
+ /* stack grows up */
+ guardpage = ptr + *sz - pagesz;
+#else
+ /* stack grows down */
+ guardpage = ptr;
+#endif
+ if (mprotect(guardpage, pagesz, PROT_NONE) != 0) {
+ abort();
+ }
+
+#ifdef CONFIG_DEBUG_STACK_USAGE
+ for (ptr2 = ptr + pagesz; ptr2 < ptr + *sz; ptr2 += sizeof(uint32_t)) {
+ *(uint32_t *)ptr2 = 0xdeadbeaf;
+ }
+#endif
+
+ return ptr;
+}
+
+#ifdef CONFIG_DEBUG_STACK_USAGE
+static __thread unsigned int max_stack_usage;
+#endif
+
+void qemu_free_stack(void *stack, size_t sz)
+{
+#ifdef CONFIG_DEBUG_STACK_USAGE
+ unsigned int usage;
+ void *ptr;
+
+ for (ptr = stack + getpagesize(); ptr < stack + sz;
+ ptr += sizeof(uint32_t)) {
+ if (*(uint32_t *)ptr != 0xdeadbeaf) {
+ break;
}
+ }
+ usage = sz - (uintptr_t) (ptr - stack);
+ if (usage > max_stack_usage) {
+ error_report("thread %d max stack usage increased from %u to %u",
+ qemu_get_thread_id(), max_stack_usage, usage);
+ max_stack_usage = usage;
+ }
+#endif
- pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+ munmap(stack, sz);
+}
+
+void sigaction_invoke(struct sigaction *action,
+ struct qemu_signalfd_siginfo *info)
+{
+ siginfo_t si = { 0 };
+ si.si_signo = info->ssi_signo;
+ si.si_errno = info->ssi_errno;
+ si.si_code = info->ssi_code;
+
+ /* Convert the minimal set of fields defined by POSIX.
+ * Positive si_code values are reserved for kernel-generated
+ * signals, where the valid siginfo fields are determined by
+ * the signal number. But according to POSIX, it is unspecified
+ * whether SI_USER and SI_QUEUE have values less than or equal to
+ * zero.
+ */
+ if (info->ssi_code == SI_USER || info->ssi_code == SI_QUEUE ||
+ info->ssi_code <= 0) {
+ /* SIGTERM, etc. */
+ si.si_pid = info->ssi_pid;
+ si.si_uid = info->ssi_uid;
+ } else if (info->ssi_signo == SIGILL || info->ssi_signo == SIGFPE ||
+ info->ssi_signo == SIGSEGV || info->ssi_signo == SIGBUS) {
+ si.si_addr = (void *)(uintptr_t)info->ssi_addr;
+ } else if (info->ssi_signo == SIGCHLD) {
+ si.si_pid = info->ssi_pid;
+ si.si_status = info->ssi_status;
+ si.si_uid = info->ssi_uid;
}
+ action->sa_sigaction(info->ssi_signo, &si, NULL);
}
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