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-rw-r--r--semihosting/syscalls.c978
1 files changed, 978 insertions, 0 deletions
diff --git a/semihosting/syscalls.c b/semihosting/syscalls.c
new file mode 100644
index 0000000000..4847f66c02
--- /dev/null
+++ b/semihosting/syscalls.c
@@ -0,0 +1,978 @@
+/*
+ * Syscall implementations for semihosting.
+ *
+ * Copyright (c) 2022 Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "exec/gdbstub.h"
+#include "semihosting/guestfd.h"
+#include "semihosting/syscalls.h"
+#include "semihosting/console.h"
+#ifdef CONFIG_USER_ONLY
+#include "qemu.h"
+#else
+#include "semihosting/softmmu-uaccess.h"
+#endif
+
+
+/*
+ * Validate or compute the length of the string (including terminator).
+ */
+static int validate_strlen(CPUState *cs, target_ulong str, target_ulong tlen)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ char c;
+
+ if (tlen == 0) {
+ ssize_t slen = target_strlen(str);
+
+ if (slen < 0) {
+ return -EFAULT;
+ }
+ if (slen >= INT32_MAX) {
+ return -ENAMETOOLONG;
+ }
+ return slen + 1;
+ }
+ if (tlen > INT32_MAX) {
+ return -ENAMETOOLONG;
+ }
+ if (get_user_u8(c, str + tlen - 1)) {
+ return -EFAULT;
+ }
+ if (c != 0) {
+ return -EINVAL;
+ }
+ return tlen;
+}
+
+static int validate_lock_user_string(char **pstr, CPUState *cs,
+ target_ulong tstr, target_ulong tlen)
+{
+ int ret = validate_strlen(cs, tstr, tlen);
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ char *str = NULL;
+
+ if (ret > 0) {
+ str = lock_user(VERIFY_READ, tstr, ret, true);
+ ret = str ? 0 : -EFAULT;
+ }
+ *pstr = str;
+ return ret;
+}
+
+/*
+ * TODO: Note that gdb always stores the stat structure big-endian.
+ * So far, that's ok, as the only two targets using this are also
+ * big-endian. Until we do something with gdb, also produce the
+ * same big-endian result from the host.
+ */
+static int copy_stat_to_user(CPUState *cs, target_ulong addr,
+ const struct stat *s)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ struct gdb_stat *p;
+
+ if (s->st_dev != (uint32_t)s->st_dev ||
+ s->st_ino != (uint32_t)s->st_ino) {
+ return -EOVERFLOW;
+ }
+
+ p = lock_user(VERIFY_WRITE, addr, sizeof(struct gdb_stat), 0);
+ if (!p) {
+ return -EFAULT;
+ }
+
+ p->gdb_st_dev = cpu_to_be32(s->st_dev);
+ p->gdb_st_ino = cpu_to_be32(s->st_ino);
+ p->gdb_st_mode = cpu_to_be32(s->st_mode);
+ p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
+ p->gdb_st_uid = cpu_to_be32(s->st_uid);
+ p->gdb_st_gid = cpu_to_be32(s->st_gid);
+ p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
+ p->gdb_st_size = cpu_to_be64(s->st_size);
+#ifdef _WIN32
+ /* Windows stat is missing some fields. */
+ p->gdb_st_blksize = 0;
+ p->gdb_st_blocks = 0;
+#else
+ p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
+ p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
+#endif
+ p->gdb_st_atime = cpu_to_be32(s->st_atime);
+ p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
+ p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
+
+ unlock_user(p, addr, sizeof(struct gdb_stat));
+ return 0;
+}
+
+/*
+ * GDB semihosting syscall implementations.
+ */
+
+static gdb_syscall_complete_cb gdb_open_complete;
+
+static void gdb_open_cb(CPUState *cs, uint64_t ret, int err)
+{
+ if (!err) {
+ int guestfd = alloc_guestfd();
+ associate_guestfd(guestfd, ret);
+ ret = guestfd;
+ }
+ gdb_open_complete(cs, ret, err);
+}
+
+static void gdb_open(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len,
+ int gdb_flags, int mode)
+{
+ int len = validate_strlen(cs, fname, fname_len);
+ if (len < 0) {
+ complete(cs, -1, -len);
+ return;
+ }
+
+ gdb_open_complete = complete;
+ gdb_do_syscall(gdb_open_cb, "open,%s,%x,%x",
+ fname, len, (target_ulong)gdb_flags, (target_ulong)mode);
+}
+
+static void gdb_close(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf)
+{
+ gdb_do_syscall(complete, "close,%x", (target_ulong)gf->hostfd);
+}
+
+static void gdb_read(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ gdb_do_syscall(complete, "read,%x,%x,%x",
+ (target_ulong)gf->hostfd, buf, len);
+}
+
+static void gdb_write(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ gdb_do_syscall(complete, "write,%x,%x,%x",
+ (target_ulong)gf->hostfd, buf, len);
+}
+
+static void gdb_lseek(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, int64_t off, int gdb_whence)
+{
+ gdb_do_syscall(complete, "lseek,%x,%lx,%x",
+ (target_ulong)gf->hostfd, off, (target_ulong)gdb_whence);
+}
+
+static void gdb_isatty(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf)
+{
+ gdb_do_syscall(complete, "isatty,%x", (target_ulong)gf->hostfd);
+}
+
+static void gdb_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong addr)
+{
+ gdb_do_syscall(complete, "fstat,%x,%x", (target_ulong)gf->hostfd, addr);
+}
+
+static void gdb_stat(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len,
+ target_ulong addr)
+{
+ int len = validate_strlen(cs, fname, fname_len);
+ if (len < 0) {
+ complete(cs, -1, -len);
+ return;
+ }
+
+ gdb_do_syscall(complete, "stat,%s,%x", fname, len, addr);
+}
+
+static void gdb_remove(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len)
+{
+ int len = validate_strlen(cs, fname, fname_len);
+ if (len < 0) {
+ complete(cs, -1, -len);
+ return;
+ }
+
+ gdb_do_syscall(complete, "unlink,%s", fname, len);
+}
+
+static void gdb_rename(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong oname, target_ulong oname_len,
+ target_ulong nname, target_ulong nname_len)
+{
+ int olen, nlen;
+
+ olen = validate_strlen(cs, oname, oname_len);
+ if (olen < 0) {
+ complete(cs, -1, -olen);
+ return;
+ }
+ nlen = validate_strlen(cs, nname, nname_len);
+ if (nlen < 0) {
+ complete(cs, -1, -nlen);
+ return;
+ }
+
+ gdb_do_syscall(complete, "rename,%s,%s", oname, olen, nname, nlen);
+}
+
+static void gdb_system(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong cmd, target_ulong cmd_len)
+{
+ int len = validate_strlen(cs, cmd, cmd_len);
+ if (len < 0) {
+ complete(cs, -1, -len);
+ return;
+ }
+
+ gdb_do_syscall(complete, "system,%s", cmd, len);
+}
+
+static void gdb_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong tv_addr, target_ulong tz_addr)
+{
+ gdb_do_syscall(complete, "gettimeofday,%x,%x", tv_addr, tz_addr);
+}
+
+/*
+ * Host semihosting syscall implementations.
+ */
+
+static void host_open(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len,
+ int gdb_flags, int mode)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ char *p;
+ int ret, host_flags;
+
+ ret = validate_lock_user_string(&p, cs, fname, fname_len);
+ if (ret < 0) {
+ complete(cs, -1, -ret);
+ return;
+ }
+
+ if (gdb_flags & GDB_O_WRONLY) {
+ host_flags = O_WRONLY;
+ } else if (gdb_flags & GDB_O_RDWR) {
+ host_flags = O_RDWR;
+ } else {
+ host_flags = O_RDONLY;
+ }
+ if (gdb_flags & GDB_O_CREAT) {
+ host_flags |= O_CREAT;
+ }
+ if (gdb_flags & GDB_O_TRUNC) {
+ host_flags |= O_TRUNC;
+ }
+ if (gdb_flags & GDB_O_EXCL) {
+ host_flags |= O_EXCL;
+ }
+
+ ret = open(p, host_flags, mode);
+ if (ret < 0) {
+ complete(cs, -1, errno);
+ } else {
+ int guestfd = alloc_guestfd();
+ associate_guestfd(guestfd, ret);
+ complete(cs, guestfd, 0);
+ }
+ unlock_user(p, fname, 0);
+}
+
+static void host_close(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf)
+{
+ /*
+ * Only close the underlying host fd if it's one we opened on behalf
+ * of the guest in SYS_OPEN.
+ */
+ if (gf->hostfd != STDIN_FILENO &&
+ gf->hostfd != STDOUT_FILENO &&
+ gf->hostfd != STDERR_FILENO &&
+ close(gf->hostfd) < 0) {
+ complete(cs, -1, errno);
+ } else {
+ complete(cs, 0, 0);
+ }
+}
+
+static void host_read(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ void *ptr = lock_user(VERIFY_WRITE, buf, len, 0);
+ ssize_t ret;
+
+ if (!ptr) {
+ complete(cs, -1, EFAULT);
+ return;
+ }
+ do {
+ ret = read(gf->hostfd, ptr, len);
+ } while (ret == -1 && errno == EINTR);
+ if (ret == -1) {
+ complete(cs, -1, errno);
+ unlock_user(ptr, buf, 0);
+ } else {
+ complete(cs, ret, 0);
+ unlock_user(ptr, buf, ret);
+ }
+}
+
+static void host_write(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ void *ptr = lock_user(VERIFY_READ, buf, len, 1);
+ ssize_t ret;
+
+ if (!ptr) {
+ complete(cs, -1, EFAULT);
+ return;
+ }
+ ret = write(gf->hostfd, ptr, len);
+ complete(cs, ret, ret == -1 ? errno : 0);
+ unlock_user(ptr, buf, 0);
+}
+
+static void host_lseek(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, int64_t off, int whence)
+{
+ /* So far, all hosts use the same values. */
+ QEMU_BUILD_BUG_ON(GDB_SEEK_SET != SEEK_SET);
+ QEMU_BUILD_BUG_ON(GDB_SEEK_CUR != SEEK_CUR);
+ QEMU_BUILD_BUG_ON(GDB_SEEK_END != SEEK_END);
+
+ off_t ret = off;
+ int err = 0;
+
+ if (ret == off) {
+ ret = lseek(gf->hostfd, ret, whence);
+ if (ret == -1) {
+ err = errno;
+ }
+ } else {
+ ret = -1;
+ err = EINVAL;
+ }
+ complete(cs, ret, err);
+}
+
+static void host_isatty(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf)
+{
+ int ret = isatty(gf->hostfd);
+ complete(cs, ret, ret ? 0 : errno);
+}
+
+static void host_flen(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf)
+{
+ struct stat buf;
+
+ if (fstat(gf->hostfd, &buf) < 0) {
+ complete(cs, -1, errno);
+ } else {
+ complete(cs, buf.st_size, 0);
+ }
+}
+
+static void host_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong addr)
+{
+ struct stat buf;
+ int ret;
+
+ ret = fstat(gf->hostfd, &buf);
+ if (ret) {
+ complete(cs, -1, errno);
+ return;
+ }
+ ret = copy_stat_to_user(cs, addr, &buf);
+ complete(cs, ret ? -1 : 0, ret ? -ret : 0);
+}
+
+static void host_stat(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len,
+ target_ulong addr)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ struct stat buf;
+ char *name;
+ int ret, err;
+
+ ret = validate_lock_user_string(&name, cs, fname, fname_len);
+ if (ret < 0) {
+ complete(cs, -1, -ret);
+ return;
+ }
+
+ ret = stat(name, &buf);
+ if (ret) {
+ err = errno;
+ } else {
+ ret = copy_stat_to_user(cs, addr, &buf);
+ err = 0;
+ if (ret < 0) {
+ err = -ret;
+ ret = -1;
+ }
+ }
+ complete(cs, ret, err);
+ unlock_user(name, fname, 0);
+}
+
+static void host_remove(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ char *p;
+ int ret;
+
+ ret = validate_lock_user_string(&p, cs, fname, fname_len);
+ if (ret < 0) {
+ complete(cs, -1, -ret);
+ return;
+ }
+
+ ret = remove(p);
+ complete(cs, ret, ret ? errno : 0);
+ unlock_user(p, fname, 0);
+}
+
+static void host_rename(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong oname, target_ulong oname_len,
+ target_ulong nname, target_ulong nname_len)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ char *ostr, *nstr;
+ int ret;
+
+ ret = validate_lock_user_string(&ostr, cs, oname, oname_len);
+ if (ret < 0) {
+ complete(cs, -1, -ret);
+ return;
+ }
+ ret = validate_lock_user_string(&nstr, cs, nname, nname_len);
+ if (ret < 0) {
+ unlock_user(ostr, oname, 0);
+ complete(cs, -1, -ret);
+ return;
+ }
+
+ ret = rename(ostr, nstr);
+ complete(cs, ret, ret ? errno : 0);
+ unlock_user(ostr, oname, 0);
+ unlock_user(nstr, nname, 0);
+}
+
+static void host_system(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong cmd, target_ulong cmd_len)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ char *p;
+ int ret;
+
+ ret = validate_lock_user_string(&p, cs, cmd, cmd_len);
+ if (ret < 0) {
+ complete(cs, -1, -ret);
+ return;
+ }
+
+ ret = system(p);
+ complete(cs, ret, ret == -1 ? errno : 0);
+ unlock_user(p, cmd, 0);
+}
+
+static void host_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong tv_addr, target_ulong tz_addr)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ struct gdb_timeval *p;
+ int64_t rt;
+
+ /* GDB fails on non-null TZ, so be consistent. */
+ if (tz_addr != 0) {
+ complete(cs, -1, EINVAL);
+ return;
+ }
+
+ p = lock_user(VERIFY_WRITE, tv_addr, sizeof(struct gdb_timeval), 0);
+ if (!p) {
+ complete(cs, -1, EFAULT);
+ return;
+ }
+
+ /* TODO: Like stat, gdb always produces big-endian results; match it. */
+ rt = g_get_real_time();
+ p->tv_sec = cpu_to_be32(rt / G_USEC_PER_SEC);
+ p->tv_usec = cpu_to_be64(rt % G_USEC_PER_SEC);
+ unlock_user(p, tv_addr, sizeof(struct gdb_timeval));
+}
+
+#ifndef CONFIG_USER_ONLY
+static void host_poll_one(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, GIOCondition cond, int timeout)
+{
+ /*
+ * Since this is only used by xtensa in system mode, and stdio is
+ * handled through GuestFDConsole, and there are no semihosting
+ * system calls for sockets and the like, that means this descriptor
+ * must be a normal file. Normal files never block and are thus
+ * always ready.
+ */
+ complete(cs, cond & (G_IO_IN | G_IO_OUT), 0);
+}
+#endif
+
+/*
+ * Static file semihosting syscall implementations.
+ */
+
+static void staticfile_read(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ target_ulong rest = gf->staticfile.len - gf->staticfile.off;
+ void *ptr;
+
+ if (len > rest) {
+ len = rest;
+ }
+ ptr = lock_user(VERIFY_WRITE, buf, len, 0);
+ if (!ptr) {
+ complete(cs, -1, EFAULT);
+ return;
+ }
+ memcpy(ptr, gf->staticfile.data + gf->staticfile.off, len);
+ gf->staticfile.off += len;
+ complete(cs, len, 0);
+ unlock_user(ptr, buf, len);
+}
+
+static void staticfile_lseek(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, int64_t off, int gdb_whence)
+{
+ int64_t ret;
+
+ switch (gdb_whence) {
+ case GDB_SEEK_SET:
+ ret = off;
+ break;
+ case GDB_SEEK_CUR:
+ ret = gf->staticfile.off + off;
+ break;
+ case GDB_SEEK_END:
+ ret = gf->staticfile.len + off;
+ break;
+ default:
+ ret = -1;
+ break;
+ }
+ if (ret >= 0 && ret <= gf->staticfile.len) {
+ gf->staticfile.off = ret;
+ complete(cs, ret, 0);
+ } else {
+ complete(cs, -1, EINVAL);
+ }
+}
+
+static void staticfile_flen(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf)
+{
+ complete(cs, gf->staticfile.len, 0);
+}
+
+/*
+ * Console semihosting syscall implementations.
+ */
+
+static void console_read(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ char *ptr;
+ int ret;
+
+ ptr = lock_user(VERIFY_WRITE, buf, len, 0);
+ if (!ptr) {
+ complete(cs, -1, EFAULT);
+ return;
+ }
+ ret = qemu_semihosting_console_read(cs, ptr, len);
+ complete(cs, ret, 0);
+ unlock_user(ptr, buf, ret);
+}
+
+static void console_write(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+ char *ptr = lock_user(VERIFY_READ, buf, len, 1);
+ int ret;
+
+ if (!ptr) {
+ complete(cs, -1, EFAULT);
+ return;
+ }
+ ret = qemu_semihosting_console_write(ptr, len);
+ complete(cs, ret ? ret : -1, ret ? 0 : EIO);
+ unlock_user(ptr, buf, ret);
+}
+
+static void console_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong addr)
+{
+ static const struct stat tty_buf = {
+ .st_mode = 020666, /* S_IFCHR, ugo+rw */
+ .st_rdev = 5, /* makedev(5, 0) -- linux /dev/tty */
+ };
+ int ret;
+
+ ret = copy_stat_to_user(cs, addr, &tty_buf);
+ complete(cs, ret ? -1 : 0, ret ? -ret : 0);
+}
+
+#ifndef CONFIG_USER_ONLY
+static void console_poll_one(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, GIOCondition cond, int timeout)
+{
+ /* The semihosting console does not support urgent data or errors. */
+ cond &= G_IO_IN | G_IO_OUT;
+
+ /*
+ * Since qemu_semihosting_console_write never blocks, we can
+ * consider output always ready -- leave G_IO_OUT alone.
+ * All that remains is to conditionally signal input ready.
+ * Since output ready causes an immediate return, only block
+ * for G_IO_IN alone.
+ *
+ * TODO: Implement proper timeout. For now, only support
+ * indefinite wait or immediate poll.
+ */
+ if (cond == G_IO_IN && timeout < 0) {
+ qemu_semihosting_console_block_until_ready(cs);
+ /* We returned -- input must be ready. */
+ } else if ((cond & G_IO_IN) && !qemu_semihosting_console_ready()) {
+ cond &= ~G_IO_IN;
+ }
+
+ complete(cs, cond, 0);
+}
+#endif
+
+/*
+ * Syscall entry points.
+ */
+
+void semihost_sys_open(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len,
+ int gdb_flags, int mode)
+{
+ if (use_gdb_syscalls()) {
+ gdb_open(cs, complete, fname, fname_len, gdb_flags, mode);
+ } else {
+ host_open(cs, complete, fname, fname_len, gdb_flags, mode);
+ }
+}
+
+void semihost_sys_close(CPUState *cs, gdb_syscall_complete_cb complete, int fd)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (!gf) {
+ complete(cs, -1, EBADF);
+ return;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ gdb_close(cs, complete, gf);
+ break;
+ case GuestFDHost:
+ host_close(cs, complete, gf);
+ break;
+ case GuestFDStatic:
+ case GuestFDConsole:
+ complete(cs, 0, 0);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ dealloc_guestfd(fd);
+}
+
+void semihost_sys_read_gf(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ /*
+ * Bound length for 64-bit guests on 32-bit hosts, not overlowing ssize_t.
+ * Note the Linux kernel does this with MAX_RW_COUNT, so it's not a bad
+ * idea to do this unconditionally.
+ */
+ if (len > INT32_MAX) {
+ len = INT32_MAX;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ gdb_read(cs, complete, gf, buf, len);
+ break;
+ case GuestFDHost:
+ host_read(cs, complete, gf, buf, len);
+ break;
+ case GuestFDStatic:
+ staticfile_read(cs, complete, gf, buf, len);
+ break;
+ case GuestFDConsole:
+ console_read(cs, complete, gf, buf, len);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+}
+
+void semihost_sys_read(CPUState *cs, gdb_syscall_complete_cb complete,
+ int fd, target_ulong buf, target_ulong len)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (gf) {
+ semihost_sys_read_gf(cs, complete, gf, buf, len);
+ } else {
+ complete(cs, -1, EBADF);
+ }
+}
+
+void semihost_sys_write_gf(CPUState *cs, gdb_syscall_complete_cb complete,
+ GuestFD *gf, target_ulong buf, target_ulong len)
+{
+ /*
+ * Bound length for 64-bit guests on 32-bit hosts, not overlowing ssize_t.
+ * Note the Linux kernel does this with MAX_RW_COUNT, so it's not a bad
+ * idea to do this unconditionally.
+ */
+ if (len > INT32_MAX) {
+ len = INT32_MAX;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ gdb_write(cs, complete, gf, buf, len);
+ break;
+ case GuestFDHost:
+ host_write(cs, complete, gf, buf, len);
+ break;
+ case GuestFDConsole:
+ console_write(cs, complete, gf, buf, len);
+ break;
+ case GuestFDStatic:
+ /* Static files are never open for writing: EBADF. */
+ complete(cs, -1, EBADF);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+}
+
+void semihost_sys_write(CPUState *cs, gdb_syscall_complete_cb complete,
+ int fd, target_ulong buf, target_ulong len)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (gf) {
+ semihost_sys_write_gf(cs, complete, gf, buf, len);
+ } else {
+ complete(cs, -1, EBADF);
+ }
+}
+
+void semihost_sys_lseek(CPUState *cs, gdb_syscall_complete_cb complete,
+ int fd, int64_t off, int gdb_whence)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (!gf) {
+ complete(cs, -1, EBADF);
+ return;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ gdb_lseek(cs, complete, gf, off, gdb_whence);
+ return;
+ case GuestFDHost:
+ host_lseek(cs, complete, gf, off, gdb_whence);
+ break;
+ case GuestFDStatic:
+ staticfile_lseek(cs, complete, gf, off, gdb_whence);
+ break;
+ case GuestFDConsole:
+ complete(cs, -1, ESPIPE);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+}
+
+void semihost_sys_isatty(CPUState *cs, gdb_syscall_complete_cb complete, int fd)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (!gf) {
+ complete(cs, 0, EBADF);
+ return;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ gdb_isatty(cs, complete, gf);
+ break;
+ case GuestFDHost:
+ host_isatty(cs, complete, gf);
+ break;
+ case GuestFDStatic:
+ complete(cs, 0, ENOTTY);
+ break;
+ case GuestFDConsole:
+ complete(cs, 1, 0);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+}
+
+void semihost_sys_flen(CPUState *cs, gdb_syscall_complete_cb fstat_cb,
+ gdb_syscall_complete_cb flen_cb, int fd,
+ target_ulong fstat_addr)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (!gf) {
+ flen_cb(cs, -1, EBADF);
+ return;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ gdb_fstat(cs, fstat_cb, gf, fstat_addr);
+ break;
+ case GuestFDHost:
+ host_flen(cs, flen_cb, gf);
+ break;
+ case GuestFDStatic:
+ staticfile_flen(cs, flen_cb, gf);
+ break;
+ case GuestFDConsole:
+ default:
+ g_assert_not_reached();
+ }
+}
+
+void semihost_sys_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
+ int fd, target_ulong addr)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (!gf) {
+ complete(cs, -1, EBADF);
+ return;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ gdb_fstat(cs, complete, gf, addr);
+ break;
+ case GuestFDHost:
+ host_fstat(cs, complete, gf, addr);
+ break;
+ case GuestFDConsole:
+ console_fstat(cs, complete, gf, addr);
+ break;
+ case GuestFDStatic:
+ default:
+ g_assert_not_reached();
+ }
+}
+
+void semihost_sys_stat(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len,
+ target_ulong addr)
+{
+ if (use_gdb_syscalls()) {
+ gdb_stat(cs, complete, fname, fname_len, addr);
+ } else {
+ host_stat(cs, complete, fname, fname_len, addr);
+ }
+}
+
+void semihost_sys_remove(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong fname, target_ulong fname_len)
+{
+ if (use_gdb_syscalls()) {
+ gdb_remove(cs, complete, fname, fname_len);
+ } else {
+ host_remove(cs, complete, fname, fname_len);
+ }
+}
+
+void semihost_sys_rename(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong oname, target_ulong oname_len,
+ target_ulong nname, target_ulong nname_len)
+{
+ if (use_gdb_syscalls()) {
+ gdb_rename(cs, complete, oname, oname_len, nname, nname_len);
+ } else {
+ host_rename(cs, complete, oname, oname_len, nname, nname_len);
+ }
+}
+
+void semihost_sys_system(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong cmd, target_ulong cmd_len)
+{
+ if (use_gdb_syscalls()) {
+ gdb_system(cs, complete, cmd, cmd_len);
+ } else {
+ host_system(cs, complete, cmd, cmd_len);
+ }
+}
+
+void semihost_sys_gettimeofday(CPUState *cs, gdb_syscall_complete_cb complete,
+ target_ulong tv_addr, target_ulong tz_addr)
+{
+ if (use_gdb_syscalls()) {
+ gdb_gettimeofday(cs, complete, tv_addr, tz_addr);
+ } else {
+ host_gettimeofday(cs, complete, tv_addr, tz_addr);
+ }
+}
+
+#ifndef CONFIG_USER_ONLY
+void semihost_sys_poll_one(CPUState *cs, gdb_syscall_complete_cb complete,
+ int fd, GIOCondition cond, int timeout)
+{
+ GuestFD *gf = get_guestfd(fd);
+
+ if (!gf) {
+ complete(cs, G_IO_NVAL, 1);
+ return;
+ }
+ switch (gf->type) {
+ case GuestFDGDB:
+ complete(cs, G_IO_NVAL, 1);
+ break;
+ case GuestFDHost:
+ host_poll_one(cs, complete, gf, cond, timeout);
+ break;
+ case GuestFDConsole:
+ console_poll_one(cs, complete, gf, cond, timeout);
+ break;
+ case GuestFDStatic:
+ default:
+ g_assert_not_reached();
+ }
+}
+#endif