@@ -8140,172 +8140,131 @@ static int host_to_target_cpu_mask(const unsigned long *host_mask,
}
#ifdef TARGET_NR_getdents
-static int do_getdents(abi_long arg1, abi_long arg2, abi_long arg3)
+static int do_getdents(abi_long arg1, abi_long arg2, abi_long count)
{
- int ret;
+ g_autofree void *hdirp = NULL;
+ void *tdirp;
+ int hlen, hoff, toff;
+ int hreclen, treclen;
-#ifdef EMULATE_GETDENTS_WITH_GETDENTS
-# if TARGET_ABI_BITS == 32 && HOST_LONG_BITS == 64
- struct target_dirent *target_dirp;
- struct linux_dirent *dirp;
- abi_long count = arg3;
-
- dirp = g_try_malloc(count);
- if (!dirp) {
+ hdirp = g_try_malloc(count);
+ if (!hdirp) {
return -TARGET_ENOMEM;
}
- ret = get_errno(sys_getdents(arg1, dirp, count));
- if (!is_error(ret)) {
- struct linux_dirent *de;
- struct target_dirent *tde;
- int len = ret;
- int reclen, treclen;
- int count1, tnamelen;
-
- count1 = 0;
- de = dirp;
- target_dirp = lock_user(VERIFY_WRITE, arg2, count, 0);
- if (!target_dirp) {
- return -TARGET_EFAULT;
- }
- tde = target_dirp;
- while (len > 0) {
- reclen = de->d_reclen;
- tnamelen = reclen - offsetof(struct linux_dirent, d_name);
- assert(tnamelen >= 0);
- treclen = tnamelen + offsetof(struct target_dirent, d_name);
- assert(count1 + treclen <= count);
- tde->d_reclen = tswap16(treclen);
- tde->d_ino = tswapal(de->d_ino);
- tde->d_off = tswapal(de->d_off);
- memcpy(tde->d_name, de->d_name, tnamelen);
- de = (struct linux_dirent *)((char *)de + reclen);
- len -= reclen;
- tde = (struct target_dirent *)((char *)tde + treclen);
- count1 += treclen;
- }
- ret = count1;
- unlock_user(target_dirp, arg2, ret);
- }
- g_free(dirp);
-# else
- struct linux_dirent *dirp;
- abi_long count = arg3;
-
- dirp = lock_user(VERIFY_WRITE, arg2, count, 0);
- if (!dirp) {
- return -TARGET_EFAULT;
- }
- ret = get_errno(sys_getdents(arg1, dirp, count));
- if (!is_error(ret)) {
- struct linux_dirent *de;
- int len = ret;
- int reclen;
- de = dirp;
- while (len > 0) {
- reclen = de->d_reclen;
- if (reclen > len) {
- break;
- }
- de->d_reclen = tswap16(reclen);
- tswapls(&de->d_ino);
- tswapls(&de->d_off);
- de = (struct linux_dirent *)((char *)de + reclen);
- len -= reclen;
- }
- }
- unlock_user(dirp, arg2, ret);
-# endif
+#ifdef EMULATE_GETDENTS_WITH_GETDENTS
+ hlen = sys_getdents(arg1, hdirp, count);
#else
- /* Implement getdents in terms of getdents64 */
- struct linux_dirent64 *dirp;
- abi_long count = arg3;
+ hlen = sys_getdents64(arg1, hdirp, count);
+#endif
- dirp = lock_user(VERIFY_WRITE, arg2, count, 0);
- if (!dirp) {
+ hlen = get_errno(hlen);
+ if (is_error(hlen)) {
+ return hlen;
+ }
+
+ tdirp = lock_user(VERIFY_WRITE, arg2, count, 0);
+ if (!tdirp) {
return -TARGET_EFAULT;
}
- ret = get_errno(sys_getdents64(arg1, dirp, count));
- if (!is_error(ret)) {
- /*
- * Convert the dirent64 structs to target dirent. We do this
- * in-place, since we can guarantee that a target_dirent is no
- * larger than a dirent64; however this means we have to be
- * careful to read everything before writing in the new format.
- */
- struct linux_dirent64 *de;
- struct target_dirent *tde;
- int len = ret;
- int tlen = 0;
- de = dirp;
- tde = (struct target_dirent *)dirp;
- while (len > 0) {
- int namelen, treclen;
- int reclen = de->d_reclen;
- uint64_t ino = de->d_ino;
- int64_t off = de->d_off;
- uint8_t type = de->d_type;
-
- namelen = strlen(de->d_name);
- treclen = offsetof(struct target_dirent, d_name) + namelen + 2;
- treclen = QEMU_ALIGN_UP(treclen, sizeof(abi_long));
-
- memmove(tde->d_name, de->d_name, namelen + 1);
- tde->d_ino = tswapal(ino);
- tde->d_off = tswapal(off);
- tde->d_reclen = tswap16(treclen);
- /*
- * The target_dirent type is in what was formerly a padding
- * byte at the end of the structure:
- */
- *(((char *)tde) + treclen - 1) = type;
-
- de = (struct linux_dirent64 *)((char *)de + reclen);
- tde = (struct target_dirent *)((char *)tde + treclen);
- len -= reclen;
- tlen += treclen;
- }
- ret = tlen;
- }
- unlock_user(dirp, arg2, ret);
+ for (hoff = toff = 0; hoff < hlen; hoff += hreclen, toff += treclen) {
+#ifdef EMULATE_GETDENTS_WITH_GETDENTS
+ struct linux_dirent *hde = hdirp + hoff;
+#else
+ struct linux_dirent64 *hde = hdirp + hoff;
#endif
- return ret;
+ struct target_dirent *tde = tdirp + toff;
+ int namelen;
+ uint8_t type;
+
+ /*
+ * If somehow the host dirent is smaller than the target dirent,
+ * then the host could return more dirent in the buffer than we
+ * can pass on to the host. This could be fixed by returning
+ * fewer dirent to the guest and lseek on the dirfd to reset the
+ * file pointer to the final hde->d_off.
+ */
+ QEMU_BUILD_BUG_ON(sizeof(*hde) < sizeof(*tde));
+
+ namelen = strlen(hde->d_name);
+ hreclen = hde->d_reclen;
+ treclen = offsetof(struct target_dirent, d_name) + namelen + 2;
+ treclen = QEMU_ALIGN_UP(treclen, __alignof(struct target_dirent));
+
+ tde->d_ino = tswapal(hde->d_ino);
+ tde->d_off = tswapal(hde->d_off);
+ tde->d_reclen = tswap16(treclen);
+ memcpy(tde->d_name, hde->d_name, namelen + 1);
+
+ /*
+ * The getdents type is in what was formerly a padding byte at the
+ * end of the structure.
+ */
+#ifdef EMULATE_GETDENTS_WITH_GETDENTS
+ type = *((uint8_t *)hde + hreclen - 1);
+#else
+ type = hde->d_type;
+#endif
+ *((uint8_t *)tde + treclen - 1) = type;
+ }
+
+ unlock_user(tdirp, arg2, toff);
+ return toff;
}
#endif /* TARGET_NR_getdents */
#if defined(TARGET_NR_getdents64) && defined(__NR_getdents64)
-static int do_getdents64(abi_long arg1, abi_long arg2, abi_long arg3)
+static int do_getdents64(abi_long arg1, abi_long arg2, abi_long count)
{
- struct linux_dirent64 *dirp;
- abi_long count = arg3;
- int ret;
+ g_autofree void *hdirp = NULL;
+ void *tdirp;
+ int hlen, hoff, toff;
+ int hreclen, treclen;
- dirp = lock_user(VERIFY_WRITE, arg2, count, 0);
- if (!dirp) {
+ hdirp = g_try_malloc(count);
+ if (!hdirp) {
+ return -TARGET_ENOMEM;
+ }
+
+ hlen = get_errno(sys_getdents64(arg1, hdirp, count));
+ if (is_error(hlen)) {
+ return hlen;
+ }
+
+ tdirp = lock_user(VERIFY_WRITE, arg2, count, 0);
+ if (!tdirp) {
return -TARGET_EFAULT;
}
- ret = get_errno(sys_getdents64(arg1, dirp, count));
- if (!is_error(ret)) {
- struct linux_dirent64 *de;
- int len = ret;
- int reclen;
- de = dirp;
- while (len > 0) {
- reclen = de->d_reclen;
- if (reclen > len) {
- break;
- }
- de->d_reclen = tswap16(reclen);
- tswap64s((uint64_t *)&de->d_ino);
- tswap64s((uint64_t *)&de->d_off);
- de = (struct linux_dirent64 *)((char *)de + reclen);
- len -= reclen;
- }
+
+ for (hoff = toff = 0; hoff < hlen; hoff += hreclen, toff += treclen) {
+ struct linux_dirent64 *hde = hdirp + hoff;
+ struct target_dirent64 *tde = tdirp + toff;
+ int namelen;
+
+ /*
+ * If somehow the host dirent is smaller than the target dirent,
+ * then the host could return more dirent in the buffer than we
+ * can pass on to the host. This could be fixed by returning
+ * fewer dirent to the guest and lseek on the dirfd to reset the
+ * file pointer to the final hde->d_off.
+ */
+ QEMU_BUILD_BUG_ON(sizeof(*hde) < sizeof(*tde));
+
+ namelen = strlen(hde->d_name) + 1;
+ hreclen = hde->d_reclen;
+ treclen = offsetof(struct target_dirent64, d_name) + namelen;
+ treclen = QEMU_ALIGN_UP(treclen, __alignof(struct target_dirent64));
+
+ tde->d_ino = tswap64(hde->d_ino);
+ tde->d_off = tswap64(hde->d_off);
+ tde->d_reclen = tswap16(treclen);
+ tde->d_type = hde->d_type;
+ memcpy(tde->d_name, hde->d_name, namelen);
}
- unlock_user(dirp, arg2, ret);
- return ret;
+
+ unlock_user(tdirp, arg2, toff);
+ return toff;
}
#endif /* TARGET_NR_getdents64 */
Always allocate host storage; this ensures that the struct is sufficiently aligned for the host. Merge the three host implementations of getdents via a few ifdefs. Utilize the same method for do_getdents64. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/704 Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- linux-user/syscall.c | 251 ++++++++++++++++++------------------------- 1 file changed, 105 insertions(+), 146 deletions(-)