Merge branch 'linux-user-for-upstream' of git://gitorious.org/qemu-maemo/qemu

* 'linux-user-for-upstream' of git://gitorious.org/qemu-maemo/qemu:
  linux-user: fix for loopmount ioctl
  linux-user: fix build errors for mmap2-only ports
  user: speed up init_paths a bit
  linux-user: implement sched_{g,s}etaffinity
  linux-user/FLAT: allow targets to override FLAT processing
  linux-user/FLAT: fix auto-stack sizing
  linux-user: decode MAP_{UNINITIALIZED,EXECUTABLE} in strace
  linux-user: add ppoll syscall support
  linux-user/elfload: add FDPIC support
  linux-user: fix sizeof handling for getsockopt
  linux-user: Fix possible realloc memory leak
  linux-user: Add support for -version option

Makefile.target

@@ -107,7 +107,7 @@ ifdef CONFIG_LINUX_USER
 
 $(call set-vpath, $(SRC_PATH)/linux-user:$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR))
 
-QEMU_CFLAGS+=-I$(SRC_PATH)/linux-user -I$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR)
+QEMU_CFLAGS+=-I$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR) -I$(SRC_PATH)/linux-user
 obj-y = main.o syscall.o strace.o mmap.o signal.o thunk.o \
       elfload.o linuxload.o uaccess.o gdbstub.o cpu-uname.o \
       qemu-malloc.o $(oslib-obj-y)

elf.h

@@ -1191,6 +1191,25 @@ typedef struct elf64_note {
   Elf64_Word n_type;	/* Content type */
 } Elf64_Nhdr;
 
+
+/* This data structure represents a PT_LOAD segment.  */
+struct elf32_fdpic_loadseg {
+  /* Core address to which the segment is mapped.  */
+  Elf32_Addr addr;
+  /* VMA recorded in the program header.  */
+  Elf32_Addr p_vaddr;
+  /* Size of this segment in memory.  */
+  Elf32_Word p_memsz;
+};
+struct elf32_fdpic_loadmap {
+  /* Protocol version number, must be zero.  */
+  Elf32_Half version;
+  /* Number of segments in this map.  */
+  Elf32_Half nsegs;
+  /* The actual memory map.  */
+  struct elf32_fdpic_loadseg segs[/*nsegs*/];
+};
+
 #ifdef ELF_CLASS
 #if ELF_CLASS == ELFCLASS32
 

linux-user/elfload.c

@@ -1075,6 +1075,33 @@ static void zero_bss(abi_ulong elf_bss, abi_ulong last_bss, int prot)
     }
 }
 
+#ifdef CONFIG_USE_FDPIC
+static abi_ulong loader_build_fdpic_loadmap(struct image_info *info, abi_ulong sp)
+{
+    uint16_t n;
+    struct elf32_fdpic_loadseg *loadsegs = info->loadsegs;
+
+    /* elf32_fdpic_loadseg */
+    n = info->nsegs;
+    while (n--) {
+        sp -= 12;
+        put_user_u32(loadsegs[n].addr, sp+0);
+        put_user_u32(loadsegs[n].p_vaddr, sp+4);
+        put_user_u32(loadsegs[n].p_memsz, sp+8);
+    }
+
+    /* elf32_fdpic_loadmap */
+    sp -= 4;
+    put_user_u16(0, sp+0); /* version */
+    put_user_u16(info->nsegs, sp+2); /* nsegs */
+
+    info->personality = PER_LINUX_FDPIC;
+    info->loadmap_addr = sp;
+
+    return sp;
+}
+#endif
+
 static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
                                    struct elfhdr *exec,
                                    struct image_info *info,
@@ -1087,6 +1114,21 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
     const int n = sizeof(elf_addr_t);
 
     sp = p;
+
+#ifdef CONFIG_USE_FDPIC
+    /* Needs to be before we load the env/argc/... */
+    if (elf_is_fdpic(exec)) {
+        /* Need 4 byte alignment for these structs */
+        sp &= ~3;
+        sp = loader_build_fdpic_loadmap(info, sp);
+        info->other_info = interp_info;
+        if (interp_info) {
+            interp_info->other_info = info;
+            sp = loader_build_fdpic_loadmap(interp_info, sp);
+        }
+    }
+#endif
+
     u_platform = 0;
     k_platform = ELF_PLATFORM;
     if (k_platform) {
@@ -1197,6 +1239,11 @@ static void load_elf_image(const char *image_name, int image_fd,
     }
     bswap_phdr(phdr, ehdr->e_phnum);
 
+#ifdef CONFIG_USE_FDPIC
+    info->nsegs = 0;
+    info->pt_dynamic_addr = 0;
+#endif
+
     /* Find the maximum size of the image and allocate an appropriate
        amount of memory to handle that.  */
     loaddr = -1, hiaddr = 0;
@@ -1210,6 +1257,9 @@ static void load_elf_image(const char *image_name, int image_fd,
             if (a > hiaddr) {
                 hiaddr = a;
             }
+#ifdef CONFIG_USE_FDPIC
+            ++info->nsegs;
+#endif
         }
     }
 
@@ -1290,6 +1340,27 @@ static void load_elf_image(const char *image_name, int image_fd,
     }
     load_bias = load_addr - loaddr;
 
+#ifdef CONFIG_USE_FDPIC
+    {
+        struct elf32_fdpic_loadseg *loadsegs = info->loadsegs =
+            qemu_malloc(sizeof(*loadsegs) * info->nsegs);
+
+        for (i = 0; i < ehdr->e_phnum; ++i) {
+            switch (phdr[i].p_type) {
+            case PT_DYNAMIC:
+                info->pt_dynamic_addr = phdr[i].p_vaddr + load_bias;
+                break;
+            case PT_LOAD:
+                loadsegs->addr = phdr[i].p_vaddr + load_bias;
+                loadsegs->p_vaddr = phdr[i].p_vaddr;
+                loadsegs->p_memsz = phdr[i].p_memsz;
+                ++loadsegs;
+                break;
+            }
+        }
+    }
+#endif
+
     info->load_bias = load_bias;
     info->load_addr = load_addr;
     info->entry = ehdr->e_entry + load_bias;
@@ -1481,7 +1552,7 @@ static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias)
     struct elf_shdr *shdr;
     char *strings;
     struct syminfo *s;
-    struct elf_sym *syms;
+    struct elf_sym *syms, *new_syms;
 
     shnum = hdr->e_shnum;
     i = shnum * sizeof(struct elf_shdr);
@@ -1550,12 +1621,14 @@ static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias)
        that we threw away.  Whether or not this has any effect on the
        memory allocation depends on the malloc implementation and how
        many symbols we managed to discard.  */
-    syms = realloc(syms, nsyms * sizeof(*syms));
+    new_syms = realloc(syms, nsyms * sizeof(*syms));
-    if (syms == NULL) {
+    if (new_syms == NULL) {
         free(s);
+        free(syms);
         free(strings);
         return;
     }
+    syms = new_syms;
 
     qsort(syms, nsyms, sizeof(*syms), symcmp);
 

linux-user/flatload.c

@@ -41,6 +41,8 @@
 
 #include "qemu.h"
 #include "flat.h"
+#define ntohl(x) be32_to_cpu(x)
+#include <target_flat.h>
 
 //#define DEBUG
 
@@ -50,14 +52,6 @@
 #define	DBG_FLT(...)
 #endif
 
-#define flat_reloc_valid(reloc, size)             ((reloc) <= (size))
-#define flat_old_ram_flag(flag)                   (flag)
-#ifdef TARGET_WORDS_BIGENDIAN
-#define flat_get_relocate_addr(relval)            (relval)
-#else
-#define flat_get_relocate_addr(relval)            bswap32(relval)
-#endif
-
 #define RELOC_FAILED 0xff00ff01		/* Relocation incorrect somewhere */
 #define UNLOADED_LIB 0x7ff000ff		/* Placeholder for unused library */
 
@@ -78,8 +72,6 @@ static int load_flat_shared_library(int id, struct lib_info *p);
 
 struct linux_binprm;
 
-#define ntohl(x) be32_to_cpu(x)
-
 /****************************************************************************/
 /*
  * create_flat_tables() parses the env- and arg-strings in new user
@@ -625,6 +617,7 @@ static int load_flat_file(struct linux_binprm * bprm,
      * __start to address 4 so that is okay).
      */
     if (rev > OLD_FLAT_VERSION) {
+        abi_ulong persistent = 0;
         for (i = 0; i < relocs; i++) {
             abi_ulong addr, relval;
 
@@ -633,6 +626,9 @@ static int load_flat_file(struct linux_binprm * bprm,
                relocated first).  */
             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
                 return -EFAULT;
+            relval = ntohl(relval);
+            if (flat_set_persistent(relval, &persistent))
+                continue;
             addr = flat_get_relocate_addr(relval);
             rp = calc_reloc(addr, libinfo, id, 1);
             if (rp == RELOC_FAILED)
@@ -641,22 +637,20 @@ static int load_flat_file(struct linux_binprm * bprm,
             /* Get the pointer's value.  */
             if (get_user_ual(addr, rp))
                 return -EFAULT;
+            addr = flat_get_addr_from_rp(rp, relval, flags, &persistent);
             if (addr != 0) {
                 /*
                  * Do the relocation.  PIC relocs in the data section are
                  * already in target order
                  */
-
-#ifndef TARGET_WORDS_BIGENDIAN
                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
-                    addr = bswap32(addr);
+                    addr = ntohl(addr);
-#endif
                 addr = calc_reloc(addr, libinfo, id, 0);
                 if (addr == RELOC_FAILED)
                     return -ENOEXEC;
 
                 /* Write back the relocated pointer.  */
-                if (put_user_ual(addr, rp))
+                if (flat_put_addr_at_rp(rp, addr, relval))
                     return -EFAULT;
             }
         }
@@ -733,8 +727,15 @@ int load_flt_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
      * pedantic and include space for the argv/envp array as it may have
      * a lot of entries.
      */
-#define TOP_OF_ARGS (TARGET_PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
+    stack_len = 0;
-    stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
+    for (i = 0; i < bprm->argc; ++i) {
+        /* the argv strings */
+        stack_len += strlen(bprm->argv[i]);
+    }
+    for (i = 0; i < bprm->envc; ++i) {
+        /* the envp strings */
+        stack_len += strlen(bprm->envp[i]);
+    }
     stack_len += (bprm->argc + 1) * 4; /* the argv array */
     stack_len += (bprm->envc + 1) * 4; /* the envp array */
 
@@ -775,7 +776,8 @@ int load_flt_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
     stack_len *= sizeof(abi_ulong);
     if ((sp + stack_len) & 15)
         sp -= 16 - ((sp + stack_len) & 15);
-    sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, 1);
+    sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p,
+                             flat_argvp_envp_on_stack());
 
     /* Fake some return addresses to ensure the call chain will
      * initialise library in order for us.  We are required to call

linux-user/ioctls.h

@@ -312,10 +312,8 @@
   IOCTL(LOOP_CLR_FD, 0, TYPE_INT)
   IOCTL(LOOP_SET_STATUS, IOC_W, MK_PTR(MK_STRUCT(STRUCT_loop_info)))
   IOCTL(LOOP_GET_STATUS, IOC_W, MK_PTR(MK_STRUCT(STRUCT_loop_info)))
-#if 0 /* These have some problems - not fully tested */
   IOCTL(LOOP_SET_STATUS64, IOC_W, MK_PTR(MK_STRUCT(STRUCT_loop_info64)))
   IOCTL(LOOP_GET_STATUS64, IOC_W, MK_PTR(MK_STRUCT(STRUCT_loop_info64)))
-#endif
   IOCTL(LOOP_CHANGE_FD, 0, TYPE_INT)
 
   IOCTL(MTIOCTOP, IOC_W, MK_PTR(MK_STRUCT(STRUCT_mtop)))

linux-user/main.c

@@ -2624,14 +2624,21 @@ void cpu_loop (CPUState *env)
 }
 #endif /* TARGET_ALPHA */
 
+static void version(void)
+{
+    printf("qemu-" TARGET_ARCH " version " QEMU_VERSION QEMU_PKGVERSION
+           ", Copyright (c) 2003-2008 Fabrice Bellard\n");
+}
+
 static void usage(void)
 {
-    printf("qemu-" TARGET_ARCH " version " QEMU_VERSION QEMU_PKGVERSION ", Copyright (c) 2003-2008 Fabrice Bellard\n"
+    version();
-           "usage: qemu-" TARGET_ARCH " [options] program [arguments...]\n"
+    printf("usage: qemu-" TARGET_ARCH " [options] program [arguments...]\n"
            "Linux CPU emulator (compiled for %s emulation)\n"
            "\n"
            "Standard options:\n"
            "-h                print this help\n"
+           "-version          display version information and exit\n"
            "-g port           wait gdb connection to port\n"
            "-L path           set the elf interpreter prefix (default=%s)\n"
            "-s size           set the stack size in bytes (default=%ld)\n"
@@ -2886,8 +2893,10 @@ int main(int argc, char **argv, char **envp)
             singlestep = 1;
         } else if (!strcmp(r, "strace")) {
             do_strace = 1;
-        } else
+        } else if (!strcmp(r, "version")) {
-        {
+            version();
+            exit(0);
+        } else {
             usage();
         }
     }

linux-user/qemu.h

@@ -51,6 +51,13 @@ struct image_info {
         abi_ulong       arg_start;
         abi_ulong       arg_end;
 	int		personality;
+#ifdef CONFIG_USE_FDPIC
+        abi_ulong       loadmap_addr;
+        uint16_t        nsegs;
+        void           *loadsegs;
+        abi_ulong       pt_dynamic_addr;
+        struct image_info *other_info;
+#endif
 };
 
 #ifdef TARGET_I386

linux-user/strace.c

@@ -398,6 +398,7 @@ UNUSED static struct flags mmap_flags[] = {
     FLAG_TARGET(MAP_DENYWRITE),
     FLAG_TARGET(MAP_FIXED),
     FLAG_TARGET(MAP_GROWSDOWN),
+    FLAG_TARGET(MAP_EXECUTABLE),
 #ifdef MAP_LOCKED
     FLAG_TARGET(MAP_LOCKED),
 #endif
@@ -407,6 +408,9 @@ UNUSED static struct flags mmap_flags[] = {
     FLAG_TARGET(MAP_NORESERVE),
 #ifdef MAP_POPULATE
     FLAG_TARGET(MAP_POPULATE),
+#endif
+#ifdef TARGET_MAP_UNINITIALIZED
+    FLAG_TARGET(MAP_UNINITIALIZED),
 #endif
     FLAG_END,
 };
@@ -1199,7 +1203,7 @@ print_utimensat(const struct syscallname *name,
 }
 #endif
 
-#ifdef TARGET_NR_mmap
+#if defined(TARGET_NR_mmap) || defined(TARGET_NR_mmap2)
 static void
 print_mmap(const struct syscallname *name,
     abi_long arg0, abi_long arg1, abi_long arg2,

linux-user/syscall.c

@@ -235,6 +235,12 @@ _syscall6(int,sys_futex,int *,uaddr,int,op,int,val,
           const struct timespec *,timeout,int *,uaddr2,int,val3)
 #endif
 #endif
+#define __NR_sys_sched_getaffinity __NR_sched_getaffinity
+_syscall3(int, sys_sched_getaffinity, pid_t, pid, unsigned int, len,
+          unsigned long *, user_mask_ptr);
+#define __NR_sys_sched_setaffinity __NR_sched_setaffinity
+_syscall3(int, sys_sched_setaffinity, pid_t, pid, unsigned int, len,
+          unsigned long *, user_mask_ptr);
 
 static bitmask_transtbl fcntl_flags_tbl[] = {
   { TARGET_O_ACCMODE,   TARGET_O_WRONLY,    O_ACCMODE,   O_WRONLY,    },
@@ -529,6 +535,15 @@ static int sys_inotify_init1(int flags)
 #undef TARGET_NR_inotify_rm_watch
 #endif /* CONFIG_INOTIFY  */
 
+#if defined(TARGET_NR_ppoll)
+#ifndef __NR_ppoll
+# define __NR_ppoll -1
+#endif
+#define __NR_sys_ppoll __NR_ppoll
+_syscall5(int, sys_ppoll, struct pollfd *, fds, nfds_t, nfds,
+          struct timespec *, timeout, const __sigset_t *, sigmask,
+          size_t, sigsetsize)
+#endif
 
 extern int personality(int);
 extern int flock(int, int);
@@ -1448,7 +1463,7 @@ static abi_long do_getsockopt(int sockfd, int level, int optname,
             return -TARGET_EFAULT;
         if (len < 0)
             return -TARGET_EINVAL;
-        lv = sizeof(int);
+        lv = sizeof(lv);
         ret = get_errno(getsockopt(sockfd, level, optname, &val, &lv));
         if (ret < 0)
             return ret;
@@ -1485,7 +1500,7 @@ static abi_long do_getsockopt(int sockfd, int level, int optname,
                 return -TARGET_EFAULT;
             if (len < 0)
                 return -TARGET_EINVAL;
-            lv = sizeof(int);
+            lv = sizeof(lv);
             ret = get_errno(getsockopt(sockfd, level, optname, &val, &lv));
             if (ret < 0)
                 return ret;
@@ -6230,8 +6245,13 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
         ret = do_select(arg1, arg2, arg3, arg4, arg5);
         break;
 #endif
-#ifdef TARGET_NR_poll
+#if defined(TARGET_NR_poll) || defined(TARGET_NR_ppoll)
+# ifdef TARGET_NR_poll
     case TARGET_NR_poll:
+# endif
+# ifdef TARGET_NR_ppoll
+    case TARGET_NR_ppoll:
+# endif
         {
             struct target_pollfd *target_pfd;
             unsigned int nfds = arg2;
@@ -6242,12 +6262,51 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             target_pfd = lock_user(VERIFY_WRITE, arg1, sizeof(struct target_pollfd) * nfds, 1);
             if (!target_pfd)
                 goto efault;
+
             pfd = alloca(sizeof(struct pollfd) * nfds);
             for(i = 0; i < nfds; i++) {
                 pfd[i].fd = tswap32(target_pfd[i].fd);
                 pfd[i].events = tswap16(target_pfd[i].events);
             }
-            ret = get_errno(poll(pfd, nfds, timeout));
+
+# ifdef TARGET_NR_ppoll
+            if (num == TARGET_NR_ppoll) {
+                struct timespec _timeout_ts, *timeout_ts = &_timeout_ts;
+                target_sigset_t *target_set;
+                sigset_t _set, *set = &_set;
+
+                if (arg3) {
+                    if (target_to_host_timespec(timeout_ts, arg3)) {
+                        unlock_user(target_pfd, arg1, 0);
+                        goto efault;
+                    }
+                } else {
+                    timeout_ts = NULL;
+                }
+
+                if (arg4) {
+                    target_set = lock_user(VERIFY_READ, arg4, sizeof(target_sigset_t), 1);
+                    if (!target_set) {
+                        unlock_user(target_pfd, arg1, 0);
+                        goto efault;
+                    }
+                    target_to_host_sigset(set, target_set);
+                } else {
+                    set = NULL;
+                }
+
+                ret = get_errno(sys_ppoll(pfd, nfds, timeout_ts, set, _NSIG/8));
+
+                if (!is_error(ret) && arg3) {
+                    host_to_target_timespec(arg3, timeout_ts);
+                }
+                if (arg4) {
+                    unlock_user(target_set, arg4, 0);
+                }
+            } else
+# endif
+                ret = get_errno(poll(pfd, nfds, timeout));
+
             if (!is_error(ret)) {
                 for(i = 0; i < nfds; i++) {
                     target_pfd[i].revents = tswap16(pfd[i].revents);
@@ -6301,6 +6360,67 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
            return value. */
         ret = -TARGET_ENOTDIR;
         break;
+    case TARGET_NR_sched_getaffinity:
+        {
+            unsigned int mask_size;
+            unsigned long *mask;
+
+            /*
+             * sched_getaffinity needs multiples of ulong, so need to take
+             * care of mismatches between target ulong and host ulong sizes.
+             */
+            if (arg2 & (sizeof(abi_ulong) - 1)) {
+                ret = -TARGET_EINVAL;
+                break;
+            }
+            mask_size = (arg2 + (sizeof(*mask) - 1)) & ~(sizeof(*mask) - 1);
+
+            mask = alloca(mask_size);
+            ret = get_errno(sys_sched_getaffinity(arg1, mask_size, mask));
+
+            if (!is_error(ret)) {
+                if (arg2 > ret) {
+                    /* Zero out any extra space kernel didn't fill */
+                    unsigned long zero = arg2 - ret;
+                    p = alloca(zero);
+                    memset(p, 0, zero);
+                    if (copy_to_user(arg3 + zero, p, zero)) {
+                        goto efault;
+                    }
+                    arg2 = ret;
+                }
+                if (copy_to_user(arg3, mask, arg2)) {
+                    goto efault;
+                }
+                ret = arg2;
+            }
+        }
+        break;
+    case TARGET_NR_sched_setaffinity:
+        {
+            unsigned int mask_size;
+            unsigned long *mask;
+
+            /*
+             * sched_setaffinity needs multiples of ulong, so need to take
+             * care of mismatches between target ulong and host ulong sizes.
+             */
+            if (arg2 & (sizeof(abi_ulong) - 1)) {
+                ret = -TARGET_EINVAL;
+                break;
+            }
+            mask_size = (arg2 + (sizeof(*mask) - 1)) & ~(sizeof(*mask) - 1);
+
+            mask = alloca(mask_size);
+            if (!lock_user_struct(VERIFY_READ, p, arg3, 1)) {
+                goto efault;
+            }
+            memcpy(mask, p, arg2);
+            unlock_user_struct(p, arg2, 0);
+
+            ret = get_errno(sys_sched_setaffinity(arg1, mask_size, mask));
+        }
+        break;
     case TARGET_NR_sched_setparam:
         {
             struct sched_param *target_schp;

linux-user/syscall_defs.h

@@ -999,6 +999,7 @@ struct target_winsize {
 #define TARGET_MAP_NORESERVE	0x4000		/* don't check for reservations */
 #define TARGET_MAP_POPULATE	0x8000		/* populate (prefault) pagetables */
 #define TARGET_MAP_NONBLOCK	0x10000		/* do not block on IO */
+#define TARGET_MAP_UNINITIALIZED 0x4000000	/* for anonymous mmap, memory could be uninitialized */
 #endif
 
 #if (defined(TARGET_I386) && defined(TARGET_ABI32)) || defined(TARGET_ARM) || defined(TARGET_CRIS)

linux-user/target_flat.h

@@ -0,0 +1,10 @@
+/* If your arch needs to do custom stuff, create your own target_flat.h
+ * header file in linux-user/<your arch>/
+ */
+#define flat_argvp_envp_on_stack()                           1
+#define flat_reloc_valid(reloc, size)                        ((reloc) <= (size))
+#define flat_old_ram_flag(flag)                              (flag)
+#define flat_get_relocate_addr(relval)                       (relval)
+#define flat_get_addr_from_rp(rp, relval, flags, persistent) (rp)
+#define flat_set_persistent(relval, persistent)              (*persistent)
+#define flat_put_addr_at_rp(rp, addr, relval)                put_user_ual(addr, rp)

path.c

@@ -38,7 +38,8 @@ static int strneq(const char *s1, unsigned int n, const char *s2)
     return s2[i] == 0;
 }
 
-static struct pathelem *add_entry(struct pathelem *root, const char *name);
+static struct pathelem *add_entry(struct pathelem *root, const char *name,
+                                  unsigned char type);
 
 static struct pathelem *new_entry(const char *root,
                                   struct pathelem *parent,
@@ -56,6 +57,15 @@ static struct pathelem *new_entry(const char *root,
 
 #define streq(a,b) (strcmp((a), (b)) == 0)
 
+/* Not all systems provide this feature */
+#if defined(DT_DIR) && defined(DT_UNKNOWN)
+# define dirent_type(dirent) ((dirent)->d_type)
+# define is_dir_maybe(type)  ((type) == DT_DIR || (type) == DT_UNKNOWN)
+#else
+# define dirent_type(dirent) (1)
+# define is_dir_maybe(type)  (type)
+#endif
+
 static struct pathelem *add_dir_maybe(struct pathelem *path)
 {
     DIR *dir;
@@ -65,7 +75,7 @@ static struct pathelem *add_dir_maybe(struct pathelem *path)
 
         while ((dirent = readdir(dir)) != NULL) {
             if (!streq(dirent->d_name,".") && !streq(dirent->d_name,"..")){
-                path = add_entry(path, dirent->d_name);
+                path = add_entry(path, dirent->d_name, dirent_type(dirent));
             }
         }
         closedir(dir);
@@ -73,16 +83,22 @@ static struct pathelem *add_dir_maybe(struct pathelem *path)
     return path;
 }
 
-static struct pathelem *add_entry(struct pathelem *root, const char *name)
+static struct pathelem *add_entry(struct pathelem *root, const char *name,
+                                  unsigned char type)
 {
+    struct pathelem **e;
+
     root->num_entries++;
 
     root = realloc(root, sizeof(*root)
                    + sizeof(root->entries[0])*root->num_entries);
+    e = &root->entries[root->num_entries-1];
+
+    *e = new_entry(root->pathname, root, name);
+    if (is_dir_maybe(type)) {
+        *e = add_dir_maybe(*e);
+    }
 
-    root->entries[root->num_entries-1] = new_entry(root->pathname, root, name);
-    root->entries[root->num_entries-1]
-        = add_dir_maybe(root->entries[root->num_entries-1]);
     return root;
 }