[Qemu-devel] [PATCH v2] linux-user: fix emulation of getdents

[Dmitry V. Levin]

In case when TARGET_ABI_BITS == 32 && HOST_LONG_BITS == 64, the last
byte of the target dirent structure (aka d_type byte) was never copied
from the host dirent structure, thus breaking everything that relies
on valid d_type value, e.g. glob(3).

Signed-off-by: Dmitry V. Levin <address@hidden>
---
 linux-user/syscall.c      | 8 ++++----
 linux-user/syscall_defs.h | 3 ++-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 41c869b..adc3270 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -7030,10 +7030,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
arg1,
                     tde->d_ino = tswapal(de->d_ino);
                     tde->d_off = tswapal(de->d_off);
                    tnamelen = treclen - (2 * sizeof(abi_long) + 2);
-                   if (tnamelen > 256)
-                        tnamelen = 256;
-                    /* XXX: may not be correct */
-                    pstrcpy(tde->d_name, tnamelen, de->d_name);
+                    if (tnamelen > sizeof(tde->d_name)) {
+                        tnamelen = sizeof(tde->d_name);
+                    }
+                    memcpy(tde->d_name, de->d_name, tnamelen);
                     de = (struct linux_dirent *)((char *)de + reclen);
                     len -= reclen;
                     tde = (struct target_dirent *)((char *)tde + treclen);
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 2cfda5a..19fe414 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -258,7 +258,8 @@ struct target_dirent {
        abi_long        d_ino;
        abi_long        d_off;
        unsigned short  d_reclen;
-       char            d_name[256]; /* We must not include limits.h! */
+       char            d_name[257];    /* 257 = NAME_MAX + '\0' + d_type, */
+                                        /* we must not include limits.h! */
 };
 
 struct target_dirent64 {

-- 
ldv