[Qemu-devel] [PATCH 0/2] get rid of qemu_utimens()

[Qemu-devel] [PATCH 0/2] get rid of qemu_utimens()

[Greg Kurz]

It is currently only used by 9pfs and virtfs-proxy-helper. This series convert
them to utimensat() and futimens().

--
Greg

---

Greg Kurz (2):
      9pfs: assume utimensat() and futimens() are present
      util: drop old utimensat() compat code


 configure                   |   22 --------------------
 fsdev/virtfs-proxy-helper.c |    3 ++-
 hw/9pfs/9p-handle.c         |    5 -----
 include/sysemu/os-posix.h   |   11 ----------
 util/oslib-posix.c          |   47 -------------------------------------------
 5 files changed, 2 insertions(+), 86 deletions(-)

[Qemu-devel] [PATCH 1/2] 9pfs: assume utimensat() and futimens() are present

[Greg Kurz]

The utimensat() and futimens() syscalls have been around for ages (ie,
glibc 2.6 and linux 2.6.22), and the decision was already taken to
switch to utimensat() anyway when fixing CVE-2016-9602 in 2.9.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 fsdev/virtfs-proxy-helper.c |    3 ++-
 hw/9pfs/9p-handle.c         |    5 -----
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/fsdev/virtfs-proxy-helper.c b/fsdev/virtfs-proxy-helper.c
index 54f7ad1c48f0..617e19cd0b88 100644
--- a/fsdev/virtfs-proxy-helper.c
+++ b/fsdev/virtfs-proxy-helper.c
@@ -945,7 +945,8 @@ static int process_requests(int sock)
                                      &spec[0].tv_sec, &spec[0].tv_nsec,
                                      &spec[1].tv_sec, &spec[1].tv_nsec);
             if (retval > 0) {
-                retval = qemu_utimens(path.data, spec);
+                retval = utimensat(AT_FDCWD, path.data, spec,
+                                   AT_SYMLINK_NOFOLLOW);
                 if (retval < 0) {
                     retval = -errno;
                 }
diff --git a/hw/9pfs/9p-handle.c b/hw/9pfs/9p-handle.c
index 1687661bc95a..9875f1894cc5 100644
--- a/hw/9pfs/9p-handle.c
+++ b/hw/9pfs/9p-handle.c
@@ -378,7 +378,6 @@ static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
                             const struct timespec *buf)
 {
     int ret;
-#ifdef CONFIG_UTIMENSAT
     int fd;
     struct handle_data *data = (struct handle_data *)ctx->private;
 
@@ -388,10 +387,6 @@ static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
     }
     ret = futimens(fd, buf);
     close(fd);
-#else
-    ret = -1;
-    errno = ENOSYS;
-#endif
     return ret;
 }
 

[Qemu-devel] [PATCH 2/2] util: drop old utimensat() compat code

[Greg Kurz]

Now that 9pfs and virtfs-proxy-helper have been converted to utimensat(),
we don't need to keep qemu_utimens() anymore.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 configure                 |   22 ---------------------
 include/sysemu/os-posix.h |   11 -----------
 util/oslib-posix.c        |   47 ---------------------------------------------
 3 files changed, 80 deletions(-)

diff --git a/configure b/configure
index 139638e922e0..1dea17ed2e73 100755
--- a/configure
+++ b/configure
@@ -3623,25 +3623,6 @@ if compile_prog "" "" ; then
   inotify1=yes
 fi
 
-# check if utimensat and futimens are supported
-utimens=no
-cat > $TMPC << EOF
-#define _ATFILE_SOURCE
-#include <stddef.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-
-int main(void)
-{
-    utimensat(AT_FDCWD, "foo", NULL, 0);
-    futimens(0, NULL);
-    return 0;
-}
-EOF
-if compile_prog "" "" ; then
-  utimens=yes
-fi
-
 # check if pipe2 is there
 pipe2=no
 cat > $TMPC << EOF
@@ -5427,9 +5408,6 @@ fi
 if test "$curses" = "yes" ; then
   echo "CONFIG_CURSES=y" >> $config_host_mak
 fi
-if test "$utimens" = "yes" ; then
-  echo "CONFIG_UTIMENSAT=y" >> $config_host_mak
-fi
 if test "$pipe2" = "yes" ; then
   echo "CONFIG_PIPE2=y" >> $config_host_mak
 fi
diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h
index 900bdcb45ad0..629c8c648b7a 100644
--- a/include/sysemu/os-posix.h
+++ b/include/sysemu/os-posix.h
@@ -51,17 +51,6 @@ int os_mlock(void);
 typedef struct timeval qemu_timeval;
 #define qemu_gettimeofday(tp) gettimeofday(tp, NULL)
 
-#ifndef CONFIG_UTIMENSAT
-#ifndef UTIME_NOW
-# define UTIME_NOW     ((1l << 30) - 1l)
-#endif
-#ifndef UTIME_OMIT
-# define UTIME_OMIT    ((1l << 30) - 2l)
-#endif
-#endif
-typedef struct timespec qemu_timespec;
-int qemu_utimens(const char *path, const qemu_timespec *times);
-
 bool is_daemonized(void);
 
 /**
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 4d9189e9efcf..7e28c161b257 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -207,53 +207,6 @@ int qemu_pipe(int pipefd[2])
     return ret;
 }
 
-int qemu_utimens(const char *path, const struct timespec *times)
-{
-    struct timeval tv[2], tv_now;
-    struct stat st;
-    int i;
-#ifdef CONFIG_UTIMENSAT
-    int ret;
-
-    ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
-    if (ret != -1 || errno != ENOSYS) {
-        return ret;
-    }
-#endif
-    /* Fallback: use utimes() instead of utimensat() */
-
-    /* happy if special cases */
-    if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
-        return 0;
-    }
-    if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
-        return utimes(path, NULL);
-    }
-
-    /* prepare for hard cases */
-    if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
-        gettimeofday(&tv_now, NULL);
-    }
-    if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
-        stat(path, &st);
-    }
-
-    for (i = 0; i < 2; i++) {
-        if (times[i].tv_nsec == UTIME_NOW) {
-            tv[i].tv_sec = tv_now.tv_sec;
-            tv[i].tv_usec = tv_now.tv_usec;
-        } else if (times[i].tv_nsec == UTIME_OMIT) {
-            tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
-            tv[i].tv_usec = 0;
-        } else {
-            tv[i].tv_sec = times[i].tv_sec;
-            tv[i].tv_usec = times[i].tv_nsec / 1000;
-        }
-    }
-
-    return utimes(path, &tv[0]);
-}
-
 char *
 qemu_get_local_state_pathname(const char *relative_pathname)
 {

Re: [Qemu-devel] [PATCH 0/2] get rid of qemu_utimens()

[Eric Blake]

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On 05/19/2017 09:50 AM, Greg Kurz wrote:
> It is currently only used by 9pfs and virtfs-proxy-helper. This series convert
> them to utimensat() and futimens().
> 
> --
> Greg
> 
> ---
> 
> Greg Kurz (2):
>       9pfs: assume utimensat() and futimens() are present
>       util: drop old utimensat() compat code

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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