[Qemu-devel] [PATCH 0/2] linux-user: fix eventfd()

[Qemu-devel] [PATCH 0/2] linux-user: fix eventfd()

[Laurent Vivier]

This patch series byte-swap the uint64_t data stream
of a file-descriptor opened with eventfd().

It allows to pass more LTP test cases:

eventfd01    1  TPASS  :  counter value matches required
eventfd01    2  TPASS  :  read failed with EAGAIN as expected
eventfd01    3  TPASS  :  counter value matches required
eventfd01    4  TPASS  :  write failed with EAGAIN as expected
eventfd01    5  TPASS  :  read failed with EINVAL as expected
eventfd01    6  TPASS  :  write failed with EINVAL as expected
eventfd01    7  TPASS  :  write failed with EINVAL as expected
eventfd01    8  TPASS  :  fd is set in readfds
eventfd01    9  TPASS  :  fd is not set in readfds
eventfd01   10  TPASS  :  fd is set in writefds
eventfd01   11  TPASS  :  fd is not set in writefds
eventfd01    1  TPASS  :  counter value matches required
eventfd01    2  TPASS  :  read failed with EAGAIN as expected
eventfd01    3  TPASS  :  counter value matches required
eventfd01    4  TPASS  :  write failed with EAGAIN as expected
eventfd01    5  TPASS  :  read failed with EINVAL as expected
eventfd01    6  TPASS  :  write failed with EINVAL as expected
eventfd01    7  TPASS  :  write failed with EINVAL as expected
eventfd01    8  TPASS  :  fd is set in readfds
eventfd01    9  TPASS  :  fd is not set in readfds
eventfd01   10  TPASS  :  fd is set in writefds
eventfd01   11  TPASS  :  fd is not set in writefds
eventfd01   12  TPASS  :  counter value write from child successful
eventfd01   13  TCONF  :  eventfd01.c:642: eventfd support is not available in AIO subsystem
eventfd01   14  TCONF  :  eventfd01.c:647: eventfd support is not available in AIO subsystem
eventfd01   15  TCONF  :  eventfd01.c:652: eventfd support is not available in AIO subsystem

Laurent Vivier (2):
  linux-user: call fd_trans_target_to_host_data() for write()
  linux-user: fix eventfd

 linux-user/syscall.c | 38 +++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

-- 
2.9.3

[Qemu-devel] [PATCH 1/2] linux-user: call fd_trans_target_to_host_data() for write()

[Laurent Vivier]

As for sendmsg() or sendto(), we must call the target to
host data translator if it is defined. This is needed for
eventfd(): the write() syscall allows to add a value to
the internal counter, and so, it must be byte-swapped to
the host order.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/syscall.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index cec8428..b2b563e 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -7767,7 +7767,17 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
     case TARGET_NR_write:
         if (!(p = lock_user(VERIFY_READ, arg2, arg3, 1)))
             goto efault;
-        ret = get_errno(safe_write(arg1, p, arg3));
+        if (fd_trans_target_to_host_data(arg1)) {
+            void *copy = g_malloc(arg3);
+            memcpy(copy, p, arg3);
+            ret = fd_trans_target_to_host_data(arg1)(copy, arg3);
+            if (ret >= 0) {
+                ret = get_errno(safe_write(arg1, copy, ret));
+            }
+            g_free(copy);
+        } else {
+            ret = get_errno(safe_write(arg1, p, arg3));
+        }
         unlock_user(p, arg2, 0);
         break;
 #ifdef TARGET_NR_open
-- 
2.9.3

[Qemu-devel] [PATCH 2/2] linux-user: fix eventfd

[Laurent Vivier]

When a fd is opened using eventfd(), a read provides
a 64bit counter in the host byte order, and a
write increase the internal counter by the provided
64bit value.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/syscall.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index b2b563e..2da8426 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -7671,6 +7671,28 @@ static target_timer_t get_timer_id(abi_long arg)
     return timerid;
 }
 
+static abi_long swap_data_eventfd(void *buf, size_t len)
+{
+    uint64_t *counter = buf;
+    int i;
+
+    if (len < sizeof(uint64_t)) {
+        return -EINVAL;
+    }
+
+    for (i = 0; i < len; i += sizeof(uint64_t)) {
+        *counter = tswap64(*counter);
+        counter++;
+    }
+
+    return len;
+}
+
+static TargetFdTrans target_eventfd_trans = {
+    .host_to_target_data = swap_data_eventfd,
+    .target_to_host_data = swap_data_eventfd,
+};
+
 /* do_syscall() should always have a single exit point at the end so
    that actions, such as logging of syscall results, can be performed.
    All errnos that do_syscall() returns must be -TARGET_<errcode>. */
@@ -11876,7 +11898,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 #if defined(TARGET_NR_eventfd)
     case TARGET_NR_eventfd:
         ret = get_errno(eventfd(arg1, 0));
-        fd_trans_unregister(ret);
+        fd_trans_register(ret, &target_eventfd_trans);
         break;
 #endif
 #if defined(TARGET_NR_eventfd2)
@@ -11890,7 +11912,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             host_flags |= O_CLOEXEC;
         }
         ret = get_errno(eventfd(arg1, host_flags));
-        fd_trans_unregister(ret);
+        fd_trans_register(ret, &target_eventfd_trans);
         break;
     }
 #endif
-- 
2.9.3

Re: [Qemu-devel] [PATCH 0/2] linux-user: fix eventfd()

[Laurent Vivier]

Ping?

Laurent

Le 01/03/2017 à 10:37, Laurent Vivier a écrit :
> This patch series byte-swap the uint64_t data stream
> of a file-descriptor opened with eventfd().
> 
> It allows to pass more LTP test cases:
> 
> eventfd01    1  TPASS  :  counter value matches required
> eventfd01    2  TPASS  :  read failed with EAGAIN as expected
> eventfd01    3  TPASS  :  counter value matches required
> eventfd01    4  TPASS  :  write failed with EAGAIN as expected
> eventfd01    5  TPASS  :  read failed with EINVAL as expected
> eventfd01    6  TPASS  :  write failed with EINVAL as expected
> eventfd01    7  TPASS  :  write failed with EINVAL as expected
> eventfd01    8  TPASS  :  fd is set in readfds
> eventfd01    9  TPASS  :  fd is not set in readfds
> eventfd01   10  TPASS  :  fd is set in writefds
> eventfd01   11  TPASS  :  fd is not set in writefds
> eventfd01    1  TPASS  :  counter value matches required
> eventfd01    2  TPASS  :  read failed with EAGAIN as expected
> eventfd01    3  TPASS  :  counter value matches required
> eventfd01    4  TPASS  :  write failed with EAGAIN as expected
> eventfd01    5  TPASS  :  read failed with EINVAL as expected
> eventfd01    6  TPASS  :  write failed with EINVAL as expected
> eventfd01    7  TPASS  :  write failed with EINVAL as expected
> eventfd01    8  TPASS  :  fd is set in readfds
> eventfd01    9  TPASS  :  fd is not set in readfds
> eventfd01   10  TPASS  :  fd is set in writefds
> eventfd01   11  TPASS  :  fd is not set in writefds
> eventfd01   12  TPASS  :  counter value write from child successful
> eventfd01   13  TCONF  :  eventfd01.c:642: eventfd support is not available in AIO subsystem
> eventfd01   14  TCONF  :  eventfd01.c:647: eventfd support is not available in AIO subsystem
> eventfd01   15  TCONF  :  eventfd01.c:652: eventfd support is not available in AIO subsystem
> 
> Laurent Vivier (2):
>   linux-user: call fd_trans_target_to_host_data() for write()
>   linux-user: fix eventfd
> 
>  linux-user/syscall.c | 38 +++++++++++++++++++++++++++++++++++---
>  1 file changed, 35 insertions(+), 3 deletions(-)
> 

Re: [Qemu-devel] [PATCH 0/2] linux-user: fix eventfd()

[Riku Voipio]

On Tue, Apr 25, 2017 at 06:32:30PM +0200, Laurent Vivier wrote:
> Ping?

Applied, thanks. 

> Laurent
> 
> Le 01/03/2017 à 10:37, Laurent Vivier a écrit :
> > This patch series byte-swap the uint64_t data stream
> > of a file-descriptor opened with eventfd().
> > 
> > It allows to pass more LTP test cases:
> > 
> > eventfd01    1  TPASS  :  counter value matches required
> > eventfd01    2  TPASS  :  read failed with EAGAIN as expected
> > eventfd01    3  TPASS  :  counter value matches required
> > eventfd01    4  TPASS  :  write failed with EAGAIN as expected
> > eventfd01    5  TPASS  :  read failed with EINVAL as expected
> > eventfd01    6  TPASS  :  write failed with EINVAL as expected
> > eventfd01    7  TPASS  :  write failed with EINVAL as expected
> > eventfd01    8  TPASS  :  fd is set in readfds
> > eventfd01    9  TPASS  :  fd is not set in readfds
> > eventfd01   10  TPASS  :  fd is set in writefds
> > eventfd01   11  TPASS  :  fd is not set in writefds
> > eventfd01    1  TPASS  :  counter value matches required
> > eventfd01    2  TPASS  :  read failed with EAGAIN as expected
> > eventfd01    3  TPASS  :  counter value matches required
> > eventfd01    4  TPASS  :  write failed with EAGAIN as expected
> > eventfd01    5  TPASS  :  read failed with EINVAL as expected
> > eventfd01    6  TPASS  :  write failed with EINVAL as expected
> > eventfd01    7  TPASS  :  write failed with EINVAL as expected
> > eventfd01    8  TPASS  :  fd is set in readfds
> > eventfd01    9  TPASS  :  fd is not set in readfds
> > eventfd01   10  TPASS  :  fd is set in writefds
> > eventfd01   11  TPASS  :  fd is not set in writefds
> > eventfd01   12  TPASS  :  counter value write from child successful
> > eventfd01   13  TCONF  :  eventfd01.c:642: eventfd support is not available in AIO subsystem
> > eventfd01   14  TCONF  :  eventfd01.c:647: eventfd support is not available in AIO subsystem
> > eventfd01   15  TCONF  :  eventfd01.c:652: eventfd support is not available in AIO subsystem
> > 
> > Laurent Vivier (2):
> >   linux-user: call fd_trans_target_to_host_data() for write()
> >   linux-user: fix eventfd
> > 
> >  linux-user/syscall.c | 38 +++++++++++++++++++++++++++++++++++---
> >  1 file changed, 35 insertions(+), 3 deletions(-)
> > 
>