RE: [PATCH v3 1/4] poll() exits too early with EFAULT if 1st arg is NULL

From: Joachim Schmitz <jojo@schmitz-digital.de>
Date: Sep 7, 2012, 12:52 UTC
Message-ID: <003a01cd8cf7$af821100$0e863300$@schmitz-digital.de>

If poll() is used as a milli-second sleep, like in help.c, by passing a NULL in the 1st and a 0 in the 2nd arg, it exits with EFAULT.

As per Paolo Bonzini, the original author, this is a bug and to be fixed like in this commit, which is not to exit if the 2nd arg is 0.

Signed-off-by: Joachim Schmitz <jojo@schmitz-digital.de>
---
 compat/win32/poll.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compat/win32/poll.c b/compat/win32/poll.c
index 403eaa7..9e7a25c 100644
--- a/compat/win32/poll.c
+++ b/compat/win32/poll.c
@@ -349,7 +349,7 @@ poll (struct pollfd *pfd, nfds_t nfd, int timeout)
 
   /* EFAULT is not necessary to implement, but let's do it in the
      simplest case. */
-  if (!pfd)
+  if (!pfd && nfd)
     {
       errno = EFAULT;
       return -1;

-- 
1.7.12