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SubjectEINTR vs ERESTARTSYS, ERESTARTSYS not defined
The accept() call does indeed return errno==ERESTARTSYS to user space
when coming back from signal handling, even though other things like
poll() return errno==EINTR. This would not really be a problem except
for this in include/linux/errno.h starting at line 6:

+=============================================================================
| #ifdef __KERNEL__
|
| /* Should never be seen by user programs */
| #define ERESTARTSYS 512
| #define ERESTARTNOINTR 513
| #define ERESTARTNOHAND 514 /* restart if no handler.. */
| #define ENOIOCTLCMD 515 /* No ioctl command */
+=============================================================================

So which way is it _supposed_ to be (so someone can patch things up
to make it consistent):

1. User space should never see ERESTARTSYS from any system call

2. ERESTARTSYS can be seen from system call and is defined somewhere

In user space I have to define __KERNEL__ to get programs to compile
when coded to know about all possible (valid?) values of errno from
system calls. As seen from strace:

+=============================================================================
| [pid 6453] accept(5, 0xbffff908, [16]) = ? ERESTARTSYS (To be restarted)
| [pid 6453] --- SIGALRM (Alarm clock) ---
| [pid 6453] getppid() = 6452
| [pid 6453] gettimeofday({1006439405, 5879}, NULL) = 0
| [pid 6453] setitimer(ITIMER_REAL, {it_interval={0, 0}, it_value={9, 994121}}, NULL) = 0
| [pid 6453] rt_sigreturn(0x5) = -1 EINTR (Interrupted system call)
| [pid 6453] accept(5, 0xbffff908, [16]) = ? ERESTARTSYS (To be restarted)
| [pid 6453] --- SIGALRM (Alarm clock) ---
| [pid 6453] getppid() = 6452
| [pid 6453] gettimeofday({1006439415, 6422}, NULL) = 0
| [pid 6453] setitimer(ITIMER_REAL, {it_interval={0, 0}, it_value={9, 993578}}, NULL) = 0
| [pid 6453] rt_sigreturn(0x5) = -1 EINTR (Interrupted system call)
| [pid 6453] accept(5, 0xbffff908, [16]) = ? ERESTARTSYS (To be restarted)
+=============================================================================

--
-----------------------------------------------------------------
| Phil Howard - KA9WGN | Dallas | http://linuxhomepage.com/ |
| phil-nospam@ipal.net | Texas, USA | http://phil.ipal.org/ |
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