• Steven Rostedt's avatar
    [PATCH] convert signal handling of NODEFER to act like other Unix boxes. · 69be8f18
    Steven Rostedt authored
    
    
    It has been reported that the way Linux handles NODEFER for signals is
    not consistent with the way other Unix boxes handle it.  I've written a
    program to test the behavior of how this flag affects signals and had
    several reports from people who ran this on various Unix boxes,
    confirming that Linux seems to be unique on the way this is handled.
    
    The way NODEFER affects signals on other Unix boxes is as follows:
    
    1) If NODEFER is set, other signals in sa_mask are still blocked.
    
    2) If NODEFER is set and the signal is in sa_mask, then the signal is
    still blocked. (Note: this is the behavior of all tested but Linux _and_
    NetBSD 2.0 *).
    
    The way NODEFER affects signals on Linux:
    
    1) If NODEFER is set, other signals are _not_ blocked regardless of
    sa_mask (Even NetBSD doesn't do this).
    
    2) If NODEFER is set and the signal is in sa_mask, then the signal being
    handled is not blocked.
    
    The patch converts signal handling in all current Linux architectures to
    the way most Unix boxes work.
    
    Unix boxes that were tested:  DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
    3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.
    
    * NetBSD was the only other Unix to behave like Linux on point #2. The
    main concern was brought up by point #1 which even NetBSD isn't like
    Linux.  So with this patch, we leave NetBSD as the lonely one that
    behaves differently here with #2.
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    69be8f18
signal.c 14.1 KB