Commit 8be1f786 authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds

[PATCH] uml: let page faults always be delivered immediately

This allows page faults to be delivered when they happen.  Without this, it
can happen that a page fault will occur when SIGSEGV is disabled, and the
host will then just kill UML because it can't invoke the handler.
Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 5c08f794
......@@ -57,11 +57,7 @@ void init_new_thread_signals(int altstack)
{
int flags = altstack ? SA_ONSTACK : 0;
/* NODEFER is set here because SEGV isn't turned back on when the
* handler is ready to receive signals. This causes any segfault
* during a copy_user to kill the process because the fault is blocked.
*/
set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags | SA_NODEFER,
set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
set_handler(SIGTRAP, (__sighandler_t) sig_handler, flags,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
......
......@@ -23,6 +23,13 @@ void sig_handler_common_tt(int sig, void *sc_ptr)
unprotect_kernel_mem();
/* This is done because to allow SIGSEGV to be delivered inside a SEGV
* handler. This can happen in copy_user, and if SEGV is disabled,
* the process will die.
*/
if(sig == SIGSEGV)
change_sig(SIGSEGV, 1);
r = &TASK_REGS(get_current())->tt;
save_regs = *r;
is_user = user_context(SC_SP(sc));
......
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