tree e2a5db3f28670ff0e86f2f75d1c6de210a51967f
parent 3587b1b097d70c2eb9fee95ea7995d13c05f66e5
author Al Viro <viro@zeniv.linux.org.uk> 1353295623 -0500
committer David S. Miller <davem@davemloft.net> 1353295623 -0500

sparc64: not any error from do_sigaltstack() should fail rt_sigreturn()

If a signal handler is executed on altstack and another signal comes,
we will end up with rt_sigreturn() on return from the second handler
getting -EPERM from do_sigaltstack().  It's perfectly OK, since we
are not asking to change the settings; in fact, they couldn't have been
changed during the second handler execution exactly because we'd been
on altstack all along.  64bit sigreturn on sparc treats any error from
do_sigaltstack() as "SIGSEGV now"; we need to switch to the same semantics
we are using on other architectures.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>