From: Baruch Siach Date: Mon, 14 Oct 2013 22:22:43 +0000 (+0400) Subject: xtensa: don't use alternate signal stack on threads X-Git-Url: https://git.stricted.de/?p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git;a=commitdiff_plain;h=54a702cb065e49976f61d2130c16f585bfba6c44 xtensa: don't use alternate signal stack on threads commit cba9a90053e3b7973eff4f1946f33032e98eeed5 upstream. According to create_thread(3): "The new thread does not inherit the creating thread's alternate signal stack". Since commit f9a3879a (Fix sigaltstack corruption among cloned threads), current->sas_ss_size is set to 0 for cloned processes sharing VM with their parent. Don't use the (nonexistent) alternate signal stack in this case. This has been broken since commit 29c4dfd9 ([XTENSA] Remove non-rt signal handling). Fixes the SA_ONSTACK part of the nptl/tst-cancel20 test from uClibc. Signed-off-by: Baruch Siach Signed-off-by: Max Filippov Signed-off-by: Chris Zankel Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index 718eca1850bd..98b67d5f1514 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -341,7 +341,7 @@ static int setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info, sp = regs->areg[1]; - if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) { + if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && sas_ss_flags(sp) == 0) { sp = current->sas_ss_sp + current->sas_ss_size; }