From 44c64e6b15ceab6a4927f54e1081a74ba096b95a Mon Sep 17 00:00:00 2001 From: Chris Zankel Date: Fri, 11 Jan 2008 11:44:17 -0800 Subject: [XTENSA] Add support for the sa_restorer function Supporting the sa_restorer function allows for better security since the sigreturn system call doesn't need to be placed on the stack, so the stack doesn't need to be executable. This requires support from the c-library as it has to provide the restorer function. Signed-off-by: Chris Zankel --- arch/xtensa/kernel/signal.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'arch/xtensa') diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index 299be42d116..f2220b5bdce 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -381,14 +381,19 @@ static void setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info, err |= setup_sigcontext(frame, regs); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); - /* Create sys_rt_sigreturn syscall in stack frame */ + if (ka->sa.sa_flags & SA_RESTORER) { + ra = (unsigned long)ka->sa.sa_restorer; + } else { - err |= gen_return_code(frame->retcode); + /* Create sys_rt_sigreturn syscall in stack frame */ - if (err) { - goto give_sigsegv; + err |= gen_return_code(frame->retcode); + + if (err) { + goto give_sigsegv; + } + ra = (unsigned long) frame->retcode; } - /* * Create signal handler execution context. @@ -402,7 +407,6 @@ static void setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info, /* Set up a stack frame for a call4 * Note: PS.CALLINC is set to one by start_thread */ - ra = (unsigned long) frame->retcode; regs->areg[4] = (((unsigned long) ra) & 0x3fffffff) | 0x40000000; regs->areg[6] = (unsigned long) signal; regs->areg[7] = (unsigned long) &frame->info; -- cgit v1.2.3-18-g5258