um: extend fpstate to _xstate to support YMM registers

Extends fpstate to _xstate, in order to hold AVX/YMM registers.

To avoid oversized stack frame, the following functions have been
refactored by using malloc.
 - sig_handler_common
 - timer_real_alarm_handler

Signed-off-by: Eli Cooper <elicooper@gmx.com>

1 files changed, 20 insertions, 8 deletions

diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index 7801666514ed..8acaf4e384c0 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -29,23 +29,29 @@ void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = {
 
 static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
 {
-	struct uml_pt_regs r;
+	struct uml_pt_regs *r;
 	int save_errno = errno;
 
-	r.is_user = 0;
+	r = malloc(sizeof(struct uml_pt_regs));
+	if (!r)
+		panic("out of memory");
+
+	r->is_user = 0;
 	if (sig == SIGSEGV) {
 		/* For segfaults, we want the data from the sigcontext. */
-		get_regs_from_mc(&r, mc);
-		GET_FAULTINFO_FROM_MC(r.faultinfo, mc);
+		get_regs_from_mc(r, mc);
+		GET_FAULTINFO_FROM_MC(r->faultinfo, mc);
 	}
 
 	/* enable signals if sig isn't IRQ signal */
 	if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGALRM))
 		unblock_signals();
 
-	(*sig_info[sig])(sig, si, &r);
+	(*sig_info[sig])(sig, si, r);
 
 	errno = save_errno;
+
+	free(r);
 }
 
 /*
@@ -83,11 +89,17 @@ void sig_handler(int sig, struct siginfo *si, mcontext_t *mc)
 
 static void timer_real_alarm_handler(mcontext_t *mc)
 {
-	struct uml_pt_regs regs;
+	struct uml_pt_regs *regs;
+
+	regs = malloc(sizeof(struct uml_pt_regs));
+	if (!regs)
+		panic("out of memory");
 
 	if (mc != NULL)
-		get_regs_from_mc(&regs, mc);
-	timer_handler(SIGALRM, NULL, &regs);
+		get_regs_from_mc(regs, mc);
+	timer_handler(SIGALRM, NULL, regs);
+
+	free(regs);
 }
 
 void timer_alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc)