um: pass siginfo to guest process

UML guest processes now get correct siginfo_t for SIGTRAP, SIGFPE,
SIGILL and SIGBUS. Specifically, si_addr and si_code are now correct
where previously they were si_addr = NULL and si_code = 128.

Signed-off-by: Martin Pärtel <martin.partel@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 15 insertions, 11 deletions

diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index 2d22f1fcd8e2..6366ce904b9b 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -13,8 +13,9 @@
 #include "kern_util.h"
 #include "os.h"
 #include "sysdep/mcontext.h"
+#include "internal.h"
 
-void (*sig_info[NSIG])(int, struct uml_pt_regs *) = {
+void (*sig_info[NSIG])(int, siginfo_t *, struct uml_pt_regs *) = {
 	[SIGTRAP]	= relay_signal,
 	[SIGFPE]	= relay_signal,
 	[SIGILL]	= relay_signal,
@@ -24,7 +25,7 @@ void (*sig_info[NSIG])(int, struct uml_pt_regs *) = {
 	[SIGIO]		= sigio_handler,
 	[SIGVTALRM]	= timer_handler };
 
-static void sig_handler_common(int sig, mcontext_t *mc)
+static void sig_handler_common(int sig, siginfo_t *si, mcontext_t *mc)
 {
 	struct uml_pt_regs r;
 	int save_errno = errno;
@@ -40,7 +41,7 @@ static void sig_handler_common(int sig, mcontext_t *mc)
 	if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGVTALRM))
 		unblock_signals();
 
-	(*sig_info[sig])(sig, &r);
+	(*sig_info[sig])(sig, si, &r);
 
 	errno = save_errno;
 }
@@ -60,7 +61,7 @@ static void sig_handler_common(int sig, mcontext_t *mc)
 static int signals_enabled;
 static unsigned int signals_pending;
 
-void sig_handler(int sig, mcontext_t *mc)
+void sig_handler(int sig, siginfo_t *si, mcontext_t *mc)
 {
 	int enabled;
 
@@ -72,7 +73,7 @@ void sig_handler(int sig, mcontext_t *mc)
 
 	block_signals();
 
-	sig_handler_common(sig, mc);
+	sig_handler_common(sig, si, mc);
 
 	set_signals(enabled);
 }
@@ -85,10 +86,10 @@ static void real_alarm_handler(mcontext_t *mc)
 		get_regs_from_mc(&regs, mc);
 	regs.is_user = 0;
 	unblock_signals();
-	timer_handler(SIGVTALRM, &regs);
+	timer_handler(SIGVTALRM, NULL, &regs);
 }
 
-void alarm_handler(int sig, mcontext_t *mc)
+void alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc)
 {
 	int enabled;
 
@@ -119,7 +120,7 @@ void set_sigstack(void *sig_stack, int size)
 		panic("enabling signal stack failed, errno = %d\n", errno);
 }
 
-static void (*handlers[_NSIG])(int sig, mcontext_t *mc) = {
+static void (*handlers[_NSIG])(int sig, siginfo_t *si, mcontext_t *mc) = {
 	[SIGSEGV] = sig_handler,
 	[SIGBUS] = sig_handler,
 	[SIGILL] = sig_handler,
@@ -132,7 +133,7 @@ static void (*handlers[_NSIG])(int sig, mcontext_t *mc) = {
 };
 
 
-static void hard_handler(int sig, siginfo_t *info, void *p)
+static void hard_handler(int sig, siginfo_t *si, void *p)
 {
 	struct ucontext *uc = p;
 	mcontext_t *mc = &uc->uc_mcontext;
@@ -161,7 +162,7 @@ static void hard_handler(int sig, siginfo_t *info, void *p)
 		while ((sig = ffs(pending)) != 0){
 			sig--;
 			pending &= ~(1 << sig);
-			(*handlers[sig])(sig, mc);
+			(*handlers[sig])(sig, si, mc);
 		}
 
 		/*
@@ -273,9 +274,12 @@ void unblock_signals(void)
 		 * Deal with SIGIO first because the alarm handler might
 		 * schedule, leaving the pending SIGIO stranded until we come
 		 * back here.
+		 *
+		 * SIGIO's handler doesn't use siginfo or mcontext,
+		 * so they can be NULL.
 		 */
 		if (save_pending & SIGIO_MASK)
-			sig_handler_common(SIGIO, NULL);
+			sig_handler_common(SIGIO, NULL, NULL);
 
 		if (save_pending & SIGVTALRM_MASK)
 			real_alarm_handler(NULL);