vx32

commit 2b906e6f109d26364a2a7309c428ee5cbf0648bc
parent c14f1cf9af928d769bb73c5aaac69e7ba15bdb71
Author: Russ Cox <rsc@swtch.com>
Date:   Sun, 29 Jun 2008 15:14:59 -0400

libvx32/Linux: segmentation faults do not update cr2!

Diffstat:
M
src/libvx32/linux.c
 | 
6
+++++-

1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/src/libvx32/linux.c b/src/libvx32/linux.c
@@ -320,7 +320,11 @@ int vx32_sighandler(int signo, siginfo_t *si, void *v)
 		if (emu->trapenv == NULL)
 			return 0;
 		emu->cpu.traperr = ctx->err;
-		emu->cpu.trapva = ctx->cr2;
+		// Usually, ctx->cr2 == si->si_addr.
+		// But on a segmentation fault (as opposed to a paging fault),
+		// cr2 is not updated and the kernel sends an si_addr == 0.
+		// Be sure to use si_addr, not cr2.
+		emu->cpu.trapva = (uint32_t)si->si_addr;
 		memmove(mc->gregs, emu->trapenv->gregs, 19*4);
 		return 1;
 	}