[Pdbg] [PATCH] libpdbg: Fix segfault when auto-detecting host backend

[Alistair Popple]

A NULL-dereference causes a segfault when running on the host with no
backend specified. Instead the backend should be auto-detected.

Signed-off-by: Alistair Popple <alistair at popple.id.au>
---
 libpdbg/dtb.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/libpdbg/dtb.c b/libpdbg/dtb.c
index 53e9b73..c0fb374 100644
--- a/libpdbg/dtb.c
+++ b/libpdbg/dtb.c
@@ -83,10 +83,12 @@ static void *ppc_target(void)
 	char line[256];
 	FILE *cpuinfo;
 
-	if (!strcmp(pdbg_backend_option, "p8"))
-		return &_binary_p8_host_dtb_o_start;
-	else if (!strcmp(pdbg_backend_option, "p9"))
-		return &_binary_p9_host_dtb_o_start;
+	if (pdbg_backend_option) {
+		if (!strcmp(pdbg_backend_option, "p8"))
+			return &_binary_p8_host_dtb_o_start;
+		else if (!strcmp(pdbg_backend_option, "p9"))
+			return &_binary_p9_host_dtb_o_start;
+	}
 
 	cpuinfo = fopen("/proc/cpuinfo", "r");
 	if (!cpuinfo)
-- 
2.20.1