[kvm-unit-tests PATCH v2 2/6] lib/stack: print base addresses on efi

[Nadav Amit <nadav.amit@gmail.com>]

From: Nadav Amit <namit@vmware.com>

Making sense from dumped stacks when running EFI tests is very hard due
to the relocation. Fix it by adjusting the address back to the original
address.

Introduce CONFIG_RELOC, which would be set on arm64 and on EFI configs.

Signed-off-by: Nadav Amit <namit@vmware.com>

---

v1->v2: Introduce CONFIG_RELOC to support ARM64 [Andrew]
---
 configure   |  3 +++
 lib/stack.c | 31 +++++++++++++++++++++++++++++--
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index b665f7d..8a3c8fe 100755
--- a/configure
+++ b/configure
@@ -416,6 +416,9 @@ EOF
 if [ "$arch" = "arm" ] || [ "$arch" = "arm64" ]; then
     echo "TARGET=$target" >> config.mak
 fi
+if [ "$efi" = "y" ] || [ "$arch" = "arm64" ]; then
+    echo "CONFIG_RELOC=y" >> config.mak
+fi
 
 cat <<EOF > lib/config.h
 #ifndef _CONFIG_H_
diff --git a/lib/stack.c b/lib/stack.c
index bdb23fd..dd6bfa8 100644
--- a/lib/stack.c
+++ b/lib/stack.c
@@ -6,13 +6,38 @@
  */
 
 #include <libcflat.h>
+#include <stdbool.h>
 #include <stack.h>
 
 #define MAX_DEPTH 20
 
+#ifdef CONFIG_RELOC
+extern char _text, _etext;
+
+static bool base_address(const void *rebased_addr, unsigned long *addr)
+{
+	unsigned long ra = (unsigned long)rebased_addr;
+	unsigned long start = (unsigned long)&_text;
+	unsigned long end = (unsigned long)&_etext;
+
+	if (ra < start || ra >= end)
+		return false;
+
+	*addr = ra - start;
+	return true;
+}
+#else
+static bool base_address(const void *rebased_addr, unsigned long *addr)
+{
+	*addr = (unsigned long)rebased_addr;
+	return true;
+}
+#endif
+
 static void print_stack(const void **return_addrs, int depth,
 			bool top_is_return_address)
 {
+	unsigned long addr;
 	int i = 0;
 
 	printf("\tSTACK:");
@@ -20,12 +45,14 @@ static void print_stack(const void **return_addrs, int depth,
 	/* @addr indicates a non-return address, as expected by the stack
 	 * pretty printer script. */
 	if (depth > 0 && !top_is_return_address) {
-		printf(" @%lx", (unsigned long) return_addrs[0]);
+		if (base_address(return_addrs[0], &addr))
+			printf(" @%lx", addr);
 		i++;
 	}
 
 	for (; i < depth; i++) {
-		printf(" %lx", (unsigned long) return_addrs[i]);
+		if (base_address(return_addrs[i], &addr))
+			printf(" %lx", addr);
 	}
 	printf("\n");
 }
-- 
2.34.1