[CRIU] [PATCHv2 08/12] rt-vdso: Be verbose if !blobs_matches()

[Dmitry Safonov]

(00.251007) pie: 4: vdso: Runtime vdso mismatches dumpee, generate proxy

And I want to know why :)

Signed-off-by: Dmitry Safonov <dima at arista.com>
---
 criu/pie/parasite-vdso.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/criu/pie/parasite-vdso.c b/criu/pie/parasite-vdso.c
index 90e20f767c33..00bc2bffa29e 100644
--- a/criu/pie/parasite-vdso.c
+++ b/criu/pie/parasite-vdso.c
@@ -95,23 +95,44 @@ static int __vdso_fill_symtable(uintptr_t mem, size_t size,
 static bool blobs_matches(VmaEntry *vdso_img, VmaEntry *vvar_img,
 		struct vdso_symtable *sym_img, struct vdso_symtable *sym_rt)
 {
+	unsigned long vdso_size = vma_entry_len(vdso_img);
+	unsigned long rt_vdso_size = sym_rt->vdso_size;
 	size_t i;
 
-	if (vma_entry_len(vdso_img) != sym_rt->vdso_size)
+	if (vdso_size != rt_vdso_size) {
+		pr_info("size differs: %lx != %lx (rt)\n",
+			vdso_size, rt_vdso_size);
 		return false;
+	}
 
 	for (i = 0; i < ARRAY_SIZE(sym_img->symbols); i++) {
-		if (sym_img->symbols[i].offset != sym_rt->symbols[i].offset)
+		unsigned long sym_offset	= sym_img->symbols[i].offset;
+		unsigned long rt_sym_offset	= sym_rt->symbols[i].offset;
+		char *sym_name			= sym_img->symbols[i].name;
+
+		if (sym_offset != rt_sym_offset) {
+			pr_info("[%zu]`%s` offset differs: %lx != %lx (rt)\n",
+				i, sym_name, sym_offset, rt_sym_offset);
 			return false;
+		}
 	}
 
 	if (vvar_img && sym_rt->vvar_size != VVAR_BAD_SIZE) {
 		bool vdso_firstly = (vvar_img->start > vdso_img->start);
+		unsigned long vvar_size = vma_entry_len(vvar_img);
+		unsigned long rt_vvar_size = sym_rt->vvar_size;
 
-		if (sym_rt->vvar_size != vma_entry_len(vvar_img))
+		if (vvar_size != rt_vvar_size) {
+			pr_info("vvar size differs: %lx != %lx (rt)\n",
+				vdso_size, rt_vdso_size);
 			return false;
+		}
 
-		return (vdso_firstly == sym_rt->vdso_before_vvar);
+		if (vdso_firstly != sym_rt->vdso_before_vvar) {
+			pr_info("[%s] pair has different order\n",
+				vdso_firstly ? "vdso/vvar" : "vvar/vdso");
+			return false;
+		}
 	}
 
 	return true;
-- 
2.21.0