dump: Set correct vaddr for ELF dump

vaddr needs to be equal to the paddr since the dump file represents the
physical memory image.

Without setting vaddr correctly, GDB would load all the different memory
regions on top of each other to vaddr 0, thus making GDB showing the wrong
memory data for a given address.

Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20190109082203.27142-1-arilou@gmail.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>

dump.c

@@ -192,7 +192,7 @@ static void write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
     phdr.p_paddr = cpu_to_dump64(s, memory_mapping->phys_addr);
     phdr.p_filesz = cpu_to_dump64(s, filesz);
     phdr.p_memsz = cpu_to_dump64(s, memory_mapping->length);
-    phdr.p_vaddr = cpu_to_dump64(s, memory_mapping->virt_addr);
+    phdr.p_vaddr = cpu_to_dump64(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
 
     assert(memory_mapping->length >= filesz);
 
@@ -216,7 +216,8 @@ static void write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
     phdr.p_paddr = cpu_to_dump32(s, memory_mapping->phys_addr);
     phdr.p_filesz = cpu_to_dump32(s, filesz);
     phdr.p_memsz = cpu_to_dump32(s, memory_mapping->length);
-    phdr.p_vaddr = cpu_to_dump32(s, memory_mapping->virt_addr);
+    phdr.p_vaddr =
+        cpu_to_dump32(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
 
     assert(memory_mapping->length >= filesz);
 

scripts/dump-guest-memory.py

@@ -163,6 +163,7 @@ def add_segment(self, p_type, p_paddr, p_size):
         phdr = get_arch_phdr(self.endianness, self.elfclass)
         phdr.p_type = p_type
         phdr.p_paddr = p_paddr
+        phdr.p_vaddr = p_paddr
         phdr.p_filesz = p_size
         phdr.p_memsz = p_size
         self.segments.append(phdr)