Re: [Qemu-devel] [PATCH v2] dump: Set correct vaddr for ELF dump

[Laszlo Ersek <lersek@redhat.com>]

On 01/08/19 14:05, Marc-André Lureau wrote:
> On Tue, Jan 8, 2019 at 5:02 PM Jon Doron <arilou@gmail.com> wrote:
>>
>> 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>
> 
> Not sure we are doing everything correctly, but solves the non-paging
> GDB case, so:
> 
> Tested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Same thoughts here.

Acked-by: Laszlo Ersek <lersek@redhat.com>

Thanks
Laszlo

>> ---
>>  dump.c                       | 5 +++--
>>  scripts/dump-guest-memory.py | 1 +
>>  2 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/dump.c b/dump.c
>> index 4ec94c5e25..7a56e254d4 100644
>> --- a/dump.c
>> +++ b/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);
>>
>> diff --git a/scripts/dump-guest-memory.py b/scripts/dump-guest-memory.py
>> index 198cd0fe40..2c587cbefc 100644
>> --- a/scripts/dump-guest-memory.py
>> +++ b/scripts/dump-guest-memory.py
>> @@ -163,6 +163,7 @@ class ELF(object):
>>          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)
>> --
>> 2.19.2
>>