Re: [Qemu-devel] [PATCH] linux-user: Safety belt for h2g

[Jan Kiszka <jan.kiszka@web.de>]

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Aurelien Jarno wrote:
> On Wed, Dec 03, 2008 at 01:29:39PM +0200, Kirill A. Shutemov wrote:
>> From: Jan Kiszka <jan.kiszka@web.de>
>>
>> h2g can only work on 64-bit hosts if the provided address is mappable to
>> the guest range. Neglecting this was already the source for several
>> bugs. Instrument the macro so that it will trigger earlier in the
>> future (at least as long as we have this kind of mapping mechanism).
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
>> Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
> 
> Applied. I have seen the patch has been modified since Jan Kiszka posted
> it to the mailing list. Not sure a Signed-off-by still applies in that
> case.

Kirill correctly pointed out to me that target_ulong should rather be
abi_ulong here and in the other patch.

Good to see these changes finally merged!

Jan

> 
>> ---
>>  cpu-all.h |   10 +++++++++-
>>  1 files changed, 9 insertions(+), 1 deletions(-)
>>
>> diff --git a/cpu-all.h b/cpu-all.h
>> index 73c7b4c..526ace2 100644
>> --- a/cpu-all.h
>> +++ b/cpu-all.h
>> @@ -621,6 +621,9 @@ static inline void stfq_be_p(void *ptr, float64 v)
>>  /* MMU memory access macros */
>>  
>>  #if defined(CONFIG_USER_ONLY)
>> +#include <assert.h>
>> +#include "qemu-types.h"
>> +
>>  /* On some host systems the guest address space is reserved on the host.
>>   * This allows the guest address space to be offset to a convenient location.
>>   */
>> @@ -629,7 +632,12 @@ static inline void stfq_be_p(void *ptr, float64 v)
>>  
>>  /* All direct uses of g2h and h2g need to go away for usermode softmmu.  */
>>  #define g2h(x) ((void *)((unsigned long)(x) + GUEST_BASE))
>> -#define h2g(x) ((target_ulong)((unsigned long)(x) - GUEST_BASE))
>> +#define h2g(x) ({ \
>> +    unsigned long __ret = (unsigned long)(x) - GUEST_BASE; \
>> +    /* Check if given address fits target address space */ \
>> +    assert(__ret == (abi_ulong)__ret); \
>> +    (abi_ulong)__ret; \
>> +})
>>  
>>  #define saddr(x) g2h(x)
>>  #define laddr(x) g2h(x)
>> -- 
>> 1.6.0.2.GIT
>>
>>
>>
>>
> 



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