[Qemu-devel] exec.c:283: warning: cast from pointer to integer of different size

[Qemu-devel] exec.c:283: warning: cast from pointer to integer of different size

[Jan Kiszka]

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Hi Paul,

trying to get rid of some of the various compiler warnings, specifically
on 64-bit hosts, I came across this:

> #if defined(CONFIG_USER_ONLY)
>         unsigned long addr;
>         size_t len = sizeof(PageDesc) * L2_SIZE;
>         /* Don't use qemu_malloc because it may recurse.  */
>         p = mmap(0, len, PROT_READ | PROT_WRITE,
>                  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
>         *lp = p;
>         addr = h2g(p);
>         if (addr == (target_ulong)addr) {
>             page_set_flags(addr & TARGET_PAGE_MASK,
>                            TARGET_PAGE_ALIGN(addr + len),
>                            PAGE_RESERVED); 
>         }
> #else

Something is fishy here. h2g already returns target_ulong (and generates
compiler warnings at this chance), but the succeeding line seems to
assume that addr can still be larger than that. Now I wonder what this
code is actually supposed to do.

Jan




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Re: [Qemu-devel] exec.c:283: warning: cast from pointer to integer of different size

[Laurent Desnogues]

On Mon, Jun 23, 2008 at 8:28 AM, Jan Kiszka <jan.kiszka@web.de> wrote:
> Hi Paul,
>
> trying to get rid of some of the various compiler warnings, specifically
> on 64-bit hosts, I came across this:
>
>> #if defined(CONFIG_USER_ONLY)
>>         unsigned long addr;
>>         size_t len = sizeof(PageDesc) * L2_SIZE;
>>         /* Don't use qemu_malloc because it may recurse.  */
>>         p = mmap(0, len, PROT_READ | PROT_WRITE,
>>                  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
>>         *lp = p;
>>         addr = h2g(p);
>>         if (addr == (target_ulong)addr) {
>>             page_set_flags(addr & TARGET_PAGE_MASK,
>>                            TARGET_PAGE_ALIGN(addr + len),
>>                            PAGE_RESERVED);
>>         }
>> #else
>
> Something is fishy here. h2g already returns target_ulong (and generates
> compiler warnings at this chance), but the succeeding line seems to
> assume that addr can still be larger than that. Now I wonder what this
> code is actually supposed to do.

I already reported this two weeks ago and got no feedback.

http://lists.gnu.org/archive/html/qemu-devel/2008-06/msg00324.html


Laurent