l4-hackers Digest, Vol 59, Issue 7
Valery V. Sedletski
_valerius at mail.ru
Wed Mar 12 04:44:02 CET 2008
On Mon, 10 Mar 2008 12:00:02 +0100, Adam Lackorzynski <adam at os.inf.tu-dresden.de> wrote:
>> 4019e0: 83 0a 00 orl $0x0,(%edx)
>> So it is the function:
>> /** Touch data areas to force mapping read-write */
>> static inline void
>> l4_touch_rw(const void*addr, unsigned size)
>> const char *bptr, *eptr;
>> bptr = (const char*)(((unsigned)addr) & L4_PAGEMASK);
>> eptr = (const char*)(((unsigned)addr+size-1) & L4_PAGEMASK);
>> asm volatile("or $0,%0 \n"
>> : "m" (*(const unsigned*)bptr)
>> And instruction "orl" is inside "asm volatile" block.
>> So, this function touches an area (BSS in this case) to make mapping read-write. But
>> why this does not work?
>I have no idea, I've never seen this before. Is there the possibility to
>update the source so that we can work on the same basis?
OK, I'll try to update the sources. (First I must update a svn client as my svn
client under Linux is too old (I have Red Hat 9.0)). I used an old sources from CVS,
not newer SVN sources.
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