Messages in this thread | | | From | David Mosberger <> | Date | Thu, 15 Apr 2004 10:45:44 -0700 | Subject | Re: [PATCH] (IA64) Fix ugly __[PS]* macros in <asm-ia64/pgtable.h> |
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>>>>> On Thu, 15 Apr 2004 16:26:00 +0100, Jamie Lokier <jamie@shareable.org> said:
>> As you can see, the data-segment is mapped with EXEC bit turned on. >> Ditto for the stack segment, which I think is this one:
>> 000000011fffe000-0000000120000000 rwxp 0000000000000000 00:00 0
Jamie> The stack is mapped executable, and the data segment is mapped Jamie> non-executable, according to /proc/self/maps which reflects the Jamie> PROT_EXEC request. But in fact because of hardware limitations, Jamie> despite the "rw-p" my data segment is actually executable.
Yes, but Alpha doesn't have this limitation.
Jamie> If you map a segment without PROT_EXEC on Alpha, using a kernel newer Jamie> than 1.1.84, you'll get a non-executable mapping.
Sure.
Jamie> That's what I mean when I say the Alpha maps data without Jamie> executable permission. The ELF loader appears to ask for Jamie> exec permission anyway, which is another thing entirely.
It's not the ELF loader, it's the kernel. See VM_DATA_DEFAULT_FLAGS in asm-alpha/page.h.
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