Messages in this thread | | | Date | Thu, 23 Aug 2007 16:52:01 -0700 | From | Andrew Morton <> | Subject | Re: 2.6.23-rc3-mm1 - memory layout change? - lost support for MAP_32BIT? - mono crashes |
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On Thu, 23 Aug 2007 11:28:25 +0200 (CEST) Jiri Kosina <jkosina@suse.cz> wrote:
> Handle MAP_32BIT flags properly in x86_64 flexmmap > > We need to handle MAP_32BIT flags of mmap() properly for 64bit > applications with filexible mmap layout. > > This patch introduces x86_64-specific version of > arch_get_unmapped_area_topdown() which differs from the generic one in > handling of the MAP_32BIT flag -- when this flag is passed to mmap(), we > stick back to the legacy layout for this particular mmap, which gives > proper 32bit range. >
arch/x86_64/kernel/sys_x86_64.c | 98 ++++++++++++++++++++++++++++++++++++++++ include/asm-x86_64/pgtable.h | 1
well that's another hunk of code for us to maintain and to slow all our computers down.
It is quite unobvious to me that the whole pie-randomization thing is worth merging. Why shouldn't we just drop the lot?
<looks at the changelog>
This patch is using mmap()'s randomization functionality in such a way that it maps the main executable of (specially compiled/linked -pie/-fpie) ET_DYN binaries onto a random address (in cases in which mmap() is allowed to perform a randomization).
The code has been extraced from Ingo's exec-shield patch http://people.redhat.com/mingo/exec-shield/
that certainly doesn't tell anyone why we should merge this code into Linux. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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