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    SubjectRe: Regression in 2.6.25-rc3: s2ram segfaults before suspending
    Hi!

    > > > Klaus S. Madsen wrote:
    > > >> open("/dev/mem", O_RDWR) = 5
    > > >> mmap2(NULL, 1282, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED|MAP_FIXED, 5, 0) = 0
    > > >> mmap2(0xa0000, 393216, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 5, 0xa0) = 0xa0000
    > > > ^^^^^^^^^^^^^^^^^^^^
    > > >> close(5) = 0
    > > >> ioperm(0, 0x400, 0x1) = 0
    > > >> iopl(0x3) = 0
    > > >> access("/sys/bus/pci", R_OK) = 0
    > > >> write(1, "Calling get_mode\n", 17) = 17
    > > >> vm86(0x1, 0xb7f14ccc, 0xb7f14830, 0xc000, 0x18b6 <unfinished ...>
    > > >> --- SIGSEGV (Segmentation fault) @ 0 (0) ---
    > > >> +++ killed by SIGSEGV (core dumped) +++
    > > >
    > > > This is the VGA BIOS being mapped, it's mapped PROT_READ|PROT_WRITE, but
    > > > no PROT_EXEC; if the kernel is NX-capable it *should* segfault trying to
    > > > execute out of this area, which is exactly what will happen when vm86
    > > > executes INT 10h.
    > > >
    > > > If we can find that mmap() in the s2ram source code and add PROT_EXEC
    > > > to it, it would be interesting.
    > >
    > > Klaus, could you send your .config as well? Lets make sure that NX is
    > > even relevant in this context.
    > Allright. The mmap in question is in the x86-common.c file in libx86,
    > and adding PROT_EXEC to it solves the problem.

    Ok, sw should probably fix that in s2ram... can you mail a patch to
    me, and suspend-devel?

    > I have attached my .config.
    >
    > The only thing I don't understand is why this is suddenly a problem with
    > 2.6.25, and not with 2.6.24? Is there a bug in 2.6.24 and previously
    > that allows real-mode execution of non-executable pages?

    It is strange indeed... Should it be traced as an regression?
    Pavel
    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


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