Messages in this thread | | | Date | Mon, 3 Mar 2008 13:17:35 +0100 | From | Pavel Machek <> | Subject | Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending |
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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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