Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending

On Monday, 3 of March 2008, Pavel Machek wrote:
> 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)  <at>  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.
>