Messages in this thread | | | Date | Fri, 29 Feb 2008 13:05:46 -0800 | From | "H. Peter Anvin" <> | Subject | Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending |
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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.
-hpa
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