Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled

Rusty Russell <[email protected]> wrote:
>
> Hypervisors want to use memory at the top of the address space
>  (eg. 64MB for Xen, or 168MB for Xen w/ PAE).  Creating this hole means
>  moving the vsyscall page away from 0xffffe000.
> 
>  If we create this hole statically with a config option, we give up,
>  say, 256MB of lowmem for the case where a hypervisor-capable kernel is
>  actually running on native hardware.
> 
>  If we create this hole dynamically and leave the vsyscall page at the
>  top of kernel memory, we would have to patch up the vsyscall elf
>  header at boot time to reflect where we put it.
> 
>  Instead, this patch moves the vsyscall page into the user address
>  region, just below PAGE_OFFSET: it's still at a fixed address, but
>  it's not where the hypervisor wants to be, so resizing the hole is
>  trivial.

Seems to work.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

---

• References:
  • [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch
    • From: Rusty Russell <[email protected]>
  • Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch
    • From: Ingo Molnar <[email protected]>
  • Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch
    • From: Rusty Russell <[email protected]>
  • Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch
    • From: Andrew Morton <[email protected]>
  • Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch
    • From: Ingo Molnar <[email protected]>
  • Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch
    • From: Andrew Morton <[email protected]>
  • Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch
    • From: Linus Torvalds <[email protected]>
  • [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
    • From: Ingo Molnar <[email protected]>
  • Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
    • From: Andrew Morton <[email protected]>
  • Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
    • From: Zachary Amsden <[email protected]>
  • Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
    • From: Andrew Morton <[email protected]>
  • Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
    • From: Zachary Amsden <[email protected]>
  • Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
    • From: Rusty Russell <[email protected]>
  • Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
    • From: Rusty Russell <[email protected]>

• Prev by Date: Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
• Next by Date: Re: IA32 syscall 311 not implemented on x86_64
• Previous by thread: Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
• Next by thread: Re: [patch] i386, vdso=[0|1] boot option and /proc/sys/vm/vdso_enabled
• Index(es):
  • Date
  • Thread

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]