similar to: [PATCH 1/10] I386 sysenter arch pages fix.patch

Hi Andi, Here's a couple of patches to fix up COMPAT_VDSO: The first is a straightforward implementation of Jan's original idea of relocating the VDSO to match its mapped location. Unlike Jan and Zach's version, I changed it to relocate based on the phdrs rather than the sections; the result is pleasantly compact. The second patch takes advantage of the fact that all the

Hi Andi, Here's a couple of patches to fix up COMPAT_VDSO: The first is a straightforward implementation of Jan's original idea of relocating the VDSO to match its mapped location. Unlike Jan and Zach's version, I changed it to relocate based on the phdrs rather than the sections; the result is pleasantly compact. The second patch takes advantage of the fact that all the

AFAICT we'll pay one extra TLB entry for this patch. Zach had a patch which left the vsyscall page at the top of memory (minus hole for hypervisor) and patched the ELF header at boot. Thoughts welcome, Rusty. Name: Move vsyscall page out of fixmap, above stack Author: Gerd Hoffmann <kraxel@suse.de> Hypervisors want to use memory at the top of the address space (eg. 64MB for Xen, or

AFAICT we'll pay one extra TLB entry for this patch. Zach had a patch which left the vsyscall page at the top of memory (minus hole for hypervisor) and patched the ELF header at boot. Thoughts welcome, Rusty. Name: Move vsyscall page out of fixmap, above stack Author: Gerd Hoffmann <kraxel@suse.de> Hypervisors want to use memory at the top of the address space (eg. 64MB for Xen, or

Hi Andi, Four patches: - clean up asm/bugs.h, by moving all the C code into its own C file - split identify_cpu() into boot and secondary variants, so that boot-time setup functions can be marked __init - repost of the COMPAT_VDSO patches with a bit more robustness from unknown DT_tags, and functions marked __init, since all this is boot-time only setup. Thanks, J --

Hi Andi, Four patches: - clean up asm/bugs.h, by moving all the C code into its own C file - split identify_cpu() into boot and secondary variants, so that boot-time setup functions can be marked __init - repost of the COMPAT_VDSO patches with a bit more robustness from unknown DT_tags, and functions marked __init, since all this is boot-time only setup. Thanks, J --

On Mon, 2007-03-05 at 13:06 +0100, Ingo Molnar wrote: > Subject: [patch] paravirt: VDSO page is essential > From: Ingo Molnar <mingo@elte.hu> > > commit 3bbf54725467d604698721384d858b5983b87e8f disables the VDSO for > CONFIG_PARAVIRT kernels. This #ifdeffery was a bad change: the VDSO is > an essential component of Linux, and this change forces all of them to > use

On Mon, 2007-03-05 at 13:06 +0100, Ingo Molnar wrote: > Subject: [patch] paravirt: VDSO page is essential > From: Ingo Molnar <mingo@elte.hu> > > commit 3bbf54725467d604698721384d858b5983b87e8f disables the VDSO for > CONFIG_PARAVIRT kernels. This #ifdeffery was a bad change: the VDSO is > an essential component of Linux, and this change forces all of them to > use

Paravirt-ops guests which move the fixmap also end up moving the syscall = VDSO. This fails if it is prelinked at a fixed address, which is why = COMPAT_VDSO is broken under CONFIG_VMI (and also under CONFIG_XEN). = Several options are available to try to address this. Jan had cooked up = a patch for Xen that used build magic to find the parts of the VDSO that = need relocation. I

Paravirt-ops guests which move the fixmap also end up moving the syscall = VDSO. This fails if it is prelinked at a fixed address, which is why = COMPAT_VDSO is broken under CONFIG_VMI (and also under CONFIG_XEN). = Several options are available to try to address this. Jan had cooked up = a patch for Xen that used build magic to find the parts of the VDSO that = need relocation. I

So, is everyone happy with this smerge of Ingo and Gerd's work? Reposted below. Thanks, Rusty. -------- Forwarded Message -------- From: Linus Torvalds <torvalds@osdl.org> To: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@osdl.org> Subject: Re: [Fwd: [Fwd: FW: argh]] Date: Wed, 17 May 2006 21:35:51 -0700 (PDT) On Thu, 18 May 2006, Rusty Russell wrote: >

So, is everyone happy with this smerge of Ingo and Gerd's work? Reposted below. Thanks, Rusty. -------- Forwarded Message -------- From: Linus Torvalds <torvalds@osdl.org> To: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@osdl.org> Subject: Re: [Fwd: [Fwd: FW: argh]] Date: Wed, 17 May 2006 21:35:51 -0700 (PDT) On Thu, 18 May 2006, Rusty Russell wrote: >

As usual, written and (build-)tested on 2.6.27.4 and made apply to the 2.6.18 tree without further testing. Signed-off-by: Jan Beulich <jbeulich@novell.com> Index: head-2008-11-04/drivers/xen/blktap/blktap.c =================================================================== --- head-2008-11-04.orig/drivers/xen/blktap/blktap.c 2008-10-01 16:35:04.000000000 +0200 +++

I implemented sysenter for 32-on-64, since it seemed straightforward enough. It mostly works, but every now and again I get vcpus just hanging in blocked state, as if events are being lost or ignored. Its very similar to the symptoms that other people have reported against the pvops kernel, which I have not managed to reproduce. Perhaps using sysenter is exacerbating an existing bug...

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Xen Security Advisory CVE-2013-1917 / XSA-44 version 2 Xen PV DoS vulnerability with SYSENTER UPDATES IN VERSION 2 ==================== Public release. ISSUE DESCRIPTION ================= The SYSENTER instruction can be used by PV guests to accelerate system call processing. This

The SYSENTER instruction jumps to a pre-programmed address at privilege level 0. We must not allow execution of guest code at that privilege level, so disable sysenter when we enter the guest (and re-enable it on return). This fixes current case where guest userspace can crash host. This save/restore adds 3% to guest context switch times. (If only there were some kind of scheduler hook or

The SYSENTER instruction jumps to a pre-programmed address at privilege level 0. We must not allow execution of guest code at that privilege level, so disable sysenter when we enter the guest (and re-enable it on return). This fixes current case where guest userspace can crash host. This save/restore adds 3% to guest context switch times. (If only there were some kind of scheduler hook or

From: Jason Gunthorpe <jgg at mellanox.com> There is no reason to get the invalidate_range_start() callback via an indirection through hmm_mirror, just register a normal notifier directly. Cc: Ben Skeggs <bskeggs at redhat.com> Cc: dri-devel at lists.freedesktop.org Cc: nouveau at lists.freedesktop.org Cc: Ralph Campbell <rcampbell at nvidia.com> Signed-off-by: Jason Gunthorpe

This was set to zero immediately before the #GP injection code, since SYSENTER doesn''t really have a return address. Reported-by: Ian Campbell <Ian.Campbell@citrix.com> Furthermore, UREGS_cs and UREGS_rip don''t need to be written a second time, as the PUSHes above already can/do take care of putting in place the intended values. Signed-off-by: Jan Beulich

This adds support for CONFIG_COMPAT_VDSO. As this will certainly raise questions, I left in the code needed for an alternative approach (which requires mode C code, but less build script changes). Signed-off-by: Jan Beulich <jbeulich@novell.com> Index: head-2007-02-27/arch/i386/Kconfig =================================================================== ---