similar to: [patch 0/2] Updates to compat VDSOs

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 --

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

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

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 =================================================================== ---

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 =================================================================== ---

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 =================================================================== ---

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: >

Hi Andi, Here's a little batch of cleanups: - re-enable VDSO when PARAVIRT is enabled - make the parainstructions symbols match the other altinstructions naming convention - add kernel command-line options to disable altinstructions for smp and pv_ops Oh, and I'm mailing your noreplacement patch back at you, for no particularly good reason. J --

Hi Andi, Here's a little batch of cleanups: - re-enable VDSO when PARAVIRT is enabled - make the parainstructions symbols match the other altinstructions naming convention - add kernel command-line options to disable altinstructions for smp and pv_ops Oh, and I'm mailing your noreplacement patch back at you, for no particularly good reason. J --

VMI is broken under COMPAT_VDSO, as Xen and other non hardware assisted hypervisors will be. I have been working on a fix for this which works for older glibcs that panic when the new relocatable VDSO is used. However, I believe at this time that the fix is going to be too radical to consider at this stage in the release of 2.6.21. We don't expect this config option to be turned on by

VMI is broken under COMPAT_VDSO, as Xen and other non hardware assisted hypervisors will be. I have been working on a fix for this which works for older glibcs that panic when the new relocatable VDSO is used. However, I believe at this time that the fix is going to be too radical to consider at this stage in the release of 2.6.21. We don't expect this config option to be turned on by

Create a configurable hole in the linear address space at the top of memory. A more advanced interface is needed to negotiate how much space the hypervisor is allowed to steal, but in the end, it seems most likely that a fixed constant size will be chosen for the compiled kernel, potentially propagated to an information page used by paravirtual initialization to determine interface compatibility.

Create a configurable hole in the linear address space at the top of memory. A more advanced interface is needed to negotiate how much space the hypervisor is allowed to steal, but in the end, it seems most likely that a fixed constant size will be chosen for the compiled kernel, potentially propagated to an information page used by paravirtual initialization to determine interface compatibility.

Hi Andi, What problem do they cause together? There's certainly no problem with Xen+vdso (in fact, its actually very useful so that it picks up the right libc with Xen-friendly TLS). J

Hi Andi, What problem do they cause together? There's certainly no problem with Xen+vdso (in fact, its actually very useful so that it picks up the right libc with Xen-friendly TLS). J

identify_cpu() is used to identify both the boot CPU and secondary CPUs, but it performs some actions which only apply to the boot CPU. Those functions are therefore really __init functions, but because they're called by identify_cpu(), they must be marked __cpuinit. This patch splits identify_cpu() into identify_boot_cpu() and identify_secondary_cpu(), and calls the appropriate init