The patch titled
x86/paravirt: revert exports to restore old behaviour
has been removed from the -mm tree. Its filename was
x86-paravirt-revert-exports-to-restore-old-behaviour.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: x86/paravirt: revert exports to restore old behaviour
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Subdividing the paravirt_ops structure caused a regression in certain
non-GPL modules which try to use mmu_ops and cpu_ops. This restores the
old behaviour, and makes it consistent with the non-CONFIG_PARAVIRT case.
Takashi Iwai <tiwai@xxxxxxx> adds:
> I took at this problem (as I have an nvidia card on one of my
> workstations), and found out that the following suffer from
> EXPORT_SYMBOL_GPL changes:
>
> * local_disable_irq(), local_irq_save*(), etc.
> * MSR-related macros like rdmsr(), wrmsr(), read_cr0(), etc.
> wbinvd(), too.
> * pmd_val(), pgd_val(), etc are all involved with pv_mm_ops.
> pmd_large() and pmd_bad() is also indirectly involved.
> __flush_tlb() and friends suffer, too.
Christoph Hellwig objects to this patch on the grounds that modules
shouldn't be using these operations anyway. I don't think this is a
particularly good reason to reject the patch, for several reasons:
1. These operations are still available to modules when not using
CONFIG_PARAVIRT, since they are implicitly exported as inline
functions via the kernel headers. Exporting the same functionality as
GPL-only symbols just adds a gratuitious difference between
CONFIG_PARAVIRT and non-CONFIG_PARAVIRT configurations. If we really
think these operations are not for module use (or non-GPL module use),
then we should solve the problem in a general way.
2. It's a regression from previous kernels, which would work these
modules even with CONFIG_PARAVIRT enabled.
3. The operations in question seem pretty reasonable for modules to
use. The control registers/MSRs can be accessed directly anyway, so there's
no benefit in preventing modules from using standard interfaces. And it seems
reasonable to allow a graphics driver to create its own mappings if it wants.
Therefore, I think this patch should go in for 2.6.24. If people
really think that these operations should not be available to modules,
then we can address that separately.
Signed-off-by: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@xxxxxxxxxx>
Cc: Tobias Powalowski <t.powa@xxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Cc: Zachary Amsden <zach@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/paravirt_32.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN arch/x86/kernel/paravirt_32.c~x86-paravirt-revert-exports-to-restore-old-behaviour arch/x86/kernel/paravirt_32.c
--- a/arch/x86/kernel/paravirt_32.c~x86-paravirt-revert-exports-to-restore-old-behaviour
+++ a/arch/x86/kernel/paravirt_32.c
@@ -465,8 +465,8 @@ struct pv_mmu_ops pv_mmu_ops = {
};
EXPORT_SYMBOL_GPL(pv_time_ops);
-EXPORT_SYMBOL_GPL(pv_cpu_ops);
-EXPORT_SYMBOL_GPL(pv_mmu_ops);
+EXPORT_SYMBOL (pv_cpu_ops);
+EXPORT_SYMBOL (pv_mmu_ops);
EXPORT_SYMBOL_GPL(pv_apic_ops);
EXPORT_SYMBOL_GPL(pv_info);
EXPORT_SYMBOL (pv_irq_ops);
_
Patches currently in -mm which might be from jeremy@xxxxxxxx are
origin.patch
git-x86.patch
maps4-simplify-interdependence-of-maps-and-smaps.patch
maps4-move-clear_refs-code-to-task_mmuc.patch
maps4-regroup-task_mmu-by-interface.patch
maps4-add-proc-kpagecount-interface.patch
-
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