linux/arch/x86
Rick Edgecombe 6ecc21bb43 mm: Move pte/pmd_mkwrite() callers with no VMA to _novma()
The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm changes to function properly.

One of these unusual properties is that shadow stack memory is writable,
but only in limited ways. These limits are applied via a specific PTE
bit combination. Nevertheless, the memory is writable, and core mm code
will need to apply the writable permissions in the typical paths that
call pte_mkwrite(). Future patches will make pte_mkwrite() take a VMA, so
that the x86 implementation of it can know whether to create regular
writable or shadow stack mappings.

But there are a couple of challenges to this. Modifying the signatures of
each arch pte_mkwrite() implementation would be error prone because some
are generated with macros and would need to be re-implemented. Also, some
pte_mkwrite() callers operate on kernel memory without a VMA.

So this can be done in a three step process. First pte_mkwrite() can be
renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite()
added that just calls pte_mkwrite_novma(). Next callers without a VMA can
be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers
can be changed to take/pass a VMA.

Earlier work did the first step, so next move the callers that don't have
a VMA to pte_mkwrite_novma(). Also do the same for pmd_mkwrite().  This
will be ok for the shadow stack feature, as these callers are on kernel
memory which will not need to be made shadow stack, and the other
architectures only currently support one type of memory in pte_mkwrite()

Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/all/20230613001108.3040476-3-rick.p.edgecombe%40intel.com
2023-07-11 14:10:57 -07:00
..
boot - Fix a race window where load_unaligned_zeropad() could cause 2023-06-26 16:32:47 -07:00
coco - Some SEV and CC platform helpers cleanup and simplifications now that 2023-06-27 13:26:30 -07:00
configs
crypto This push fixes an alignment crash in x86/aria. 2023-05-29 07:05:49 -04:00
entry - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
events Perf events changes for v6.5: 2023-06-27 14:43:02 -07:00
hyperv - Some SEV and CC platform helpers cleanup and simplifications now that 2023-06-27 13:26:30 -07:00
ia32 x86/signal/32: Merge native and compat 32-bit signal code 2022-10-19 09:58:49 +02:00
include mm: Rename arch pte_mkwrite()'s to pte_mkwrite_novma() 2023-07-11 14:10:56 -07:00
kernel A single fix for the mechanism to park CPUs with an INIT IPI. 2023-07-09 10:08:38 -07:00
kvm ARM64: 2023-07-03 15:32:22 -07:00
lib Locking changes for v6.5: 2023-06-27 14:14:30 -07:00
math-emu x86/fpu: Include asm/fpu/regset.h 2023-05-18 11:56:18 -07:00
mm Merge branch 'expand-stack' 2023-06-28 20:35:21 -07:00
net bpf: Fix a bpf_jit_dump issue for x86_64 with sysctl bpf_jit_enable. 2023-06-12 16:47:18 +02:00
pci - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
platform A single regression fix for x86: 2023-07-01 11:40:01 -07:00
power x86/topology: Remove CPU0 hotplug option 2023-05-15 13:44:49 +02:00
purgatory hardening updates for v6.5-rc1 2023-06-27 21:24:18 -07:00
ras
realmode x86/realmode: Make stack lock work in trampoline_compat() 2023-05-30 14:11:47 +02:00
tools ELF: fix all "Elf" typos 2023-04-08 13:45:37 -07:00
um um: make stub data pages size tweakable 2023-04-20 23:08:43 +02:00
video drm changes for 6.5-rc1: 2023-06-29 11:00:17 -07:00
virt/vmx/tdx
xen mm: Move pte/pmd_mkwrite() callers with no VMA to _novma() 2023-07-11 14:10:57 -07:00
.gitignore
Kbuild
Kconfig Tracing updates for 6.5: 2023-06-30 10:33:17 -07:00
Kconfig.assembler crypto: x86/aria-avx - fix build failure with old binutils 2023-01-20 18:29:31 +08:00
Kconfig.cpu x86/cpu: Remove X86_FEATURE_NAMES 2023-05-15 20:03:08 +02:00
Kconfig.debug docs: move x86 documentation into Documentation/arch/ 2023-03-30 12:58:51 -06:00
Makefile x86/unwind/orc: Add ELF section with ORC version identifier 2023-06-16 17:17:42 +02:00
Makefile_32.cpu
Makefile.postlink x86/build: Avoid relocation information in final vmlinux 2023-06-14 19:54:40 +02:00
Makefile.um um: Only disable SSE on clang to work around old GCC bugs 2023-04-04 09:57:05 +02:00