* [PATCH v2 0/7] KVM: arm64: permit MAP_SHARED mappings with MTE enabled
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
Hi,
This patch series allows VMMs to use shared mappings in MTE enabled
guests. The first four patches are based on the series that Catalin sent
out, whose cover letter [1] I quote from below:
> This series aims to fix the races between initialising the tags on a
> page and setting the PG_mte_tagged flag. Currently the flag is set
> either before or after that tag initialisation and this can lead to CoW
> copying stale tags. The first patch moves the flag setting after the
> tags have been initialised, solving the CoW issue. However, concurrent
> mprotect() on a shared mapping may (very rarely) lead to valid tags
> being zeroed.
>
> The second skips the sanitise_mte_tags() call in kvm_set_spte_gfn(),
> deferring it to user_mem_abort(). The outcome is that no
> sanitise_mte_tags() can be simplified to skip the pfn_to_online_page()
> check and only rely on VM_MTE_ALLOWED vma flag that can be checked in
> user_mem_abort().
>
> The third and fourth patches use PG_arch_3 as a lock for page tagging,
> based on Peter Collingbourne's idea of a two-bit lock.
>
> I think the first patch can be queued but the rest needs some in depth
> review and test. With this series (if correct) we could allos MAP_SHARED
> on KVM guest memory but this is to be discussed separately as there are
> some KVM ABI implications.
I rebased Catalin's series onto -next, addressed the issues that I
identified in the review and added the proposed userspace enablement
patches after the series.
[1] https://lore.kernel.org/all/20220705142619.4135905-1-catalin.marinas@arm.com/
Catalin Marinas (3):
arm64: mte: Fix/clarify the PG_mte_tagged semantics
KVM: arm64: Simplify the sanitise_mte_tags() logic
arm64: mte: Lock a page for MTE tag initialisation
Peter Collingbourne (4):
mm: Add PG_arch_3 page flag
KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled
KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled
Documentation: document the ABI changes for KVM_CAP_ARM_MTE
Documentation/virt/kvm/api.rst | 5 +--
arch/arm64/include/asm/mte.h | 62 ++++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 3 +-
arch/arm64/kernel/cpufeature.c | 4 ++-
arch/arm64/kernel/elfcore.c | 2 +-
arch/arm64/kernel/hibernate.c | 2 +-
arch/arm64/kernel/mte.c | 17 +++++----
arch/arm64/kvm/guest.c | 18 ++++++----
arch/arm64/kvm/mmu.c | 55 ++++++++++++----------------
arch/arm64/mm/copypage.c | 6 ++--
arch/arm64/mm/fault.c | 4 ++-
arch/arm64/mm/mteswap.c | 5 ++-
fs/proc/page.c | 1 +
include/linux/page-flags.h | 1 +
include/trace/events/mmflags.h | 7 ++--
mm/huge_memory.c | 1 +
16 files changed, 134 insertions(+), 59 deletions(-)
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply [flat|nested] 36+ messages in thread
* [PATCH v2 0/7] KVM: arm64: permit MAP_SHARED mappings with MTE enabled
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: kvm, Will Deacon, Catalin Marinas, Cornelia Huck, Steven Price,
Marc Zyngier, Vincenzo Frascino, Peter Collingbourne,
Evgenii Stepanov
Hi,
This patch series allows VMMs to use shared mappings in MTE enabled
guests. The first four patches are based on the series that Catalin sent
out, whose cover letter [1] I quote from below:
> This series aims to fix the races between initialising the tags on a
> page and setting the PG_mte_tagged flag. Currently the flag is set
> either before or after that tag initialisation and this can lead to CoW
> copying stale tags. The first patch moves the flag setting after the
> tags have been initialised, solving the CoW issue. However, concurrent
> mprotect() on a shared mapping may (very rarely) lead to valid tags
> being zeroed.
>
> The second skips the sanitise_mte_tags() call in kvm_set_spte_gfn(),
> deferring it to user_mem_abort(). The outcome is that no
> sanitise_mte_tags() can be simplified to skip the pfn_to_online_page()
> check and only rely on VM_MTE_ALLOWED vma flag that can be checked in
> user_mem_abort().
>
> The third and fourth patches use PG_arch_3 as a lock for page tagging,
> based on Peter Collingbourne's idea of a two-bit lock.
>
> I think the first patch can be queued but the rest needs some in depth
> review and test. With this series (if correct) we could allos MAP_SHARED
> on KVM guest memory but this is to be discussed separately as there are
> some KVM ABI implications.
I rebased Catalin's series onto -next, addressed the issues that I
identified in the review and added the proposed userspace enablement
patches after the series.
[1] https://lore.kernel.org/all/20220705142619.4135905-1-catalin.marinas@arm.com/
Catalin Marinas (3):
arm64: mte: Fix/clarify the PG_mte_tagged semantics
KVM: arm64: Simplify the sanitise_mte_tags() logic
arm64: mte: Lock a page for MTE tag initialisation
Peter Collingbourne (4):
mm: Add PG_arch_3 page flag
KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled
KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled
Documentation: document the ABI changes for KVM_CAP_ARM_MTE
Documentation/virt/kvm/api.rst | 5 +--
arch/arm64/include/asm/mte.h | 62 ++++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 3 +-
arch/arm64/kernel/cpufeature.c | 4 ++-
arch/arm64/kernel/elfcore.c | 2 +-
arch/arm64/kernel/hibernate.c | 2 +-
arch/arm64/kernel/mte.c | 17 +++++----
arch/arm64/kvm/guest.c | 18 ++++++----
arch/arm64/kvm/mmu.c | 55 ++++++++++++----------------
arch/arm64/mm/copypage.c | 6 ++--
arch/arm64/mm/fault.c | 4 ++-
arch/arm64/mm/mteswap.c | 5 ++-
fs/proc/page.c | 1 +
include/linux/page-flags.h | 1 +
include/trace/events/mmflags.h | 7 ++--
mm/huge_memory.c | 1 +
16 files changed, 134 insertions(+), 59 deletions(-)
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 36+ messages in thread
* [PATCH v2 0/7] KVM: arm64: permit MAP_SHARED mappings with MTE enabled
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
Hi,
This patch series allows VMMs to use shared mappings in MTE enabled
guests. The first four patches are based on the series that Catalin sent
out, whose cover letter [1] I quote from below:
> This series aims to fix the races between initialising the tags on a
> page and setting the PG_mte_tagged flag. Currently the flag is set
> either before or after that tag initialisation and this can lead to CoW
> copying stale tags. The first patch moves the flag setting after the
> tags have been initialised, solving the CoW issue. However, concurrent
> mprotect() on a shared mapping may (very rarely) lead to valid tags
> being zeroed.
>
> The second skips the sanitise_mte_tags() call in kvm_set_spte_gfn(),
> deferring it to user_mem_abort(). The outcome is that no
> sanitise_mte_tags() can be simplified to skip the pfn_to_online_page()
> check and only rely on VM_MTE_ALLOWED vma flag that can be checked in
> user_mem_abort().
>
> The third and fourth patches use PG_arch_3 as a lock for page tagging,
> based on Peter Collingbourne's idea of a two-bit lock.
>
> I think the first patch can be queued but the rest needs some in depth
> review and test. With this series (if correct) we could allos MAP_SHARED
> on KVM guest memory but this is to be discussed separately as there are
> some KVM ABI implications.
I rebased Catalin's series onto -next, addressed the issues that I
identified in the review and added the proposed userspace enablement
patches after the series.
[1] https://lore.kernel.org/all/20220705142619.4135905-1-catalin.marinas@arm.com/
Catalin Marinas (3):
arm64: mte: Fix/clarify the PG_mte_tagged semantics
KVM: arm64: Simplify the sanitise_mte_tags() logic
arm64: mte: Lock a page for MTE tag initialisation
Peter Collingbourne (4):
mm: Add PG_arch_3 page flag
KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled
KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled
Documentation: document the ABI changes for KVM_CAP_ARM_MTE
Documentation/virt/kvm/api.rst | 5 +--
arch/arm64/include/asm/mte.h | 62 ++++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 3 +-
arch/arm64/kernel/cpufeature.c | 4 ++-
arch/arm64/kernel/elfcore.c | 2 +-
arch/arm64/kernel/hibernate.c | 2 +-
arch/arm64/kernel/mte.c | 17 +++++----
arch/arm64/kvm/guest.c | 18 ++++++----
arch/arm64/kvm/mmu.c | 55 ++++++++++++----------------
arch/arm64/mm/copypage.c | 6 ++--
arch/arm64/mm/fault.c | 4 ++-
arch/arm64/mm/mteswap.c | 5 ++-
fs/proc/page.c | 1 +
include/linux/page-flags.h | 1 +
include/trace/events/mmflags.h | 7 ++--
mm/huge_memory.c | 1 +
16 files changed, 134 insertions(+), 59 deletions(-)
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 36+ messages in thread
* [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-22 1:50 ` Peter Collingbourne
-1 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Catalin Marinas, Cornelia Huck, Will Deacon, Marc Zyngier,
Evgenii Stepanov, kvm, Steven Price, Vincenzo Frascino,
Peter Collingbourne
From: Catalin Marinas <catalin.marinas@arm.com>
Currently the PG_mte_tagged page flag mostly means the page contains
valid tags and it should be set after the tags have been cleared or
restored. However, in mte_sync_tags() it is set before setting the tags
to avoid, in theory, a race with concurrent mprotect(PROT_MTE) for
shared pages. However, a concurrent mprotect(PROT_MTE) with a copy on
write in another thread can cause the new page to have stale tags.
Similarly, tag reading via ptrace() can read stale tags of the
PG_mte_tagged flag is set before actually clearing/restoring the tags.
Fix the PG_mte_tagged semantics so that it is only set after the tags
have been cleared or restored. This is safe for swap restoring into a
MAP_SHARED or CoW page since the core code takes the page lock. Add two
functions to test and set the PG_mte_tagged flag with acquire and
release semantics. The downside is that concurrent mprotect(PROT_MTE) on
a MAP_SHARED page may cause tag loss. This is already the case for KVM
guests if a VMM changes the page protection while the guest triggers a
user_mem_abort().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/include/asm/mte.h | 30 ++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 2 +-
arch/arm64/kernel/cpufeature.c | 4 +++-
arch/arm64/kernel/elfcore.c | 2 +-
arch/arm64/kernel/hibernate.c | 2 +-
arch/arm64/kernel/mte.c | 12 +++++++-----
arch/arm64/kvm/guest.c | 4 ++--
arch/arm64/kvm/mmu.c | 4 ++--
arch/arm64/mm/copypage.c | 4 ++--
arch/arm64/mm/fault.c | 2 +-
arch/arm64/mm/mteswap.c | 2 +-
11 files changed, 51 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index aa523591a44e..c69218c56980 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -37,6 +37,29 @@ void mte_free_tag_storage(char *storage);
/* track which pages have valid allocation tags */
#define PG_mte_tagged PG_arch_2
+static inline void set_page_mte_tagged(struct page *page)
+{
+ /*
+ * Ensure that the tags written prior to this function are visible
+ * before the page flags update.
+ */
+ smp_wmb();
+ set_bit(PG_mte_tagged, &page->flags);
+}
+
+static inline bool page_mte_tagged(struct page *page)
+{
+ bool ret = test_bit(PG_mte_tagged, &page->flags);
+
+ /*
+ * If the page is tagged, ensure ordering with a likely subsequent
+ * read of the tags.
+ */
+ if (ret)
+ smp_rmb();
+ return ret;
+}
+
void mte_zero_clear_page_tags(void *addr);
void mte_sync_tags(pte_t old_pte, pte_t pte);
void mte_copy_page_tags(void *kto, const void *kfrom);
@@ -54,6 +77,13 @@ size_t mte_probe_user_range(const char __user *uaddr, size_t size);
/* unused if !CONFIG_ARM64_MTE, silence the compiler */
#define PG_mte_tagged 0
+static inline set_page_mte_tagged(struct page *page)
+{
+}
+static inline bool page_mte_tagged(struct page *page)
+{
+ return false;
+}
static inline void mte_zero_clear_page_tags(void *addr)
{
}
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index b5df82aa99e6..82719fa42c0e 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1050,7 +1050,7 @@ static inline void arch_swap_invalidate_area(int type)
static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
{
if (system_supports_mte() && mte_restore_tags(entry, &folio->page))
- set_bit(PG_mte_tagged, &folio->flags);
+ set_page_mte_tagged(&folio->page);
}
#endif /* CONFIG_ARM64_MTE */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index fae4c7a785d8..c66f0ffaaf47 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2020,8 +2020,10 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
* Clear the tags in the zero page. This needs to be done via the
* linear map which has the Tagged attribute.
*/
- if (!test_and_set_bit(PG_mte_tagged, &ZERO_PAGE(0)->flags))
+ if (!page_mte_tagged(ZERO_PAGE(0))) {
mte_clear_page_tags(lm_alias(empty_zero_page));
+ set_page_mte_tagged(ZERO_PAGE(0));
+ }
kasan_init_hw_tags_cpu();
}
diff --git a/arch/arm64/kernel/elfcore.c b/arch/arm64/kernel/elfcore.c
index 27ef7ad3ffd2..353009d7f307 100644
--- a/arch/arm64/kernel/elfcore.c
+++ b/arch/arm64/kernel/elfcore.c
@@ -47,7 +47,7 @@ static int mte_dump_tag_range(struct coredump_params *cprm,
* Pages mapped in user space as !pte_access_permitted() (e.g.
* PROT_EXEC only) may not have the PG_mte_tagged flag set.
*/
- if (!test_bit(PG_mte_tagged, &page->flags)) {
+ if (!page_mte_tagged(page)) {
put_page(page);
dump_skip(cprm, MTE_PAGE_TAG_STORAGE);
continue;
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index af5df48ba915..788597a6b6a2 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -271,7 +271,7 @@ static int swsusp_mte_save_tags(void)
if (!page)
continue;
- if (!test_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
continue;
ret = save_tags(page, pfn);
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index b2b730233274..2287316639f3 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -41,14 +41,17 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (check_swap && is_swap_pte(old_pte)) {
swp_entry_t entry = pte_to_swp_entry(old_pte);
- if (!non_swap_entry(entry) && mte_restore_tags(entry, page))
+ if (!non_swap_entry(entry) && mte_restore_tags(entry, page)) {
+ set_page_mte_tagged(page);
return;
+ }
}
if (!pte_is_tagged)
return;
mte_clear_page_tags(page_address(page));
+ set_page_mte_tagged(page);
}
void mte_sync_tags(pte_t old_pte, pte_t pte)
@@ -64,7 +67,7 @@ void mte_sync_tags(pte_t old_pte, pte_t pte)
/* if PG_mte_tagged is set, tags have already been initialised */
for (i = 0; i < nr_pages; i++, page++) {
- if (!test_and_set_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
mte_sync_page_tags(page, old_pte, check_swap,
pte_is_tagged);
}
@@ -91,8 +94,7 @@ int memcmp_pages(struct page *page1, struct page *page2)
* pages is tagged, set_pte_at() may zero or change the tags of the
* other page via mte_sync_tags().
*/
- if (test_bit(PG_mte_tagged, &page1->flags) ||
- test_bit(PG_mte_tagged, &page2->flags))
+ if (page_mte_tagged(page1) || page_mte_tagged(page2))
return addr1 != addr2;
return ret;
@@ -398,7 +400,7 @@ static int __access_remote_tags(struct mm_struct *mm, unsigned long addr,
put_page(page);
break;
}
- WARN_ON_ONCE(!test_bit(PG_mte_tagged, &page->flags));
+ WARN_ON_ONCE(!page_mte_tagged(page));
/* limit access to the end of the page */
offset = offset_in_page(addr);
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 8c607199cad1..3b04e69006b4 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -1058,7 +1058,7 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
maddr = page_address(page);
if (!write) {
- if (test_bit(PG_mte_tagged, &page->flags))
+ if (page_mte_tagged(page))
num_tags = mte_copy_tags_to_user(tags, maddr,
MTE_GRANULES_PER_PAGE);
else
@@ -1075,7 +1075,7 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
* completed fully
*/
if (num_tags == MTE_GRANULES_PER_PAGE)
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
kvm_release_pfn_dirty(pfn);
}
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 87f1cd0df36e..c9012707f69c 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1075,9 +1075,9 @@ static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
return -EFAULT;
for (i = 0; i < nr_pages; i++, page++) {
- if (!test_bit(PG_mte_tagged, &page->flags)) {
+ if (!page_mte_tagged(page)) {
mte_clear_page_tags(page_address(page));
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
}
}
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 24913271e898..4223389b6180 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -21,9 +21,9 @@ void copy_highpage(struct page *to, struct page *from)
copy_page(kto, kfrom);
- if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
- set_bit(PG_mte_tagged, &to->flags);
+ if (system_supports_mte() && page_mte_tagged(from)) {
mte_copy_page_tags(kto, kfrom);
+ set_page_mte_tagged(to);
}
}
EXPORT_SYMBOL(copy_highpage);
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index c33f1fad2745..d095bfa16771 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -931,5 +931,5 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
void tag_clear_highpage(struct page *page)
{
mte_zero_clear_page_tags(page_address(page));
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
index 4334dec93bd4..a78c1db23c68 100644
--- a/arch/arm64/mm/mteswap.c
+++ b/arch/arm64/mm/mteswap.c
@@ -24,7 +24,7 @@ int mte_save_tags(struct page *page)
{
void *tag_storage, *ret;
- if (!test_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
return 0;
tag_storage = mte_allocate_tag_storage();
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: kvm, Peter Collingbourne, Catalin Marinas, Cornelia Huck,
Steven Price, Marc Zyngier, Vincenzo Frascino, Will Deacon,
Evgenii Stepanov
From: Catalin Marinas <catalin.marinas@arm.com>
Currently the PG_mte_tagged page flag mostly means the page contains
valid tags and it should be set after the tags have been cleared or
restored. However, in mte_sync_tags() it is set before setting the tags
to avoid, in theory, a race with concurrent mprotect(PROT_MTE) for
shared pages. However, a concurrent mprotect(PROT_MTE) with a copy on
write in another thread can cause the new page to have stale tags.
Similarly, tag reading via ptrace() can read stale tags of the
PG_mte_tagged flag is set before actually clearing/restoring the tags.
Fix the PG_mte_tagged semantics so that it is only set after the tags
have been cleared or restored. This is safe for swap restoring into a
MAP_SHARED or CoW page since the core code takes the page lock. Add two
functions to test and set the PG_mte_tagged flag with acquire and
release semantics. The downside is that concurrent mprotect(PROT_MTE) on
a MAP_SHARED page may cause tag loss. This is already the case for KVM
guests if a VMM changes the page protection while the guest triggers a
user_mem_abort().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/include/asm/mte.h | 30 ++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 2 +-
arch/arm64/kernel/cpufeature.c | 4 +++-
arch/arm64/kernel/elfcore.c | 2 +-
arch/arm64/kernel/hibernate.c | 2 +-
arch/arm64/kernel/mte.c | 12 +++++++-----
arch/arm64/kvm/guest.c | 4 ++--
arch/arm64/kvm/mmu.c | 4 ++--
arch/arm64/mm/copypage.c | 4 ++--
arch/arm64/mm/fault.c | 2 +-
arch/arm64/mm/mteswap.c | 2 +-
11 files changed, 51 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index aa523591a44e..c69218c56980 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -37,6 +37,29 @@ void mte_free_tag_storage(char *storage);
/* track which pages have valid allocation tags */
#define PG_mte_tagged PG_arch_2
+static inline void set_page_mte_tagged(struct page *page)
+{
+ /*
+ * Ensure that the tags written prior to this function are visible
+ * before the page flags update.
+ */
+ smp_wmb();
+ set_bit(PG_mte_tagged, &page->flags);
+}
+
+static inline bool page_mte_tagged(struct page *page)
+{
+ bool ret = test_bit(PG_mte_tagged, &page->flags);
+
+ /*
+ * If the page is tagged, ensure ordering with a likely subsequent
+ * read of the tags.
+ */
+ if (ret)
+ smp_rmb();
+ return ret;
+}
+
void mte_zero_clear_page_tags(void *addr);
void mte_sync_tags(pte_t old_pte, pte_t pte);
void mte_copy_page_tags(void *kto, const void *kfrom);
@@ -54,6 +77,13 @@ size_t mte_probe_user_range(const char __user *uaddr, size_t size);
/* unused if !CONFIG_ARM64_MTE, silence the compiler */
#define PG_mte_tagged 0
+static inline set_page_mte_tagged(struct page *page)
+{
+}
+static inline bool page_mte_tagged(struct page *page)
+{
+ return false;
+}
static inline void mte_zero_clear_page_tags(void *addr)
{
}
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index b5df82aa99e6..82719fa42c0e 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1050,7 +1050,7 @@ static inline void arch_swap_invalidate_area(int type)
static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
{
if (system_supports_mte() && mte_restore_tags(entry, &folio->page))
- set_bit(PG_mte_tagged, &folio->flags);
+ set_page_mte_tagged(&folio->page);
}
#endif /* CONFIG_ARM64_MTE */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index fae4c7a785d8..c66f0ffaaf47 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2020,8 +2020,10 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
* Clear the tags in the zero page. This needs to be done via the
* linear map which has the Tagged attribute.
*/
- if (!test_and_set_bit(PG_mte_tagged, &ZERO_PAGE(0)->flags))
+ if (!page_mte_tagged(ZERO_PAGE(0))) {
mte_clear_page_tags(lm_alias(empty_zero_page));
+ set_page_mte_tagged(ZERO_PAGE(0));
+ }
kasan_init_hw_tags_cpu();
}
diff --git a/arch/arm64/kernel/elfcore.c b/arch/arm64/kernel/elfcore.c
index 27ef7ad3ffd2..353009d7f307 100644
--- a/arch/arm64/kernel/elfcore.c
+++ b/arch/arm64/kernel/elfcore.c
@@ -47,7 +47,7 @@ static int mte_dump_tag_range(struct coredump_params *cprm,
* Pages mapped in user space as !pte_access_permitted() (e.g.
* PROT_EXEC only) may not have the PG_mte_tagged flag set.
*/
- if (!test_bit(PG_mte_tagged, &page->flags)) {
+ if (!page_mte_tagged(page)) {
put_page(page);
dump_skip(cprm, MTE_PAGE_TAG_STORAGE);
continue;
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index af5df48ba915..788597a6b6a2 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -271,7 +271,7 @@ static int swsusp_mte_save_tags(void)
if (!page)
continue;
- if (!test_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
continue;
ret = save_tags(page, pfn);
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index b2b730233274..2287316639f3 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -41,14 +41,17 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (check_swap && is_swap_pte(old_pte)) {
swp_entry_t entry = pte_to_swp_entry(old_pte);
- if (!non_swap_entry(entry) && mte_restore_tags(entry, page))
+ if (!non_swap_entry(entry) && mte_restore_tags(entry, page)) {
+ set_page_mte_tagged(page);
return;
+ }
}
if (!pte_is_tagged)
return;
mte_clear_page_tags(page_address(page));
+ set_page_mte_tagged(page);
}
void mte_sync_tags(pte_t old_pte, pte_t pte)
@@ -64,7 +67,7 @@ void mte_sync_tags(pte_t old_pte, pte_t pte)
/* if PG_mte_tagged is set, tags have already been initialised */
for (i = 0; i < nr_pages; i++, page++) {
- if (!test_and_set_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
mte_sync_page_tags(page, old_pte, check_swap,
pte_is_tagged);
}
@@ -91,8 +94,7 @@ int memcmp_pages(struct page *page1, struct page *page2)
* pages is tagged, set_pte_at() may zero or change the tags of the
* other page via mte_sync_tags().
*/
- if (test_bit(PG_mte_tagged, &page1->flags) ||
- test_bit(PG_mte_tagged, &page2->flags))
+ if (page_mte_tagged(page1) || page_mte_tagged(page2))
return addr1 != addr2;
return ret;
@@ -398,7 +400,7 @@ static int __access_remote_tags(struct mm_struct *mm, unsigned long addr,
put_page(page);
break;
}
- WARN_ON_ONCE(!test_bit(PG_mte_tagged, &page->flags));
+ WARN_ON_ONCE(!page_mte_tagged(page));
/* limit access to the end of the page */
offset = offset_in_page(addr);
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 8c607199cad1..3b04e69006b4 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -1058,7 +1058,7 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
maddr = page_address(page);
if (!write) {
- if (test_bit(PG_mte_tagged, &page->flags))
+ if (page_mte_tagged(page))
num_tags = mte_copy_tags_to_user(tags, maddr,
MTE_GRANULES_PER_PAGE);
else
@@ -1075,7 +1075,7 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
* completed fully
*/
if (num_tags == MTE_GRANULES_PER_PAGE)
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
kvm_release_pfn_dirty(pfn);
}
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 87f1cd0df36e..c9012707f69c 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1075,9 +1075,9 @@ static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
return -EFAULT;
for (i = 0; i < nr_pages; i++, page++) {
- if (!test_bit(PG_mte_tagged, &page->flags)) {
+ if (!page_mte_tagged(page)) {
mte_clear_page_tags(page_address(page));
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
}
}
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 24913271e898..4223389b6180 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -21,9 +21,9 @@ void copy_highpage(struct page *to, struct page *from)
copy_page(kto, kfrom);
- if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
- set_bit(PG_mte_tagged, &to->flags);
+ if (system_supports_mte() && page_mte_tagged(from)) {
mte_copy_page_tags(kto, kfrom);
+ set_page_mte_tagged(to);
}
}
EXPORT_SYMBOL(copy_highpage);
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index c33f1fad2745..d095bfa16771 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -931,5 +931,5 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
void tag_clear_highpage(struct page *page)
{
mte_zero_clear_page_tags(page_address(page));
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
index 4334dec93bd4..a78c1db23c68 100644
--- a/arch/arm64/mm/mteswap.c
+++ b/arch/arm64/mm/mteswap.c
@@ -24,7 +24,7 @@ int mte_save_tags(struct page *page)
{
void *tag_storage, *ret;
- if (!test_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
return 0;
tag_storage = mte_allocate_tag_storage();
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Catalin Marinas, Cornelia Huck, Will Deacon, Marc Zyngier,
Evgenii Stepanov, kvm, Steven Price, Vincenzo Frascino,
Peter Collingbourne
From: Catalin Marinas <catalin.marinas@arm.com>
Currently the PG_mte_tagged page flag mostly means the page contains
valid tags and it should be set after the tags have been cleared or
restored. However, in mte_sync_tags() it is set before setting the tags
to avoid, in theory, a race with concurrent mprotect(PROT_MTE) for
shared pages. However, a concurrent mprotect(PROT_MTE) with a copy on
write in another thread can cause the new page to have stale tags.
Similarly, tag reading via ptrace() can read stale tags of the
PG_mte_tagged flag is set before actually clearing/restoring the tags.
Fix the PG_mte_tagged semantics so that it is only set after the tags
have been cleared or restored. This is safe for swap restoring into a
MAP_SHARED or CoW page since the core code takes the page lock. Add two
functions to test and set the PG_mte_tagged flag with acquire and
release semantics. The downside is that concurrent mprotect(PROT_MTE) on
a MAP_SHARED page may cause tag loss. This is already the case for KVM
guests if a VMM changes the page protection while the guest triggers a
user_mem_abort().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/include/asm/mte.h | 30 ++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 2 +-
arch/arm64/kernel/cpufeature.c | 4 +++-
arch/arm64/kernel/elfcore.c | 2 +-
arch/arm64/kernel/hibernate.c | 2 +-
arch/arm64/kernel/mte.c | 12 +++++++-----
arch/arm64/kvm/guest.c | 4 ++--
arch/arm64/kvm/mmu.c | 4 ++--
arch/arm64/mm/copypage.c | 4 ++--
arch/arm64/mm/fault.c | 2 +-
arch/arm64/mm/mteswap.c | 2 +-
11 files changed, 51 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index aa523591a44e..c69218c56980 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -37,6 +37,29 @@ void mte_free_tag_storage(char *storage);
/* track which pages have valid allocation tags */
#define PG_mte_tagged PG_arch_2
+static inline void set_page_mte_tagged(struct page *page)
+{
+ /*
+ * Ensure that the tags written prior to this function are visible
+ * before the page flags update.
+ */
+ smp_wmb();
+ set_bit(PG_mte_tagged, &page->flags);
+}
+
+static inline bool page_mte_tagged(struct page *page)
+{
+ bool ret = test_bit(PG_mte_tagged, &page->flags);
+
+ /*
+ * If the page is tagged, ensure ordering with a likely subsequent
+ * read of the tags.
+ */
+ if (ret)
+ smp_rmb();
+ return ret;
+}
+
void mte_zero_clear_page_tags(void *addr);
void mte_sync_tags(pte_t old_pte, pte_t pte);
void mte_copy_page_tags(void *kto, const void *kfrom);
@@ -54,6 +77,13 @@ size_t mte_probe_user_range(const char __user *uaddr, size_t size);
/* unused if !CONFIG_ARM64_MTE, silence the compiler */
#define PG_mte_tagged 0
+static inline set_page_mte_tagged(struct page *page)
+{
+}
+static inline bool page_mte_tagged(struct page *page)
+{
+ return false;
+}
static inline void mte_zero_clear_page_tags(void *addr)
{
}
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index b5df82aa99e6..82719fa42c0e 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1050,7 +1050,7 @@ static inline void arch_swap_invalidate_area(int type)
static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
{
if (system_supports_mte() && mte_restore_tags(entry, &folio->page))
- set_bit(PG_mte_tagged, &folio->flags);
+ set_page_mte_tagged(&folio->page);
}
#endif /* CONFIG_ARM64_MTE */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index fae4c7a785d8..c66f0ffaaf47 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2020,8 +2020,10 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
* Clear the tags in the zero page. This needs to be done via the
* linear map which has the Tagged attribute.
*/
- if (!test_and_set_bit(PG_mte_tagged, &ZERO_PAGE(0)->flags))
+ if (!page_mte_tagged(ZERO_PAGE(0))) {
mte_clear_page_tags(lm_alias(empty_zero_page));
+ set_page_mte_tagged(ZERO_PAGE(0));
+ }
kasan_init_hw_tags_cpu();
}
diff --git a/arch/arm64/kernel/elfcore.c b/arch/arm64/kernel/elfcore.c
index 27ef7ad3ffd2..353009d7f307 100644
--- a/arch/arm64/kernel/elfcore.c
+++ b/arch/arm64/kernel/elfcore.c
@@ -47,7 +47,7 @@ static int mte_dump_tag_range(struct coredump_params *cprm,
* Pages mapped in user space as !pte_access_permitted() (e.g.
* PROT_EXEC only) may not have the PG_mte_tagged flag set.
*/
- if (!test_bit(PG_mte_tagged, &page->flags)) {
+ if (!page_mte_tagged(page)) {
put_page(page);
dump_skip(cprm, MTE_PAGE_TAG_STORAGE);
continue;
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index af5df48ba915..788597a6b6a2 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -271,7 +271,7 @@ static int swsusp_mte_save_tags(void)
if (!page)
continue;
- if (!test_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
continue;
ret = save_tags(page, pfn);
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index b2b730233274..2287316639f3 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -41,14 +41,17 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (check_swap && is_swap_pte(old_pte)) {
swp_entry_t entry = pte_to_swp_entry(old_pte);
- if (!non_swap_entry(entry) && mte_restore_tags(entry, page))
+ if (!non_swap_entry(entry) && mte_restore_tags(entry, page)) {
+ set_page_mte_tagged(page);
return;
+ }
}
if (!pte_is_tagged)
return;
mte_clear_page_tags(page_address(page));
+ set_page_mte_tagged(page);
}
void mte_sync_tags(pte_t old_pte, pte_t pte)
@@ -64,7 +67,7 @@ void mte_sync_tags(pte_t old_pte, pte_t pte)
/* if PG_mte_tagged is set, tags have already been initialised */
for (i = 0; i < nr_pages; i++, page++) {
- if (!test_and_set_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
mte_sync_page_tags(page, old_pte, check_swap,
pte_is_tagged);
}
@@ -91,8 +94,7 @@ int memcmp_pages(struct page *page1, struct page *page2)
* pages is tagged, set_pte_at() may zero or change the tags of the
* other page via mte_sync_tags().
*/
- if (test_bit(PG_mte_tagged, &page1->flags) ||
- test_bit(PG_mte_tagged, &page2->flags))
+ if (page_mte_tagged(page1) || page_mte_tagged(page2))
return addr1 != addr2;
return ret;
@@ -398,7 +400,7 @@ static int __access_remote_tags(struct mm_struct *mm, unsigned long addr,
put_page(page);
break;
}
- WARN_ON_ONCE(!test_bit(PG_mte_tagged, &page->flags));
+ WARN_ON_ONCE(!page_mte_tagged(page));
/* limit access to the end of the page */
offset = offset_in_page(addr);
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 8c607199cad1..3b04e69006b4 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -1058,7 +1058,7 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
maddr = page_address(page);
if (!write) {
- if (test_bit(PG_mte_tagged, &page->flags))
+ if (page_mte_tagged(page))
num_tags = mte_copy_tags_to_user(tags, maddr,
MTE_GRANULES_PER_PAGE);
else
@@ -1075,7 +1075,7 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
* completed fully
*/
if (num_tags == MTE_GRANULES_PER_PAGE)
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
kvm_release_pfn_dirty(pfn);
}
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 87f1cd0df36e..c9012707f69c 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1075,9 +1075,9 @@ static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
return -EFAULT;
for (i = 0; i < nr_pages; i++, page++) {
- if (!test_bit(PG_mte_tagged, &page->flags)) {
+ if (!page_mte_tagged(page)) {
mte_clear_page_tags(page_address(page));
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
}
}
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 24913271e898..4223389b6180 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -21,9 +21,9 @@ void copy_highpage(struct page *to, struct page *from)
copy_page(kto, kfrom);
- if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
- set_bit(PG_mte_tagged, &to->flags);
+ if (system_supports_mte() && page_mte_tagged(from)) {
mte_copy_page_tags(kto, kfrom);
+ set_page_mte_tagged(to);
}
}
EXPORT_SYMBOL(copy_highpage);
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index c33f1fad2745..d095bfa16771 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -931,5 +931,5 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
void tag_clear_highpage(struct page *page)
{
mte_zero_clear_page_tags(page_address(page));
- set_bit(PG_mte_tagged, &page->flags);
+ set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
index 4334dec93bd4..a78c1db23c68 100644
--- a/arch/arm64/mm/mteswap.c
+++ b/arch/arm64/mm/mteswap.c
@@ -24,7 +24,7 @@ int mte_save_tags(struct page *page)
{
void *tag_storage, *ret;
- if (!test_bit(PG_mte_tagged, &page->flags))
+ if (!page_mte_tagged(page))
return 0;
tag_storage = mte_allocate_tag_storage();
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 2/7] KVM: arm64: Simplify the sanitise_mte_tags() logic
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-22 1:50 ` Peter Collingbourne
-1 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Catalin Marinas, Cornelia Huck, Will Deacon, Marc Zyngier,
Evgenii Stepanov, kvm, Steven Price, Vincenzo Frascino,
Peter Collingbourne
From: Catalin Marinas <catalin.marinas@arm.com>
Currently sanitise_mte_tags() checks if it's an online page before
attempting to sanitise the tags. Such detection should be done in the
caller via the VM_MTE_ALLOWED vma flag. Since kvm_set_spte_gfn() does
not have the vma, leave the page unmapped if not already tagged. Tag
initialisation will be done on a subsequent access fault in
user_mem_abort().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 40 +++++++++++++++-------------------------
1 file changed, 15 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index c9012707f69c..1a3707aeb41f 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1056,23 +1056,14 @@ static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva)
* - mmap_lock protects between a VM faulting a page in and the VMM performing
* an mprotect() to add VM_MTE
*/
-static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
- unsigned long size)
+static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
+ unsigned long size)
{
unsigned long i, nr_pages = size >> PAGE_SHIFT;
- struct page *page;
+ struct page *page = pfn_to_page(pfn);
if (!kvm_has_mte(kvm))
- return 0;
-
- /*
- * pfn_to_online_page() is used to reject ZONE_DEVICE pages
- * that may not support tags.
- */
- page = pfn_to_online_page(pfn);
-
- if (!page)
- return -EFAULT;
+ return;
for (i = 0; i < nr_pages; i++, page++) {
if (!page_mte_tagged(page)) {
@@ -1080,8 +1071,6 @@ static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
set_page_mte_tagged(page);
}
}
-
- return 0;
}
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
@@ -1092,7 +1081,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
bool write_fault, writable, force_pte = false;
bool exec_fault;
bool device = false;
- bool shared;
unsigned long mmu_seq;
struct kvm *kvm = vcpu->kvm;
struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
@@ -1142,8 +1130,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
vma_shift = get_vma_page_shift(vma, hva);
}
- shared = (vma->vm_flags & VM_SHARED);
-
switch (vma_shift) {
#ifndef __PAGETABLE_PMD_FOLDED
case PUD_SHIFT:
@@ -1264,12 +1250,13 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) {
/* Check the VMM hasn't introduced a new VM_SHARED VMA */
- if (!shared)
- ret = sanitise_mte_tags(kvm, pfn, vma_pagesize);
- else
+ if ((vma->vm_flags & VM_MTE_ALLOWED) &&
+ !(vma->vm_flags & VM_SHARED)) {
+ sanitise_mte_tags(kvm, pfn, vma_pagesize);
+ } else {
ret = -EFAULT;
- if (ret)
goto out_unlock;
+ }
}
if (writable)
@@ -1491,15 +1478,18 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
kvm_pfn_t pfn = pte_pfn(range->pte);
- int ret;
if (!kvm->arch.mmu.pgt)
return false;
WARN_ON(range->end - range->start != 1);
- ret = sanitise_mte_tags(kvm, pfn, PAGE_SIZE);
- if (ret)
+ /*
+ * If the page isn't tagged, defer to user_mem_abort() for sanitising
+ * the MTE tags. The S2 pte should have been unmapped by
+ * mmu_notifier_invalidate_range_end().
+ */
+ if (kvm_has_mte(kvm) && !page_mte_tagged(pfn_to_page(pfn)))
return false;
/*
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 2/7] KVM: arm64: Simplify the sanitise_mte_tags() logic
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: kvm, Peter Collingbourne, Catalin Marinas, Cornelia Huck,
Steven Price, Marc Zyngier, Vincenzo Frascino, Will Deacon,
Evgenii Stepanov
From: Catalin Marinas <catalin.marinas@arm.com>
Currently sanitise_mte_tags() checks if it's an online page before
attempting to sanitise the tags. Such detection should be done in the
caller via the VM_MTE_ALLOWED vma flag. Since kvm_set_spte_gfn() does
not have the vma, leave the page unmapped if not already tagged. Tag
initialisation will be done on a subsequent access fault in
user_mem_abort().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 40 +++++++++++++++-------------------------
1 file changed, 15 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index c9012707f69c..1a3707aeb41f 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1056,23 +1056,14 @@ static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva)
* - mmap_lock protects between a VM faulting a page in and the VMM performing
* an mprotect() to add VM_MTE
*/
-static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
- unsigned long size)
+static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
+ unsigned long size)
{
unsigned long i, nr_pages = size >> PAGE_SHIFT;
- struct page *page;
+ struct page *page = pfn_to_page(pfn);
if (!kvm_has_mte(kvm))
- return 0;
-
- /*
- * pfn_to_online_page() is used to reject ZONE_DEVICE pages
- * that may not support tags.
- */
- page = pfn_to_online_page(pfn);
-
- if (!page)
- return -EFAULT;
+ return;
for (i = 0; i < nr_pages; i++, page++) {
if (!page_mte_tagged(page)) {
@@ -1080,8 +1071,6 @@ static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
set_page_mte_tagged(page);
}
}
-
- return 0;
}
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
@@ -1092,7 +1081,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
bool write_fault, writable, force_pte = false;
bool exec_fault;
bool device = false;
- bool shared;
unsigned long mmu_seq;
struct kvm *kvm = vcpu->kvm;
struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
@@ -1142,8 +1130,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
vma_shift = get_vma_page_shift(vma, hva);
}
- shared = (vma->vm_flags & VM_SHARED);
-
switch (vma_shift) {
#ifndef __PAGETABLE_PMD_FOLDED
case PUD_SHIFT:
@@ -1264,12 +1250,13 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) {
/* Check the VMM hasn't introduced a new VM_SHARED VMA */
- if (!shared)
- ret = sanitise_mte_tags(kvm, pfn, vma_pagesize);
- else
+ if ((vma->vm_flags & VM_MTE_ALLOWED) &&
+ !(vma->vm_flags & VM_SHARED)) {
+ sanitise_mte_tags(kvm, pfn, vma_pagesize);
+ } else {
ret = -EFAULT;
- if (ret)
goto out_unlock;
+ }
}
if (writable)
@@ -1491,15 +1478,18 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
kvm_pfn_t pfn = pte_pfn(range->pte);
- int ret;
if (!kvm->arch.mmu.pgt)
return false;
WARN_ON(range->end - range->start != 1);
- ret = sanitise_mte_tags(kvm, pfn, PAGE_SIZE);
- if (ret)
+ /*
+ * If the page isn't tagged, defer to user_mem_abort() for sanitising
+ * the MTE tags. The S2 pte should have been unmapped by
+ * mmu_notifier_invalidate_range_end().
+ */
+ if (kvm_has_mte(kvm) && !page_mte_tagged(pfn_to_page(pfn)))
return false;
/*
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 2/7] KVM: arm64: Simplify the sanitise_mte_tags() logic
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Catalin Marinas, Cornelia Huck, Will Deacon, Marc Zyngier,
Evgenii Stepanov, kvm, Steven Price, Vincenzo Frascino,
Peter Collingbourne
From: Catalin Marinas <catalin.marinas@arm.com>
Currently sanitise_mte_tags() checks if it's an online page before
attempting to sanitise the tags. Such detection should be done in the
caller via the VM_MTE_ALLOWED vma flag. Since kvm_set_spte_gfn() does
not have the vma, leave the page unmapped if not already tagged. Tag
initialisation will be done on a subsequent access fault in
user_mem_abort().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 40 +++++++++++++++-------------------------
1 file changed, 15 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index c9012707f69c..1a3707aeb41f 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1056,23 +1056,14 @@ static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva)
* - mmap_lock protects between a VM faulting a page in and the VMM performing
* an mprotect() to add VM_MTE
*/
-static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
- unsigned long size)
+static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
+ unsigned long size)
{
unsigned long i, nr_pages = size >> PAGE_SHIFT;
- struct page *page;
+ struct page *page = pfn_to_page(pfn);
if (!kvm_has_mte(kvm))
- return 0;
-
- /*
- * pfn_to_online_page() is used to reject ZONE_DEVICE pages
- * that may not support tags.
- */
- page = pfn_to_online_page(pfn);
-
- if (!page)
- return -EFAULT;
+ return;
for (i = 0; i < nr_pages; i++, page++) {
if (!page_mte_tagged(page)) {
@@ -1080,8 +1071,6 @@ static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
set_page_mte_tagged(page);
}
}
-
- return 0;
}
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
@@ -1092,7 +1081,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
bool write_fault, writable, force_pte = false;
bool exec_fault;
bool device = false;
- bool shared;
unsigned long mmu_seq;
struct kvm *kvm = vcpu->kvm;
struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
@@ -1142,8 +1130,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
vma_shift = get_vma_page_shift(vma, hva);
}
- shared = (vma->vm_flags & VM_SHARED);
-
switch (vma_shift) {
#ifndef __PAGETABLE_PMD_FOLDED
case PUD_SHIFT:
@@ -1264,12 +1250,13 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) {
/* Check the VMM hasn't introduced a new VM_SHARED VMA */
- if (!shared)
- ret = sanitise_mte_tags(kvm, pfn, vma_pagesize);
- else
+ if ((vma->vm_flags & VM_MTE_ALLOWED) &&
+ !(vma->vm_flags & VM_SHARED)) {
+ sanitise_mte_tags(kvm, pfn, vma_pagesize);
+ } else {
ret = -EFAULT;
- if (ret)
goto out_unlock;
+ }
}
if (writable)
@@ -1491,15 +1478,18 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
kvm_pfn_t pfn = pte_pfn(range->pte);
- int ret;
if (!kvm->arch.mmu.pgt)
return false;
WARN_ON(range->end - range->start != 1);
- ret = sanitise_mte_tags(kvm, pfn, PAGE_SIZE);
- if (ret)
+ /*
+ * If the page isn't tagged, defer to user_mem_abort() for sanitising
+ * the MTE tags. The S2 pte should have been unmapped by
+ * mmu_notifier_invalidate_range_end().
+ */
+ if (kvm_has_mte(kvm) && !page_mte_tagged(pfn_to_page(pfn)))
return false;
/*
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 3/7] mm: Add PG_arch_3 page flag
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-22 1:50 ` Peter Collingbourne
-1 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
As with PG_arch_2, this flag is only allowed on 64-bit architectures due
to the shortage of bits available. It will be used by the arm64 MTE code
in subsequent patches.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
[catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
fs/proc/page.c | 1 +
include/linux/page-flags.h | 1 +
include/trace/events/mmflags.h | 7 ++++---
mm/huge_memory.c | 1 +
4 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/proc/page.c b/fs/proc/page.c
index a2873a617ae8..438b8aa7249d 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
#ifdef CONFIG_64BIT
u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
+ u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
#endif
return u;
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 465ff35a8c00..ad01a3abf6c8 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -134,6 +134,7 @@ enum pageflags {
#endif
#ifdef CONFIG_64BIT
PG_arch_2,
+ PG_arch_3,
#endif
#ifdef CONFIG_KASAN_HW_TAGS
PG_skip_kasan_poison,
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 11524cda4a95..704380179986 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -91,9 +91,9 @@
#endif
#ifdef CONFIG_64BIT
-#define IF_HAVE_PG_ARCH_2(flag,string) ,{1UL << flag, string}
+#define IF_HAVE_PG_ARCH_2_3(flag,string) ,{1UL << flag, string}
#else
-#define IF_HAVE_PG_ARCH_2(flag,string)
+#define IF_HAVE_PG_ARCH_2_3(flag,string)
#endif
#ifdef CONFIG_KASAN_HW_TAGS
@@ -129,7 +129,8 @@ IF_HAVE_PG_UNCACHED(PG_uncached, "uncached" ) \
IF_HAVE_PG_HWPOISON(PG_hwpoison, "hwpoison" ) \
IF_HAVE_PG_IDLE(PG_young, "young" ) \
IF_HAVE_PG_IDLE(PG_idle, "idle" ) \
-IF_HAVE_PG_ARCH_2(PG_arch_2, "arch_2" ) \
+IF_HAVE_PG_ARCH_2_3(PG_arch_2, "arch_2" ) \
+IF_HAVE_PG_ARCH_2_3(PG_arch_3, "arch_3" ) \
IF_HAVE_PG_SKIP_KASAN_POISON(PG_skip_kasan_poison, "skip_kasan_poison")
#define show_page_flags(flags) \
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 8320874901f1..d6e8789e9ebb 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2399,6 +2399,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
(1L << PG_unevictable) |
#ifdef CONFIG_64BIT
(1L << PG_arch_2) |
+ (1L << PG_arch_3) |
#endif
(1L << PG_dirty)));
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 3/7] mm: Add PG_arch_3 page flag
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: kvm, Will Deacon, Catalin Marinas, Cornelia Huck, Steven Price,
Marc Zyngier, Vincenzo Frascino, Peter Collingbourne,
Evgenii Stepanov
As with PG_arch_2, this flag is only allowed on 64-bit architectures due
to the shortage of bits available. It will be used by the arm64 MTE code
in subsequent patches.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
[catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
fs/proc/page.c | 1 +
include/linux/page-flags.h | 1 +
include/trace/events/mmflags.h | 7 ++++---
mm/huge_memory.c | 1 +
4 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/proc/page.c b/fs/proc/page.c
index a2873a617ae8..438b8aa7249d 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
#ifdef CONFIG_64BIT
u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
+ u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
#endif
return u;
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 465ff35a8c00..ad01a3abf6c8 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -134,6 +134,7 @@ enum pageflags {
#endif
#ifdef CONFIG_64BIT
PG_arch_2,
+ PG_arch_3,
#endif
#ifdef CONFIG_KASAN_HW_TAGS
PG_skip_kasan_poison,
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 11524cda4a95..704380179986 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -91,9 +91,9 @@
#endif
#ifdef CONFIG_64BIT
-#define IF_HAVE_PG_ARCH_2(flag,string) ,{1UL << flag, string}
+#define IF_HAVE_PG_ARCH_2_3(flag,string) ,{1UL << flag, string}
#else
-#define IF_HAVE_PG_ARCH_2(flag,string)
+#define IF_HAVE_PG_ARCH_2_3(flag,string)
#endif
#ifdef CONFIG_KASAN_HW_TAGS
@@ -129,7 +129,8 @@ IF_HAVE_PG_UNCACHED(PG_uncached, "uncached" ) \
IF_HAVE_PG_HWPOISON(PG_hwpoison, "hwpoison" ) \
IF_HAVE_PG_IDLE(PG_young, "young" ) \
IF_HAVE_PG_IDLE(PG_idle, "idle" ) \
-IF_HAVE_PG_ARCH_2(PG_arch_2, "arch_2" ) \
+IF_HAVE_PG_ARCH_2_3(PG_arch_2, "arch_2" ) \
+IF_HAVE_PG_ARCH_2_3(PG_arch_3, "arch_3" ) \
IF_HAVE_PG_SKIP_KASAN_POISON(PG_skip_kasan_poison, "skip_kasan_poison")
#define show_page_flags(flags) \
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 8320874901f1..d6e8789e9ebb 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2399,6 +2399,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
(1L << PG_unevictable) |
#ifdef CONFIG_64BIT
(1L << PG_arch_2) |
+ (1L << PG_arch_3) |
#endif
(1L << PG_dirty)));
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 3/7] mm: Add PG_arch_3 page flag
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
As with PG_arch_2, this flag is only allowed on 64-bit architectures due
to the shortage of bits available. It will be used by the arm64 MTE code
in subsequent patches.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
[catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
fs/proc/page.c | 1 +
include/linux/page-flags.h | 1 +
include/trace/events/mmflags.h | 7 ++++---
mm/huge_memory.c | 1 +
4 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/proc/page.c b/fs/proc/page.c
index a2873a617ae8..438b8aa7249d 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
#ifdef CONFIG_64BIT
u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
+ u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
#endif
return u;
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 465ff35a8c00..ad01a3abf6c8 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -134,6 +134,7 @@ enum pageflags {
#endif
#ifdef CONFIG_64BIT
PG_arch_2,
+ PG_arch_3,
#endif
#ifdef CONFIG_KASAN_HW_TAGS
PG_skip_kasan_poison,
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 11524cda4a95..704380179986 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -91,9 +91,9 @@
#endif
#ifdef CONFIG_64BIT
-#define IF_HAVE_PG_ARCH_2(flag,string) ,{1UL << flag, string}
+#define IF_HAVE_PG_ARCH_2_3(flag,string) ,{1UL << flag, string}
#else
-#define IF_HAVE_PG_ARCH_2(flag,string)
+#define IF_HAVE_PG_ARCH_2_3(flag,string)
#endif
#ifdef CONFIG_KASAN_HW_TAGS
@@ -129,7 +129,8 @@ IF_HAVE_PG_UNCACHED(PG_uncached, "uncached" ) \
IF_HAVE_PG_HWPOISON(PG_hwpoison, "hwpoison" ) \
IF_HAVE_PG_IDLE(PG_young, "young" ) \
IF_HAVE_PG_IDLE(PG_idle, "idle" ) \
-IF_HAVE_PG_ARCH_2(PG_arch_2, "arch_2" ) \
+IF_HAVE_PG_ARCH_2_3(PG_arch_2, "arch_2" ) \
+IF_HAVE_PG_ARCH_2_3(PG_arch_3, "arch_3" ) \
IF_HAVE_PG_SKIP_KASAN_POISON(PG_skip_kasan_poison, "skip_kasan_poison")
#define show_page_flags(flags) \
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 8320874901f1..d6e8789e9ebb 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2399,6 +2399,7 @@ static void __split_huge_page_tail(struct page *head, int tail,
(1L << PG_unevictable) |
#ifdef CONFIG_64BIT
(1L << PG_arch_2) |
+ (1L << PG_arch_3) |
#endif
(1L << PG_dirty)));
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 4/7] arm64: mte: Lock a page for MTE tag initialisation
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-22 1:50 ` Peter Collingbourne
-1 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Catalin Marinas, Cornelia Huck, Will Deacon, Marc Zyngier,
Evgenii Stepanov, kvm, Steven Price, Vincenzo Frascino,
Peter Collingbourne
From: Catalin Marinas <catalin.marinas@arm.com>
Initialising the tags and setting PG_mte_tagged flag for a page can race
between multiple set_pte_at() on shared pages or setting the stage 2 pte
via user_mem_abort(). Introduce a new PG_mte_lock flag as PG_arch_3 and
set it before attempting page initialisation. Given that PG_mte_tagged
is never cleared for a page, consider setting this flag to mean page
unlocked and wait on this bit with acquire semantics if the page is
locked:
- try_page_mte_tagging() - lock the page for tagging, return true if it
can be tagged, false if already tagged. No acquire semantics if it
returns true (PG_mte_tagged not set) as there is no serialisation with
a previous set_page_mte_tagged().
- set_page_mte_tagged() - set PG_mte_tagged with release semantics.
The two-bit locking is based on Peter Collingbourne's idea.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/include/asm/mte.h | 32 ++++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 1 +
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/mte.c | 7 +++++--
arch/arm64/kvm/guest.c | 16 ++++++++++------
arch/arm64/kvm/mmu.c | 2 +-
arch/arm64/mm/copypage.c | 2 ++
arch/arm64/mm/fault.c | 2 ++
arch/arm64/mm/mteswap.c | 3 +++
9 files changed, 57 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index c69218c56980..8e007046bba6 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -36,6 +36,8 @@ void mte_free_tag_storage(char *storage);
/* track which pages have valid allocation tags */
#define PG_mte_tagged PG_arch_2
+/* simple lock to avoid multiple threads tagging the same page */
+#define PG_mte_lock PG_arch_3
static inline void set_page_mte_tagged(struct page *page)
{
@@ -60,6 +62,32 @@ static inline bool page_mte_tagged(struct page *page)
return ret;
}
+/*
+ * Lock the page for tagging and return 'true' if the page can be tagged,
+ * 'false' if already tagged. PG_mte_tagged is never cleared and therefore the
+ * locking only happens once for page initialisation.
+ *
+ * The page MTE lock state:
+ *
+ * Locked: PG_mte_lock && !PG_mte_tagged
+ * Unlocked: !PG_mte_lock || PG_mte_tagged
+ *
+ * Acquire semantics only if the page is tagged (returning 'false').
+ */
+static inline bool try_page_mte_tagging(struct page *page)
+{
+ if (!test_and_set_bit(PG_mte_lock, &page->flags))
+ return true;
+
+ /*
+ * The tags are either being initialised or have already been initialised,
+ * wait for the PG_mte_tagged flag to be set.
+ */
+ smp_cond_load_acquire(&page->flags, VAL & (1UL << PG_mte_tagged));
+
+ return false;
+}
+
void mte_zero_clear_page_tags(void *addr);
void mte_sync_tags(pte_t old_pte, pte_t pte);
void mte_copy_page_tags(void *kto, const void *kfrom);
@@ -84,6 +112,10 @@ static inline bool page_mte_tagged(struct page *page)
{
return false;
}
+static inline bool try_page_mte_tagging(struct page *page)
+{
+ return false;
+}
static inline void mte_zero_clear_page_tags(void *addr)
{
}
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 82719fa42c0e..e6b82ad1e9e6 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1049,6 +1049,7 @@ static inline void arch_swap_invalidate_area(int type)
#define __HAVE_ARCH_SWAP_RESTORE
static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
{
+ /* mte_restore_tags() takes the PG_mte_lock */
if (system_supports_mte() && mte_restore_tags(entry, &folio->page))
set_page_mte_tagged(&folio->page);
}
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c66f0ffaaf47..31787dafe95e 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2020,7 +2020,7 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
* Clear the tags in the zero page. This needs to be done via the
* linear map which has the Tagged attribute.
*/
- if (!page_mte_tagged(ZERO_PAGE(0))) {
+ if (try_page_mte_tagging(ZERO_PAGE(0))) {
mte_clear_page_tags(lm_alias(empty_zero_page));
set_page_mte_tagged(ZERO_PAGE(0));
}
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index 2287316639f3..634e089b5933 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -41,6 +41,7 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (check_swap && is_swap_pte(old_pte)) {
swp_entry_t entry = pte_to_swp_entry(old_pte);
+ /* mte_restore_tags() takes the PG_mte_lock */
if (!non_swap_entry(entry) && mte_restore_tags(entry, page)) {
set_page_mte_tagged(page);
return;
@@ -50,8 +51,10 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (!pte_is_tagged)
return;
- mte_clear_page_tags(page_address(page));
- set_page_mte_tagged(page);
+ if (try_page_mte_tagging(page)) {
+ mte_clear_page_tags(page_address(page));
+ set_page_mte_tagged(page);
+ }
}
void mte_sync_tags(pte_t old_pte, pte_t pte)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 3b04e69006b4..059b38e7a9e8 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -1067,15 +1067,19 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
clear_user(tags, MTE_GRANULES_PER_PAGE);
kvm_release_pfn_clean(pfn);
} else {
+ /*
+ * Only locking to serialise with a concurrent
+ * set_pte_at() in the VMM but still overriding the
+ * tags, hence ignoring the return value.
+ */
+ try_page_mte_tagging(page);
num_tags = mte_copy_tags_from_user(maddr, tags,
MTE_GRANULES_PER_PAGE);
- /*
- * Set the flag after checking the write
- * completed fully
- */
- if (num_tags == MTE_GRANULES_PER_PAGE)
- set_page_mte_tagged(page);
+ /* uaccess failed, don't leave stale tags */
+ if (num_tags != MTE_GRANULES_PER_PAGE)
+ mte_clear_page_tags(page);
+ set_page_mte_tagged(page);
kvm_release_pfn_dirty(pfn);
}
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 1a3707aeb41f..750a69a97994 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1066,7 +1066,7 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
return;
for (i = 0; i < nr_pages; i++, page++) {
- if (!page_mte_tagged(page)) {
+ if (try_page_mte_tagging(page)) {
mte_clear_page_tags(page_address(page));
set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 4223389b6180..a3fa650ceca4 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -22,6 +22,8 @@ void copy_highpage(struct page *to, struct page *from)
copy_page(kto, kfrom);
if (system_supports_mte() && page_mte_tagged(from)) {
+ /* It's a new page, shouldn't have been tagged yet */
+ WARN_ON_ONCE(!try_page_mte_tagging(to));
mte_copy_page_tags(kto, kfrom);
set_page_mte_tagged(to);
}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index d095bfa16771..6407a29cab0d 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -930,6 +930,8 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
void tag_clear_highpage(struct page *page)
{
+ /* Newly allocated page, shouldn't have been tagged yet */
+ WARN_ON_ONCE(!try_page_mte_tagging(page));
mte_zero_clear_page_tags(page_address(page));
set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
index a78c1db23c68..cd5ad0936e16 100644
--- a/arch/arm64/mm/mteswap.c
+++ b/arch/arm64/mm/mteswap.c
@@ -53,6 +53,9 @@ bool mte_restore_tags(swp_entry_t entry, struct page *page)
if (!tags)
return false;
+ /* racing tag restoring? */
+ if (!try_page_mte_tagging(page))
+ return false;
mte_restore_page_tags(page_address(page), tags);
return true;
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 4/7] arm64: mte: Lock a page for MTE tag initialisation
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: kvm, Peter Collingbourne, Catalin Marinas, Cornelia Huck,
Steven Price, Marc Zyngier, Vincenzo Frascino, Will Deacon,
Evgenii Stepanov
From: Catalin Marinas <catalin.marinas@arm.com>
Initialising the tags and setting PG_mte_tagged flag for a page can race
between multiple set_pte_at() on shared pages or setting the stage 2 pte
via user_mem_abort(). Introduce a new PG_mte_lock flag as PG_arch_3 and
set it before attempting page initialisation. Given that PG_mte_tagged
is never cleared for a page, consider setting this flag to mean page
unlocked and wait on this bit with acquire semantics if the page is
locked:
- try_page_mte_tagging() - lock the page for tagging, return true if it
can be tagged, false if already tagged. No acquire semantics if it
returns true (PG_mte_tagged not set) as there is no serialisation with
a previous set_page_mte_tagged().
- set_page_mte_tagged() - set PG_mte_tagged with release semantics.
The two-bit locking is based on Peter Collingbourne's idea.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/include/asm/mte.h | 32 ++++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 1 +
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/mte.c | 7 +++++--
arch/arm64/kvm/guest.c | 16 ++++++++++------
arch/arm64/kvm/mmu.c | 2 +-
arch/arm64/mm/copypage.c | 2 ++
arch/arm64/mm/fault.c | 2 ++
arch/arm64/mm/mteswap.c | 3 +++
9 files changed, 57 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index c69218c56980..8e007046bba6 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -36,6 +36,8 @@ void mte_free_tag_storage(char *storage);
/* track which pages have valid allocation tags */
#define PG_mte_tagged PG_arch_2
+/* simple lock to avoid multiple threads tagging the same page */
+#define PG_mte_lock PG_arch_3
static inline void set_page_mte_tagged(struct page *page)
{
@@ -60,6 +62,32 @@ static inline bool page_mte_tagged(struct page *page)
return ret;
}
+/*
+ * Lock the page for tagging and return 'true' if the page can be tagged,
+ * 'false' if already tagged. PG_mte_tagged is never cleared and therefore the
+ * locking only happens once for page initialisation.
+ *
+ * The page MTE lock state:
+ *
+ * Locked: PG_mte_lock && !PG_mte_tagged
+ * Unlocked: !PG_mte_lock || PG_mte_tagged
+ *
+ * Acquire semantics only if the page is tagged (returning 'false').
+ */
+static inline bool try_page_mte_tagging(struct page *page)
+{
+ if (!test_and_set_bit(PG_mte_lock, &page->flags))
+ return true;
+
+ /*
+ * The tags are either being initialised or have already been initialised,
+ * wait for the PG_mte_tagged flag to be set.
+ */
+ smp_cond_load_acquire(&page->flags, VAL & (1UL << PG_mte_tagged));
+
+ return false;
+}
+
void mte_zero_clear_page_tags(void *addr);
void mte_sync_tags(pte_t old_pte, pte_t pte);
void mte_copy_page_tags(void *kto, const void *kfrom);
@@ -84,6 +112,10 @@ static inline bool page_mte_tagged(struct page *page)
{
return false;
}
+static inline bool try_page_mte_tagging(struct page *page)
+{
+ return false;
+}
static inline void mte_zero_clear_page_tags(void *addr)
{
}
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 82719fa42c0e..e6b82ad1e9e6 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1049,6 +1049,7 @@ static inline void arch_swap_invalidate_area(int type)
#define __HAVE_ARCH_SWAP_RESTORE
static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
{
+ /* mte_restore_tags() takes the PG_mte_lock */
if (system_supports_mte() && mte_restore_tags(entry, &folio->page))
set_page_mte_tagged(&folio->page);
}
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c66f0ffaaf47..31787dafe95e 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2020,7 +2020,7 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
* Clear the tags in the zero page. This needs to be done via the
* linear map which has the Tagged attribute.
*/
- if (!page_mte_tagged(ZERO_PAGE(0))) {
+ if (try_page_mte_tagging(ZERO_PAGE(0))) {
mte_clear_page_tags(lm_alias(empty_zero_page));
set_page_mte_tagged(ZERO_PAGE(0));
}
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index 2287316639f3..634e089b5933 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -41,6 +41,7 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (check_swap && is_swap_pte(old_pte)) {
swp_entry_t entry = pte_to_swp_entry(old_pte);
+ /* mte_restore_tags() takes the PG_mte_lock */
if (!non_swap_entry(entry) && mte_restore_tags(entry, page)) {
set_page_mte_tagged(page);
return;
@@ -50,8 +51,10 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (!pte_is_tagged)
return;
- mte_clear_page_tags(page_address(page));
- set_page_mte_tagged(page);
+ if (try_page_mte_tagging(page)) {
+ mte_clear_page_tags(page_address(page));
+ set_page_mte_tagged(page);
+ }
}
void mte_sync_tags(pte_t old_pte, pte_t pte)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 3b04e69006b4..059b38e7a9e8 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -1067,15 +1067,19 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
clear_user(tags, MTE_GRANULES_PER_PAGE);
kvm_release_pfn_clean(pfn);
} else {
+ /*
+ * Only locking to serialise with a concurrent
+ * set_pte_at() in the VMM but still overriding the
+ * tags, hence ignoring the return value.
+ */
+ try_page_mte_tagging(page);
num_tags = mte_copy_tags_from_user(maddr, tags,
MTE_GRANULES_PER_PAGE);
- /*
- * Set the flag after checking the write
- * completed fully
- */
- if (num_tags == MTE_GRANULES_PER_PAGE)
- set_page_mte_tagged(page);
+ /* uaccess failed, don't leave stale tags */
+ if (num_tags != MTE_GRANULES_PER_PAGE)
+ mte_clear_page_tags(page);
+ set_page_mte_tagged(page);
kvm_release_pfn_dirty(pfn);
}
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 1a3707aeb41f..750a69a97994 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1066,7 +1066,7 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
return;
for (i = 0; i < nr_pages; i++, page++) {
- if (!page_mte_tagged(page)) {
+ if (try_page_mte_tagging(page)) {
mte_clear_page_tags(page_address(page));
set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 4223389b6180..a3fa650ceca4 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -22,6 +22,8 @@ void copy_highpage(struct page *to, struct page *from)
copy_page(kto, kfrom);
if (system_supports_mte() && page_mte_tagged(from)) {
+ /* It's a new page, shouldn't have been tagged yet */
+ WARN_ON_ONCE(!try_page_mte_tagging(to));
mte_copy_page_tags(kto, kfrom);
set_page_mte_tagged(to);
}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index d095bfa16771..6407a29cab0d 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -930,6 +930,8 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
void tag_clear_highpage(struct page *page)
{
+ /* Newly allocated page, shouldn't have been tagged yet */
+ WARN_ON_ONCE(!try_page_mte_tagging(page));
mte_zero_clear_page_tags(page_address(page));
set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
index a78c1db23c68..cd5ad0936e16 100644
--- a/arch/arm64/mm/mteswap.c
+++ b/arch/arm64/mm/mteswap.c
@@ -53,6 +53,9 @@ bool mte_restore_tags(swp_entry_t entry, struct page *page)
if (!tags)
return false;
+ /* racing tag restoring? */
+ if (!try_page_mte_tagging(page))
+ return false;
mte_restore_page_tags(page_address(page), tags);
return true;
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 4/7] arm64: mte: Lock a page for MTE tag initialisation
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Catalin Marinas, Cornelia Huck, Will Deacon, Marc Zyngier,
Evgenii Stepanov, kvm, Steven Price, Vincenzo Frascino,
Peter Collingbourne
From: Catalin Marinas <catalin.marinas@arm.com>
Initialising the tags and setting PG_mte_tagged flag for a page can race
between multiple set_pte_at() on shared pages or setting the stage 2 pte
via user_mem_abort(). Introduce a new PG_mte_lock flag as PG_arch_3 and
set it before attempting page initialisation. Given that PG_mte_tagged
is never cleared for a page, consider setting this flag to mean page
unlocked and wait on this bit with acquire semantics if the page is
locked:
- try_page_mte_tagging() - lock the page for tagging, return true if it
can be tagged, false if already tagged. No acquire semantics if it
returns true (PG_mte_tagged not set) as there is no serialisation with
a previous set_page_mte_tagged().
- set_page_mte_tagged() - set PG_mte_tagged with release semantics.
The two-bit locking is based on Peter Collingbourne's idea.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
---
arch/arm64/include/asm/mte.h | 32 ++++++++++++++++++++++++++++++++
arch/arm64/include/asm/pgtable.h | 1 +
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/mte.c | 7 +++++--
arch/arm64/kvm/guest.c | 16 ++++++++++------
arch/arm64/kvm/mmu.c | 2 +-
arch/arm64/mm/copypage.c | 2 ++
arch/arm64/mm/fault.c | 2 ++
arch/arm64/mm/mteswap.c | 3 +++
9 files changed, 57 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index c69218c56980..8e007046bba6 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -36,6 +36,8 @@ void mte_free_tag_storage(char *storage);
/* track which pages have valid allocation tags */
#define PG_mte_tagged PG_arch_2
+/* simple lock to avoid multiple threads tagging the same page */
+#define PG_mte_lock PG_arch_3
static inline void set_page_mte_tagged(struct page *page)
{
@@ -60,6 +62,32 @@ static inline bool page_mte_tagged(struct page *page)
return ret;
}
+/*
+ * Lock the page for tagging and return 'true' if the page can be tagged,
+ * 'false' if already tagged. PG_mte_tagged is never cleared and therefore the
+ * locking only happens once for page initialisation.
+ *
+ * The page MTE lock state:
+ *
+ * Locked: PG_mte_lock && !PG_mte_tagged
+ * Unlocked: !PG_mte_lock || PG_mte_tagged
+ *
+ * Acquire semantics only if the page is tagged (returning 'false').
+ */
+static inline bool try_page_mte_tagging(struct page *page)
+{
+ if (!test_and_set_bit(PG_mte_lock, &page->flags))
+ return true;
+
+ /*
+ * The tags are either being initialised or have already been initialised,
+ * wait for the PG_mte_tagged flag to be set.
+ */
+ smp_cond_load_acquire(&page->flags, VAL & (1UL << PG_mte_tagged));
+
+ return false;
+}
+
void mte_zero_clear_page_tags(void *addr);
void mte_sync_tags(pte_t old_pte, pte_t pte);
void mte_copy_page_tags(void *kto, const void *kfrom);
@@ -84,6 +112,10 @@ static inline bool page_mte_tagged(struct page *page)
{
return false;
}
+static inline bool try_page_mte_tagging(struct page *page)
+{
+ return false;
+}
static inline void mte_zero_clear_page_tags(void *addr)
{
}
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 82719fa42c0e..e6b82ad1e9e6 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1049,6 +1049,7 @@ static inline void arch_swap_invalidate_area(int type)
#define __HAVE_ARCH_SWAP_RESTORE
static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
{
+ /* mte_restore_tags() takes the PG_mte_lock */
if (system_supports_mte() && mte_restore_tags(entry, &folio->page))
set_page_mte_tagged(&folio->page);
}
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c66f0ffaaf47..31787dafe95e 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2020,7 +2020,7 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
* Clear the tags in the zero page. This needs to be done via the
* linear map which has the Tagged attribute.
*/
- if (!page_mte_tagged(ZERO_PAGE(0))) {
+ if (try_page_mte_tagging(ZERO_PAGE(0))) {
mte_clear_page_tags(lm_alias(empty_zero_page));
set_page_mte_tagged(ZERO_PAGE(0));
}
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index 2287316639f3..634e089b5933 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -41,6 +41,7 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (check_swap && is_swap_pte(old_pte)) {
swp_entry_t entry = pte_to_swp_entry(old_pte);
+ /* mte_restore_tags() takes the PG_mte_lock */
if (!non_swap_entry(entry) && mte_restore_tags(entry, page)) {
set_page_mte_tagged(page);
return;
@@ -50,8 +51,10 @@ static void mte_sync_page_tags(struct page *page, pte_t old_pte,
if (!pte_is_tagged)
return;
- mte_clear_page_tags(page_address(page));
- set_page_mte_tagged(page);
+ if (try_page_mte_tagging(page)) {
+ mte_clear_page_tags(page_address(page));
+ set_page_mte_tagged(page);
+ }
}
void mte_sync_tags(pte_t old_pte, pte_t pte)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 3b04e69006b4..059b38e7a9e8 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -1067,15 +1067,19 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
clear_user(tags, MTE_GRANULES_PER_PAGE);
kvm_release_pfn_clean(pfn);
} else {
+ /*
+ * Only locking to serialise with a concurrent
+ * set_pte_at() in the VMM but still overriding the
+ * tags, hence ignoring the return value.
+ */
+ try_page_mte_tagging(page);
num_tags = mte_copy_tags_from_user(maddr, tags,
MTE_GRANULES_PER_PAGE);
- /*
- * Set the flag after checking the write
- * completed fully
- */
- if (num_tags == MTE_GRANULES_PER_PAGE)
- set_page_mte_tagged(page);
+ /* uaccess failed, don't leave stale tags */
+ if (num_tags != MTE_GRANULES_PER_PAGE)
+ mte_clear_page_tags(page);
+ set_page_mte_tagged(page);
kvm_release_pfn_dirty(pfn);
}
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 1a3707aeb41f..750a69a97994 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1066,7 +1066,7 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
return;
for (i = 0; i < nr_pages; i++, page++) {
- if (!page_mte_tagged(page)) {
+ if (try_page_mte_tagging(page)) {
mte_clear_page_tags(page_address(page));
set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 4223389b6180..a3fa650ceca4 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -22,6 +22,8 @@ void copy_highpage(struct page *to, struct page *from)
copy_page(kto, kfrom);
if (system_supports_mte() && page_mte_tagged(from)) {
+ /* It's a new page, shouldn't have been tagged yet */
+ WARN_ON_ONCE(!try_page_mte_tagging(to));
mte_copy_page_tags(kto, kfrom);
set_page_mte_tagged(to);
}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index d095bfa16771..6407a29cab0d 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -930,6 +930,8 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
void tag_clear_highpage(struct page *page)
{
+ /* Newly allocated page, shouldn't have been tagged yet */
+ WARN_ON_ONCE(!try_page_mte_tagging(page));
mte_zero_clear_page_tags(page_address(page));
set_page_mte_tagged(page);
}
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
index a78c1db23c68..cd5ad0936e16 100644
--- a/arch/arm64/mm/mteswap.c
+++ b/arch/arm64/mm/mteswap.c
@@ -53,6 +53,9 @@ bool mte_restore_tags(swp_entry_t entry, struct page *page)
if (!tags)
return false;
+ /* racing tag restoring? */
+ if (!try_page_mte_tagging(page))
+ return false;
mte_restore_page_tags(page_address(page), tags);
return true;
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 5/7] KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-22 1:50 ` Peter Collingbourne
-1 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
Previously we allowed creating a memslot containing a private mapping that
was not VM_MTE_ALLOWED, but would later reject KVM_RUN with -EFAULT. Now
we reject the memory region at memslot creation time.
Since this is a minor tweak to the ABI (a VMM that created one of
these memslots would fail later anyway), no VMM to my knowledge has
MTE support yet, and the hardware with the necessary features is not
generally available, we can probably make this ABI change at this point.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 750a69a97994..d54be80e31dd 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1073,6 +1073,19 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
}
}
+static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
+{
+ /*
+ * VM_SHARED mappings are not allowed with MTE to avoid races
+ * when updating the PG_mte_tagged page flag, see
+ * sanitise_mte_tags for more details.
+ */
+ if (vma->vm_flags & VM_SHARED)
+ return false;
+
+ return vma->vm_flags & VM_MTE_ALLOWED;
+}
+
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_memory_slot *memslot, unsigned long hva,
unsigned long fault_status)
@@ -1249,9 +1262,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
}
if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) {
- /* Check the VMM hasn't introduced a new VM_SHARED VMA */
- if ((vma->vm_flags & VM_MTE_ALLOWED) &&
- !(vma->vm_flags & VM_SHARED)) {
+ /* Check the VMM hasn't introduced a new disallowed VMA */
+ if (kvm_vma_mte_allowed(vma)) {
sanitise_mte_tags(kvm, pfn, vma_pagesize);
} else {
ret = -EFAULT;
@@ -1695,12 +1707,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
if (!vma)
break;
- /*
- * VM_SHARED mappings are not allowed with MTE to avoid races
- * when updating the PG_mte_tagged page flag, see
- * sanitise_mte_tags for more details.
- */
- if (kvm_has_mte(kvm) && vma->vm_flags & VM_SHARED) {
+ if (kvm_has_mte(kvm) && !kvm_vma_mte_allowed(vma)) {
ret = -EINVAL;
break;
}
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 5/7] KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: kvm, Will Deacon, Catalin Marinas, Cornelia Huck, Steven Price,
Marc Zyngier, Vincenzo Frascino, Peter Collingbourne,
Evgenii Stepanov
Previously we allowed creating a memslot containing a private mapping that
was not VM_MTE_ALLOWED, but would later reject KVM_RUN with -EFAULT. Now
we reject the memory region at memslot creation time.
Since this is a minor tweak to the ABI (a VMM that created one of
these memslots would fail later anyway), no VMM to my knowledge has
MTE support yet, and the hardware with the necessary features is not
generally available, we can probably make this ABI change at this point.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 750a69a97994..d54be80e31dd 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1073,6 +1073,19 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
}
}
+static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
+{
+ /*
+ * VM_SHARED mappings are not allowed with MTE to avoid races
+ * when updating the PG_mte_tagged page flag, see
+ * sanitise_mte_tags for more details.
+ */
+ if (vma->vm_flags & VM_SHARED)
+ return false;
+
+ return vma->vm_flags & VM_MTE_ALLOWED;
+}
+
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_memory_slot *memslot, unsigned long hva,
unsigned long fault_status)
@@ -1249,9 +1262,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
}
if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) {
- /* Check the VMM hasn't introduced a new VM_SHARED VMA */
- if ((vma->vm_flags & VM_MTE_ALLOWED) &&
- !(vma->vm_flags & VM_SHARED)) {
+ /* Check the VMM hasn't introduced a new disallowed VMA */
+ if (kvm_vma_mte_allowed(vma)) {
sanitise_mte_tags(kvm, pfn, vma_pagesize);
} else {
ret = -EFAULT;
@@ -1695,12 +1707,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
if (!vma)
break;
- /*
- * VM_SHARED mappings are not allowed with MTE to avoid races
- * when updating the PG_mte_tagged page flag, see
- * sanitise_mte_tags for more details.
- */
- if (kvm_has_mte(kvm) && vma->vm_flags & VM_SHARED) {
+ if (kvm_has_mte(kvm) && !kvm_vma_mte_allowed(vma)) {
ret = -EINVAL;
break;
}
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 5/7] KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
Previously we allowed creating a memslot containing a private mapping that
was not VM_MTE_ALLOWED, but would later reject KVM_RUN with -EFAULT. Now
we reject the memory region at memslot creation time.
Since this is a minor tweak to the ABI (a VMM that created one of
these memslots would fail later anyway), no VMM to my knowledge has
MTE support yet, and the hardware with the necessary features is not
generally available, we can probably make this ABI change at this point.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 750a69a97994..d54be80e31dd 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1073,6 +1073,19 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
}
}
+static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
+{
+ /*
+ * VM_SHARED mappings are not allowed with MTE to avoid races
+ * when updating the PG_mte_tagged page flag, see
+ * sanitise_mte_tags for more details.
+ */
+ if (vma->vm_flags & VM_SHARED)
+ return false;
+
+ return vma->vm_flags & VM_MTE_ALLOWED;
+}
+
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_memory_slot *memslot, unsigned long hva,
unsigned long fault_status)
@@ -1249,9 +1262,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
}
if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) {
- /* Check the VMM hasn't introduced a new VM_SHARED VMA */
- if ((vma->vm_flags & VM_MTE_ALLOWED) &&
- !(vma->vm_flags & VM_SHARED)) {
+ /* Check the VMM hasn't introduced a new disallowed VMA */
+ if (kvm_vma_mte_allowed(vma)) {
sanitise_mte_tags(kvm, pfn, vma_pagesize);
} else {
ret = -EFAULT;
@@ -1695,12 +1707,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
if (!vma)
break;
- /*
- * VM_SHARED mappings are not allowed with MTE to avoid races
- * when updating the PG_mte_tagged page flag, see
- * sanitise_mte_tags for more details.
- */
- if (kvm_has_mte(kvm) && vma->vm_flags & VM_SHARED) {
+ if (kvm_has_mte(kvm) && !kvm_vma_mte_allowed(vma)) {
ret = -EINVAL;
break;
}
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 6/7] KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-22 1:50 ` Peter Collingbourne
-1 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
Certain VMMs such as crosvm have features (e.g. sandboxing) that depend
on being able to map guest memory as MAP_SHARED. The current restriction
on sharing MAP_SHARED pages with the guest is preventing the use of
those features with MTE. Now that the races between tasks concurrently
clearing tags on the same page have been fixed, remove this restriction.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d54be80e31dd..fc65dc20655d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1075,14 +1075,6 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
{
- /*
- * VM_SHARED mappings are not allowed with MTE to avoid races
- * when updating the PG_mte_tagged page flag, see
- * sanitise_mte_tags for more details.
- */
- if (vma->vm_flags & VM_SHARED)
- return false;
-
return vma->vm_flags & VM_MTE_ALLOWED;
}
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 6/7] KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: kvm, Will Deacon, Catalin Marinas, Cornelia Huck, Steven Price,
Marc Zyngier, Vincenzo Frascino, Peter Collingbourne,
Evgenii Stepanov
Certain VMMs such as crosvm have features (e.g. sandboxing) that depend
on being able to map guest memory as MAP_SHARED. The current restriction
on sharing MAP_SHARED pages with the guest is preventing the use of
those features with MTE. Now that the races between tasks concurrently
clearing tags on the same page have been fixed, remove this restriction.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d54be80e31dd..fc65dc20655d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1075,14 +1075,6 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
{
- /*
- * VM_SHARED mappings are not allowed with MTE to avoid races
- * when updating the PG_mte_tagged page flag, see
- * sanitise_mte_tags for more details.
- */
- if (vma->vm_flags & VM_SHARED)
- return false;
-
return vma->vm_flags & VM_MTE_ALLOWED;
}
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 6/7] KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
Certain VMMs such as crosvm have features (e.g. sandboxing) that depend
on being able to map guest memory as MAP_SHARED. The current restriction
on sharing MAP_SHARED pages with the guest is preventing the use of
those features with MTE. Now that the races between tasks concurrently
clearing tags on the same page have been fixed, remove this restriction.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
arch/arm64/kvm/mmu.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d54be80e31dd..fc65dc20655d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1075,14 +1075,6 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
{
- /*
- * VM_SHARED mappings are not allowed with MTE to avoid races
- * when updating the PG_mte_tagged page flag, see
- * sanitise_mte_tags for more details.
- */
- if (vma->vm_flags & VM_SHARED)
- return false;
-
return vma->vm_flags & VM_MTE_ALLOWED;
}
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 7/7] Documentation: document the ABI changes for KVM_CAP_ARM_MTE
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-22 1:50 ` Peter Collingbourne
-1 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
Document both the restriction on VM_MTE_ALLOWED mappings and
the relaxation for shared mappings.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
Documentation/virt/kvm/api.rst | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index ebc5a519574f..5bb74b73bff3 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7486,8 +7486,9 @@ hibernation of the host; however the VMM needs to manually save/restore the
tags as appropriate if the VM is migrated.
When this capability is enabled all memory in memslots must be mapped as
-not-shareable (no MAP_SHARED), attempts to create a memslot with a
-MAP_SHARED mmap will result in an -EINVAL return.
+``MAP_ANONYMOUS`` or with a RAM-based file mapping (``tmpfs``, ``memfd``),
+attempts to create a memslot with an invalid mmap will result in an
+-EINVAL return.
When enabled the VMM may make use of the ``KVM_ARM_MTE_COPY_TAGS`` ioctl to
perform a bulk copy of tags to/from the guest.
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 7/7] Documentation: document the ABI changes for KVM_CAP_ARM_MTE
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: kvm, Will Deacon, Catalin Marinas, Cornelia Huck, Steven Price,
Marc Zyngier, Vincenzo Frascino, Peter Collingbourne,
Evgenii Stepanov
Document both the restriction on VM_MTE_ALLOWED mappings and
the relaxation for shared mappings.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
Documentation/virt/kvm/api.rst | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index ebc5a519574f..5bb74b73bff3 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7486,8 +7486,9 @@ hibernation of the host; however the VMM needs to manually save/restore the
tags as appropriate if the VM is migrated.
When this capability is enabled all memory in memslots must be mapped as
-not-shareable (no MAP_SHARED), attempts to create a memslot with a
-MAP_SHARED mmap will result in an -EINVAL return.
+``MAP_ANONYMOUS`` or with a RAM-based file mapping (``tmpfs``, ``memfd``),
+attempts to create a memslot with an invalid mmap will result in an
+-EINVAL return.
When enabled the VMM may make use of the ``KVM_ARM_MTE_COPY_TAGS`` ioctl to
perform a bulk copy of tags to/from the guest.
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 36+ messages in thread
* [PATCH v2 7/7] Documentation: document the ABI changes for KVM_CAP_ARM_MTE
@ 2022-07-22 1:50 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 1:50 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Peter Collingbourne, Cornelia Huck, Catalin Marinas, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
Document both the restriction on VM_MTE_ALLOWED mappings and
the relaxation for shared mappings.
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
Documentation/virt/kvm/api.rst | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index ebc5a519574f..5bb74b73bff3 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7486,8 +7486,9 @@ hibernation of the host; however the VMM needs to manually save/restore the
tags as appropriate if the VM is migrated.
When this capability is enabled all memory in memslots must be mapped as
-not-shareable (no MAP_SHARED), attempts to create a memslot with a
-MAP_SHARED mmap will result in an -EINVAL return.
+``MAP_ANONYMOUS`` or with a RAM-based file mapping (``tmpfs``, ``memfd``),
+attempts to create a memslot with an invalid mmap will result in an
+-EINVAL return.
When enabled the VMM may make use of the ``KVM_ARM_MTE_COPY_TAGS`` ioctl to
perform a bulk copy of tags to/from the guest.
--
2.37.1.359.gd136c6c3e2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 36+ messages in thread
* Re: [PATCH v2 3/7] mm: Add PG_arch_3 page flag
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-22 14:16 ` Marc Zyngier
-1 siblings, 0 replies; 36+ messages in thread
From: Marc Zyngier @ 2022-07-22 14:16 UTC (permalink / raw)
To: Peter Collingbourne
Cc: linux-arm-kernel, kvmarm, Cornelia Huck, Catalin Marinas,
Will Deacon, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
On Fri, 22 Jul 2022 02:50:29 +0100,
Peter Collingbourne <pcc@google.com> wrote:
>
> As with PG_arch_2, this flag is only allowed on 64-bit architectures due
> to the shortage of bits available. It will be used by the arm64 MTE code
> in subsequent patches.
>
> Signed-off-by: Peter Collingbourne <pcc@google.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Steven Price <steven.price@arm.com>
> [catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> ---
> fs/proc/page.c | 1 +
> include/linux/page-flags.h | 1 +
> include/trace/events/mmflags.h | 7 ++++---
> mm/huge_memory.c | 1 +
> 4 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/fs/proc/page.c b/fs/proc/page.c
> index a2873a617ae8..438b8aa7249d 100644
> --- a/fs/proc/page.c
> +++ b/fs/proc/page.c
> @@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
> u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
> #ifdef CONFIG_64BIT
> u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
> + u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
Are PG_arch_2 and PG_arch_3 supposed to share the same user bit in
/proc/kpageflags? This seems odd.
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply [flat|nested] 36+ messages in thread
* Re: [PATCH v2 3/7] mm: Add PG_arch_3 page flag
@ 2022-07-22 14:16 ` Marc Zyngier
0 siblings, 0 replies; 36+ messages in thread
From: Marc Zyngier @ 2022-07-22 14:16 UTC (permalink / raw)
To: Peter Collingbourne
Cc: kvm, Catalin Marinas, Cornelia Huck, Steven Price,
linux-arm-kernel, Vincenzo Frascino, Will Deacon, kvmarm,
Evgenii Stepanov
On Fri, 22 Jul 2022 02:50:29 +0100,
Peter Collingbourne <pcc@google.com> wrote:
>
> As with PG_arch_2, this flag is only allowed on 64-bit architectures due
> to the shortage of bits available. It will be used by the arm64 MTE code
> in subsequent patches.
>
> Signed-off-by: Peter Collingbourne <pcc@google.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Steven Price <steven.price@arm.com>
> [catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> ---
> fs/proc/page.c | 1 +
> include/linux/page-flags.h | 1 +
> include/trace/events/mmflags.h | 7 ++++---
> mm/huge_memory.c | 1 +
> 4 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/fs/proc/page.c b/fs/proc/page.c
> index a2873a617ae8..438b8aa7249d 100644
> --- a/fs/proc/page.c
> +++ b/fs/proc/page.c
> @@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
> u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
> #ifdef CONFIG_64BIT
> u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
> + u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
Are PG_arch_2 and PG_arch_3 supposed to share the same user bit in
/proc/kpageflags? This seems odd.
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 36+ messages in thread
* Re: [PATCH v2 3/7] mm: Add PG_arch_3 page flag
@ 2022-07-22 14:16 ` Marc Zyngier
0 siblings, 0 replies; 36+ messages in thread
From: Marc Zyngier @ 2022-07-22 14:16 UTC (permalink / raw)
To: Peter Collingbourne
Cc: linux-arm-kernel, kvmarm, Cornelia Huck, Catalin Marinas,
Will Deacon, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
On Fri, 22 Jul 2022 02:50:29 +0100,
Peter Collingbourne <pcc@google.com> wrote:
>
> As with PG_arch_2, this flag is only allowed on 64-bit architectures due
> to the shortage of bits available. It will be used by the arm64 MTE code
> in subsequent patches.
>
> Signed-off-by: Peter Collingbourne <pcc@google.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Steven Price <steven.price@arm.com>
> [catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> ---
> fs/proc/page.c | 1 +
> include/linux/page-flags.h | 1 +
> include/trace/events/mmflags.h | 7 ++++---
> mm/huge_memory.c | 1 +
> 4 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/fs/proc/page.c b/fs/proc/page.c
> index a2873a617ae8..438b8aa7249d 100644
> --- a/fs/proc/page.c
> +++ b/fs/proc/page.c
> @@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
> u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
> #ifdef CONFIG_64BIT
> u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
> + u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
Are PG_arch_2 and PG_arch_3 supposed to share the same user bit in
/proc/kpageflags? This seems odd.
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 36+ messages in thread
* Re: [PATCH v2 3/7] mm: Add PG_arch_3 page flag
2022-07-22 14:16 ` Marc Zyngier
(?)
@ 2022-07-22 17:04 ` Peter Collingbourne
-1 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 17:04 UTC (permalink / raw)
To: Marc Zyngier
Cc: linux-arm-kernel, kvmarm, Cornelia Huck, Catalin Marinas,
Will Deacon, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
On Fri, Jul 22, 2022 at 03:16:34PM +0100, Marc Zyngier wrote:
> On Fri, 22 Jul 2022 02:50:29 +0100,
> Peter Collingbourne <pcc@google.com> wrote:
> >
> > As with PG_arch_2, this flag is only allowed on 64-bit architectures due
> > to the shortage of bits available. It will be used by the arm64 MTE code
> > in subsequent patches.
> >
> > Signed-off-by: Peter Collingbourne <pcc@google.com>
> > Cc: Will Deacon <will@kernel.org>
> > Cc: Marc Zyngier <maz@kernel.org>
> > Cc: Steven Price <steven.price@arm.com>
> > [catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> > ---
> > fs/proc/page.c | 1 +
> > include/linux/page-flags.h | 1 +
> > include/trace/events/mmflags.h | 7 ++++---
> > mm/huge_memory.c | 1 +
> > 4 files changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/proc/page.c b/fs/proc/page.c
> > index a2873a617ae8..438b8aa7249d 100644
> > --- a/fs/proc/page.c
> > +++ b/fs/proc/page.c
> > @@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
> > u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
> > #ifdef CONFIG_64BIT
> > u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
> > + u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
>
> Are PG_arch_2 and PG_arch_3 supposed to share the same user bit in
> /proc/kpageflags? This seems odd.
No, that was an oversight, thanks for the catch. I will fix it up like
so in v3.
Peter
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 438b8aa7249d..0129aa3cfb7a 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -220,7 +220,7 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
#ifdef CONFIG_64BIT
u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
- u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
+ u |= kpf_copy_bit(k, KPF_ARCH_3, PG_arch_3);
#endif
return u;
diff --git a/include/linux/kernel-page-flags.h b/include/linux/kernel-page-flags.h
index eee1877a354e..859f4b0c1b2b 100644
--- a/include/linux/kernel-page-flags.h
+++ b/include/linux/kernel-page-flags.h
@@ -18,5 +18,6 @@
#define KPF_UNCACHED 39
#define KPF_SOFTDIRTY 40
#define KPF_ARCH_2 41
+#define KPF_ARCH_3 42
#endif /* LINUX_KERNEL_PAGE_FLAGS_H */
diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
index 381dcc00cb62..364373f5bba0 100644
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c
@@ -79,6 +79,7 @@
#define KPF_UNCACHED 39
#define KPF_SOFTDIRTY 40
#define KPF_ARCH_2 41
+#define KPF_ARCH_3 42
/* [47-] take some arbitrary free slots for expanding overloaded flags
* not part of kernel API
@@ -138,6 +139,7 @@ static const char * const page_flag_names[] = {
[KPF_UNCACHED] = "c:uncached",
[KPF_SOFTDIRTY] = "f:softdirty",
[KPF_ARCH_2] = "H:arch_2",
+ [KPF_ARCH_3] = "H:arch_3",
[KPF_ANON_EXCLUSIVE] = "d:anon_exclusive",
[KPF_READAHEAD] = "I:readahead",
^ permalink raw reply related [flat|nested] 36+ messages in thread
* Re: [PATCH v2 3/7] mm: Add PG_arch_3 page flag
@ 2022-07-22 17:04 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 17:04 UTC (permalink / raw)
To: Marc Zyngier
Cc: kvm, Catalin Marinas, Cornelia Huck, Steven Price,
linux-arm-kernel, Vincenzo Frascino, Will Deacon, kvmarm,
Evgenii Stepanov
On Fri, Jul 22, 2022 at 03:16:34PM +0100, Marc Zyngier wrote:
> On Fri, 22 Jul 2022 02:50:29 +0100,
> Peter Collingbourne <pcc@google.com> wrote:
> >
> > As with PG_arch_2, this flag is only allowed on 64-bit architectures due
> > to the shortage of bits available. It will be used by the arm64 MTE code
> > in subsequent patches.
> >
> > Signed-off-by: Peter Collingbourne <pcc@google.com>
> > Cc: Will Deacon <will@kernel.org>
> > Cc: Marc Zyngier <maz@kernel.org>
> > Cc: Steven Price <steven.price@arm.com>
> > [catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> > ---
> > fs/proc/page.c | 1 +
> > include/linux/page-flags.h | 1 +
> > include/trace/events/mmflags.h | 7 ++++---
> > mm/huge_memory.c | 1 +
> > 4 files changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/proc/page.c b/fs/proc/page.c
> > index a2873a617ae8..438b8aa7249d 100644
> > --- a/fs/proc/page.c
> > +++ b/fs/proc/page.c
> > @@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
> > u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
> > #ifdef CONFIG_64BIT
> > u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
> > + u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
>
> Are PG_arch_2 and PG_arch_3 supposed to share the same user bit in
> /proc/kpageflags? This seems odd.
No, that was an oversight, thanks for the catch. I will fix it up like
so in v3.
Peter
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 438b8aa7249d..0129aa3cfb7a 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -220,7 +220,7 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
#ifdef CONFIG_64BIT
u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
- u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
+ u |= kpf_copy_bit(k, KPF_ARCH_3, PG_arch_3);
#endif
return u;
diff --git a/include/linux/kernel-page-flags.h b/include/linux/kernel-page-flags.h
index eee1877a354e..859f4b0c1b2b 100644
--- a/include/linux/kernel-page-flags.h
+++ b/include/linux/kernel-page-flags.h
@@ -18,5 +18,6 @@
#define KPF_UNCACHED 39
#define KPF_SOFTDIRTY 40
#define KPF_ARCH_2 41
+#define KPF_ARCH_3 42
#endif /* LINUX_KERNEL_PAGE_FLAGS_H */
diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
index 381dcc00cb62..364373f5bba0 100644
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c
@@ -79,6 +79,7 @@
#define KPF_UNCACHED 39
#define KPF_SOFTDIRTY 40
#define KPF_ARCH_2 41
+#define KPF_ARCH_3 42
/* [47-] take some arbitrary free slots for expanding overloaded flags
* not part of kernel API
@@ -138,6 +139,7 @@ static const char * const page_flag_names[] = {
[KPF_UNCACHED] = "c:uncached",
[KPF_SOFTDIRTY] = "f:softdirty",
[KPF_ARCH_2] = "H:arch_2",
+ [KPF_ARCH_3] = "H:arch_3",
[KPF_ANON_EXCLUSIVE] = "d:anon_exclusive",
[KPF_READAHEAD] = "I:readahead",
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 36+ messages in thread
* Re: [PATCH v2 3/7] mm: Add PG_arch_3 page flag
@ 2022-07-22 17:04 ` Peter Collingbourne
0 siblings, 0 replies; 36+ messages in thread
From: Peter Collingbourne @ 2022-07-22 17:04 UTC (permalink / raw)
To: Marc Zyngier
Cc: linux-arm-kernel, kvmarm, Cornelia Huck, Catalin Marinas,
Will Deacon, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino
On Fri, Jul 22, 2022 at 03:16:34PM +0100, Marc Zyngier wrote:
> On Fri, 22 Jul 2022 02:50:29 +0100,
> Peter Collingbourne <pcc@google.com> wrote:
> >
> > As with PG_arch_2, this flag is only allowed on 64-bit architectures due
> > to the shortage of bits available. It will be used by the arm64 MTE code
> > in subsequent patches.
> >
> > Signed-off-by: Peter Collingbourne <pcc@google.com>
> > Cc: Will Deacon <will@kernel.org>
> > Cc: Marc Zyngier <maz@kernel.org>
> > Cc: Steven Price <steven.price@arm.com>
> > [catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> > ---
> > fs/proc/page.c | 1 +
> > include/linux/page-flags.h | 1 +
> > include/trace/events/mmflags.h | 7 ++++---
> > mm/huge_memory.c | 1 +
> > 4 files changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/proc/page.c b/fs/proc/page.c
> > index a2873a617ae8..438b8aa7249d 100644
> > --- a/fs/proc/page.c
> > +++ b/fs/proc/page.c
> > @@ -220,6 +220,7 @@ u64 stable_page_flags(struct page *page)
> > u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
> > #ifdef CONFIG_64BIT
> > u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
> > + u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
>
> Are PG_arch_2 and PG_arch_3 supposed to share the same user bit in
> /proc/kpageflags? This seems odd.
No, that was an oversight, thanks for the catch. I will fix it up like
so in v3.
Peter
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 438b8aa7249d..0129aa3cfb7a 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -220,7 +220,7 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
#ifdef CONFIG_64BIT
u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
- u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_3);
+ u |= kpf_copy_bit(k, KPF_ARCH_3, PG_arch_3);
#endif
return u;
diff --git a/include/linux/kernel-page-flags.h b/include/linux/kernel-page-flags.h
index eee1877a354e..859f4b0c1b2b 100644
--- a/include/linux/kernel-page-flags.h
+++ b/include/linux/kernel-page-flags.h
@@ -18,5 +18,6 @@
#define KPF_UNCACHED 39
#define KPF_SOFTDIRTY 40
#define KPF_ARCH_2 41
+#define KPF_ARCH_3 42
#endif /* LINUX_KERNEL_PAGE_FLAGS_H */
diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
index 381dcc00cb62..364373f5bba0 100644
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c
@@ -79,6 +79,7 @@
#define KPF_UNCACHED 39
#define KPF_SOFTDIRTY 40
#define KPF_ARCH_2 41
+#define KPF_ARCH_3 42
/* [47-] take some arbitrary free slots for expanding overloaded flags
* not part of kernel API
@@ -138,6 +139,7 @@ static const char * const page_flag_names[] = {
[KPF_UNCACHED] = "c:uncached",
[KPF_SOFTDIRTY] = "f:softdirty",
[KPF_ARCH_2] = "H:arch_2",
+ [KPF_ARCH_3] = "H:arch_3",
[KPF_ANON_EXCLUSIVE] = "d:anon_exclusive",
[KPF_READAHEAD] = "I:readahead",
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 36+ messages in thread
* Re: [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-23 1:53 ` kernel test robot
-1 siblings, 0 replies; 36+ messages in thread
From: kernel test robot @ 2022-07-23 1:53 UTC (permalink / raw)
To: Peter Collingbourne, linux-arm-kernel, kvmarm
Cc: kbuild-all, Catalin Marinas, Cornelia Huck, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino, Peter Collingbourne
Hi Peter,
I love your patch! Yet something to improve:
[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on next-20220722]
[cannot apply to kvmarm/next arm/for-next soc/for-next xilinx-xlnx/master linus/master v5.19-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: arm64-randconfig-s032-20220721 (https://download.01.org/0day-ci/archive/20220723/202207230959.jvdok5UK-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 12.1.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://github.com/intel-lab-lkp/linux/commit/3323e416892d6b5326503b9afc2ee835162b819b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
git checkout 3323e416892d6b5326503b9afc2ee835162b819b
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 prepare
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from arch/arm64/include/asm/pgtable.h:12,
from include/linux/pgtable.h:6,
from include/linux/kasan.h:33,
from include/linux/slab.h:140,
from include/linux/resource_ext.h:11,
from include/linux/acpi.h:14,
from include/acpi/apei.h:9,
from include/acpi/ghes.h:5,
from include/linux/arm_sdei.h:8,
from arch/arm64/kernel/asm-offsets.c:10:
>> arch/arm64/include/asm/mte.h:80:15: error: return type defaults to 'int' [-Werror=implicit-int]
80 | static inline set_page_mte_tagged(struct page *page)
| ^~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
make[2]: *** [scripts/Makefile.build:117: arch/arm64/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1200: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:219: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/int +80 arch/arm64/include/asm/mte.h
79
> 80 static inline set_page_mte_tagged(struct page *page)
81 {
82 }
83 static inline bool page_mte_tagged(struct page *page)
84 {
85 return false;
86 }
87 static inline void mte_zero_clear_page_tags(void *addr)
88 {
89 }
90 static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
91 {
92 }
93 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
94 {
95 }
96 static inline void mte_thread_init_user(void)
97 {
98 }
99 static inline void mte_thread_switch(struct task_struct *next)
100 {
101 }
102 static inline void mte_suspend_enter(void)
103 {
104 }
105 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
106 {
107 return 0;
108 }
109 static inline long get_mte_ctrl(struct task_struct *task)
110 {
111 return 0;
112 }
113 static inline int mte_ptrace_copy_tags(struct task_struct *child,
114 long request, unsigned long addr,
115 unsigned long data)
116 {
117 return -EIO;
118 }
119
--
0-DAY CI Kernel Test Service
https://01.org/lkp
^ permalink raw reply [flat|nested] 36+ messages in thread
* Re: [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
@ 2022-07-23 1:53 ` kernel test robot
0 siblings, 0 replies; 36+ messages in thread
From: kernel test robot @ 2022-07-23 1:53 UTC (permalink / raw)
To: Peter Collingbourne, linux-arm-kernel, kvmarm
Cc: kbuild-all, kvm, Peter Collingbourne, Catalin Marinas,
Cornelia Huck, Steven Price, Marc Zyngier, Vincenzo Frascino,
Will Deacon, Evgenii Stepanov
Hi Peter,
I love your patch! Yet something to improve:
[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on next-20220722]
[cannot apply to kvmarm/next arm/for-next soc/for-next xilinx-xlnx/master linus/master v5.19-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: arm64-randconfig-s032-20220721 (https://download.01.org/0day-ci/archive/20220723/202207230959.jvdok5UK-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 12.1.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://github.com/intel-lab-lkp/linux/commit/3323e416892d6b5326503b9afc2ee835162b819b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
git checkout 3323e416892d6b5326503b9afc2ee835162b819b
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 prepare
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from arch/arm64/include/asm/pgtable.h:12,
from include/linux/pgtable.h:6,
from include/linux/kasan.h:33,
from include/linux/slab.h:140,
from include/linux/resource_ext.h:11,
from include/linux/acpi.h:14,
from include/acpi/apei.h:9,
from include/acpi/ghes.h:5,
from include/linux/arm_sdei.h:8,
from arch/arm64/kernel/asm-offsets.c:10:
>> arch/arm64/include/asm/mte.h:80:15: error: return type defaults to 'int' [-Werror=implicit-int]
80 | static inline set_page_mte_tagged(struct page *page)
| ^~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
make[2]: *** [scripts/Makefile.build:117: arch/arm64/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1200: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:219: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/int +80 arch/arm64/include/asm/mte.h
79
> 80 static inline set_page_mte_tagged(struct page *page)
81 {
82 }
83 static inline bool page_mte_tagged(struct page *page)
84 {
85 return false;
86 }
87 static inline void mte_zero_clear_page_tags(void *addr)
88 {
89 }
90 static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
91 {
92 }
93 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
94 {
95 }
96 static inline void mte_thread_init_user(void)
97 {
98 }
99 static inline void mte_thread_switch(struct task_struct *next)
100 {
101 }
102 static inline void mte_suspend_enter(void)
103 {
104 }
105 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
106 {
107 return 0;
108 }
109 static inline long get_mte_ctrl(struct task_struct *task)
110 {
111 return 0;
112 }
113 static inline int mte_ptrace_copy_tags(struct task_struct *child,
114 long request, unsigned long addr,
115 unsigned long data)
116 {
117 return -EIO;
118 }
119
--
0-DAY CI Kernel Test Service
https://01.org/lkp
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 36+ messages in thread
* Re: [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
@ 2022-07-23 1:53 ` kernel test robot
0 siblings, 0 replies; 36+ messages in thread
From: kernel test robot @ 2022-07-23 1:53 UTC (permalink / raw)
To: Peter Collingbourne, linux-arm-kernel, kvmarm
Cc: kbuild-all, Catalin Marinas, Cornelia Huck, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino, Peter Collingbourne
Hi Peter,
I love your patch! Yet something to improve:
[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on next-20220722]
[cannot apply to kvmarm/next arm/for-next soc/for-next xilinx-xlnx/master linus/master v5.19-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: arm64-randconfig-s032-20220721 (https://download.01.org/0day-ci/archive/20220723/202207230959.jvdok5UK-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 12.1.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://github.com/intel-lab-lkp/linux/commit/3323e416892d6b5326503b9afc2ee835162b819b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
git checkout 3323e416892d6b5326503b9afc2ee835162b819b
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 prepare
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from arch/arm64/include/asm/pgtable.h:12,
from include/linux/pgtable.h:6,
from include/linux/kasan.h:33,
from include/linux/slab.h:140,
from include/linux/resource_ext.h:11,
from include/linux/acpi.h:14,
from include/acpi/apei.h:9,
from include/acpi/ghes.h:5,
from include/linux/arm_sdei.h:8,
from arch/arm64/kernel/asm-offsets.c:10:
>> arch/arm64/include/asm/mte.h:80:15: error: return type defaults to 'int' [-Werror=implicit-int]
80 | static inline set_page_mte_tagged(struct page *page)
| ^~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
make[2]: *** [scripts/Makefile.build:117: arch/arm64/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1200: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:219: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/int +80 arch/arm64/include/asm/mte.h
79
> 80 static inline set_page_mte_tagged(struct page *page)
81 {
82 }
83 static inline bool page_mte_tagged(struct page *page)
84 {
85 return false;
86 }
87 static inline void mte_zero_clear_page_tags(void *addr)
88 {
89 }
90 static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
91 {
92 }
93 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
94 {
95 }
96 static inline void mte_thread_init_user(void)
97 {
98 }
99 static inline void mte_thread_switch(struct task_struct *next)
100 {
101 }
102 static inline void mte_suspend_enter(void)
103 {
104 }
105 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
106 {
107 return 0;
108 }
109 static inline long get_mte_ctrl(struct task_struct *task)
110 {
111 return 0;
112 }
113 static inline int mte_ptrace_copy_tags(struct task_struct *child,
114 long request, unsigned long addr,
115 unsigned long data)
116 {
117 return -EIO;
118 }
119
--
0-DAY CI Kernel Test Service
https://01.org/lkp
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 36+ messages in thread
* Re: [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
2022-07-22 1:50 ` Peter Collingbourne
(?)
@ 2022-07-24 1:54 ` kernel test robot
-1 siblings, 0 replies; 36+ messages in thread
From: kernel test robot @ 2022-07-24 1:54 UTC (permalink / raw)
To: Peter Collingbourne, linux-arm-kernel, kvmarm
Cc: llvm, kbuild-all, Catalin Marinas, Cornelia Huck, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino, Peter Collingbourne
Hi Peter,
I love your patch! Yet something to improve:
[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on next-20220722]
[cannot apply to kvmarm/next arm/for-next soc/for-next xilinx-xlnx/master linus/master v5.19-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: arm64-buildonly-randconfig-r004-20220722 (https://download.01.org/0day-ci/archive/20220724/202207240907.aR4gvNkj-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 72686d68c137551cce816416190a18d45b4d4e2a)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/3323e416892d6b5326503b9afc2ee835162b819b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
git checkout 3323e416892d6b5326503b9afc2ee835162b819b
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 prepare
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from arch/arm64/kernel/asm-offsets.c:10:
In file included from include/linux/arm_sdei.h:8:
In file included from include/acpi/ghes.h:5:
In file included from include/acpi/apei.h:9:
In file included from include/linux/acpi.h:15:
In file included from include/linux/device.h:32:
In file included from include/linux/device/driver.h:21:
In file included from include/linux/module.h:19:
In file included from include/linux/elf.h:6:
In file included from arch/arm64/include/asm/elf.h:141:
In file included from include/linux/fs.h:33:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:11:
In file included from include/linux/uaccess.h:11:
In file included from arch/arm64/include/asm/uaccess.h:24:
>> arch/arm64/include/asm/mte.h:80:15: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
static inline set_page_mte_tagged(struct page *page)
~~~~~~~~~~~~~ ^
int
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:456:22: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:456:10: warning: array index 7 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:456:42: warning: array index 6 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:456:53: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:458:22: warning: array index 2 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:458:10: warning: array index 5 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:458:42: warning: array index 4 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:458:53: warning: array index 2 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:460:22: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:460:10: warning: array index 3 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:460:42: warning: array index 2 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:460:53: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
12 warnings and 1 error generated.
make[2]: *** [scripts/Makefile.build:117: arch/arm64/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1200: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:219: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/int +80 arch/arm64/include/asm/mte.h
79
> 80 static inline set_page_mte_tagged(struct page *page)
81 {
82 }
83 static inline bool page_mte_tagged(struct page *page)
84 {
85 return false;
86 }
87 static inline void mte_zero_clear_page_tags(void *addr)
88 {
89 }
90 static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
91 {
92 }
93 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
94 {
95 }
96 static inline void mte_thread_init_user(void)
97 {
98 }
99 static inline void mte_thread_switch(struct task_struct *next)
100 {
101 }
102 static inline void mte_suspend_enter(void)
103 {
104 }
105 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
106 {
107 return 0;
108 }
109 static inline long get_mte_ctrl(struct task_struct *task)
110 {
111 return 0;
112 }
113 static inline int mte_ptrace_copy_tags(struct task_struct *child,
114 long request, unsigned long addr,
115 unsigned long data)
116 {
117 return -EIO;
118 }
119
--
0-DAY CI Kernel Test Service
https://01.org/lkp
^ permalink raw reply [flat|nested] 36+ messages in thread
* Re: [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
@ 2022-07-24 1:54 ` kernel test robot
0 siblings, 0 replies; 36+ messages in thread
From: kernel test robot @ 2022-07-24 1:54 UTC (permalink / raw)
To: Peter Collingbourne, linux-arm-kernel, kvmarm
Cc: Cornelia Huck, kbuild-all, kvm, Peter Collingbourne,
Marc Zyngier, llvm, Steven Price, Catalin Marinas,
Vincenzo Frascino, Will Deacon, Evgenii Stepanov
Hi Peter,
I love your patch! Yet something to improve:
[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on next-20220722]
[cannot apply to kvmarm/next arm/for-next soc/for-next xilinx-xlnx/master linus/master v5.19-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: arm64-buildonly-randconfig-r004-20220722 (https://download.01.org/0day-ci/archive/20220724/202207240907.aR4gvNkj-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 72686d68c137551cce816416190a18d45b4d4e2a)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/3323e416892d6b5326503b9afc2ee835162b819b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
git checkout 3323e416892d6b5326503b9afc2ee835162b819b
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 prepare
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from arch/arm64/kernel/asm-offsets.c:10:
In file included from include/linux/arm_sdei.h:8:
In file included from include/acpi/ghes.h:5:
In file included from include/acpi/apei.h:9:
In file included from include/linux/acpi.h:15:
In file included from include/linux/device.h:32:
In file included from include/linux/device/driver.h:21:
In file included from include/linux/module.h:19:
In file included from include/linux/elf.h:6:
In file included from arch/arm64/include/asm/elf.h:141:
In file included from include/linux/fs.h:33:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:11:
In file included from include/linux/uaccess.h:11:
In file included from arch/arm64/include/asm/uaccess.h:24:
>> arch/arm64/include/asm/mte.h:80:15: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
static inline set_page_mte_tagged(struct page *page)
~~~~~~~~~~~~~ ^
int
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:456:22: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:456:10: warning: array index 7 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:456:42: warning: array index 6 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:456:53: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:458:22: warning: array index 2 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:458:10: warning: array index 5 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:458:42: warning: array index 4 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:458:53: warning: array index 2 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:460:22: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:460:10: warning: array index 3 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:460:42: warning: array index 2 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:460:53: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
12 warnings and 1 error generated.
make[2]: *** [scripts/Makefile.build:117: arch/arm64/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1200: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:219: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/int +80 arch/arm64/include/asm/mte.h
79
> 80 static inline set_page_mte_tagged(struct page *page)
81 {
82 }
83 static inline bool page_mte_tagged(struct page *page)
84 {
85 return false;
86 }
87 static inline void mte_zero_clear_page_tags(void *addr)
88 {
89 }
90 static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
91 {
92 }
93 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
94 {
95 }
96 static inline void mte_thread_init_user(void)
97 {
98 }
99 static inline void mte_thread_switch(struct task_struct *next)
100 {
101 }
102 static inline void mte_suspend_enter(void)
103 {
104 }
105 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
106 {
107 return 0;
108 }
109 static inline long get_mte_ctrl(struct task_struct *task)
110 {
111 return 0;
112 }
113 static inline int mte_ptrace_copy_tags(struct task_struct *child,
114 long request, unsigned long addr,
115 unsigned long data)
116 {
117 return -EIO;
118 }
119
--
0-DAY CI Kernel Test Service
https://01.org/lkp
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 36+ messages in thread
* Re: [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics
@ 2022-07-24 1:54 ` kernel test robot
0 siblings, 0 replies; 36+ messages in thread
From: kernel test robot @ 2022-07-24 1:54 UTC (permalink / raw)
To: Peter Collingbourne, linux-arm-kernel, kvmarm
Cc: llvm, kbuild-all, Catalin Marinas, Cornelia Huck, Will Deacon,
Marc Zyngier, Evgenii Stepanov, kvm, Steven Price,
Vincenzo Frascino, Peter Collingbourne
Hi Peter,
I love your patch! Yet something to improve:
[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on next-20220722]
[cannot apply to kvmarm/next arm/for-next soc/for-next xilinx-xlnx/master linus/master v5.19-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: arm64-buildonly-randconfig-r004-20220722 (https://download.01.org/0day-ci/archive/20220724/202207240907.aR4gvNkj-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 72686d68c137551cce816416190a18d45b4d4e2a)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/3323e416892d6b5326503b9afc2ee835162b819b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220722-095300
git checkout 3323e416892d6b5326503b9afc2ee835162b819b
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 prepare
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from arch/arm64/kernel/asm-offsets.c:10:
In file included from include/linux/arm_sdei.h:8:
In file included from include/acpi/ghes.h:5:
In file included from include/acpi/apei.h:9:
In file included from include/linux/acpi.h:15:
In file included from include/linux/device.h:32:
In file included from include/linux/device/driver.h:21:
In file included from include/linux/module.h:19:
In file included from include/linux/elf.h:6:
In file included from arch/arm64/include/asm/elf.h:141:
In file included from include/linux/fs.h:33:
In file included from include/linux/percpu-rwsem.h:7:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:11:
In file included from include/linux/uaccess.h:11:
In file included from arch/arm64/include/asm/uaccess.h:24:
>> arch/arm64/include/asm/mte.h:80:15: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
static inline set_page_mte_tagged(struct page *page)
~~~~~~~~~~~~~ ^
int
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:456:22: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:456:10: warning: array index 7 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:456:42: warning: array index 6 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:456:53: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:458:22: warning: array index 2 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:458:10: warning: array index 5 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:458:42: warning: array index 4 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:458:53: warning: array index 2 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:460:22: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
In file included from arch/arm64/kernel/asm-offsets.c:12:
In file included from include/linux/kexec.h:31:
include/linux/compat.h:460:10: warning: array index 3 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:460:42: warning: array index 2 is past the end of the array (which contains 2 elements) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/linux/compat.h:131:2: note: array 'sig' declared here
compat_sigset_word sig[_COMPAT_NSIG_WORDS];
^
include/linux/compat.h:460:53: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
^ ~
include/uapi/asm-generic/signal.h:62:2: note: array 'sig' declared here
unsigned long sig[_NSIG_WORDS];
^
12 warnings and 1 error generated.
make[2]: *** [scripts/Makefile.build:117: arch/arm64/kernel/asm-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1200: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:219: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/int +80 arch/arm64/include/asm/mte.h
79
> 80 static inline set_page_mte_tagged(struct page *page)
81 {
82 }
83 static inline bool page_mte_tagged(struct page *page)
84 {
85 return false;
86 }
87 static inline void mte_zero_clear_page_tags(void *addr)
88 {
89 }
90 static inline void mte_sync_tags(pte_t old_pte, pte_t pte)
91 {
92 }
93 static inline void mte_copy_page_tags(void *kto, const void *kfrom)
94 {
95 }
96 static inline void mte_thread_init_user(void)
97 {
98 }
99 static inline void mte_thread_switch(struct task_struct *next)
100 {
101 }
102 static inline void mte_suspend_enter(void)
103 {
104 }
105 static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
106 {
107 return 0;
108 }
109 static inline long get_mte_ctrl(struct task_struct *task)
110 {
111 return 0;
112 }
113 static inline int mte_ptrace_copy_tags(struct task_struct *child,
114 long request, unsigned long addr,
115 unsigned long data)
116 {
117 return -EIO;
118 }
119
--
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^ permalink raw reply [flat|nested] 36+ messages in thread
end of thread, other threads:[~2022-07-24 1:57 UTC | newest]
Thread overview: 36+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-07-22 1:50 [PATCH v2 0/7] KVM: arm64: permit MAP_SHARED mappings with MTE enabled Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` [PATCH v2 1/7] arm64: mte: Fix/clarify the PG_mte_tagged semantics Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-23 1:53 ` kernel test robot
2022-07-23 1:53 ` kernel test robot
2022-07-23 1:53 ` kernel test robot
2022-07-24 1:54 ` kernel test robot
2022-07-24 1:54 ` kernel test robot
2022-07-24 1:54 ` kernel test robot
2022-07-22 1:50 ` [PATCH v2 2/7] KVM: arm64: Simplify the sanitise_mte_tags() logic Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` [PATCH v2 3/7] mm: Add PG_arch_3 page flag Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 14:16 ` Marc Zyngier
2022-07-22 14:16 ` Marc Zyngier
2022-07-22 14:16 ` Marc Zyngier
2022-07-22 17:04 ` Peter Collingbourne
2022-07-22 17:04 ` Peter Collingbourne
2022-07-22 17:04 ` Peter Collingbourne
2022-07-22 1:50 ` [PATCH v2 4/7] arm64: mte: Lock a page for MTE tag initialisation Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` [PATCH v2 5/7] KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` [PATCH v2 6/7] KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` [PATCH v2 7/7] Documentation: document the ABI changes for KVM_CAP_ARM_MTE Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
2022-07-22 1:50 ` Peter Collingbourne
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