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-rw-r--r--arch/arm64/include/asm/mte.h4
-rw-r--r--arch/arm64/include/asm/page.h8
-rw-r--r--arch/arm64/lib/mte.S20
-rw-r--r--arch/arm64/mm/fault.c26
-rw-r--r--arch/arm64/mm/proc.S10
-rw-r--r--include/linux/gfp.h9
-rw-r--r--include/linux/highmem.h8
-rw-r--r--mm/kasan/hw_tags.c9
-rw-r--r--mm/page_alloc.c13
9 files changed, 96 insertions, 11 deletions
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index bc88a1ced0d7..67bf259ae768 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -37,6 +37,7 @@ void mte_free_tag_storage(char *storage);
/* track which pages have valid allocation tags */
#define PG_mte_tagged PG_arch_2
+void mte_zero_clear_page_tags(void *addr);
void mte_sync_tags(pte_t *ptep, pte_t pte);
void mte_copy_page_tags(void *kto, const void *kfrom);
void mte_thread_init_user(void);
@@ -53,6 +54,9 @@ int mte_ptrace_copy_tags(struct task_struct *child, long request,
/* unused if !CONFIG_ARM64_MTE, silence the compiler */
#define PG_mte_tagged 0
+static inline void mte_zero_clear_page_tags(void *addr)
+{
+}
static inline void mte_sync_tags(pte_t *ptep, pte_t pte)
{
}
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index e1fc0f60e79f..ed1b9dcf12b2 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -13,6 +13,7 @@
#ifndef __ASSEMBLY__
#include <linux/personality.h> /* for READ_IMPLIES_EXEC */
+#include <linux/types.h> /* for gfp_t */
#include <asm/pgtable-types.h>
struct page;
@@ -28,10 +29,13 @@ void copy_user_highpage(struct page *to, struct page *from,
void copy_highpage(struct page *to, struct page *from);
#define __HAVE_ARCH_COPY_HIGHPAGE
-#define alloc_zeroed_user_highpage_movable(vma, vaddr) \
- alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, vma, vaddr)
+struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
+ unsigned long vaddr);
#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE
+void tag_clear_highpage(struct page *to);
+#define __HAVE_ARCH_TAG_CLEAR_HIGHPAGE
+
#define clear_user_page(page, vaddr, pg) clear_page(page)
#define copy_user_page(to, from, vaddr, pg) copy_page(to, from)
diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S
index 351537c12f36..e83643b3995f 100644
--- a/arch/arm64/lib/mte.S
+++ b/arch/arm64/lib/mte.S
@@ -37,6 +37,26 @@ SYM_FUNC_START(mte_clear_page_tags)
SYM_FUNC_END(mte_clear_page_tags)
/*
+ * Zero the page and tags at the same time
+ *
+ * Parameters:
+ * x0 - address to the beginning of the page
+ */
+SYM_FUNC_START(mte_zero_clear_page_tags)
+ mrs x1, dczid_el0
+ and w1, w1, #0xf
+ mov x2, #4
+ lsl x1, x2, x1
+ and x0, x0, #(1 << MTE_TAG_SHIFT) - 1 // clear the tag
+
+1: dc gzva, x0
+ add x0, x0, x1
+ tst x0, #(PAGE_SIZE - 1)
+ b.ne 1b
+ ret
+SYM_FUNC_END(mte_zero_clear_page_tags)
+
+/*
* Copy the tags from the source page to the destination one
* x0 - address of the destination page
* x1 - address of the source page
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 871c82ab0a30..180c0343d82a 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -921,3 +921,29 @@ void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr,
debug_exception_exit(regs);
}
NOKPROBE_SYMBOL(do_debug_exception);
+
+/*
+ * Used during anonymous page fault handling.
+ */
+struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
+ unsigned long vaddr)
+{
+ gfp_t flags = GFP_HIGHUSER_MOVABLE | __GFP_ZERO;
+
+ /*
+ * If the page is mapped with PROT_MTE, initialise the tags at the
+ * point of allocation and page zeroing as this is usually faster than
+ * separate DC ZVA and STGM.
+ */
+ if (vma->vm_flags & VM_MTE)
+ flags |= __GFP_ZEROTAGS;
+
+ return alloc_page_vma(flags, vma, vaddr);
+}
+
+void tag_clear_highpage(struct page *page)
+{
+ mte_zero_clear_page_tags(page_address(page));
+ page_kasan_tag_reset(page);
+ set_bit(PG_mte_tagged, &page->flags);
+}
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 97d7bcd8d4f2..48fd1df3d05a 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -46,9 +46,13 @@
#endif
#ifdef CONFIG_KASAN_HW_TAGS
-#define TCR_KASAN_HW_FLAGS SYS_TCR_EL1_TCMA1 | TCR_TBI1 | TCR_TBID1
+#define TCR_MTE_FLAGS SYS_TCR_EL1_TCMA1 | TCR_TBI1 | TCR_TBID1
#else
-#define TCR_KASAN_HW_FLAGS 0
+/*
+ * The mte_zero_clear_page_tags() implementation uses DC GZVA, which relies on
+ * TBI being enabled at EL1.
+ */
+#define TCR_MTE_FLAGS TCR_TBI1 | TCR_TBID1
#endif
/*
@@ -464,7 +468,7 @@ SYM_FUNC_START(__cpu_setup)
msr_s SYS_TFSRE0_EL1, xzr
/* set the TCR_EL1 bits */
- mov_q x10, TCR_KASAN_HW_FLAGS
+ mov_q x10, TCR_MTE_FLAGS
orr tcr, tcr, x10
1:
#endif
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 11da8af06704..68ba237365dc 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -53,8 +53,9 @@ struct vm_area_struct;
#define ___GFP_HARDWALL 0x100000u
#define ___GFP_THISNODE 0x200000u
#define ___GFP_ACCOUNT 0x400000u
+#define ___GFP_ZEROTAGS 0x800000u
#ifdef CONFIG_LOCKDEP
-#define ___GFP_NOLOCKDEP 0x800000u
+#define ___GFP_NOLOCKDEP 0x1000000u
#else
#define ___GFP_NOLOCKDEP 0
#endif
@@ -229,16 +230,20 @@ struct vm_area_struct;
* %__GFP_COMP address compound page metadata.
*
* %__GFP_ZERO returns a zeroed page on success.
+ *
+ * %__GFP_ZEROTAGS returns a page with zeroed memory tags on success, if
+ * __GFP_ZERO is set.
*/
#define __GFP_NOWARN ((__force gfp_t)___GFP_NOWARN)
#define __GFP_COMP ((__force gfp_t)___GFP_COMP)
#define __GFP_ZERO ((__force gfp_t)___GFP_ZERO)
+#define __GFP_ZEROTAGS ((__force gfp_t)___GFP_ZEROTAGS)
/* Disable lockdep for GFP context tracking */
#define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)
/* Room for N __GFP_FOO bits */
-#define __GFP_BITS_SHIFT (23 + IS_ENABLED(CONFIG_LOCKDEP))
+#define __GFP_BITS_SHIFT (24 + IS_ENABLED(CONFIG_LOCKDEP))
#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
/**
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 54d0643b8fcf..8c6e8e996c87 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -185,6 +185,14 @@ static inline void clear_highpage(struct page *page)
kunmap_atomic(kaddr);
}
+#ifndef __HAVE_ARCH_TAG_CLEAR_HIGHPAGE
+
+static inline void tag_clear_highpage(struct page *page)
+{
+}
+
+#endif
+
/*
* If we pass in a base or tail page, we can zero up to PAGE_SIZE.
* If we pass in a head page, we can zero up to the size of the compound page.
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index 9d0f6f934016..41fd5326ee0a 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -246,7 +246,14 @@ void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags)
*/
bool init = !want_init_on_free() && want_init_on_alloc(flags);
- kasan_unpoison_pages(page, order, init);
+ if (flags & __GFP_ZEROTAGS) {
+ int i;
+
+ for (i = 0; i != 1 << order; ++i)
+ tag_clear_highpage(page + i);
+ } else {
+ kasan_unpoison_pages(page, order, init);
+ }
}
void kasan_free_pages(struct page *page, unsigned int order)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4fddb7cac3c6..13937e793fda 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1219,10 +1219,16 @@ out:
return ret;
}
-static void kernel_init_free_pages(struct page *page, int numpages)
+static void kernel_init_free_pages(struct page *page, int numpages, bool zero_tags)
{
int i;
+ if (zero_tags) {
+ for (i = 0; i < numpages; i++)
+ tag_clear_highpage(page + i);
+ return;
+ }
+
/* s390's use of memset() could override KASAN redzones. */
kasan_disable_current();
for (i = 0; i < numpages; i++) {
@@ -1314,7 +1320,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
bool init = want_init_on_free();
if (init)
- kernel_init_free_pages(page, 1 << order);
+ kernel_init_free_pages(page, 1 << order, false);
if (!skip_kasan_poison)
kasan_poison_pages(page, order, init);
}
@@ -2349,7 +2355,8 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
kasan_unpoison_pages(page, order, init);
if (init)
- kernel_init_free_pages(page, 1 << order);
+ kernel_init_free_pages(page, 1 << order,
+ gfp_flags & __GFP_ZEROTAGS);
}
set_page_owner(page, order, gfp_flags);
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-28 04:45:45 +0000