diff options
| author | Reiji Watanabe <reijiw@google.com> | 2021-12-05 16:47:36 -0800 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2021-12-06 17:02:10 +0000 |
| commit | 685e2564daa1493053fcd7f1dbed38b35ee2f3cb (patch) | |
| tree | f7409f8ee9f4ac811079d1f671cce80cf530d0e8 /arch | |
| parent | f0616abd4e67143b45b04b565839148458857347 (diff) | |
arm64: mte: DC {GVA,GZVA} shouldn't be used when DCZID_EL0.DZP == 1
Currently, mte_set_mem_tag_range() and mte_zero_clear_page_tags() use
DC {GVA,GZVA} unconditionally. But, they should make sure that
DCZID_EL0.DZP, which indicates whether or not use of those instructions
is prohibited, is zero when using those instructions.
Use ST{G,ZG,Z2G} instead when DCZID_EL0.DZP == 1.
Fixes: 013bb59dbb7c ("arm64: mte: handle tags zeroing at page allocation time")
Fixes: 3d0cca0b02ac ("kasan: speed up mte_set_mem_tag_range")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Link: https://lore.kernel.org/r/20211206004736.1520989-3-reijiw@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/mte-kasan.h | 8 | ||||
| -rw-r--r-- | arch/arm64/lib/mte.S | 8 |
2 files changed, 12 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/mte-kasan.h b/arch/arm64/include/asm/mte-kasan.h index 478b9bcf69ad..e4704a403237 100644 --- a/arch/arm64/include/asm/mte-kasan.h +++ b/arch/arm64/include/asm/mte-kasan.h @@ -84,10 +84,12 @@ static inline void __dc_gzva(u64 p) static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag, bool init) { - u64 curr, mask, dczid_bs, end1, end2, end3; + u64 curr, mask, dczid, dczid_bs, dczid_dzp, end1, end2, end3; /* Read DC G(Z)VA block size from the system register. */ - dczid_bs = 4ul << (read_cpuid(DCZID_EL0) & 0xf); + dczid = read_cpuid(DCZID_EL0); + dczid_bs = 4ul << (dczid & 0xf); + dczid_dzp = (dczid >> 4) & 1; curr = (u64)__tag_set(addr, tag); mask = dczid_bs - 1; @@ -106,7 +108,7 @@ static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag, */ #define SET_MEMTAG_RANGE(stg_post, dc_gva) \ do { \ - if (size >= 2 * dczid_bs) { \ + if (!dczid_dzp && size >= 2 * dczid_bs) {\ do { \ curr = stg_post(curr); \ } while (curr < end1); \ diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S index e83643b3995f..f531dcb95174 100644 --- a/arch/arm64/lib/mte.S +++ b/arch/arm64/lib/mte.S @@ -43,17 +43,23 @@ SYM_FUNC_END(mte_clear_page_tags) * x0 - address to the beginning of the page */ SYM_FUNC_START(mte_zero_clear_page_tags) + and x0, x0, #(1 << MTE_TAG_SHIFT) - 1 // clear the tag mrs x1, dczid_el0 + tbnz x1, #4, 2f // Branch if DC GZVA is prohibited 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 + +2: stz2g x0, [x0], #(MTE_GRANULE_SIZE * 2) + tst x0, #(PAGE_SIZE - 1) + b.ne 2b + ret SYM_FUNC_END(mte_zero_clear_page_tags) /* |