Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index c21b936..d31e116 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -1,9 +1,9 @@
# SPDX-License-Identifier: GPL-2.0
lib-y := clear_user.o delay.o copy_from_user.o \
copy_to_user.o copy_in_user.o copy_page.o \
- clear_page.o memchr.o memcpy.o memmove.o memset.o \
- memcmp.o strcmp.o strncmp.o strlen.o strnlen.o \
- strchr.o strrchr.o tishift.o
+ clear_page.o csum.o memchr.o memcpy.o memmove.o \
+ memset.o memcmp.o strcmp.o strncmp.o strlen.o \
+ strnlen.o strchr.o strrchr.o tishift.o
ifeq ($(CONFIG_KERNEL_MODE_NEON), y)
obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o
@@ -16,3 +16,5 @@
obj-$(CONFIG_CRC32) += crc32.o
obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
+
+obj-$(CONFIG_ARM64_MTE) += mte.o
diff --git a/arch/arm64/lib/clear_page.S b/arch/arm64/lib/clear_page.S
index 073acbf..1fd5d79 100644
--- a/arch/arm64/lib/clear_page.S
+++ b/arch/arm64/lib/clear_page.S
@@ -14,8 +14,9 @@
* Parameters:
* x0 - dest
*/
-SYM_FUNC_START(clear_page)
+SYM_FUNC_START_PI(clear_page)
mrs x1, dczid_el0
+ tbnz x1, #4, 2f /* Branch if DC ZVA is prohibited */
and w1, w1, #0xf
mov x2, #4
lsl x1, x2, x1
@@ -25,5 +26,14 @@
tst x0, #(PAGE_SIZE - 1)
b.ne 1b
ret
-SYM_FUNC_END(clear_page)
+
+2: stnp xzr, xzr, [x0]
+ stnp xzr, xzr, [x0, #16]
+ stnp xzr, xzr, [x0, #32]
+ stnp xzr, xzr, [x0, #48]
+ add x0, x0, #64
+ tst x0, #(PAGE_SIZE - 1)
+ b.ne 2b
+ ret
+SYM_FUNC_END_PI(clear_page)
EXPORT_SYMBOL(clear_page)
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 8e25e89..957a6d0 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -20,41 +20,43 @@
* x0 - bytes not copied
*/
- .macro ldrb1 ptr, regB, val
- uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
+ .macro ldrb1 reg, ptr, val
+ uao_user_alternative 9998f, ldrb, ldtrb, \reg, \ptr, \val
.endm
- .macro strb1 ptr, regB, val
- strb \ptr, [\regB], \val
+ .macro strb1 reg, ptr, val
+ strb \reg, [\ptr], \val
.endm
- .macro ldrh1 ptr, regB, val
- uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
+ .macro ldrh1 reg, ptr, val
+ uao_user_alternative 9997f, ldrh, ldtrh, \reg, \ptr, \val
.endm
- .macro strh1 ptr, regB, val
- strh \ptr, [\regB], \val
+ .macro strh1 reg, ptr, val
+ strh \reg, [\ptr], \val
.endm
- .macro ldr1 ptr, regB, val
- uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
+ .macro ldr1 reg, ptr, val
+ uao_user_alternative 9997f, ldr, ldtr, \reg, \ptr, \val
.endm
- .macro str1 ptr, regB, val
- str \ptr, [\regB], \val
+ .macro str1 reg, ptr, val
+ str \reg, [\ptr], \val
.endm
- .macro ldp1 ptr, regB, regC, val
- uao_ldp 9998f, \ptr, \regB, \regC, \val
+ .macro ldp1 reg1, reg2, ptr, val
+ uao_ldp 9997f, \reg1, \reg2, \ptr, \val
.endm
- .macro stp1 ptr, regB, regC, val
- stp \ptr, \regB, [\regC], \val
+ .macro stp1 reg1, reg2, ptr, val
+ stp \reg1, \reg2, [\ptr], \val
.endm
end .req x5
+srcin .req x15
SYM_FUNC_START(__arch_copy_from_user)
add end, x0, x2
+ mov srcin, x1
#include "copy_template.S"
mov x0, #0 // Nothing to copy
ret
@@ -63,6 +65,11 @@
.section .fixup,"ax"
.align 2
+9997: cmp dst, dstin
+ b.ne 9998f
+ // Before being absolutely sure we couldn't copy anything, try harder
+USER(9998f, ldtrb tmp1w, [srcin])
+ strb tmp1w, [dst], #1
9998: sub x0, end, dst // bytes not copied
ret
.previous
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index 6671390..35c01da 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -21,42 +21,43 @@
* Returns:
* x0 - bytes not copied
*/
- .macro ldrb1 ptr, regB, val
- uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
+ .macro ldrb1 reg, ptr, val
+ uao_user_alternative 9998f, ldrb, ldtrb, \reg, \ptr, \val
.endm
- .macro strb1 ptr, regB, val
- uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
+ .macro strb1 reg, ptr, val
+ uao_user_alternative 9998f, strb, sttrb, \reg, \ptr, \val
.endm
- .macro ldrh1 ptr, regB, val
- uao_user_alternative 9998f, ldrh, ldtrh, \ptr, \regB, \val
+ .macro ldrh1 reg, ptr, val
+ uao_user_alternative 9997f, ldrh, ldtrh, \reg, \ptr, \val
.endm
- .macro strh1 ptr, regB, val
- uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
+ .macro strh1 reg, ptr, val
+ uao_user_alternative 9997f, strh, sttrh, \reg, \ptr, \val
.endm
- .macro ldr1 ptr, regB, val
- uao_user_alternative 9998f, ldr, ldtr, \ptr, \regB, \val
+ .macro ldr1 reg, ptr, val
+ uao_user_alternative 9997f, ldr, ldtr, \reg, \ptr, \val
.endm
- .macro str1 ptr, regB, val
- uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
+ .macro str1 reg, ptr, val
+ uao_user_alternative 9997f, str, sttr, \reg, \ptr, \val
.endm
- .macro ldp1 ptr, regB, regC, val
- uao_ldp 9998f, \ptr, \regB, \regC, \val
+ .macro ldp1 reg1, reg2, ptr, val
+ uao_ldp 9997f, \reg1, \reg2, \ptr, \val
.endm
- .macro stp1 ptr, regB, regC, val
- uao_stp 9998f, \ptr, \regB, \regC, \val
+ .macro stp1 reg1, reg2, ptr, val
+ uao_stp 9997f, \reg1, \reg2, \ptr, \val
.endm
end .req x5
-
+srcin .req x15
SYM_FUNC_START(__arch_copy_in_user)
add end, x0, x2
+ mov srcin, x1
#include "copy_template.S"
mov x0, #0
ret
@@ -65,6 +66,12 @@
.section .fixup,"ax"
.align 2
+9997: cmp dst, dstin
+ b.ne 9998f
+ // Before being absolutely sure we couldn't copy anything, try harder
+USER(9998f, ldtrb tmp1w, [srcin])
+USER(9998f, sttrb tmp1w, [dst])
+ add dst, dst, #1
9998: sub x0, end, dst // bytes not copied
ret
.previous
diff --git a/arch/arm64/lib/copy_page.S b/arch/arm64/lib/copy_page.S
index e125a84..29144f4 100644
--- a/arch/arm64/lib/copy_page.S
+++ b/arch/arm64/lib/copy_page.S
@@ -17,7 +17,7 @@
* x0 - dest
* x1 - src
*/
-SYM_FUNC_START(copy_page)
+SYM_FUNC_START_PI(copy_page)
alternative_if ARM64_HAS_NO_HW_PREFETCH
// Prefetch three cache lines ahead.
prfm pldl1strm, [x1, #128]
@@ -34,46 +34,46 @@
ldp x14, x15, [x1, #96]
ldp x16, x17, [x1, #112]
- mov x18, #(PAGE_SIZE - 128)
+ add x0, x0, #256
add x1, x1, #128
1:
- subs x18, x18, #128
+ tst x0, #(PAGE_SIZE - 1)
alternative_if ARM64_HAS_NO_HW_PREFETCH
prfm pldl1strm, [x1, #384]
alternative_else_nop_endif
- stnp x2, x3, [x0]
+ stnp x2, x3, [x0, #-256]
ldp x2, x3, [x1]
- stnp x4, x5, [x0, #16]
+ stnp x4, x5, [x0, #16 - 256]
ldp x4, x5, [x1, #16]
- stnp x6, x7, [x0, #32]
+ stnp x6, x7, [x0, #32 - 256]
ldp x6, x7, [x1, #32]
- stnp x8, x9, [x0, #48]
+ stnp x8, x9, [x0, #48 - 256]
ldp x8, x9, [x1, #48]
- stnp x10, x11, [x0, #64]
+ stnp x10, x11, [x0, #64 - 256]
ldp x10, x11, [x1, #64]
- stnp x12, x13, [x0, #80]
+ stnp x12, x13, [x0, #80 - 256]
ldp x12, x13, [x1, #80]
- stnp x14, x15, [x0, #96]
+ stnp x14, x15, [x0, #96 - 256]
ldp x14, x15, [x1, #96]
- stnp x16, x17, [x0, #112]
+ stnp x16, x17, [x0, #112 - 256]
ldp x16, x17, [x1, #112]
add x0, x0, #128
add x1, x1, #128
- b.gt 1b
+ b.ne 1b
- stnp x2, x3, [x0]
- stnp x4, x5, [x0, #16]
- stnp x6, x7, [x0, #32]
- stnp x8, x9, [x0, #48]
- stnp x10, x11, [x0, #64]
- stnp x12, x13, [x0, #80]
- stnp x14, x15, [x0, #96]
- stnp x16, x17, [x0, #112]
+ stnp x2, x3, [x0, #-256]
+ stnp x4, x5, [x0, #16 - 256]
+ stnp x6, x7, [x0, #32 - 256]
+ stnp x8, x9, [x0, #48 - 256]
+ stnp x10, x11, [x0, #64 - 256]
+ stnp x12, x13, [x0, #80 - 256]
+ stnp x14, x15, [x0, #96 - 256]
+ stnp x16, x17, [x0, #112 - 256]
ret
-SYM_FUNC_END(copy_page)
+SYM_FUNC_END_PI(copy_page)
EXPORT_SYMBOL(copy_page)
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 1a104d0..8570535 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -19,41 +19,43 @@
* Returns:
* x0 - bytes not copied
*/
- .macro ldrb1 ptr, regB, val
- ldrb \ptr, [\regB], \val
+ .macro ldrb1 reg, ptr, val
+ ldrb \reg, [\ptr], \val
.endm
- .macro strb1 ptr, regB, val
- uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
+ .macro strb1 reg, ptr, val
+ uao_user_alternative 9998f, strb, sttrb, \reg, \ptr, \val
.endm
- .macro ldrh1 ptr, regB, val
- ldrh \ptr, [\regB], \val
+ .macro ldrh1 reg, ptr, val
+ ldrh \reg, [\ptr], \val
.endm
- .macro strh1 ptr, regB, val
- uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
+ .macro strh1 reg, ptr, val
+ uao_user_alternative 9997f, strh, sttrh, \reg, \ptr, \val
.endm
- .macro ldr1 ptr, regB, val
- ldr \ptr, [\regB], \val
+ .macro ldr1 reg, ptr, val
+ ldr \reg, [\ptr], \val
.endm
- .macro str1 ptr, regB, val
- uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
+ .macro str1 reg, ptr, val
+ uao_user_alternative 9997f, str, sttr, \reg, \ptr, \val
.endm
- .macro ldp1 ptr, regB, regC, val
- ldp \ptr, \regB, [\regC], \val
+ .macro ldp1 reg1, reg2, ptr, val
+ ldp \reg1, \reg2, [\ptr], \val
.endm
- .macro stp1 ptr, regB, regC, val
- uao_stp 9998f, \ptr, \regB, \regC, \val
+ .macro stp1 reg1, reg2, ptr, val
+ uao_stp 9997f, \reg1, \reg2, \ptr, \val
.endm
end .req x5
+srcin .req x15
SYM_FUNC_START(__arch_copy_to_user)
add end, x0, x2
+ mov srcin, x1
#include "copy_template.S"
mov x0, #0
ret
@@ -62,6 +64,12 @@
.section .fixup,"ax"
.align 2
+9997: cmp dst, dstin
+ b.ne 9998f
+ // Before being absolutely sure we couldn't copy anything, try harder
+ ldrb tmp1w, [srcin]
+USER(9998f, sttrb tmp1w, [dst])
+ add dst, dst, #1
9998: sub x0, end, dst // bytes not copied
ret
.previous
diff --git a/arch/arm64/lib/crc32.S b/arch/arm64/lib/crc32.S
index 243e107..0f9e10e 100644
--- a/arch/arm64/lib/crc32.S
+++ b/arch/arm64/lib/crc32.S
@@ -9,7 +9,7 @@
#include <asm/alternative.h>
#include <asm/assembler.h>
- .cpu generic+crc
+ .arch armv8-a+crc
.macro __crc32, c
cmp x2, #16
diff --git a/arch/arm64/lib/csum.c b/arch/arm64/lib/csum.c
new file mode 100644
index 0000000..78b87a6
--- /dev/null
+++ b/arch/arm64/lib/csum.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2019-2020 Arm Ltd.
+
+#include <linux/compiler.h>
+#include <linux/kasan-checks.h>
+#include <linux/kernel.h>
+
+#include <net/checksum.h>
+
+/* Looks dumb, but generates nice-ish code */
+static u64 accumulate(u64 sum, u64 data)
+{
+ __uint128_t tmp = (__uint128_t)sum + data;
+ return tmp + (tmp >> 64);
+}
+
+/*
+ * We over-read the buffer and this makes KASAN unhappy. Instead, disable
+ * instrumentation and call kasan explicitly.
+ */
+unsigned int __no_sanitize_address do_csum(const unsigned char *buff, int len)
+{
+ unsigned int offset, shift, sum;
+ const u64 *ptr;
+ u64 data, sum64 = 0;
+
+ if (unlikely(len == 0))
+ return 0;
+
+ offset = (unsigned long)buff & 7;
+ /*
+ * This is to all intents and purposes safe, since rounding down cannot
+ * result in a different page or cache line being accessed, and @buff
+ * should absolutely not be pointing to anything read-sensitive. We do,
+ * however, have to be careful not to piss off KASAN, which means using
+ * unchecked reads to accommodate the head and tail, for which we'll
+ * compensate with an explicit check up-front.
+ */
+ kasan_check_read(buff, len);
+ ptr = (u64 *)(buff - offset);
+ len = len + offset - 8;
+
+ /*
+ * Head: zero out any excess leading bytes. Shifting back by the same
+ * amount should be at least as fast as any other way of handling the
+ * odd/even alignment, and means we can ignore it until the very end.
+ */
+ shift = offset * 8;
+ data = *ptr++;
+#ifdef __LITTLE_ENDIAN
+ data = (data >> shift) << shift;
+#else
+ data = (data << shift) >> shift;
+#endif
+
+ /*
+ * Body: straightforward aligned loads from here on (the paired loads
+ * underlying the quadword type still only need dword alignment). The
+ * main loop strictly excludes the tail, so the second loop will always
+ * run at least once.
+ */
+ while (unlikely(len > 64)) {
+ __uint128_t tmp1, tmp2, tmp3, tmp4;
+
+ tmp1 = *(__uint128_t *)ptr;
+ tmp2 = *(__uint128_t *)(ptr + 2);
+ tmp3 = *(__uint128_t *)(ptr + 4);
+ tmp4 = *(__uint128_t *)(ptr + 6);
+
+ len -= 64;
+ ptr += 8;
+
+ /* This is the "don't dump the carry flag into a GPR" idiom */
+ tmp1 += (tmp1 >> 64) | (tmp1 << 64);
+ tmp2 += (tmp2 >> 64) | (tmp2 << 64);
+ tmp3 += (tmp3 >> 64) | (tmp3 << 64);
+ tmp4 += (tmp4 >> 64) | (tmp4 << 64);
+ tmp1 = ((tmp1 >> 64) << 64) | (tmp2 >> 64);
+ tmp1 += (tmp1 >> 64) | (tmp1 << 64);
+ tmp3 = ((tmp3 >> 64) << 64) | (tmp4 >> 64);
+ tmp3 += (tmp3 >> 64) | (tmp3 << 64);
+ tmp1 = ((tmp1 >> 64) << 64) | (tmp3 >> 64);
+ tmp1 += (tmp1 >> 64) | (tmp1 << 64);
+ tmp1 = ((tmp1 >> 64) << 64) | sum64;
+ tmp1 += (tmp1 >> 64) | (tmp1 << 64);
+ sum64 = tmp1 >> 64;
+ }
+ while (len > 8) {
+ __uint128_t tmp;
+
+ sum64 = accumulate(sum64, data);
+ tmp = *(__uint128_t *)ptr;
+
+ len -= 16;
+ ptr += 2;
+
+#ifdef __LITTLE_ENDIAN
+ data = tmp >> 64;
+ sum64 = accumulate(sum64, tmp);
+#else
+ data = tmp;
+ sum64 = accumulate(sum64, tmp >> 64);
+#endif
+ }
+ if (len > 0) {
+ sum64 = accumulate(sum64, data);
+ data = *ptr;
+ len -= 8;
+ }
+ /*
+ * Tail: zero any over-read bytes similarly to the head, again
+ * preserving odd/even alignment.
+ */
+ shift = len * -8;
+#ifdef __LITTLE_ENDIAN
+ data = (data << shift) >> shift;
+#else
+ data = (data >> shift) << shift;
+#endif
+ sum64 = accumulate(sum64, data);
+
+ /* Finally, folding */
+ sum64 += (sum64 >> 32) | (sum64 << 32);
+ sum = sum64 >> 32;
+ sum += (sum >> 16) | (sum << 16);
+ if (offset & 1)
+ return (u16)swab32(sum);
+
+ return sum >> 16;
+}
+
+__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ __u32 len, __u8 proto, __wsum csum)
+{
+ __uint128_t src, dst;
+ u64 sum = (__force u64)csum;
+
+ src = *(const __uint128_t *)saddr->s6_addr;
+ dst = *(const __uint128_t *)daddr->s6_addr;
+
+ sum += (__force u32)htonl(len);
+#ifdef __LITTLE_ENDIAN
+ sum += (u32)proto << 24;
+#else
+ sum += proto;
+#endif
+ src += (src >> 64) | (src << 64);
+ dst += (dst >> 64) | (dst << 64);
+
+ sum = accumulate(sum, src >> 64);
+ sum = accumulate(sum, dst >> 64);
+
+ sum += ((sum >> 32) | (sum << 32));
+ return csum_fold((__force __wsum)(sum >> 32));
+}
+EXPORT_SYMBOL(csum_ipv6_magic);
diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
index b03cbb3..dc8d2a2 100644
--- a/arch/arm64/lib/memcpy.S
+++ b/arch/arm64/lib/memcpy.S
@@ -24,36 +24,36 @@
* Returns:
* x0 - dest
*/
- .macro ldrb1 ptr, regB, val
- ldrb \ptr, [\regB], \val
+ .macro ldrb1 reg, ptr, val
+ ldrb \reg, [\ptr], \val
.endm
- .macro strb1 ptr, regB, val
- strb \ptr, [\regB], \val
+ .macro strb1 reg, ptr, val
+ strb \reg, [\ptr], \val
.endm
- .macro ldrh1 ptr, regB, val
- ldrh \ptr, [\regB], \val
+ .macro ldrh1 reg, ptr, val
+ ldrh \reg, [\ptr], \val
.endm
- .macro strh1 ptr, regB, val
- strh \ptr, [\regB], \val
+ .macro strh1 reg, ptr, val
+ strh \reg, [\ptr], \val
.endm
- .macro ldr1 ptr, regB, val
- ldr \ptr, [\regB], \val
+ .macro ldr1 reg, ptr, val
+ ldr \reg, [\ptr], \val
.endm
- .macro str1 ptr, regB, val
- str \ptr, [\regB], \val
+ .macro str1 reg, ptr, val
+ str \reg, [\ptr], \val
.endm
- .macro ldp1 ptr, regB, regC, val
- ldp \ptr, \regB, [\regC], \val
+ .macro ldp1 reg1, reg2, ptr, val
+ ldp \reg1, \reg2, [\ptr], \val
.endm
- .macro stp1 ptr, regB, regC, val
- stp \ptr, \regB, [\regC], \val
+ .macro stp1 reg1, reg2, ptr, val
+ stp \reg1, \reg2, [\ptr], \val
.endm
SYM_FUNC_START_ALIAS(__memcpy)
diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S
new file mode 100644
index 0000000..03ca6d8
--- /dev/null
+++ b/arch/arm64/lib/mte.S
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 ARM Ltd.
+ */
+#include <linux/linkage.h>
+
+#include <asm/alternative.h>
+#include <asm/assembler.h>
+#include <asm/mte.h>
+#include <asm/page.h>
+#include <asm/sysreg.h>
+
+ .arch armv8.5-a+memtag
+
+/*
+ * multitag_transfer_size - set \reg to the block size that is accessed by the
+ * LDGM/STGM instructions.
+ */
+ .macro multitag_transfer_size, reg, tmp
+ mrs_s \reg, SYS_GMID_EL1
+ ubfx \reg, \reg, #SYS_GMID_EL1_BS_SHIFT, #SYS_GMID_EL1_BS_SIZE
+ mov \tmp, #4
+ lsl \reg, \tmp, \reg
+ .endm
+
+/*
+ * Clear the tags in a page
+ * x0 - address of the page to be cleared
+ */
+SYM_FUNC_START(mte_clear_page_tags)
+ multitag_transfer_size x1, x2
+1: stgm xzr, [x0]
+ add x0, x0, x1
+ tst x0, #(PAGE_SIZE - 1)
+ b.ne 1b
+ ret
+SYM_FUNC_END(mte_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
+ */
+SYM_FUNC_START(mte_copy_page_tags)
+ mov x2, x0
+ mov x3, x1
+ multitag_transfer_size x5, x6
+1: ldgm x4, [x3]
+ stgm x4, [x2]
+ add x2, x2, x5
+ add x3, x3, x5
+ tst x2, #(PAGE_SIZE - 1)
+ b.ne 1b
+ ret
+SYM_FUNC_END(mte_copy_page_tags)
+
+/*
+ * Read tags from a user buffer (one tag per byte) and set the corresponding
+ * tags at the given kernel address. Used by PTRACE_POKEMTETAGS.
+ * x0 - kernel address (to)
+ * x1 - user buffer (from)
+ * x2 - number of tags/bytes (n)
+ * Returns:
+ * x0 - number of tags read/set
+ */
+SYM_FUNC_START(mte_copy_tags_from_user)
+ mov x3, x1
+ cbz x2, 2f
+1:
+ uao_user_alternative 2f, ldrb, ldtrb, w4, x1, 0
+ lsl x4, x4, #MTE_TAG_SHIFT
+ stg x4, [x0], #MTE_GRANULE_SIZE
+ add x1, x1, #1
+ subs x2, x2, #1
+ b.ne 1b
+
+ // exception handling and function return
+2: sub x0, x1, x3 // update the number of tags set
+ ret
+SYM_FUNC_END(mte_copy_tags_from_user)
+
+/*
+ * Get the tags from a kernel address range and write the tag values to the
+ * given user buffer (one tag per byte). Used by PTRACE_PEEKMTETAGS.
+ * x0 - user buffer (to)
+ * x1 - kernel address (from)
+ * x2 - number of tags/bytes (n)
+ * Returns:
+ * x0 - number of tags read/set
+ */
+SYM_FUNC_START(mte_copy_tags_to_user)
+ mov x3, x0
+ cbz x2, 2f
+1:
+ ldg x4, [x1]
+ ubfx x4, x4, #MTE_TAG_SHIFT, #MTE_TAG_SIZE
+ uao_user_alternative 2f, strb, sttrb, w4, x0, 0
+ add x0, x0, #1
+ add x1, x1, #MTE_GRANULE_SIZE
+ subs x2, x2, #1
+ b.ne 1b
+
+ // exception handling and function return
+2: sub x0, x0, x3 // update the number of tags copied
+ ret
+SYM_FUNC_END(mte_copy_tags_to_user)
+
+/*
+ * Save the tags in a page
+ * x0 - page address
+ * x1 - tag storage
+ */
+SYM_FUNC_START(mte_save_page_tags)
+ multitag_transfer_size x7, x5
+1:
+ mov x2, #0
+2:
+ ldgm x5, [x0]
+ orr x2, x2, x5
+ add x0, x0, x7
+ tst x0, #0xFF // 16 tag values fit in a register,
+ b.ne 2b // which is 16*16=256 bytes
+
+ str x2, [x1], #8
+
+ tst x0, #(PAGE_SIZE - 1)
+ b.ne 1b
+
+ ret
+SYM_FUNC_END(mte_save_page_tags)
+
+/*
+ * Restore the tags in a page
+ * x0 - page address
+ * x1 - tag storage
+ */
+SYM_FUNC_START(mte_restore_page_tags)
+ multitag_transfer_size x7, x5
+1:
+ ldr x2, [x1], #8
+2:
+ stgm x2, [x0]
+ add x0, x0, x7
+ tst x0, #0xFF
+ b.ne 2b
+
+ tst x0, #(PAGE_SIZE - 1)
+ b.ne 1b
+
+ ret
+SYM_FUNC_END(mte_restore_page_tags)
diff --git a/arch/arm64/lib/strcmp.S b/arch/arm64/lib/strcmp.S
index 4767540..4e79566 100644
--- a/arch/arm64/lib/strcmp.S
+++ b/arch/arm64/lib/strcmp.S
@@ -186,7 +186,7 @@
* as carry-propagation can corrupt the upper bits if the trailing
* bytes in the string contain 0x01.
* However, if there is no NUL byte in the dword, we can generate
- * the result directly. We ca not just subtract the bytes as the
+ * the result directly. We cannot just subtract the bytes as the
* MSB might be significant.
*/
CPU_BE( cbnz has_nul, 1f )