From 95099d4622f8cb224d94e314c7a8e0df60b13f87 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 09 Dec 2023 08:38:01 +0000
Subject: [PATCH] enable docker ppp
---
kernel/arch/arm64/include/asm/uaccess.h | 271 +++++++++++++++++++++++++++++++++++++----------------
1 files changed, 187 insertions(+), 84 deletions(-)
diff --git a/kernel/arch/arm64/include/asm/uaccess.h b/kernel/arch/arm64/include/asm/uaccess.h
index 16969bc..5d0111a 100644
--- a/kernel/arch/arm64/include/asm/uaccess.h
+++ b/kernel/arch/arm64/include/asm/uaccess.h
@@ -1,19 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Based on arch/arm/include/asm/uaccess.h
*
* Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_UACCESS_H
#define __ASM_UACCESS_H
@@ -30,12 +19,14 @@
#include <linux/string.h>
#include <asm/cpufeature.h>
+#include <asm/mmu.h>
+#include <asm/mte.h>
#include <asm/ptrace.h>
#include <asm/memory.h>
-#include <asm/compiler.h>
#include <asm/extable.h>
-#define get_ds() (KERNEL_DS)
+#define HAVE_GET_KERNEL_NOFAULT
+
#define get_fs() (current_thread_info()->addr_limit)
static inline void set_fs(mm_segment_t fs)
@@ -46,8 +37,7 @@
* Prevent a mispredicted conditional call to set_fs from forwarding
* the wrong address limit to access_ok under speculation.
*/
- dsb(nsh);
- isb();
+ spec_bar();
/* On user-mode return, check fs is correct */
set_thread_flag(TIF_FSCHECK);
@@ -63,7 +53,7 @@
CONFIG_ARM64_UAO));
}
-#define segment_eq(a, b) ((a) == (b))
+#define uaccess_kernel() (get_fs() == KERNEL_DS)
/*
* Test whether a block of memory is a valid user space address.
@@ -106,7 +96,7 @@
return ret;
}
-#define access_ok(type, addr, size) __range_ok(addr, size)
+#define access_ok(addr, size) __range_ok(addr, size)
#define user_addr_max get_fs
#define _ASM_EXTABLE(from, to) \
@@ -126,8 +116,8 @@
local_irq_save(flags);
ttbr = read_sysreg(ttbr1_el1);
ttbr &= ~TTBR_ASID_MASK;
- /* reserved_ttbr0 placed before swapper_pg_dir */
- write_sysreg(ttbr - RESERVED_TTBR0_SIZE, ttbr0_el1);
+ /* reserved_pg_dir placed before swapper_pg_dir */
+ write_sysreg(ttbr - PAGE_SIZE, ttbr0_el1);
isb();
/* Set reserved ASID */
write_sysreg(ttbr, ttbr1_el1);
@@ -213,13 +203,63 @@
CONFIG_ARM64_PAN)); \
} while (0)
-static inline void uaccess_disable(void)
+/*
+ * The Tag Check Flag (TCF) mode for MTE is per EL, hence TCF0
+ * affects EL0 and TCF affects EL1 irrespective of which TTBR is
+ * used.
+ * The kernel accesses TTBR0 usually with LDTR/STTR instructions
+ * when UAO is available, so these would act as EL0 accesses using
+ * TCF0.
+ * However futex.h code uses exclusives which would be executed as
+ * EL1, this can potentially cause a tag check fault even if the
+ * user disables TCF0.
+ *
+ * To address the problem we set the PSTATE.TCO bit in uaccess_enable()
+ * and reset it in uaccess_disable().
+ *
+ * The Tag check override (TCO) bit disables temporarily the tag checking
+ * preventing the issue.
+ */
+static inline void __uaccess_disable_tco(void)
{
+ asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(0),
+ ARM64_MTE, CONFIG_KASAN_HW_TAGS));
+}
+
+static inline void __uaccess_enable_tco(void)
+{
+ asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(1),
+ ARM64_MTE, CONFIG_KASAN_HW_TAGS));
+}
+
+/*
+ * These functions disable tag checking only if in MTE async mode
+ * since the sync mode generates exceptions synchronously and the
+ * nofault or load_unaligned_zeropad can handle them.
+ */
+static inline void __uaccess_disable_tco_async(void)
+{
+ if (system_uses_mte_async_mode())
+ __uaccess_disable_tco();
+}
+
+static inline void __uaccess_enable_tco_async(void)
+{
+ if (system_uses_mte_async_mode())
+ __uaccess_enable_tco();
+}
+
+static inline void uaccess_disable_privileged(void)
+{
+ __uaccess_disable_tco();
+
__uaccess_disable(ARM64_HAS_PAN);
}
-static inline void uaccess_enable(void)
+static inline void uaccess_enable_privileged(void)
{
+ __uaccess_enable_tco();
+
__uaccess_enable(ARM64_HAS_PAN);
}
@@ -266,10 +306,9 @@
* The "__xxx_error" versions set the third argument to -EFAULT if an error
* occurs, and leave it unchanged on success.
*/
-#define __get_user_asm(instr, alt_instr, reg, x, addr, err, feature) \
+#define __get_mem_asm(load, reg, x, addr, err) \
asm volatile( \
- "1:"ALTERNATIVE(instr " " reg "1, [%2]\n", \
- alt_instr " " reg "1, [%2]\n", feature) \
+ "1: " load " " reg "1, [%2]\n" \
"2:\n" \
" .section .fixup, \"ax\"\n" \
" .align 2\n" \
@@ -281,66 +320,90 @@
: "+r" (err), "=&r" (x) \
: "r" (addr), "i" (-EFAULT))
-#define __get_user_err(x, ptr, err) \
+#define __raw_get_mem(ldr, x, ptr, err) \
do { \
unsigned long __gu_val; \
- __chk_user_ptr(ptr); \
- uaccess_enable_not_uao(); \
switch (sizeof(*(ptr))) { \
case 1: \
- __get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \
- (err), ARM64_HAS_UAO); \
+ __get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err)); \
break; \
case 2: \
- __get_user_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr), \
- (err), ARM64_HAS_UAO); \
+ __get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err)); \
break; \
case 4: \
- __get_user_asm("ldr", "ldtr", "%w", __gu_val, (ptr), \
- (err), ARM64_HAS_UAO); \
+ __get_mem_asm(ldr, "%w", __gu_val, (ptr), (err)); \
break; \
case 8: \
- __get_user_asm("ldr", "ldtr", "%x", __gu_val, (ptr), \
- (err), ARM64_HAS_UAO); \
+ __get_mem_asm(ldr, "%x", __gu_val, (ptr), (err)); \
break; \
default: \
BUILD_BUG(); \
} \
- uaccess_disable_not_uao(); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
} while (0)
-#define __get_user_check(x, ptr, err) \
-({ \
- __typeof__(*(ptr)) __user *__p = (ptr); \
- might_fault(); \
- if (access_ok(VERIFY_READ, __p, sizeof(*__p))) { \
- __p = uaccess_mask_ptr(__p); \
- __get_user_err((x), __p, (err)); \
- } else { \
- (x) = 0; (err) = -EFAULT; \
- } \
-})
+/*
+ * We must not call into the scheduler between uaccess_enable_not_uao() and
+ * uaccess_disable_not_uao(). As `x` and `ptr` could contain blocking functions,
+ * we must evaluate these outside of the critical section.
+ */
+#define __raw_get_user(x, ptr, err) \
+do { \
+ __typeof__(*(ptr)) __user *__rgu_ptr = (ptr); \
+ __typeof__(x) __rgu_val; \
+ __chk_user_ptr(ptr); \
+ \
+ uaccess_enable_not_uao(); \
+ __raw_get_mem("ldtr", __rgu_val, __rgu_ptr, err); \
+ uaccess_disable_not_uao(); \
+ \
+ (x) = __rgu_val; \
+} while (0)
#define __get_user_error(x, ptr, err) \
-({ \
- __get_user_check((x), (ptr), (err)); \
- (void)0; \
-})
+do { \
+ __typeof__(*(ptr)) __user *__p = (ptr); \
+ might_fault(); \
+ if (access_ok(__p, sizeof(*__p))) { \
+ __p = uaccess_mask_ptr(__p); \
+ __raw_get_user((x), __p, (err)); \
+ } else { \
+ (x) = (__force __typeof__(x))0; (err) = -EFAULT; \
+ } \
+} while (0)
#define __get_user(x, ptr) \
({ \
int __gu_err = 0; \
- __get_user_check((x), (ptr), __gu_err); \
+ __get_user_error((x), (ptr), __gu_err); \
__gu_err; \
})
#define get_user __get_user
-#define __put_user_asm(instr, alt_instr, reg, x, addr, err, feature) \
+/*
+ * We must not call into the scheduler between __uaccess_enable_tco_async() and
+ * __uaccess_disable_tco_async(). As `dst` and `src` may contain blocking
+ * functions, we must evaluate these outside of the critical section.
+ */
+#define __get_kernel_nofault(dst, src, type, err_label) \
+do { \
+ __typeof__(dst) __gkn_dst = (dst); \
+ __typeof__(src) __gkn_src = (src); \
+ int __gkn_err = 0; \
+ \
+ __uaccess_enable_tco_async(); \
+ __raw_get_mem("ldr", *((type *)(__gkn_dst)), \
+ (__force type *)(__gkn_src), __gkn_err); \
+ __uaccess_disable_tco_async(); \
+ \
+ if (unlikely(__gkn_err)) \
+ goto err_label; \
+} while (0)
+
+#define __put_mem_asm(store, reg, x, addr, err) \
asm volatile( \
- "1:"ALTERNATIVE(instr " " reg "1, [%2]\n", \
- alt_instr " " reg "1, [%2]\n", feature) \
+ "1: " store " " reg "1, [%2]\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
@@ -351,78 +414,115 @@
: "+r" (err) \
: "r" (x), "r" (addr), "i" (-EFAULT))
-#define __put_user_err(x, ptr, err) \
+#define __raw_put_mem(str, x, ptr, err) \
do { \
__typeof__(*(ptr)) __pu_val = (x); \
- __chk_user_ptr(ptr); \
- uaccess_enable_not_uao(); \
switch (sizeof(*(ptr))) { \
case 1: \
- __put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \
- (err), ARM64_HAS_UAO); \
+ __put_mem_asm(str "b", "%w", __pu_val, (ptr), (err)); \
break; \
case 2: \
- __put_user_asm("strh", "sttrh", "%w", __pu_val, (ptr), \
- (err), ARM64_HAS_UAO); \
+ __put_mem_asm(str "h", "%w", __pu_val, (ptr), (err)); \
break; \
case 4: \
- __put_user_asm("str", "sttr", "%w", __pu_val, (ptr), \
- (err), ARM64_HAS_UAO); \
+ __put_mem_asm(str, "%w", __pu_val, (ptr), (err)); \
break; \
case 8: \
- __put_user_asm("str", "sttr", "%x", __pu_val, (ptr), \
- (err), ARM64_HAS_UAO); \
+ __put_mem_asm(str, "%x", __pu_val, (ptr), (err)); \
break; \
default: \
BUILD_BUG(); \
} \
+} while (0)
+
+/*
+ * We must not call into the scheduler between uaccess_enable_not_uao() and
+ * uaccess_disable_not_uao(). As `x` and `ptr` could contain blocking functions,
+ * we must evaluate these outside of the critical section.
+ */
+#define __raw_put_user(x, ptr, err) \
+do { \
+ __typeof__(*(ptr)) __user *__rpu_ptr = (ptr); \
+ __typeof__(*(ptr)) __rpu_val = (x); \
+ __chk_user_ptr(__rpu_ptr); \
+ \
+ uaccess_enable_not_uao(); \
+ __raw_put_mem("sttr", __rpu_val, __rpu_ptr, err); \
uaccess_disable_not_uao(); \
} while (0)
-#define __put_user_check(x, ptr, err) \
-({ \
+#define __put_user_error(x, ptr, err) \
+do { \
__typeof__(*(ptr)) __user *__p = (ptr); \
might_fault(); \
- if (access_ok(VERIFY_WRITE, __p, sizeof(*__p))) { \
+ if (access_ok(__p, sizeof(*__p))) { \
__p = uaccess_mask_ptr(__p); \
- __put_user_err((x), __p, (err)); \
+ __raw_put_user((x), __p, (err)); \
} else { \
(err) = -EFAULT; \
} \
-})
-
-#define __put_user_error(x, ptr, err) \
-({ \
- __put_user_check((x), (ptr), (err)); \
- (void)0; \
-})
+} while (0)
#define __put_user(x, ptr) \
({ \
int __pu_err = 0; \
- __put_user_check((x), (ptr), __pu_err); \
+ __put_user_error((x), (ptr), __pu_err); \
__pu_err; \
})
#define put_user __put_user
+/*
+ * We must not call into the scheduler between __uaccess_enable_tco_async() and
+ * __uaccess_disable_tco_async(). As `dst` and `src` may contain blocking
+ * functions, we must evaluate these outside of the critical section.
+ */
+#define __put_kernel_nofault(dst, src, type, err_label) \
+do { \
+ __typeof__(dst) __pkn_dst = (dst); \
+ __typeof__(src) __pkn_src = (src); \
+ int __pkn_err = 0; \
+ \
+ __uaccess_enable_tco_async(); \
+ __raw_put_mem("str", *((type *)(__pkn_src)), \
+ (__force type *)(__pkn_dst), __pkn_err); \
+ __uaccess_disable_tco_async(); \
+ \
+ if (unlikely(__pkn_err)) \
+ goto err_label; \
+} while(0)
+
extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
#define raw_copy_from_user(to, from, n) \
({ \
- __arch_copy_from_user((to), __uaccess_mask_ptr(from), (n)); \
+ unsigned long __acfu_ret; \
+ uaccess_enable_not_uao(); \
+ __acfu_ret = __arch_copy_from_user((to), \
+ __uaccess_mask_ptr(from), (n)); \
+ uaccess_disable_not_uao(); \
+ __acfu_ret; \
})
extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n);
#define raw_copy_to_user(to, from, n) \
({ \
- __arch_copy_to_user(__uaccess_mask_ptr(to), (from), (n)); \
+ unsigned long __actu_ret; \
+ uaccess_enable_not_uao(); \
+ __actu_ret = __arch_copy_to_user(__uaccess_mask_ptr(to), \
+ (from), (n)); \
+ uaccess_disable_not_uao(); \
+ __actu_ret; \
})
extern unsigned long __must_check __arch_copy_in_user(void __user *to, const void __user *from, unsigned long n);
#define raw_copy_in_user(to, from, n) \
({ \
- __arch_copy_in_user(__uaccess_mask_ptr(to), \
- __uaccess_mask_ptr(from), (n)); \
+ unsigned long __aciu_ret; \
+ uaccess_enable_not_uao(); \
+ __aciu_ret = __arch_copy_in_user(__uaccess_mask_ptr(to), \
+ __uaccess_mask_ptr(from), (n)); \
+ uaccess_disable_not_uao(); \
+ __aciu_ret; \
})
#define INLINE_COPY_TO_USER
@@ -431,8 +531,11 @@
extern unsigned long __must_check __arch_clear_user(void __user *to, unsigned long n);
static inline unsigned long __must_check __clear_user(void __user *to, unsigned long n)
{
- if (access_ok(VERIFY_WRITE, to, n))
+ if (access_ok(to, n)) {
+ uaccess_enable_not_uao();
n = __arch_clear_user(__uaccess_mask_ptr(to), n);
+ uaccess_disable_not_uao();
+ }
return n;
}
#define clear_user __clear_user
--
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