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Diffstat (limited to 'arch/arm/include/asm/uaccess.h')
-rw-r--r--arch/arm/include/asm/uaccess.h120
1 files changed, 77 insertions, 43 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 36fbc3329252..d6ae80b5df36 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -8,10 +8,14 @@
/*
* User space memory access functions
*/
+#include <linux/kernel.h>
#include <linux/string.h>
-#include <asm/memory.h>
+#include <asm/page.h>
#include <asm/domain.h>
+#include <linux/unaligned.h>
#include <asm/unified.h>
+#include <asm/pgtable.h>
+#include <asm/proc-fns.h>
#include <asm/compiler.h>
#include <asm/extable.h>
@@ -22,9 +26,10 @@
* perform such accesses (eg, via list poison values) which could then
* be exploited for priviledge escalation.
*/
+#if defined(CONFIG_CPU_SW_DOMAIN_PAN)
+
static __always_inline unsigned int uaccess_save_and_enable(void)
{
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
unsigned int old_domain = get_domain();
/* Set the current domain access to permit user accesses */
@@ -32,19 +37,49 @@ static __always_inline unsigned int uaccess_save_and_enable(void)
domain_val(DOMAIN_USER, DOMAIN_CLIENT));
return old_domain;
-#else
- return 0;
-#endif
}
static __always_inline void uaccess_restore(unsigned int flags)
{
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/* Restore the user access mask */
set_domain(flags);
-#endif
}
+#elif defined(CONFIG_CPU_TTBR0_PAN)
+
+static __always_inline unsigned int uaccess_save_and_enable(void)
+{
+ unsigned int old_ttbcr = cpu_get_ttbcr();
+
+ /*
+ * Enable TTBR0 page table walks (T0SZ = 0, EDP0 = 0) and ASID from
+ * TTBR0 (A1 = 0).
+ */
+ cpu_set_ttbcr(old_ttbcr & ~(TTBCR_A1 | TTBCR_EPD0 | TTBCR_T0SZ_MASK));
+ isb();
+
+ return old_ttbcr;
+}
+
+static inline void uaccess_restore(unsigned int flags)
+{
+ cpu_set_ttbcr(flags);
+ isb();
+}
+
+#else
+
+static inline unsigned int uaccess_save_and_enable(void)
+{
+ return 0;
+}
+
+static inline void uaccess_restore(unsigned int flags)
+{
+}
+
+#endif
+
/*
* These two are intentionally not defined anywhere - if the kernel
* code generates any references to them, that's a bug.
@@ -55,21 +90,6 @@ extern int __put_user_bad(void);
#ifdef CONFIG_MMU
/*
- * We use 33-bit arithmetic here. Success returns zero, failure returns
- * addr_limit. We take advantage that addr_limit will be zero for KERNEL_DS,
- * so this will always return success in that case.
- */
-#define __range_ok(addr, size) ({ \
- unsigned long flag, roksum; \
- __chk_user_ptr(addr); \
- __asm__(".syntax unified\n" \
- "adds %1, %2, %3; sbcscc %1, %1, %0; movcc %0, #0" \
- : "=&r" (flag), "=&r" (roksum) \
- : "r" (addr), "Ir" (size), "0" (TASK_SIZE) \
- : "cc"); \
- flag; })
-
-/*
* This is a type: either unsigned long, if the argument fits into
* that type, or otherwise unsigned long long.
*/
@@ -123,16 +143,6 @@ extern int __get_user_64t_1(void *);
extern int __get_user_64t_2(void *);
extern int __get_user_64t_4(void *);
-#define __GUP_CLOBBER_1 "lr", "cc"
-#ifdef CONFIG_CPU_USE_DOMAINS
-#define __GUP_CLOBBER_2 "ip", "lr", "cc"
-#else
-#define __GUP_CLOBBER_2 "lr", "cc"
-#endif
-#define __GUP_CLOBBER_4 "lr", "cc"
-#define __GUP_CLOBBER_32t_8 "lr", "cc"
-#define __GUP_CLOBBER_8 "lr", "cc"
-
#define __get_user_x(__r2, __p, __e, __l, __s) \
__asm__ __volatile__ ( \
__asmeq("%0", "r0") __asmeq("%1", "r2") \
@@ -140,7 +150,7 @@ extern int __get_user_64t_4(void *);
"bl __get_user_" #__s \
: "=&r" (__e), "=r" (__r2) \
: "0" (__p), "r" (__l) \
- : __GUP_CLOBBER_##__s)
+ : "ip", "lr", "cc")
/* narrowing a double-word get into a single 32bit word register: */
#ifdef __ARMEB__
@@ -162,7 +172,7 @@ extern int __get_user_64t_4(void *);
"bl __get_user_64t_" #__s \
: "=&r" (__e), "=r" (__r2) \
: "0" (__p), "r" (__l) \
- : __GUP_CLOBBER_##__s)
+ : "ip", "lr", "cc")
#else
#define __get_user_x_64t __get_user_x
#endif
@@ -240,15 +250,12 @@ extern int __put_user_8(void *, unsigned long long);
#else /* CONFIG_MMU */
-#define __addr_ok(addr) ((void)(addr), 1)
-#define __range_ok(addr, size) ((void)(addr), 0)
-
#define get_user(x, p) __get_user(x, p)
#define __put_user_check __put_user_nocheck
#endif /* CONFIG_MMU */
-#define access_ok(addr, size) (__range_ok(addr, size) == 0)
+#include <asm-generic/access_ok.h>
#ifdef CONFIG_CPU_SPECTRE
/*
@@ -276,10 +283,17 @@ extern int __put_user_8(void *, unsigned long long);
__gu_err; \
})
+/*
+ * This is a type: either unsigned long, if the argument fits into
+ * that type, or otherwise unsigned long long.
+ */
+#define __long_type(x) \
+ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
+
#define __get_user_err(x, ptr, err, __t) \
do { \
unsigned long __gu_addr = (unsigned long)(ptr); \
- unsigned long __gu_val; \
+ __long_type(x) __gu_val; \
unsigned int __ua_flags; \
__chk_user_ptr(ptr); \
might_fault(); \
@@ -288,6 +302,7 @@ do { \
case 1: __get_user_asm_byte(__gu_val, __gu_addr, err, __t); break; \
case 2: __get_user_asm_half(__gu_val, __gu_addr, err, __t); break; \
case 4: __get_user_asm_word(__gu_val, __gu_addr, err, __t); break; \
+ case 8: __get_user_asm_dword(__gu_val, __gu_addr, err, __t); break; \
default: (__gu_val) = __get_user_bad(); \
} \
uaccess_restore(__ua_flags); \
@@ -346,6 +361,22 @@ do { \
#define __get_user_asm_word(x, addr, err, __t) \
__get_user_asm(x, addr, err, "ldr" __t)
+#ifdef __ARMEB__
+#define __WORD0_OFFS 4
+#define __WORD1_OFFS 0
+#else
+#define __WORD0_OFFS 0
+#define __WORD1_OFFS 4
+#endif
+
+#define __get_user_asm_dword(x, addr, err, __t) \
+ ({ \
+ unsigned long __w0, __w1; \
+ __get_user_asm(__w0, addr + __WORD0_OFFS, err, "ldr" __t); \
+ __get_user_asm(__w1, addr + __WORD1_OFFS, err, "ldr" __t); \
+ (x) = ((u64)__w1 << 32) | (u64) __w0; \
+})
+
#define __put_user_switch(x, ptr, __err, __fn) \
do { \
const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
@@ -475,8 +506,6 @@ do { \
: "r" (x), "i" (-EFAULT) \
: "cc")
-#define HAVE_GET_KERNEL_NOFAULT
-
#define __get_kernel_nofault(dst, src, type, err_label) \
do { \
const type *__pk_ptr = (src); \
@@ -497,7 +526,10 @@ do { \
} \
default: __err = __get_user_bad(); break; \
} \
- *(type *)(dst) = __val; \
+ if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) \
+ put_unaligned(__val, (type *)(dst)); \
+ else \
+ *(type *)(dst) = __val; /* aligned by caller */ \
if (__err) \
goto err_label; \
} while (0)
@@ -507,7 +539,9 @@ do { \
const type *__pk_ptr = (dst); \
unsigned long __dst = (unsigned long)__pk_ptr; \
int __err = 0; \
- type __val = *(type *)src; \
+ type __val = IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) \
+ ? get_unaligned((type *)(src)) \
+ : *(type *)(src); /* aligned by caller */ \
switch (sizeof(type)) { \
case 1: __put_user_asm_byte(__val, __dst, __err, ""); break; \
case 2: __put_user_asm_half(__val, __dst, __err, ""); break; \
generated by cgit (git 2.34.1) at 2025-12-25 16:38:39 +0000