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Diffstat (limited to 'arch/s390/include/asm/uaccess.h')
-rw-r--r--arch/s390/include/asm/uaccess.h763
1 files changed, 531 insertions, 232 deletions
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index c2c9995466e0..a43fc88c0050 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -13,25 +13,81 @@
/*
* User space memory access functions
*/
+#include <linux/pgtable.h>
#include <asm/asm-extable.h>
#include <asm/processor.h>
-#include <asm/ctl_reg.h>
#include <asm/extable.h>
#include <asm/facility.h>
#include <asm-generic/access_ok.h>
+#include <asm/asce.h>
+#include <linux/instrumented.h>
void debug_user_asce(int exit);
-unsigned long __must_check
-raw_copy_from_user(void *to, const void __user *from, unsigned long n);
-
-unsigned long __must_check
-raw_copy_to_user(void __user *to, const void *from, unsigned long n);
+#ifdef CONFIG_KMSAN
+#define uaccess_kmsan_or_inline noinline __maybe_unused __no_sanitize_memory
+#else
+#define uaccess_kmsan_or_inline __always_inline
+#endif
-#ifndef CONFIG_KASAN
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
-#endif
+
+static uaccess_kmsan_or_inline __must_check unsigned long
+raw_copy_from_user(void *to, const void __user *from, unsigned long size)
+{
+ unsigned long osize;
+ int cc;
+
+ while (1) {
+ osize = size;
+ asm_inline volatile(
+ " lhi %%r0,%[spec]\n"
+ "0: mvcos %[to],%[from],%[size]\n"
+ "1: nopr %%r7\n"
+ CC_IPM(cc)
+ EX_TABLE_UA_MVCOS_FROM(0b, 0b)
+ EX_TABLE_UA_MVCOS_FROM(1b, 0b)
+ : CC_OUT(cc, cc), [size] "+d" (size), [to] "=Q" (*(char *)to)
+ : [spec] "I" (0x81), [from] "Q" (*(const char __user *)from)
+ : CC_CLOBBER_LIST("memory", "0"));
+ if (__builtin_constant_p(osize) && osize <= 4096)
+ return osize - size;
+ if (likely(CC_TRANSFORM(cc) == 0))
+ return osize - size;
+ size -= 4096;
+ to += 4096;
+ from += 4096;
+ }
+}
+
+static uaccess_kmsan_or_inline __must_check unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long size)
+{
+ unsigned long osize;
+ int cc;
+
+ while (1) {
+ osize = size;
+ asm_inline volatile(
+ " llilh %%r0,%[spec]\n"
+ "0: mvcos %[to],%[from],%[size]\n"
+ "1: nopr %%r7\n"
+ CC_IPM(cc)
+ EX_TABLE_UA_MVCOS_TO(0b, 0b)
+ EX_TABLE_UA_MVCOS_TO(1b, 0b)
+ : CC_OUT(cc, cc), [size] "+d" (size), [to] "=Q" (*(char __user *)to)
+ : [spec] "I" (0x81), [from] "Q" (*(const char *)from)
+ : CC_CLOBBER_LIST("memory", "0"));
+ if (__builtin_constant_p(osize) && osize <= 4096)
+ return osize - size;
+ if (likely(CC_TRANSFORM(cc) == 0))
+ return osize - size;
+ size -= 4096;
+ to += 4096;
+ from += 4096;
+ }
+}
unsigned long __must_check
_copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key);
@@ -55,163 +111,113 @@ copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned lo
return n;
}
-union oac {
- unsigned int val;
- struct {
- struct {
- unsigned short key : 4;
- unsigned short : 4;
- unsigned short as : 2;
- unsigned short : 4;
- unsigned short k : 1;
- unsigned short a : 1;
- } oac1;
- struct {
- unsigned short key : 4;
- unsigned short : 4;
- unsigned short as : 2;
- unsigned short : 4;
- unsigned short k : 1;
- unsigned short a : 1;
- } oac2;
- };
-};
-
int __noreturn __put_user_bad(void);
-#define __put_user_asm(to, from, size) \
-({ \
- union oac __oac_spec = { \
- .oac1.as = PSW_BITS_AS_SECONDARY, \
- .oac1.a = 1, \
- }; \
- int __rc; \
- \
- asm volatile( \
- " lr 0,%[spec]\n" \
- "0: mvcos %[_to],%[_from],%[_size]\n" \
- "1: xr %[rc],%[rc]\n" \
- "2:\n" \
- EX_TABLE_UA_STORE(0b, 2b, %[rc]) \
- EX_TABLE_UA_STORE(1b, 2b, %[rc]) \
- : [rc] "=&d" (__rc), [_to] "+Q" (*(to)) \
- : [_size] "d" (size), [_from] "Q" (*(from)), \
- [spec] "d" (__oac_spec.val) \
- : "cc", "0"); \
- __rc; \
-})
-
-static __always_inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
-{
- int rc;
-
- switch (size) {
- case 1:
- rc = __put_user_asm((unsigned char __user *)ptr,
- (unsigned char *)x,
- size);
- break;
- case 2:
- rc = __put_user_asm((unsigned short __user *)ptr,
- (unsigned short *)x,
- size);
- break;
- case 4:
- rc = __put_user_asm((unsigned int __user *)ptr,
- (unsigned int *)x,
- size);
- break;
- case 8:
- rc = __put_user_asm((unsigned long __user *)ptr,
- (unsigned long *)x,
- size);
- break;
- default:
- __put_user_bad();
- break;
- }
- return rc;
+#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
+
+#define DEFINE_PUT_USER_NOINSTR(type) \
+static uaccess_kmsan_or_inline int \
+__put_user_##type##_noinstr(unsigned type __user *to, \
+ unsigned type *from, \
+ unsigned long size) \
+{ \
+ asm goto( \
+ " llilh %%r0,%[spec]\n" \
+ "0: mvcos %[to],%[from],%[size]\n" \
+ "1: nopr %%r7\n" \
+ EX_TABLE(0b, %l[Efault]) \
+ EX_TABLE(1b, %l[Efault]) \
+ : [to] "+Q" (*to) \
+ : [size] "d" (size), [from] "Q" (*from), \
+ [spec] "I" (0x81) \
+ : "cc", "0" \
+ : Efault \
+ ); \
+ return 0; \
+Efault: \
+ return -EFAULT; \
}
-int __noreturn __get_user_bad(void);
+#else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
-#define __get_user_asm(to, from, size) \
-({ \
- union oac __oac_spec = { \
- .oac2.as = PSW_BITS_AS_SECONDARY, \
- .oac2.a = 1, \
- }; \
- int __rc; \
+#define DEFINE_PUT_USER_NOINSTR(type) \
+static uaccess_kmsan_or_inline int \
+__put_user_##type##_noinstr(unsigned type __user *to, \
+ unsigned type *from, \
+ unsigned long size) \
+{ \
+ int rc; \
\
- asm volatile( \
- " lr 0,%[spec]\n" \
- "0: mvcos 0(%[_to]),%[_from],%[_size]\n" \
- "1: xr %[rc],%[rc]\n" \
+ asm_inline volatile( \
+ " llilh %%r0,%[spec]\n" \
+ "0: mvcos %[to],%[from],%[size]\n" \
+ "1: lhi %[rc],0\n" \
"2:\n" \
- EX_TABLE_UA_LOAD_MEM(0b, 2b, %[rc], %[_to], %[_ksize]) \
- EX_TABLE_UA_LOAD_MEM(1b, 2b, %[rc], %[_to], %[_ksize]) \
- : [rc] "=&d" (__rc), "=Q" (*(to)) \
- : [_size] "d" (size), [_from] "Q" (*(from)), \
- [spec] "d" (__oac_spec.val), [_to] "a" (to), \
- [_ksize] "K" (size) \
+ EX_TABLE_UA_FAULT(0b, 2b, %[rc]) \
+ EX_TABLE_UA_FAULT(1b, 2b, %[rc]) \
+ : [rc] "=d" (rc), [to] "+Q" (*to) \
+ : [size] "d" (size), [from] "Q" (*from), \
+ [spec] "I" (0x81) \
: "cc", "0"); \
- __rc; \
-})
+ return rc; \
+}
-static __always_inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
-{
- int rc;
+#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
- switch (size) {
- case 1:
- rc = __get_user_asm((unsigned char *)x,
- (unsigned char __user *)ptr,
- size);
- break;
- case 2:
- rc = __get_user_asm((unsigned short *)x,
- (unsigned short __user *)ptr,
- size);
- break;
- case 4:
- rc = __get_user_asm((unsigned int *)x,
- (unsigned int __user *)ptr,
- size);
- break;
- case 8:
- rc = __get_user_asm((unsigned long *)x,
- (unsigned long __user *)ptr,
- size);
- break;
- default:
- __get_user_bad();
- break;
- }
- return rc;
+DEFINE_PUT_USER_NOINSTR(char);
+DEFINE_PUT_USER_NOINSTR(short);
+DEFINE_PUT_USER_NOINSTR(int);
+DEFINE_PUT_USER_NOINSTR(long);
+
+#define DEFINE_PUT_USER(type) \
+static __always_inline int \
+__put_user_##type(unsigned type __user *to, unsigned type *from, \
+ unsigned long size) \
+{ \
+ int rc; \
+ \
+ rc = __put_user_##type##_noinstr(to, from, size); \
+ instrument_put_user(*from, to, size); \
+ return rc; \
}
-/*
- * These are the main single-value transfer routines. They automatically
- * use the right size if we just have the right pointer type.
- */
+DEFINE_PUT_USER(char);
+DEFINE_PUT_USER(short);
+DEFINE_PUT_USER(int);
+DEFINE_PUT_USER(long);
+
#define __put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __x = (x); \
- int __pu_err = -EFAULT; \
+ int __prc; \
\
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: \
+ __prc = __put_user_char((unsigned char __user *)(ptr), \
+ (unsigned char *)&__x, \
+ sizeof(*(ptr))); \
+ break; \
case 2: \
+ __prc = __put_user_short((unsigned short __user *)(ptr),\
+ (unsigned short *)&__x, \
+ sizeof(*(ptr))); \
+ break; \
case 4: \
+ __prc = __put_user_int((unsigned int __user *)(ptr), \
+ (unsigned int *)&__x, \
+ sizeof(*(ptr))); \
+ break; \
case 8: \
- __pu_err = __put_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ __prc = __put_user_long((unsigned long __user *)(ptr), \
+ (unsigned long *)&__x, \
+ sizeof(*(ptr))); \
break; \
default: \
- __put_user_bad(); \
+ __prc = __put_user_bad(); \
break; \
} \
- __builtin_expect(__pu_err, 0); \
+ __builtin_expect(__prc, 0); \
})
#define put_user(x, ptr) \
@@ -220,45 +226,129 @@ static __always_inline int __get_user_fn(void *x, const void __user *ptr, unsign
__put_user(x, ptr); \
})
+int __noreturn __get_user_bad(void);
+
+#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
+
+#define DEFINE_GET_USER_NOINSTR(type) \
+static uaccess_kmsan_or_inline int \
+__get_user_##type##_noinstr(unsigned type *to, \
+ const unsigned type __user *from, \
+ unsigned long size) \
+{ \
+ asm goto( \
+ " lhi %%r0,%[spec]\n" \
+ "0: mvcos %[to],%[from],%[size]\n" \
+ "1: nopr %%r7\n" \
+ EX_TABLE(0b, %l[Efault]) \
+ EX_TABLE(1b, %l[Efault]) \
+ : [to] "=Q" (*to) \
+ : [size] "d" (size), [from] "Q" (*from), \
+ [spec] "I" (0x81) \
+ : "cc", "0" \
+ : Efault \
+ ); \
+ return 0; \
+Efault: \
+ *to = 0; \
+ return -EFAULT; \
+}
+
+#else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
+
+#define DEFINE_GET_USER_NOINSTR(type) \
+static uaccess_kmsan_or_inline int \
+__get_user_##type##_noinstr(unsigned type *to, \
+ const unsigned type __user *from, \
+ unsigned long size) \
+{ \
+ int rc; \
+ \
+ asm_inline volatile( \
+ " lhi %%r0,%[spec]\n" \
+ "0: mvcos %[to],%[from],%[size]\n" \
+ "1: lhi %[rc],0\n" \
+ "2:\n" \
+ EX_TABLE_UA_FAULT(0b, 2b, %[rc]) \
+ EX_TABLE_UA_FAULT(1b, 2b, %[rc]) \
+ : [rc] "=d" (rc), [to] "=Q" (*to) \
+ : [size] "d" (size), [from] "Q" (*from), \
+ [spec] "I" (0x81) \
+ : "cc", "0"); \
+ if (likely(!rc)) \
+ return 0; \
+ *to = 0; \
+ return rc; \
+}
+
+#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
+
+DEFINE_GET_USER_NOINSTR(char);
+DEFINE_GET_USER_NOINSTR(short);
+DEFINE_GET_USER_NOINSTR(int);
+DEFINE_GET_USER_NOINSTR(long);
+
+#define DEFINE_GET_USER(type) \
+static __always_inline int \
+__get_user_##type(unsigned type *to, const unsigned type __user *from, \
+ unsigned long size) \
+{ \
+ int rc; \
+ \
+ rc = __get_user_##type##_noinstr(to, from, size); \
+ instrument_get_user(*to); \
+ return rc; \
+}
+
+DEFINE_GET_USER(char);
+DEFINE_GET_USER(short);
+DEFINE_GET_USER(int);
+DEFINE_GET_USER(long);
+
#define __get_user(x, ptr) \
({ \
- int __gu_err = -EFAULT; \
+ const __user void *____guptr = (ptr); \
+ int __grc; \
\
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: { \
+ const unsigned char __user *__guptr = ____guptr; \
unsigned char __x; \
\
- __gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ __grc = __get_user_char(&__x, __guptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 2: { \
+ const unsigned short __user *__guptr = ____guptr; \
unsigned short __x; \
\
- __gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ __grc = __get_user_short(&__x, __guptr, sizeof(*(ptr)));\
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 4: { \
+ const unsigned int __user *__guptr = ____guptr; \
unsigned int __x; \
\
- __gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ __grc = __get_user_int(&__x, __guptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
case 8: { \
+ const unsigned long __user *__guptr = ____guptr; \
unsigned long __x; \
\
- __gu_err = __get_user_fn(&__x, ptr, sizeof(*(ptr))); \
+ __grc = __get_user_long(&__x, __guptr, sizeof(*(ptr))); \
(x) = *(__force __typeof__(*(ptr)) *)&__x; \
break; \
}; \
default: \
- __get_user_bad(); \
+ __grc = __get_user_bad(); \
break; \
} \
- __builtin_expect(__gu_err, 0); \
+ __builtin_expect(__grc, 0); \
})
#define get_user(x, ptr) \
@@ -274,121 +364,330 @@ long __must_check strncpy_from_user(char *dst, const char __user *src, long coun
long __must_check strnlen_user(const char __user *src, long count);
-/*
- * Zero Userspace
- */
-unsigned long __must_check __clear_user(void __user *to, unsigned long size);
+static uaccess_kmsan_or_inline __must_check unsigned long
+__clear_user(void __user *to, unsigned long size)
+{
+ unsigned long osize;
+ int cc;
+
+ while (1) {
+ osize = size;
+ asm_inline volatile(
+ " llilh %%r0,%[spec]\n"
+ "0: mvcos %[to],%[from],%[size]\n"
+ "1: nopr %%r7\n"
+ CC_IPM(cc)
+ EX_TABLE_UA_MVCOS_TO(0b, 0b)
+ EX_TABLE_UA_MVCOS_TO(1b, 0b)
+ : CC_OUT(cc, cc), [size] "+d" (size), [to] "=Q" (*(char __user *)to)
+ : [spec] "I" (0x81), [from] "Q" (*(const char *)empty_zero_page)
+ : CC_CLOBBER_LIST("memory", "0"));
+ if (__builtin_constant_p(osize) && osize <= 4096)
+ return osize - size;
+ if (CC_TRANSFORM(cc) == 0)
+ return osize - size;
+ size -= 4096;
+ to += 4096;
+ }
+}
-static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
+static __always_inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
{
might_fault();
return __clear_user(to, n);
}
-int copy_to_user_real(void __user *dest, unsigned long src, unsigned long count);
-void *s390_kernel_write(void *dst, const void *src, size_t size);
+void *__s390_kernel_write(void *dst, const void *src, size_t size);
-int __noreturn __put_kernel_bad(void);
+static inline void *s390_kernel_write(void *dst, const void *src, size_t size)
+{
+ if (__is_defined(__DECOMPRESSOR))
+ return memcpy(dst, src, size);
+ return __s390_kernel_write(dst, src, size);
+}
-#define __put_kernel_asm(val, to, insn) \
-({ \
- int __rc; \
- \
- asm volatile( \
- "0: " insn " %[_val],%[_to]\n" \
- "1: xr %[rc],%[rc]\n" \
- "2:\n" \
- EX_TABLE_UA_STORE(0b, 2b, %[rc]) \
- EX_TABLE_UA_STORE(1b, 2b, %[rc]) \
- : [rc] "=d" (__rc), [_to] "+Q" (*(to)) \
- : [_val] "d" (val) \
- : "cc"); \
- __rc; \
-})
+void __noreturn __mvc_kernel_nofault_bad(void);
-#define __put_kernel_nofault(dst, src, type, err_label) \
+#if defined(CONFIG_CC_HAS_ASM_GOTO_OUTPUT) && defined(CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS)
+
+#define __mvc_kernel_nofault(dst, src, type, err_label) \
do { \
- unsigned long __x = (unsigned long)(*((type *)(src))); \
- int __pk_err; \
- \
switch (sizeof(type)) { \
case 1: \
- __pk_err = __put_kernel_asm(__x, (type *)(dst), "stc"); \
- break; \
case 2: \
- __pk_err = __put_kernel_asm(__x, (type *)(dst), "sth"); \
- break; \
case 4: \
- __pk_err = __put_kernel_asm(__x, (type *)(dst), "st"); \
- break; \
case 8: \
- __pk_err = __put_kernel_asm(__x, (type *)(dst), "stg"); \
+ asm goto( \
+ "0: mvc %O[_dst](%[_len],%R[_dst]),%[_src]\n" \
+ "1: nopr %%r7\n" \
+ EX_TABLE(0b, %l[err_label]) \
+ EX_TABLE(1b, %l[err_label]) \
+ : [_dst] "=Q" (*(type *)dst) \
+ : [_src] "Q" (*(type *)(src)), \
+ [_len] "I" (sizeof(type)) \
+ : \
+ : err_label); \
break; \
default: \
- __pk_err = __put_kernel_bad(); \
+ __mvc_kernel_nofault_bad(); \
break; \
} \
- if (unlikely(__pk_err)) \
- goto err_label; \
} while (0)
-int __noreturn __get_kernel_bad(void);
+#else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT) && CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS */
-#define __get_kernel_asm(val, from, insn) \
-({ \
- int __rc; \
- \
- asm volatile( \
- "0: " insn " %[_val],%[_from]\n" \
- "1: xr %[rc],%[rc]\n" \
- "2:\n" \
- EX_TABLE_UA_LOAD_REG(0b, 2b, %[rc], %[_val]) \
- EX_TABLE_UA_LOAD_REG(1b, 2b, %[rc], %[_val]) \
- : [rc] "=d" (__rc), [_val] "=d" (val) \
- : [_from] "Q" (*(from)) \
- : "cc"); \
- __rc; \
-})
-
-#define __get_kernel_nofault(dst, src, type, err_label) \
+#define __mvc_kernel_nofault(dst, src, type, err_label) \
do { \
- int __gk_err; \
+ type *(__dst) = (type *)(dst); \
+ int __rc; \
\
switch (sizeof(type)) { \
- case 1: { \
- unsigned char __x; \
- \
- __gk_err = __get_kernel_asm(__x, (type *)(src), "ic"); \
- *((type *)(dst)) = (type)__x; \
- break; \
- }; \
- case 2: { \
- unsigned short __x; \
- \
- __gk_err = __get_kernel_asm(__x, (type *)(src), "lh"); \
- *((type *)(dst)) = (type)__x; \
- break; \
- }; \
- case 4: { \
- unsigned int __x; \
- \
- __gk_err = __get_kernel_asm(__x, (type *)(src), "l"); \
- *((type *)(dst)) = (type)__x; \
- break; \
- }; \
- case 8: { \
- unsigned long __x; \
- \
- __gk_err = __get_kernel_asm(__x, (type *)(src), "lg"); \
- *((type *)(dst)) = (type)__x; \
+ case 1: \
+ case 2: \
+ case 4: \
+ case 8: \
+ asm_inline volatile( \
+ "0: mvc 0(%[_len],%[_dst]),%[_src]\n" \
+ "1: lhi %[_rc],0\n" \
+ "2:\n" \
+ EX_TABLE_UA_FAULT(0b, 2b, %[_rc]) \
+ EX_TABLE_UA_FAULT(1b, 2b, %[_rc]) \
+ : [_rc] "=d" (__rc), \
+ "=m" (*__dst) \
+ : [_src] "Q" (*(type *)(src)), \
+ [_dst] "a" (__dst), \
+ [_len] "I" (sizeof(type))); \
+ if (__rc) \
+ goto err_label; \
break; \
- }; \
default: \
- __gk_err = __get_kernel_bad(); \
+ __mvc_kernel_nofault_bad(); \
break; \
} \
- if (unlikely(__gk_err)) \
- goto err_label; \
} while (0)
+#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT && CONFIG_CC_HAS_ASM_AOR_FORMAT_FLAGS */
+
+#define __get_kernel_nofault __mvc_kernel_nofault
+#define __put_kernel_nofault __mvc_kernel_nofault
+
+void __cmpxchg_user_key_called_with_bad_pointer(void);
+
+#define CMPXCHG_USER_KEY_MAX_LOOPS 128
+
+static __always_inline int __cmpxchg_user_key(unsigned long address, void *uval,
+ __uint128_t old, __uint128_t new,
+ unsigned long key, int size)
+{
+ bool sacf_flag;
+ int rc = 0;
+
+ switch (size) {
+ case 1: {
+ unsigned int prev, shift, mask, _old, _new;
+ unsigned long count;
+
+ shift = (3 ^ (address & 3)) << 3;
+ address ^= address & 3;
+ _old = ((unsigned int)old & 0xff) << shift;
+ _new = ((unsigned int)new & 0xff) << shift;
+ mask = ~(0xff << shift);
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\n"
+ " llill %[count],%[max_loops]\n"
+ "0: l %[prev],%[address]\n"
+ "1: nr %[prev],%[mask]\n"
+ " xilf %[mask],0xffffffff\n"
+ " or %[new],%[prev]\n"
+ " or %[prev],%[tmp]\n"
+ "2: lr %[tmp],%[prev]\n"
+ "3: cs %[prev],%[new],%[address]\n"
+ "4: jnl 5f\n"
+ " xr %[tmp],%[prev]\n"
+ " xr %[new],%[tmp]\n"
+ " nr %[tmp],%[mask]\n"
+ " jnz 5f\n"
+ " brct %[count],2b\n"
+ "5: sacf 768\n"
+ " spka %[default_key]\n"
+ EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
+ : [rc] "+&d" (rc),
+ [prev] "=&d" (prev),
+ [address] "+Q" (*(int *)address),
+ [tmp] "+&d" (_old),
+ [new] "+&d" (_new),
+ [mask] "+&d" (mask),
+ [count] "=a" (count)
+ : [key] "%[count]" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY),
+ [max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *(unsigned char *)uval = prev >> shift;
+ if (!count)
+ rc = -EAGAIN;
+ return rc;
+ }
+ case 2: {
+ unsigned int prev, shift, mask, _old, _new;
+ unsigned long count;
+
+ shift = (2 ^ (address & 2)) << 3;
+ address ^= address & 2;
+ _old = ((unsigned int)old & 0xffff) << shift;
+ _new = ((unsigned int)new & 0xffff) << shift;
+ mask = ~(0xffff << shift);
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\n"
+ " llill %[count],%[max_loops]\n"
+ "0: l %[prev],%[address]\n"
+ "1: nr %[prev],%[mask]\n"
+ " xilf %[mask],0xffffffff\n"
+ " or %[new],%[prev]\n"
+ " or %[prev],%[tmp]\n"
+ "2: lr %[tmp],%[prev]\n"
+ "3: cs %[prev],%[new],%[address]\n"
+ "4: jnl 5f\n"
+ " xr %[tmp],%[prev]\n"
+ " xr %[new],%[tmp]\n"
+ " nr %[tmp],%[mask]\n"
+ " jnz 5f\n"
+ " brct %[count],2b\n"
+ "5: sacf 768\n"
+ " spka %[default_key]\n"
+ EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
+ : [rc] "+&d" (rc),
+ [prev] "=&d" (prev),
+ [address] "+Q" (*(int *)address),
+ [tmp] "+&d" (_old),
+ [new] "+&d" (_new),
+ [mask] "+&d" (mask),
+ [count] "=a" (count)
+ : [key] "%[count]" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY),
+ [max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *(unsigned short *)uval = prev >> shift;
+ if (!count)
+ rc = -EAGAIN;
+ return rc;
+ }
+ case 4: {
+ unsigned int prev = old;
+
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: cs %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
+ : [rc] "+&d" (rc),
+ [prev] "+&d" (prev),
+ [address] "+Q" (*(int *)address)
+ : [new] "d" ((unsigned int)new),
+ [key] "a" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *(unsigned int *)uval = prev;
+ return rc;
+ }
+ case 8: {
+ unsigned long prev = old;
+
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: csg %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
+ : [rc] "+&d" (rc),
+ [prev] "+&d" (prev),
+ [address] "+QS" (*(long *)address)
+ : [new] "d" ((unsigned long)new),
+ [key] "a" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *(unsigned long *)uval = prev;
+ return rc;
+ }
+ case 16: {
+ __uint128_t prev = old;
+
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ " spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: cdsg %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ EX_TABLE_UA_LOAD_REGPAIR(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REGPAIR(1b, 1b, %[rc], %[prev])
+ : [rc] "+&d" (rc),
+ [prev] "+&d" (prev),
+ [address] "+QS" (*(__int128_t *)address)
+ : [new] "d" (new),
+ [key] "a" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *(__uint128_t *)uval = prev;
+ return rc;
+ }
+ }
+ __cmpxchg_user_key_called_with_bad_pointer();
+ return rc;
+}
+
+/**
+ * cmpxchg_user_key() - cmpxchg with user space target, honoring storage keys
+ * @ptr: User space address of value to compare to @old and exchange with
+ * @new. Must be aligned to sizeof(*@ptr).
+ * @uval: Address where the old value of *@ptr is written to.
+ * @old: Old value. Compared to the content pointed to by @ptr in order to
+ * determine if the exchange occurs. The old value read from *@ptr is
+ * written to *@uval.
+ * @new: New value to place at *@ptr.
+ * @key: Access key to use for checking storage key protection.
+ *
+ * Perform a cmpxchg on a user space target, honoring storage key protection.
+ * @key alone determines how key checking is performed, neither
+ * storage-protection-override nor fetch-protection-override apply.
+ * The caller must compare *@uval and @old to determine if values have been
+ * exchanged. In case of an exception *@uval is set to zero.
+ *
+ * Return: 0: cmpxchg executed
+ * -EFAULT: an exception happened when trying to access *@ptr
+ * -EAGAIN: maxed out number of retries (byte and short only)
+ */
+#define cmpxchg_user_key(ptr, uval, old, new, key) \
+({ \
+ __typeof__(ptr) __ptr = (ptr); \
+ __typeof__(uval) __uval = (uval); \
+ \
+ BUILD_BUG_ON(sizeof(*(__ptr)) != sizeof(*(__uval))); \
+ might_fault(); \
+ __chk_user_ptr(__ptr); \
+ __cmpxchg_user_key((unsigned long)(__ptr), (void *)(__uval), \
+ (old), (new), (key), sizeof(*(__ptr))); \
+})
+
#endif /* __S390_UACCESS_H */
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.