Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #ifndef _KERNEL_KCSAN_ENCODING_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #define _KERNEL_KCSAN_ENCODING_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #include <linux/bits.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) #include <linux/log2.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include "kcsan.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #define SLOT_RANGE PAGE_SIZE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #define INVALID_WATCHPOINT  0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #define CONSUMED_WATCHPOINT 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  * The maximum useful size of accesses for which we set up watchpoints is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  * max range of slots we check on an access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #define MAX_ENCODABLE_SIZE (SLOT_RANGE * (1 + KCSAN_CHECK_ADJACENT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * Number of bits we use to store size info.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #define WATCHPOINT_SIZE_BITS bits_per(MAX_ENCODABLE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  * This encoding for addresses discards the upper (1 for is-write + SIZE_BITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  * however, most 64-bit architectures do not use the full 64-bit address space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  * Also, in order for a false positive to be observable 2 things need to happen:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)  *	1. different addresses but with the same encoded address race;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)  *	2. and both map onto the same watchpoint slots;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)  * Both these are assumed to be very unlikely. However, in case it still
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)  * happens, the report logic will filter out the false positive (see report.c).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #define WATCHPOINT_ADDR_BITS (BITS_PER_LONG-1 - WATCHPOINT_SIZE_BITS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)  * Masks to set/retrieve the encoded data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #define WATCHPOINT_WRITE_MASK BIT(BITS_PER_LONG-1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #define WATCHPOINT_SIZE_MASK                                                   \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	GENMASK(BITS_PER_LONG-2, BITS_PER_LONG-2 - WATCHPOINT_SIZE_BITS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #define WATCHPOINT_ADDR_MASK                                                   \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	GENMASK(BITS_PER_LONG-3 - WATCHPOINT_SIZE_BITS, 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) static inline bool check_encodable(unsigned long addr, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	return size <= MAX_ENCODABLE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) static inline long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) encode_watchpoint(unsigned long addr, size_t size, bool is_write)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 	return (long)((is_write ? WATCHPOINT_WRITE_MASK : 0) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 		      (size << WATCHPOINT_ADDR_BITS) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 		      (addr & WATCHPOINT_ADDR_MASK));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) static __always_inline bool decode_watchpoint(long watchpoint,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 					      unsigned long *addr_masked,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 					      size_t *size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 					      bool *is_write)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 	if (watchpoint == INVALID_WATCHPOINT ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 	    watchpoint == CONSUMED_WATCHPOINT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	*addr_masked =    (unsigned long)watchpoint & WATCHPOINT_ADDR_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 	*size	     =   ((unsigned long)watchpoint & WATCHPOINT_SIZE_MASK) >> WATCHPOINT_ADDR_BITS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 	*is_write    = !!((unsigned long)watchpoint & WATCHPOINT_WRITE_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 	return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)  * Return watchpoint slot for an address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) static __always_inline int watchpoint_slot(unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) 	return (addr / PAGE_SIZE) % CONFIG_KCSAN_NUM_WATCHPOINTS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) static __always_inline bool matching_access(unsigned long addr1, size_t size1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) 					    unsigned long addr2, size_t size2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) 	unsigned long end_range1 = addr1 + size1 - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) 	unsigned long end_range2 = addr2 + size2 - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) 	return addr1 <= end_range2 && addr2 <= end_range1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) #endif /* _KERNEL_KCSAN_ENCODING_H */