1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_S390_KMSAN_H 3 #define _ASM_S390_KMSAN_H 4 5 #include <asm/lowcore.h> 6 #include <asm/page.h> 7 #include <linux/kmsan.h> 8 #include <linux/mmzone.h> 9 #include <linux/stddef.h> 10 11 #ifndef MODULE 12 13 static inline bool is_lowcore_addr(void *addr) 14 { 15 return addr >= (void *)get_lowcore() && 16 addr < (void *)(get_lowcore() + 1); 17 } 18 19 static inline void *arch_kmsan_get_meta_or_null(void *addr, bool is_origin) 20 { 21 if (is_lowcore_addr(addr)) { 22 /* 23 * Different lowcores accessed via S390_lowcore are described 24 * by the same struct page. Resolve the prefix manually in 25 * order to get a distinct struct page. 26 */ 27 addr += (void *)lowcore_ptr[raw_smp_processor_id()] - 28 (void *)get_lowcore(); 29 if (KMSAN_WARN_ON(is_lowcore_addr(addr))) 30 return NULL; 31 return kmsan_get_metadata(addr, is_origin); 32 } 33 return NULL; 34 } 35 36 static inline bool kmsan_virt_addr_valid(void *addr) 37 { 38 bool ret; 39 40 /* 41 * pfn_valid() relies on RCU, and may call into the scheduler on exiting 42 * the critical section. However, this would result in recursion with 43 * KMSAN. Therefore, disable preemption here, and re-enable preemption 44 * below while suppressing reschedules to avoid recursion. 45 * 46 * Note, this sacrifices occasionally breaking scheduling guarantees. 47 * Although, a kernel compiled with KMSAN has already given up on any 48 * performance guarantees due to being heavily instrumented. 49 */ 50 preempt_disable(); 51 ret = virt_addr_valid(addr); 52 preempt_enable_no_resched(); 53 54 return ret; 55 } 56 57 #endif /* !MODULE */ 58 59 #endif /* _ASM_S390_KMSAN_H */ 60