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#pragma once
#include "defaults.h"
/**
* Fills a vector that indicates whether pages of the calling process's virtual memory are resident in RAM. Each byte
* in the vector contains the status of a single page. The page size can be obtained via the NSystemInfo::GetPageSize()
* function. Use the IsPageInCore function to interpret the page status byte.
*
* Can be overly pessimistic:
* - Assumes nothing is in RAM on platforms other than Linux
* - Recent Linux kernels (4.21 and some backports) may return zeroes if the process doesn't have writing permissions
* for the given file. See CVE-2019-5489.
*
* @param[in] addr starting address of the memory range to be examined
* @param[in] len length (bytes) of the memory range to be examined
* @param[out] vec vector of bytes to store statuses of memory pages
* @param[in] vecLen length (bytes) of the vec, should be large enough to hold the requested pages count
* @throws yexception if there was a system error or if the vecLen is too small
*
* @note this is only a snapshot, results may be stale by the time they're used
* @see man 2 mincore
*/
void InCoreMemory(const void* addr, size_t len, unsigned char* vec, size_t vecLen);
/**
* Takes as an argument an element of the vector previously filled by InCoreMemory.
*
* @param[in] byte corresponding to the status of a single page
*
* @returns true if this page was resident in memory at the time out the InCoreMemory execution
*/
inline bool IsPageInCore(unsigned char s) {
/* From mincore(2): On return, the least significant bit of each byte will be set if the corresponding page is
* currently resident in memory, and be clear otherwise. (The settings of the other bits in each byte are
* undefined; these bits are reserved for possible later use.)
*/
return s & 1;
}
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