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| #include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <stdint.h>
#define PAGEMAP_ENTRY 8
#define GET_BIT(X,Y) (X & ((uint64_t)1<<Y)) >> Y
#define GET_PFN(X) X & 0x7FFFFFFFFFFFFF
const int __endian_bit = 1;
#define is_bigendian() ( (*(char*)&__endian_bit) == 0 )
int i, c, pid, status;
unsigned long virt_addr;
uint64_t read_val, file_offset;
char path_buf [0x100] = {};
FILE * f;
char *end;
int read_pagemap(char * path_buf, unsigned long virt_addr);
int main(int argc, char ** argv){
if(argc!=3){
printf("Argument number is not correct!\n pagemap PID VIRTUAL_ADDRESS\n");
return -1;
}
if(!memcmp(argv[1],"self",sizeof("self"))){
sprintf(path_buf, "/proc/self/pagemap");
pid = -1;
}
else{
pid = strtol(argv[1],&end, 10);
if (end == argv[1] || *end != '\0' || pid<=0){
printf("PID must be a positive number or 'self'\n");
return -1;
}
}
virt_addr = strtol(argv[2], NULL, 16);
if(pid!=-1)
sprintf(path_buf, "/proc/%u/pagemap", pid);
read_pagemap(path_buf, virt_addr);
return 0;
}
int read_pagemap(char * path_buf, unsigned long virt_addr){
printf("Big endian? %d\n", is_bigendian());
f = fopen(path_buf, "rb");
if(!f){
printf("Error! Cannot open %s\n", path_buf);
return -1;
}
file_offset = virt_addr / getpagesize() * PAGEMAP_ENTRY;
printf("Vaddr: 0x%lx, Page_size: %d, Entry_size: %d\n", virt_addr, getpagesize(), PAGEMAP_ENTRY);
printf("Reading %s at 0x%llx\n", path_buf, (unsigned long long) file_offset);
status = fseek(f, file_offset, SEEK_SET);
if(status){
perror("Failed to do fseek!");
return -1;
}
errno = 0;
read_val = 0;
unsigned char c_buf[PAGEMAP_ENTRY];
for(i=0; i < PAGEMAP_ENTRY; i++){
c = getc(f);
if(c==EOF){
printf("\nReached end of the file\n");
return 0;
}
if(is_bigendian())
c_buf[i] = c;
else
c_buf[PAGEMAP_ENTRY - i - 1] = c;
printf("[%d]0x%x ", i, c);
}
for(i=0; i < PAGEMAP_ENTRY; i++){
read_val = (read_val << 8) + c_buf[i];
}
printf("\n");
printf("Result: 0x%llx\n", (unsigned long long) read_val);
if(GET_BIT(read_val, 63))
printf("PFN: 0x%llx\n",(unsigned long long) GET_PFN(read_val));
else
printf("Page not present\n");
if(GET_BIT(read_val, 62))
printf("Page swapped\n");
fclose(f);
return 0;
}
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