64 lines
		
	
	
	
		
			1.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			64 lines
		
	
	
	
		
			1.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | #include <stdio.h>
 | ||
|  | #include <stdint.h>
 | ||
|  | #include <stdlib.h>
 | ||
|  | #include <unistd.h>
 | ||
|  | #include <sys/types.h>
 | ||
|  | #include <sys/stat.h>
 | ||
|  | #include <fcntl.h>
 | ||
|  | 
 | ||
|  | int main(int argc, char **argv) | ||
|  | { | ||
|  | 	const char *path; | ||
|  | 	char buf[5]; | ||
|  | 	int fd, rc; | ||
|  | 
 | ||
|  | 	if (argc < 2) { | ||
|  | 		fprintf(stderr, "usage: %s <path>\n", argv[0]); | ||
|  | 		return EXIT_FAILURE; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	path = argv[1]; | ||
|  | 
 | ||
|  | 	/* attributes: EFI_VARIABLE_NON_VOLATILE |
 | ||
|  | 	 *		EFI_VARIABLE_BOOTSERVICE_ACCESS | | ||
|  | 	 *		EFI_VARIABLE_RUNTIME_ACCESS | ||
|  | 	 */ | ||
|  | 	*(uint32_t *)buf = 0x7; | ||
|  | 	buf[4] = 0; | ||
|  | 
 | ||
|  | 	/* create a test variable */ | ||
|  | 	fd = open(path, O_WRONLY | O_CREAT); | ||
|  | 	if (fd < 0) { | ||
|  | 		perror("open(O_WRONLY)"); | ||
|  | 		return EXIT_FAILURE; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	rc = write(fd, buf, sizeof(buf)); | ||
|  | 	if (rc != sizeof(buf)) { | ||
|  | 		perror("write"); | ||
|  | 		return EXIT_FAILURE; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	close(fd); | ||
|  | 
 | ||
|  | 	fd = open(path, O_RDONLY); | ||
|  | 	if (fd < 0) { | ||
|  | 		perror("open"); | ||
|  | 		return EXIT_FAILURE; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	if (unlink(path) < 0) { | ||
|  | 		perror("unlink"); | ||
|  | 		return EXIT_FAILURE; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	rc = read(fd, buf, sizeof(buf)); | ||
|  | 	if (rc > 0) { | ||
|  | 		fprintf(stderr, "reading from an unlinked variable " | ||
|  | 				"shouldn't be possible\n"); | ||
|  | 		return EXIT_FAILURE; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return EXIT_SUCCESS; | ||
|  | } |