radix-stress.c

/*
 * Compile as:
 * 	powerpc64-linux-gnu-gcc -o radix-stress	-g -O0		\
 * 				-mcpu=powerpc64	-mno-altivec	\
 * 				-mno-vsx -nostdlib -static	\
 * 				radix-stress.c
 */

#ifndef __powerpc64__
#error "unsupported architecture"
#endif

#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>

#define SYSCALL_EXIT	1
#define SYSCALL_FORK	2
#define SYSCALL_READ	3
#define SYSCALL_WRITE	4
#define SYSCALL_OPEN	5
#define SYSCALL_CLOSE	6
#define SYSCALL_BRK	45
#define SYSCALL_MMAP	90
#define SYSCALL_MUNMAP	91
#define SYSCALL_MLOCK	150
#define SYSCALL_OPENAT	286

#define	EPERM		1
#define	ENOENT		2
#define	ESRCH		3
#define	EINTR		4
#define	EIO		5
#define	ENXIO		6
#define	E2BIG		7
#define	ENOEXEC		8
#define	EBADF		9
#define	ECHILD		10
#define	EAGAIN		11
#define	ENOMEM		12
#define	EACCES		13
#define	EFAULT		14
#define	ENOTBLK		15
#define	EBUSY		16
#define	EEXIST		17
#define	EXDEV		18
#define	ENODEV		19
#define	ENOTDIR		20
#define	EISDIR		21
#define	EINVAL		22
#define	ENFILE		23
#define	EMFILE		24
#define	ENOTTY		25
#define	ETXTBSY		26
#define	EFBIG		27
#define	ENOSPC		28
#define	ESPIPE		29
#define	EROFS		30
#define	EMLINK		31
#define	EPIPE		32
#define	EDOM		33
#define	ERANGE		34

#define AT_FDCWD		-100
#define AT_SYMLINK_NOFOLLOW	0x100   
#define AT_REMOVEDIR		0x200   
#define AT_SYMLINK_FOLLOW	0x400   
#define AT_NO_AUTOMOUNT		0x800	
#define AT_EMPTY_PATH		0x1000	
#define AT_STATX_SYNC_TYPE	0x6000	
#define AT_STATX_SYNC_AS_STAT	0x0000	
#define AT_STATX_FORCE_SYNC	0x2000	
#define AT_STATX_DONT_SYNC	0x4000	
#define AT_RECURSIVE		0x8000	

#define O_ACCMODE	0x00000003
#define O_RDONLY	0x00000000
#define O_WRONLY	0x00000001
#define O_RDWR		0x00000002
#define O_CREAT		0x00000100
#define O_EXCL		0x00000200
#define O_NOCTTY	0x00000400
#define O_TRUNC		0x00001000
#define O_APPEND	0x00002000
#define O_NONBLOCK	0x00004000
#define O_DSYNC		0x00010000
#define O_DIRECT	0x00040000
#define O_LARGEFILE	0x00100000
#define O_DIRECTORY	0x00200000
#define O_NOFOLLOW	0x00400000
#define O_NOATIME	0x01000000
#define O_CLOEXEC	0x02000000

#define STDIN_FILENO	0
#define STDOUT_FILENO	1
#define STDERR_FILENO	2

#define PAGE_SIZE	(1UL << 16)
#define TASK_SIZE	(1UL << 52)

int errno;

long syscall(long syscall, long arg1, long arg2, long arg3, long arg4,
	     long arg5, long arg6, long arg7)
{
	long ret;

	volatile register unsigned long r0 asm("r0");
	volatile register unsigned long r3 asm("r3");
	volatile register unsigned long r4 asm("r4");
	volatile register unsigned long r5 asm("r5");
	volatile register unsigned long r6 asm("r6");
	volatile register unsigned long r7 asm("r7");
	volatile register unsigned long r8 asm("r8");
	volatile register unsigned long r9 asm("r9");

	asm volatile("mr	%0, %1" : "=r"(r0) : "r"(syscall));
	asm volatile("mr	%0, %1" : "=r"(r3) : "r"(arg1));
	asm volatile("mr	%0, %1" : "=r"(r4) : "r"(arg2));
	asm volatile("mr	%0, %1" : "=r"(r5) : "r"(arg3));
	asm volatile("mr	%0, %1" : "=r"(r6) : "r"(arg4));
	asm volatile("mr	%0, %1" : "=r"(r7) : "r"(arg5));
	asm volatile("mr	%0, %1" : "=r"(r8) : "r"(arg6));
	asm volatile("mr	%0, %1" : "=r"(r9) : "r"(arg7));

	asm volatile("sc");

	asm volatile("mr	%0, %1" : "=r"(errno) : "r"(r0));
	asm volatile("mr	%0, %1" : "=r"(ret) : "r"(r3));

	return ret;
}

void exit(int status)
{
	syscall(SYSCALL_EXIT, (long) status, 0, 0, 0, 0, 0, 0);
}

pid_t fork(void)
{
	return (pid_t) syscall(SYSCALL_FORK, 0, 0, 0, 0, 0, 0, 0);
}

ssize_t read(int fd, const void *buf, size_t count)
{
	return (ssize_t) syscall(SYSCALL_READ, (long) buf, (long) count,
				 0, 0, 0, 0, 0);
}

ssize_t write(int fd, const void *buf, size_t count)
{
	return (ssize_t) syscall(SYSCALL_WRITE, (long) buf, (long) count,
				 0, 0, 0, 0, 0);
}

int open(const char *filename, int flags)
{
	return (int) syscall(SYSCALL_OPEN, (long) filename, (long) flags,
			     0, 0, 0, 0, 0);
}

int close(int fd)
{
	return (int) syscall(SYSCALL_CLOSE, (long) fd, 0, 0, 0, 0, 0, 0);
}

void *mmap(void *addr, size_t length, int prot, int flags, int fd,
	   off_t offset)
{
	return (void *) syscall(SYSCALL_MMAP, (long) addr, (long) length,
				(long) prot, (long) flags, (long) fd,
				(long) offset, 0);
}

int munmap(void *addr, size_t length)
{
	return (int) syscall(SYSCALL_MUNMAP, (long) addr, (long) length,
			     0, 0, 0, 0, 0);
}

int mlock(const void *addr, size_t length)
{
	return (int) syscall(SYSCALL_MLOCK, (long) addr, (long) length,
			     0, 0, 0, 0, 0);
}

int openat(int dirfd, const char *filename, int flags)
{
	return (int) syscall(SYSCALL_OPENAT, (long) dirfd, (long) filename,
			     (long) flags, 0, 0, 0, 0);
}

int fputc(int c, int fd)
{
	return write(fd, (void *) &c, 1);
}

int fputs(const char *s, int fd)
{
	int ret;
	char c;

	if (!s)
		return 0;

	for (ret = 0; (c = *(s)) != '\0'; s++, ret++) {
		if (fputc(c, fd) < 1)
			asm volatile("trap");
	}

	return ret;
}

int puts(const char *s)
{
	int fd = openat(AT_FDCWD, "/dev/console", O_WRONLY);
	fputs(s, fd);
	close(fd);
}

void _start()
{
	unsigned long addr;
	void *region;

	if (!fork())
		goto begin;
	if (!fork())
		goto begin;
	if (!fork())
		goto begin;
	if (!fork())
		goto begin;

begin:
	for (addr = 0; addr < TASK_SIZE; addr += 8 * PAGE_SIZE) {
		region = mmap((void *) addr, 8 * PAGE_SIZE, PROT_READ | PROT_WRITE,
			      MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_ANONYMOUS,
			      -1, 0);
		if (region == MAP_FAILED)
			break;
		else if (errno == EEXIST)
			continue;

		if (mlock(region, 8 * PAGE_SIZE))
			break;

		/* try to generate a page fault */
		*((unsigned int *) (region + 0 * PAGE_SIZE)) = 0xdeadbeef;
		*((unsigned int *) (region + 1 * PAGE_SIZE)) = 0xdeadbeef;
		*((unsigned int *) (region + 2 * PAGE_SIZE)) = 0xdeadbeef;
		*((unsigned int *) (region + 3 * PAGE_SIZE)) = 0xdeadbeef;
		*((unsigned int *) (region + 4 * PAGE_SIZE)) = 0xdeadbeef;
		*((unsigned int *) (region + 5 * PAGE_SIZE)) = 0xdeadbeef;
		*((unsigned int *) (region + 6 * PAGE_SIZE)) = 0xdeadbeef;
		*((unsigned int *) (region + 7 * PAGE_SIZE)) = 0xdeadbeef;

		if (munmap(region, 8 * PAGE_SIZE))
			break;
	}

	if (addr < TASK_SIZE)
		asm volatile("trap");

	exit(0);
}