Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * iopl.c - Test case for a Linux on Xen 64-bit bug
 * Copyright (c) 2015 Andrew Lutomirski
 */
 
#define _GNU_SOURCE
#include <err.h>
#include <stdio.h>
#include <stdint.h>
#include <signal.h>
#include <setjmp.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdbool.h>
#include <sched.h>
#include <sys/io.h>
 
static int nerrs = 0;
 
static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
<------><------>       int flags)
{
<------>struct sigaction sa;
<------>memset(&sa, 0, sizeof(sa));
<------>sa.sa_sigaction = handler;
<------>sa.sa_flags = SA_SIGINFO | flags;
<------>sigemptyset(&sa.sa_mask);
<------>if (sigaction(sig, &sa, 0))
<------><------>err(1, "sigaction");
 
}
 
static void clearhandler(int sig)
{
<------>struct sigaction sa;
<------>memset(&sa, 0, sizeof(sa));
<------>sa.sa_handler = SIG_DFL;
<------>sigemptyset(&sa.sa_mask);
<------>if (sigaction(sig, &sa, 0))
<------><------>err(1, "sigaction");
}
 
static jmp_buf jmpbuf;
 
static void sigsegv(int sig, siginfo_t *si, void *ctx_void)
{
<------>siglongjmp(jmpbuf, 1);
}
 
static bool try_outb(unsigned short port)
{
<------>sethandler(SIGSEGV, sigsegv, SA_RESETHAND);
<------>if (sigsetjmp(jmpbuf, 1) != 0) {
<------><------>return false;
<------>} else {
<------><------>asm volatile ("outb %%al, %w[port]"
<------><------><------>      : : [port] "Nd" (port), "a" (0));
<------><------>return true;
<------>}
<------>clearhandler(SIGSEGV);
}
 
static void expect_ok_outb(unsigned short port)
{
<------>if (!try_outb(port)) {
<------><------>printf("[FAIL]\toutb to 0x%02hx failed\n", port);
<------><------>exit(1);
<------>}
 
<------>printf("[OK]\toutb to 0x%02hx worked\n", port);
}
 
static void expect_gp_outb(unsigned short port)
{
<------>if (try_outb(port)) {
<------><------>printf("[FAIL]\toutb to 0x%02hx worked\n", port);
<------><------>nerrs++;
<------>}
 
<------>printf("[OK]\toutb to 0x%02hx failed\n", port);
}
 
#define RET_FAULTED	0
#define RET_FAIL	1
#define RET_EMUL	2
 
static int try_cli(void)
{
<------>unsigned long flags;
 
<------>sethandler(SIGSEGV, sigsegv, SA_RESETHAND);
<------>if (sigsetjmp(jmpbuf, 1) != 0) {
<------><------>return RET_FAULTED;
<------>} else {
<------><------>asm volatile("cli; pushf; pop %[flags]"
<------><------><------><------>: [flags] "=rm" (flags));
 
<------><------>/* X86_FLAGS_IF */
<------><------>if (!(flags & (1 << 9)))
<------><------><------>return RET_FAIL;
<------><------>else
<------><------><------>return RET_EMUL;
<------>}
<------>clearhandler(SIGSEGV);
}
 
static int try_sti(bool irqs_off)
{
<------>unsigned long flags;
 
<------>sethandler(SIGSEGV, sigsegv, SA_RESETHAND);
<------>if (sigsetjmp(jmpbuf, 1) != 0) {
<------><------>return RET_FAULTED;
<------>} else {
<------><------>asm volatile("sti; pushf; pop %[flags]"
<------><------><------><------>: [flags] "=rm" (flags));
 
<------><------>/* X86_FLAGS_IF */
<------><------>if (irqs_off && (flags & (1 << 9)))
<------><------><------>return RET_FAIL;
<------><------>else
<------><------><------>return RET_EMUL;
<------>}
<------>clearhandler(SIGSEGV);
}
 
static void expect_gp_sti(bool irqs_off)
{
<------>int ret = try_sti(irqs_off);
 
<------>switch (ret) {
<------>case RET_FAULTED:
<------><------>printf("[OK]\tSTI faulted\n");
<------><------>break;
<------>case RET_EMUL:
<------><------>printf("[OK]\tSTI NOPped\n");
<------><------>break;
<------>default:
<------><------>printf("[FAIL]\tSTI worked\n");
<------><------>nerrs++;
<------>}
}
 
/*
 * Returns whether it managed to disable interrupts.
 */
static bool test_cli(void)
{
<------>int ret = try_cli();
 
<------>switch (ret) {
<------>case RET_FAULTED:
<------><------>printf("[OK]\tCLI faulted\n");
<------><------>break;
<------>case RET_EMUL:
<------><------>printf("[OK]\tCLI NOPped\n");
<------><------>break;
<------>default:
<------><------>printf("[FAIL]\tCLI worked\n");
<------><------>nerrs++;
<------><------>return true;
<------>}
 
<------>return false;
}
 
int main(void)
{
<------>cpu_set_t cpuset;
 
<------>CPU_ZERO(&cpuset);
<------>CPU_SET(0, &cpuset);
<------>if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0)
<------><------>err(1, "sched_setaffinity to CPU 0");
 
<------>/* Probe for iopl support.  Note that iopl(0) works even as nonroot. */
<------>switch(iopl(3)) {
<------>case 0:
<------><------>break;
<------>case -ENOSYS:
<------><------>printf("[OK]\tiopl() nor supported\n");
<------><------>return 0;
<------>default:
<------><------>printf("[OK]\tiopl(3) failed (%d) -- try running as root\n",
<------><------>       errno);
<------><------>return 0;
<------>}
 
<------>/* Make sure that CLI/STI are blocked even with IOPL level 3 */
<------>expect_gp_sti(test_cli());
<------>expect_ok_outb(0x80);
 
<------>/* Establish an I/O bitmap to test the restore */
<------>if (ioperm(0x80, 1, 1) != 0)
<------><------>err(1, "ioperm(0x80, 1, 1) failed\n");
 
<------>/* Restore our original state prior to starting the fork test. */
<------>if (iopl(0) != 0)
<------><------>err(1, "iopl(0)");
 
<------>/*
<------> * Verify that IOPL emulation is disabled and the I/O bitmap still
<------> * works.
<------> */
<------>expect_ok_outb(0x80);
<------>expect_gp_outb(0xed);
<------>/* Drop the I/O bitmap */
<------>if (ioperm(0x80, 1, 0) != 0)
<------><------>err(1, "ioperm(0x80, 1, 0) failed\n");
 
<------>pid_t child = fork();
<------>if (child == -1)
<------><------>err(1, "fork");
 
<------>if (child == 0) {
<------><------>printf("\tchild: set IOPL to 3\n");
<------><------>if (iopl(3) != 0)
<------><------><------>err(1, "iopl");
 
<------><------>printf("[RUN]\tchild: write to 0x80\n");
<------><------>asm volatile ("outb %%al, $0x80" : : "a" (0));
 
<------><------>return 0;
<------>} else {
<------><------>int status;
<------><------>if (waitpid(child, &status, 0) != child ||
<------><------>    !WIFEXITED(status)) {
<------><------><------>printf("[FAIL]\tChild died\n");
<------><------><------>nerrs++;
<------><------>} else if (WEXITSTATUS(status) != 0) {
<------><------><------>printf("[FAIL]\tChild failed\n");
<------><------><------>nerrs++;
<------><------>} else {
<------><------><------>printf("[OK]\tChild succeeded\n");
<------><------>}
<------>}
 
<------>printf("[RUN]\tparent: write to 0x80 (should fail)\n");
 
<------>expect_gp_outb(0x80);
<------>expect_gp_sti(test_cli());
 
<------>/* Test the capability checks. */
<------>printf("\tiopl(3)\n");
<------>if (iopl(3) != 0)
<------><------>err(1, "iopl(3)");
 
<------>printf("\tDrop privileges\n");
<------>if (setresuid(1, 1, 1) != 0) {
<------><------>printf("[WARN]\tDropping privileges failed\n");
<------><------>goto done;
<------>}
 
<------>printf("[RUN]\tiopl(3) unprivileged but with IOPL==3\n");
<------>if (iopl(3) != 0) {
<------><------>printf("[FAIL]\tiopl(3) should work if iopl is already 3 even if unprivileged\n");
<------><------>nerrs++;
<------>}
 
<------>printf("[RUN]\tiopl(0) unprivileged\n");
<------>if (iopl(0) != 0) {
<------><------>printf("[FAIL]\tiopl(0) should work if iopl is already 3 even if unprivileged\n");
<------><------>nerrs++;
<------>}
 
<------>printf("[RUN]\tiopl(3) unprivileged\n");
<------>if (iopl(3) == 0) {
<------><------>printf("[FAIL]\tiopl(3) should fail if when unprivileged if iopl==0\n");
<------><------>nerrs++;
<------>} else {
<------><------>printf("[OK]\tFailed as expected\n");
<------>}
 
done:
<------>return nerrs ? 1 : 0;
}