// SPDX-License-Identifier: GPL-2.0
/*
 * Tests Memory Protection Keys (see Documentation/core-api/protection-keys.rst)
 *
 * There are examples in here of:
 *  * how to set protection keys on memory
 *  * how to set/clear bits in pkey registers (the rights register)
 *  * how to handle SEGV_PKUERR signals and extract pkey-relevant
 *    information from the siginfo
 *
 * Things to add:
 *      make sure KSM and KSM COW breaking works
 *      prefault pages in at malloc, or not
 *      protect MPX bounds tables with protection keys?
 *      make sure VMA splitting/merging is working correctly
 *      OOMs can destroy mm->mmap (see exit_mmap()), so make sure it is immune to pkeys
 *      look for pkey "leaks" where it is still set on a VMA but "freed" back to the kernel
 *      do a plain mprotect() to a mprotect_pkey() area and make sure the pkey sticks
 *
 * Compile like this:
 *      gcc      -o protection_keys    -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm
 *      gcc -m32 -o protection_keys_32 -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm
 */
#define _GNU_SOURCE
#define __SANE_USERSPACE_TYPES__
#include <errno.h>
#include <linux/futex.h>
#include <time.h>
#include <sys/time.h>
#include <sys/syscall.h>
#include <string.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <signal.h>
#include <assert.h>
#include <stdlib.h>
#include <ucontext.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ptrace.h>
#include <setjmp.h>

#include "pkey-helpers.h"

int iteration_nr = 1;
int test_nr;

u64 shadow_pkey_reg;
int dprint_in_signal;
char dprint_in_signal_buffer[DPRINT_IN_SIGNAL_BUF_SIZE];

void cat_into_file(char *str, char *file)
{
        int fd = open(file, O_RDWR);
        int ret;

        dprintf2("%s(): writing '%s' to '%s'\n", __func__, str, file);
        /*
         * these need to be raw because they are called under
         * pkey_assert()
         */
        if (fd < 0) {
                fprintf(stderr, "error opening '%s'\n", str);
                perror("error: ");
                exit(__LINE__);
        }

        ret = write(fd, str, strlen(str));
        if (ret != strlen(str)) {
                perror("write to file failed");
                fprintf(stderr, "filename: '%s' str: '%s'\n", file, str);
                exit(__LINE__);
        }
        close(fd);
}

#if CONTROL_TRACING > 0
static int warned_tracing;
int tracing_root_ok(void)
{
        if (geteuid() != 0) {
                if (!warned_tracing)
                        fprintf(stderr, "WARNING: not run as root, "
                                        "can not do tracing control\n");
                warned_tracing = 1;
                return 0;
        }
        return 1;
}
#endif

void tracing_on(void)
{
#if CONTROL_TRACING > 0
#define TRACEDIR "/sys/kernel/debug/tracing"
        char pidstr[32];

        if (!tracing_root_ok())
                return;

        sprintf(pidstr, "%d", getpid());
        cat_into_file("0", TRACEDIR "/tracing_on");
        cat_into_file("\n", TRACEDIR "/trace");
        if (1) {
                cat_into_file("function_graph", TRACEDIR "/current_tracer");
                cat_into_file("1", TRACEDIR "/options/funcgraph-proc");
        } else {
                cat_into_file("nop", TRACEDIR "/current_tracer");
        }
        cat_into_file(pidstr, TRACEDIR "/set_ftrace_pid");
        cat_into_file("1", TRACEDIR "/tracing_on");
        dprintf1("enabled tracing\n");
#endif
}

void tracing_off(void)
{
#if CONTROL_TRACING > 0
        if (!tracing_root_ok())
                return;
        cat_into_file("0", "/sys/kernel/debug/tracing/tracing_on");
#endif
}

void abort_hooks(void)
{
        fprintf(stderr, "running %s()...\n", __func__);
        tracing_off();
#ifdef SLEEP_ON_ABORT
        sleep(SLEEP_ON_ABORT);
#endif
}

/*
 * This attempts to have roughly a page of instructions followed by a few
 * instructions that do a write, and another page of instructions.  That
 * way, we are pretty sure that the write is in the second page of
 * instructions and has at least a page of padding behind it.
 *
 * *That* lets us be sure to madvise() away the write instruction, which
 * will then fault, which makes sure that the fault code handles
 * execute-only memory properly.
 */
#ifdef __powerpc64__
/* This way, both 4K and 64K alignment are maintained */
__attribute__((__aligned__(65536)))
#else
__attribute__((__aligned__(PAGE_SIZE)))
#endif
void lots_o_noops_around_write(int *write_to_me)
{
        dprintf3("running %s()\n", __func__);
        __page_o_noops();
        /* Assume this happens in the second page of instructions: */
        *write_to_me = __LINE__;
        /* pad out by another page: */
        __page_o_noops();
        dprintf3("%s() done\n", __func__);
}

void dump_mem(void *dumpme, int len_bytes)
{
        char *c = (void *)dumpme;
        int i;

        for (i = 0; i < len_bytes; i += sizeof(u64)) {
                u64 *ptr = (u64 *)(c + i);
                dprintf1("dump[%03d][@%p]: %016llx\n", i, ptr, *ptr);
        }
}

static u32 hw_pkey_get(int pkey, unsigned long flags)
{
        u64 pkey_reg = __read_pkey_reg();

        dprintf1("%s(pkey=%d, flags=%lx) = %x / %d\n",
                        __func__, pkey, flags, 0, 0);
        dprintf2("%s() raw pkey_reg: %016llx\n", __func__, pkey_reg);

        return (u32) get_pkey_bits(pkey_reg, pkey);
}

static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
{
        u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
        u64 old_pkey_reg = __read_pkey_reg();
        u64 new_pkey_reg;

        /* make sure that 'rights' only contains the bits we expect: */
        assert(!(rights & ~mask));

        /* modify bits accordingly in old pkey_reg and assign it */
        new_pkey_reg = set_pkey_bits(old_pkey_reg, pkey, rights);

        __write_pkey_reg(new_pkey_reg);

        dprintf3("%s(pkey=%d, rights=%lx, flags=%lx) = %x"
                " pkey_reg now: %016llx old_pkey_reg: %016llx\n",
                __func__, pkey, rights, flags, 0, __read_pkey_reg(),
                old_pkey_reg);
        return 0;
}

void pkey_disable_set(int pkey, int flags)
{
        unsigned long syscall_flags = 0;
        int ret;
        int pkey_rights;
        u64 orig_pkey_reg = read_pkey_reg();

        dprintf1("START->%s(%d, 0x%x)\n", __func__,
                pkey, flags);
        pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));

        pkey_rights = hw_pkey_get(pkey, syscall_flags);

        dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
                        pkey, pkey, pkey_rights);

        pkey_assert(pkey_rights >= 0);

        pkey_rights |= flags;

        ret = hw_pkey_set(pkey, pkey_rights, syscall_flags);
        assert(!ret);
        /* pkey_reg and flags have the same format */
        shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
        dprintf1("%s(%d) shadow: 0x%016llx\n",
                __func__, pkey, shadow_pkey_reg);

        pkey_assert(ret >= 0);

        pkey_rights = hw_pkey_get(pkey, syscall_flags);
        dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
                        pkey, pkey, pkey_rights);

        dprintf1("%s(%d) pkey_reg: 0x%016llx\n",
                __func__, pkey, read_pkey_reg());
        if (flags)
                pkey_assert(read_pkey_reg() >= orig_pkey_reg);
        dprintf1("END<---%s(%d, 0x%x)\n", __func__,
                pkey, flags);
}

void pkey_disable_clear(int pkey, int flags)
{
        unsigned long syscall_flags = 0;
        int ret;
        int pkey_rights = hw_pkey_get(pkey, syscall_flags);
        u64 orig_pkey_reg = read_pkey_reg();

        pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));

        dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
                        pkey, pkey, pkey_rights);
        pkey_assert(pkey_rights >= 0);

        pkey_rights &= ~flags;

        ret = hw_pkey_set(pkey, pkey_rights, 0);
        shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
        pkey_assert(ret >= 0);

        pkey_rights = hw_pkey_get(pkey, syscall_flags);
        dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
                        pkey, pkey, pkey_rights);

        dprintf1("%s(%d) pkey_reg: 0x%016llx\n", __func__,
                        pkey, read_pkey_reg());
        if (flags)
                assert(read_pkey_reg() <= orig_pkey_reg);
}

void pkey_write_allow(int pkey)
{
        pkey_disable_clear(pkey, PKEY_DISABLE_WRITE);
}
void pkey_write_deny(int pkey)
{
        pkey_disable_set(pkey, PKEY_DISABLE_WRITE);
}
void pkey_access_allow(int pkey)
{
        pkey_disable_clear(pkey, PKEY_DISABLE_ACCESS);
}
void pkey_access_deny(int pkey)
{
        pkey_disable_set(pkey, PKEY_DISABLE_ACCESS);
}

/* Failed address bound checks: */
#ifndef SEGV_BNDERR
# define SEGV_BNDERR            3
#endif

#ifndef SEGV_PKUERR
# define SEGV_PKUERR            4
#endif

static char *si_code_str(int si_code)
{
        if (si_code == SEGV_MAPERR)
                return "SEGV_MAPERR";
        if (si_code == SEGV_ACCERR)
                return "SEGV_ACCERR";
        if (si_code == SEGV_BNDERR)
                return "SEGV_BNDERR";
        if (si_code == SEGV_PKUERR)
                return "SEGV_PKUERR";
        return "UNKNOWN";
}

int pkey_faults;
int last_si_pkey = -1;
void signal_handler(int signum, siginfo_t *si, void *vucontext)
{
        ucontext_t *uctxt = vucontext;
        int trapno;
        unsigned long ip;
        char *fpregs;
#if defined(__i386__) || defined(__x86_64__) /* arch */
        u32 *pkey_reg_ptr;
        int pkey_reg_offset;
#endif /* arch */
        u64 siginfo_pkey;
        u32 *si_pkey_ptr;

        dprint_in_signal = 1;
        dprintf1(">>>>===============SIGSEGV============================\n");
        dprintf1("%s()::%d, pkey_reg: 0x%016llx shadow: %016llx\n",
                        __func__, __LINE__,
                        __read_pkey_reg(), shadow_pkey_reg);

        trapno = uctxt->uc_mcontext.gregs[REG_TRAPNO];
        ip = uctxt->uc_mcontext.gregs[REG_IP_IDX];
        fpregs = (char *) uctxt->uc_mcontext.fpregs;

        dprintf2("%s() trapno: %d ip: 0x%016lx info->si_code: %s/%d\n",
                        __func__, trapno, ip, si_code_str(si->si_code),
                        si->si_code);

#if defined(__i386__) || defined(__x86_64__) /* arch */
#ifdef __i386__
        /*
         * 32-bit has some extra padding so that userspace can tell whether
         * the XSTATE header is present in addition to the "legacy" FPU
         * state.  We just assume that it is here.
         */
        fpregs += 0x70;
#endif /* i386 */
        pkey_reg_offset = pkey_reg_xstate_offset();
        pkey_reg_ptr = (void *)(&fpregs[pkey_reg_offset]);

        /*
         * If we got a PKEY fault, we *HAVE* to have at least one bit set in
         * here.
         */
        dprintf1("pkey_reg_xstate_offset: %d\n", pkey_reg_xstate_offset());
        if (DEBUG_LEVEL > 4)
                dump_mem(pkey_reg_ptr - 128, 256);
        pkey_assert(*pkey_reg_ptr);
#endif /* arch */

        dprintf1("siginfo: %p\n", si);
        dprintf1(" fpregs: %p\n", fpregs);

        if ((si->si_code == SEGV_MAPERR) ||
            (si->si_code == SEGV_ACCERR) ||
            (si->si_code == SEGV_BNDERR)) {
                printf("non-PK si_code, exiting...\n");
                exit(4);
        }

        si_pkey_ptr = siginfo_get_pkey_ptr(si);
        dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr);
        dump_mem((u8 *)si_pkey_ptr - 8, 24);
        siginfo_pkey = *si_pkey_ptr;
        pkey_assert(siginfo_pkey < NR_PKEYS);
        last_si_pkey = siginfo_pkey;

        /*
         * need __read_pkey_reg() version so we do not do shadow_pkey_reg
         * checking
         */
        dprintf1("signal pkey_reg from  pkey_reg: %016llx\n",
                        __read_pkey_reg());
        dprintf1("pkey from siginfo: %016llx\n", siginfo_pkey);
#if defined(__i386__) || defined(__x86_64__) /* arch */
        dprintf1("signal pkey_reg from xsave: %08x\n", *pkey_reg_ptr);
        *(u64 *)pkey_reg_ptr = 0x00000000;
        dprintf1("WARNING: set PKEY_REG=0 to allow faulting instruction to continue\n");
#elif defined(__powerpc64__) /* arch */
        /* restore access and let the faulting instruction continue */
        pkey_access_allow(siginfo_pkey);
#endif /* arch */
        pkey_faults++;
        dprintf1("<<<<==================================================\n");
        dprint_in_signal = 0;
}

int wait_all_children(void)
{
        int status;
        return waitpid(-1, &status, 0);
}

void sig_chld(int x)
{
        dprint_in_signal = 1;
        dprintf2("[%d] SIGCHLD: %d\n", getpid(), x);
        dprint_in_signal = 0;
}

void setup_sigsegv_handler(void)
{
        int r, rs;
        struct sigaction newact;
        struct sigaction oldact;

        /* #PF is mapped to sigsegv */
        int signum  = SIGSEGV;

        newact.sa_handler = 0;
        newact.sa_sigaction = signal_handler;

        /*sigset_t - signals to block while in the handler */
        /* get the old signal mask. */
        rs = sigprocmask(SIG_SETMASK, 0, &newact.sa_mask);
        pkey_assert(rs == 0);

        /* call sa_sigaction, not sa_handler*/
        newact.sa_flags = SA_SIGINFO;

        newact.sa_restorer = 0;  /* void(*)(), obsolete */
        r = sigaction(signum, &newact, &oldact);
        r = sigaction(SIGALRM, &newact, &oldact);
        pkey_assert(r == 0);
}

void setup_handlers(void)
{
        signal(SIGCHLD, &sig_chld);
        setup_sigsegv_handler();
}

pid_t fork_lazy_child(void)
{
        pid_t forkret;

        forkret = fork();
        pkey_assert(forkret >= 0);
        dprintf3("[%d] fork() ret: %d\n", getpid(), forkret);

        if (!forkret) {
                /* in the child */
                while (1) {
                        dprintf1("child sleeping...\n");
                        sleep(30);
                }
        }
        return forkret;
}

int sys_mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot,
                unsigned long pkey)
{
        int sret;

        dprintf2("%s(0x%p, %zx, prot=%lx, pkey=%lx)\n", __func__,
                        ptr, size, orig_prot, pkey);

        errno = 0;
        sret = syscall(SYS_mprotect_key, ptr, size, orig_prot, pkey);
        if (errno) {
                dprintf2("SYS_mprotect_key sret: %d\n", sret);
                dprintf2("SYS_mprotect_key prot: 0x%lx\n", orig_prot);
                dprintf2("SYS_mprotect_key failed, errno: %d\n", errno);
                if (DEBUG_LEVEL >= 2)
                        perror("SYS_mprotect_pkey");
        }
        return sret;
}

int sys_pkey_alloc(unsigned long flags, unsigned long init_val)
{
        int ret = syscall(SYS_pkey_alloc, flags, init_val);
        dprintf1("%s(flags=%lx, init_val=%lx) syscall ret: %d errno: %d\n",
                        __func__, flags, init_val, ret, errno);
        return ret;
}

int alloc_pkey(void)
{
        int ret;
        unsigned long init_val = 0x0;

        dprintf1("%s()::%d, pkey_reg: 0x%016llx shadow: %016llx\n",
                        __func__, __LINE__, __read_pkey_reg(), shadow_pkey_reg);
        ret = sys_pkey_alloc(0, init_val);
        /*
         * pkey_alloc() sets PKEY register, so we need to reflect it in
         * shadow_pkey_reg:
         */
        dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
                        " shadow: 0x%016llx\n",
                        __func__, __LINE__, ret, __read_pkey_reg(),
                        shadow_pkey_reg);
        if (ret > 0) {
                /* clear both the bits: */
                shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
                                                ~PKEY_MASK);
                dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
                                " shadow: 0x%016llx\n",
                                __func__,
                                __LINE__, ret, __read_pkey_reg(),
                                shadow_pkey_reg);
                /*
                 * move the new state in from init_val
                 * (remember, we cheated and init_val == pkey_reg format)
                 */
                shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
                                                init_val);
        }
        dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
                        " shadow: 0x%016llx\n",
                        __func__, __LINE__, ret, __read_pkey_reg(),
                        shadow_pkey_reg);
        dprintf1("%s()::%d errno: %d\n", __func__, __LINE__, errno);
        /* for shadow checking: */
        read_pkey_reg();
        dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016llx"
                 " shadow: 0x%016llx\n",
                __func__, __LINE__, ret, __read_pkey_reg(),
                shadow_pkey_reg);
        return ret;
}

int sys_pkey_free(unsigned long pkey)
{
        int ret = syscall(SYS_pkey_free, pkey);
        dprintf1("%s(pkey=%ld) syscall ret: %d\n", __func__, pkey, ret);
        return ret;
}

/*
 * I had a bug where pkey bits could be set by mprotect() but
 * not cleared.  This ensures we get lots of random bit sets
 * and clears on the vma and pte pkey bits.
 */
int alloc_random_pkey(void)
{
        int max_nr_pkey_allocs;
        int ret;
        int i;
        int alloced_pkeys[NR_PKEYS];
        int nr_alloced = 0;
        int random_index;
        memset(alloced_pkeys, 0, sizeof(alloced_pkeys));

        /* allocate every possible key and make a note of which ones we got */
        max_nr_pkey_allocs = NR_PKEYS;
        for (i = 0; i < max_nr_pkey_allocs; i++) {
                int new_pkey = alloc_pkey();
                if (new_pkey < 0)
                        break;
                alloced_pkeys[nr_alloced++] = new_pkey;
        }

        pkey_assert(nr_alloced > 0);
        /* select a random one out of the allocated ones */
        random_index = rand() % nr_alloced;
        ret = alloced_pkeys[random_index];
        /* now zero it out so we don't free it next */
        alloced_pkeys[random_index] = 0;

        /* go through the allocated ones that we did not want and free them */
        for (i = 0; i < nr_alloced; i++) {
                int free_ret;
                if (!alloced_pkeys[i])
                        continue;
                free_ret = sys_pkey_free(alloced_pkeys[i]);
                pkey_assert(!free_ret);
        }
        dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx"
                         " shadow: 0x%016llx\n", __func__,
                        __LINE__, ret, __read_pkey_reg(), shadow_pkey_reg);
        return ret;
}

int mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot,
                unsigned long pkey)
{
        int nr_iterations = random() % 100;
        int ret;

        while (0) {
                int rpkey = alloc_random_pkey();
                ret = sys_mprotect_pkey(ptr, size, orig_prot, pkey);
                dprintf1("sys_mprotect_pkey(%p, %zx, prot=0x%lx, pkey=%ld) ret: %d\n",
                                ptr, size, orig_prot, pkey, ret);
                if (nr_iterations-- < 0)
                        break;

                dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx"
                        " shadow: 0x%016llx\n",
                        __func__, __LINE__, ret, __read_pkey_reg(),
                        shadow_pkey_reg);
                sys_pkey_free(rpkey);
                dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx"
                        " shadow: 0x%016llx\n",
                        __func__, __LINE__, ret, __read_pkey_reg(),
                        shadow_pkey_reg);
        }
        pkey_assert(pkey < NR_PKEYS);

        ret = sys_mprotect_pkey(ptr, size, orig_prot, pkey);
        dprintf1("mprotect_pkey(%p, %zx, prot=0x%lx, pkey=%ld) ret: %d\n",
                        ptr, size, orig_prot, pkey, ret);
        pkey_assert(!ret);
        dprintf1("%s()::%d, ret: %d pkey_reg: 0x%016llx"
                        " shadow: 0x%016llx\n", __func__,
                        __LINE__, ret, __read_pkey_reg(), shadow_pkey_reg);
        return ret;
}

struct pkey_malloc_record {
        void *ptr;
        long size;
        int prot;
};
struct pkey_malloc_record *pkey_malloc_records;
struct pkey_malloc_record *pkey_last_malloc_record;
long nr_pkey_malloc_records;
void record_pkey_malloc(void *ptr, long size, int prot)
{
        long i;
        struct pkey_malloc_record *rec = NULL;

        for (i = 0; i < nr_pkey_malloc_records; i++) {
                rec = &pkey_malloc_records[i];
                /* find a free record */
                if (rec)
                        break;
        }
        if (!rec) {
                /* every record is full */
                size_t old_nr_records = nr_pkey_malloc_records;
                size_t new_nr_records = (nr_pkey_malloc_records * 2 + 1);
                size_t new_size = new_nr_records * sizeof(struct pkey_malloc_record);
                dprintf2("new_nr_records: %zd\n", new_nr_records);
                dprintf2("new_size: %zd\n", new_size);
                pkey_malloc_records = realloc(pkey_malloc_records, new_size);
                pkey_assert(pkey_malloc_records != NULL);
                rec = &pkey_malloc_records[nr_pkey_malloc_records];
                /*
                 * realloc() does not initialize memory, so zero it from
                 * the first new record all the way to the end.
                 */
                for (i = 0; i < new_nr_records - old_nr_records; i++)
                        memset(rec + i, 0, sizeof(*rec));
        }
        dprintf3("filling malloc record[%d/%p]: {%p, %ld}\n",
                (int)(rec - pkey_malloc_records), rec, ptr, size);
        rec->ptr = ptr;
        rec->size = size;
        rec->prot = prot;
        pkey_last_malloc_record = rec;
        nr_pkey_malloc_records++;
}

void free_pkey_malloc(void *ptr)
{
        long i;
        int ret;
        dprintf3("%s(%p)\n", __func__, ptr);
        for (i = 0; i < nr_pkey_malloc_records; i++) {
                struct pkey_malloc_record *rec = &pkey_malloc_records[i];
                dprintf4("looking for ptr %p at record[%ld/%p]: {%p, %ld}\n",
                                ptr, i, rec, rec->ptr, rec->size);
                if ((ptr <  rec->ptr) ||
                    (ptr >= rec->ptr + rec->size))
                        continue;

                dprintf3("found ptr %p at record[%ld/%p]: {%p, %ld}\n",
                                ptr, i, rec, rec->ptr, rec->size);
                nr_pkey_malloc_records--;
                ret = munmap(rec->ptr, rec->size);
                dprintf3("munmap ret: %d\n", ret);
                pkey_assert(!ret);
                dprintf3("clearing rec->ptr, rec: %p\n", rec);
                rec->ptr = NULL;
                dprintf3("done clearing rec->ptr, rec: %p\n", rec);
                return;
        }
        pkey_assert(false);
}


void *malloc_pkey_with_mprotect(long size, int prot, u16 pkey)
{
        void *ptr;
        int ret;

        read_pkey_reg();
        dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
                        size, prot, pkey);
        pkey_assert(pkey < NR_PKEYS);
        ptr = mmap(NULL, size, prot, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
        pkey_assert(ptr != (void *)-1);
        ret = mprotect_pkey((void *)ptr, PAGE_SIZE, prot, pkey);
        pkey_assert(!ret);
        record_pkey_malloc(ptr, size, prot);
        read_pkey_reg();

        dprintf1("%s() for pkey %d @ %p\n", __func__, pkey, ptr);
        return ptr;
}

void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
{
        int ret;
        void *ptr;

        dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
                        size, prot, pkey);
        /*
         * Guarantee we can fit at least one huge page in the resulting
         * allocation by allocating space for 2:
         */
        size = ALIGN_UP(size, HPAGE_SIZE * 2);
        ptr = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
        pkey_assert(ptr != (void *)-1);
        record_pkey_malloc(ptr, size, prot);
        mprotect_pkey(ptr, size, prot, pkey);

        dprintf1("unaligned ptr: %p\n", ptr);
        ptr = ALIGN_PTR_UP(ptr, HPAGE_SIZE);
        dprintf1("  aligned ptr: %p\n", ptr);
        ret = madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE);
        dprintf1("MADV_HUGEPAGE ret: %d\n", ret);
        ret = madvise(ptr, HPAGE_SIZE, MADV_WILLNEED);
        dprintf1("MADV_WILLNEED ret: %d\n", ret);
        memset(ptr, 0, HPAGE_SIZE);

        dprintf1("mmap()'d thp for pkey %d @ %p\n", pkey, ptr);
        return ptr;
}

int hugetlb_setup_ok;
#define SYSFS_FMT_NR_HUGE_PAGES "/sys/kernel/mm/hugepages/hugepages-%ldkB/nr_hugepages"
#define GET_NR_HUGE_PAGES 10
void setup_hugetlbfs(void)
{
        int err;
        int fd;
        char buf[256];
        long hpagesz_kb;
        long hpagesz_mb;

        if (geteuid() != 0) {
                fprintf(stderr, "WARNING: not run as root, can not do hugetlb test\n");
                return;
        }

        cat_into_file(__stringify(GET_NR_HUGE_PAGES), "/proc/sys/vm/nr_hugepages");

        /*
         * Now go make sure that we got the pages and that they
         * are PMD-level pages. Someone might have made PUD-level
         * pages the default.
         */
        hpagesz_kb = HPAGE_SIZE / 1024;
        hpagesz_mb = hpagesz_kb / 1024;
        sprintf(buf, SYSFS_FMT_NR_HUGE_PAGES, hpagesz_kb);
        fd = open(buf, O_RDONLY);
        if (fd < 0) {
                fprintf(stderr, "opening sysfs %ldM hugetlb config: %s\n",
                        hpagesz_mb, strerror(errno));
                return;
        }

        /* -1 to guarantee leaving the trailing \0 */
        err = read(fd, buf, sizeof(buf)-1);
        close(fd);
        if (err <= 0) {
                fprintf(stderr, "reading sysfs %ldM hugetlb config: %s\n",
                        hpagesz_mb, strerror(errno));
                return;
        }

        if (atoi(buf) != GET_NR_HUGE_PAGES) {
                fprintf(stderr, "could not confirm %ldM pages, got: '%s' expected %d\n",
                        hpagesz_mb, buf, GET_NR_HUGE_PAGES);
                return;
        }

        hugetlb_setup_ok = 1;
}

void *malloc_pkey_hugetlb(long size, int prot, u16 pkey)
{
        void *ptr;
        int flags = MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB;

        if (!hugetlb_setup_ok)
                return PTR_ERR_ENOTSUP;

        dprintf1("doing %s(%ld, %x, %x)\n", __func__, size, prot, pkey);
        size = ALIGN_UP(size, HPAGE_SIZE * 2);
        pkey_assert(pkey < NR_PKEYS);
        ptr = mmap(NULL, size, PROT_NONE, flags, -1, 0);
        pkey_assert(ptr != (void *)-1);
        mprotect_pkey(ptr, size, prot, pkey);

        record_pkey_malloc(ptr, size, prot);

        dprintf1("mmap()'d hugetlbfs for pkey %d @ %p\n", pkey, ptr);
        return ptr;
}

void *malloc_pkey_mmap_dax(long size, int prot, u16 pkey)
{
        void *ptr;
        int fd;

        dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
                        size, prot, pkey);
        pkey_assert(pkey < NR_PKEYS);
        fd = open("/dax/foo", O_RDWR);
        pkey_assert(fd >= 0);

        ptr = mmap(0, size, prot, MAP_SHARED, fd, 0);
        pkey_assert(ptr != (void *)-1);

        mprotect_pkey(ptr, size, prot, pkey);

        record_pkey_malloc(ptr, size, prot);

        dprintf1("mmap()'d for pkey %d @ %p\n", pkey, ptr);
        close(fd);
        return ptr;
}

void *(*pkey_malloc[])(long size, int prot, u16 pkey) = {

        malloc_pkey_with_mprotect,
        malloc_pkey_with_mprotect_subpage,
        malloc_pkey_anon_huge,
        malloc_pkey_hugetlb
/* can not do direct with the pkey_mprotect() API:
        malloc_pkey_mmap_direct,
        malloc_pkey_mmap_dax,
*/
};

void *malloc_pkey(long size, int prot, u16 pkey)
{
        void *ret;
        static int malloc_type;
        int nr_malloc_types = ARRAY_SIZE(pkey_malloc);

        pkey_assert(pkey < NR_PKEYS);

        while (1) {
                pkey_assert(malloc_type < nr_malloc_types);

                ret = pkey_malloc[malloc_type](size, prot, pkey);
                pkey_assert(ret != (void *)-1);

                malloc_type++;
                if (malloc_type >= nr_malloc_types)
                        malloc_type = (random()%nr_malloc_types);

                /* try again if the malloc_type we tried is unsupported */
                if (ret == PTR_ERR_ENOTSUP)
                        continue;

                break;
        }

        dprintf3("%s(%ld, prot=%x, pkey=%x) returning: %p\n", __func__,
                        size, prot, pkey, ret);
        return ret;
}

int last_pkey_faults;
#define UNKNOWN_PKEY -2
void expected_pkey_fault(int pkey)
{
        dprintf2("%s(): last_pkey_faults: %d pkey_faults: %d\n",
                        __func__, last_pkey_faults, pkey_faults);
        dprintf2("%s(%d): last_si_pkey: %d\n", __func__, pkey, last_si_pkey);
        pkey_assert(last_pkey_faults + 1 == pkey_faults);

       /*
        * For exec-only memory, we do not know the pkey in
        * advance, so skip this check.
        */
        if (pkey != UNKNOWN_PKEY)
                pkey_assert(last_si_pkey == pkey);

#if defined(__i386__) || defined(__x86_64__) /* arch */
        /*
         * The signal handler shold have cleared out PKEY register to let the
         * test program continue.  We now have to restore it.
         */
        if (__read_pkey_reg() != 0)
#else /* arch */
        if (__read_pkey_reg() != shadow_pkey_reg)
#endif /* arch */
                pkey_assert(0);

        __write_pkey_reg(shadow_pkey_reg);
        dprintf1("%s() set pkey_reg=%016llx to restore state after signal "
                       "nuked it\n", __func__, shadow_pkey_reg);
        last_pkey_faults = pkey_faults;
        last_si_pkey = -1;
}

#define do_not_expect_pkey_fault(msg)   do {                    \
        if (last_pkey_faults != pkey_faults)                    \
                dprintf0("unexpected PKey fault: %s\n", msg);   \
        pkey_assert(last_pkey_faults == pkey_faults);           \
} while (0)

int test_fds[10] = { -1 };
int nr_test_fds;
void __save_test_fd(int fd)
{
        pkey_assert(fd >= 0);
        pkey_assert(nr_test_fds < ARRAY_SIZE(test_fds));
        test_fds[nr_test_fds] = fd;
        nr_test_fds++;
}

int get_test_read_fd(void)
{
        int test_fd = open("/etc/passwd", O_RDONLY);
        __save_test_fd(test_fd);
        return test_fd;
}

void close_test_fds(void)
{
        int i;

        for (i = 0; i < nr_test_fds; i++) {
                if (test_fds[i] < 0)
                        continue;
                close(test_fds[i]);
                test_fds[i] = -1;
        }
        nr_test_fds = 0;
}

#define barrier() __asm__ __volatile__("": : :"memory")
__attribute__((noinline)) int read_ptr(int *ptr)
{
        /*
         * Keep GCC from optimizing this away somehow
         */
        barrier();
        return *ptr;
}

void test_pkey_alloc_free_attach_pkey0(int *ptr, u16 pkey)
{
        int i, err;
        int max_nr_pkey_allocs;
        int alloced_pkeys[NR_PKEYS];
        int nr_alloced = 0;
        long size;

        pkey_assert(pkey_last_malloc_record);
        size = pkey_last_malloc_record->size;
        /*
         * This is a bit of a hack.  But mprotect() requires
         * huge-page-aligned sizes when operating on hugetlbfs.
         * So, make sure that we use something that's a multiple
         * of a huge page when we can.
         */
        if (size >= HPAGE_SIZE)
                size = HPAGE_SIZE;

        /* allocate every possible key and make sure key-0 never got allocated */
        max_nr_pkey_allocs = NR_PKEYS;
        for (i = 0; i < max_nr_pkey_allocs; i++) {
                int new_pkey = alloc_pkey();
                pkey_assert(new_pkey != 0);

                if (new_pkey < 0)
                        break;
                alloced_pkeys[nr_alloced++] = new_pkey;
        }
        /* free all the allocated keys */

        for (i = 0; i < nr_alloced; i++) {
                int free_ret;

                if (!alloced_pkeys[i])
                        continue;
                free_ret = sys_pkey_free(alloced_pkeys[i]);
                pkey_assert(!free_ret);
        }

        /* attach key-0 in various modes */
        err = sys_mprotect_pkey(ptr, size, PROT_READ, 0);
        pkey_assert(!err);
        err = sys_mprotect_pkey(ptr, size, PROT_WRITE, 0);
        pkey_assert(!err);
        err = sys_mprotect_pkey(ptr, size, PROT_EXEC, 0);
        pkey_assert(!err);
        err = sys_mprotect_pkey(ptr, size, PROT_READ|PROT_WRITE, 0);
        pkey_assert(!err);
        err = sys_mprotect_pkey(ptr, size, PROT_READ|PROT_WRITE|PROT_EXEC, 0);
        pkey_assert(!err);
}

void test_read_of_write_disabled_region(int *ptr, u16 pkey)
{
        int ptr_contents;

        dprintf1("disabling write access to PKEY[1], doing read\n");
        pkey_write_deny(pkey);
        ptr_contents = read_ptr(ptr);
        dprintf1("*ptr: %d\n", ptr_contents);
        dprintf1("\n");
}
void test_read_of_access_disabled_region(int *ptr, u16 pkey)
{
        int ptr_contents;

        dprintf1("disabling access to PKEY[%02d], doing read @ %p\n", pkey, ptr);
        read_pkey_reg();
        pkey_access_deny(pkey);
        ptr_contents = read_ptr(ptr);
        dprintf1("*ptr: %d\n", ptr_contents);
        expected_pkey_fault(pkey);
}

void test_read_of_access_disabled_region_with_page_already_mapped(int *ptr,
                u16 pkey)
{
        int ptr_contents;

        dprintf1("disabling access to PKEY[%02d], doing read @ %p\n",
                                pkey, ptr);
        ptr_contents = read_ptr(ptr);
        dprintf1("reading ptr before disabling the read : %d\n",
                        ptr_contents);
        read_pkey_reg();
        pkey_access_deny(pkey);
        ptr_contents = read_ptr(ptr);
        dprintf1("*ptr: %d\n", ptr_contents);
        expected_pkey_fault(pkey);
}

void test_write_of_write_disabled_region_with_page_already_mapped(int *ptr,
                u16 pkey)
{
        *ptr = __LINE__;
        dprintf1("disabling write access; after accessing the page, "
                "to PKEY[%02d], doing write\n", pkey);
        pkey_write_deny(pkey);
        *ptr = __LINE__;
        expected_pkey_fault(pkey);
}

void test_write_of_write_disabled_region(int *ptr, u16 pkey)
{
        dprintf1("disabling write access to PKEY[%02d], doing write\n", pkey);
        pkey_write_deny(pkey);
        *ptr = __LINE__;
        expected_pkey_fault(pkey);
}
void test_write_of_access_disabled_region(int *ptr, u16 pkey)
{
        dprintf1("disabling access to PKEY[%02d], doing write\n", pkey);
        pkey_access_deny(pkey);
        *ptr = __LINE__;
        expected_pkey_fault(pkey);
}

void test_write_of_access_disabled_region_with_page_already_mapped(int *ptr,
                        u16 pkey)
{
        *ptr = __LINE__;
        dprintf1("disabling access; after accessing the page, "
                " to PKEY[%02d], doing write\n", pkey);
        pkey_access_deny(pkey);
        *ptr = __LINE__;
        expected_pkey_fault(pkey);
}

void test_kernel_write_of_access_disabled_region(int *ptr, u16 pkey)
{
        int ret;
        int test_fd = get_test_read_fd();

        dprintf1("disabling access to PKEY[%02d], "
                 "having kernel read() to buffer\n", pkey);
        pkey_access_deny(pkey);
        ret = read(test_fd, ptr, 1);
        dprintf1("read ret: %d\n", ret);
        pkey_assert(ret);
}
void test_kernel_write_of_write_disabled_region(int *ptr, u16 pkey)
{
        int ret;
        int test_fd = get_test_read_fd();

        pkey_write_deny(pkey);
        ret = read(test_fd, ptr, 100);
        dprintf1("read ret: %d\n", ret);
        if (ret < 0 && (DEBUG_LEVEL > 0))
                perror("verbose read result (OK for this to be bad)");
        pkey_assert(ret);
}

void test_kernel_gup_of_access_disabled_region(int *ptr, u16 pkey)
{
        int pipe_ret, vmsplice_ret;
        struct iovec iov;
        int pipe_fds[2];

        pipe_ret = pipe(pipe_fds);

        pkey_assert(pipe_ret == 0);
        dprintf1("disabling access to PKEY[%02d], "
                 "having kernel vmsplice from buffer\n", pkey);
        pkey_access_deny(pkey);
        iov.iov_base = ptr;
        iov.iov_len = PAGE_SIZE;
        vmsplice_ret = vmsplice(pipe_fds[1], &iov, 1, SPLICE_F_GIFT);
        dprintf1("vmsplice() ret: %d\n", vmsplice_ret);
        pkey_assert(vmsplice_ret == -1);

        close(pipe_fds[0]);
        close(pipe_fds[1]);
}

void test_kernel_gup_write_to_write_disabled_region(int *ptr, u16 pkey)
{
        int ignored = 0xdada;
        int futex_ret;
        int some_int = __LINE__;

        dprintf1("disabling write to PKEY[%02d], "
                 "doing futex gunk in buffer\n", pkey);
        *ptr = some_int;
        pkey_write_deny(pkey);
        futex_ret = syscall(SYS_futex, ptr, FUTEX_WAIT, some_int-1, NULL,
                        &ignored, ignored);
        if (DEBUG_LEVEL > 0)
                perror("futex");
        dprintf1("futex() ret: %d\n", futex_ret);
}

/* Assumes that all pkeys other than 'pkey' are unallocated */
void test_pkey_syscalls_on_non_allocated_pkey(int *ptr, u16 pkey)
{
        int err;
        int i;

        /* Note: 0 is the default pkey, so don't mess with it */
        for (i = 1; i < NR_PKEYS; i++) {
                if (pkey == i)
                        continue;

                dprintf1("trying get/set/free to non-allocated pkey: %2d\n", i);
                err = sys_pkey_free(i);
                pkey_assert(err);

                err = sys_pkey_free(i);
                pkey_assert(err);

                err = sys_mprotect_pkey(ptr, PAGE_SIZE, PROT_READ, i);
                pkey_assert(err);
        }
}

/* Assumes that all pkeys other than 'pkey' are unallocated */
void test_pkey_syscalls_bad_args(int *ptr, u16 pkey)
{
        int err;
        int bad_pkey = NR_PKEYS+99;

        /* pass a known-invalid pkey in: */
        err = sys_mprotect_pkey(ptr, PAGE_SIZE, PROT_READ, bad_pkey);
        pkey_assert(err);
}

void become_child(void)
{
        pid_t forkret;

        forkret = fork();
        pkey_assert(forkret >= 0);
        dprintf3("[%d] fork() ret: %d\n", getpid(), forkret);

        if (!forkret) {
                /* in the child */
                return;
        }
        exit(0);
}

/* Assumes that all pkeys other than 'pkey' are unallocated */
void test_pkey_alloc_exhaust(int *ptr, u16 pkey)
{
        int err;
        int allocated_pkeys[NR_PKEYS] = {0};
        int nr_allocated_pkeys = 0;
        int i;

        for (i = 0; i < NR_PKEYS*3; i++) {
                int new_pkey;
                dprintf1("%s() alloc loop: %d\n", __func__, i);
                new_pkey = alloc_pkey();
                dprintf4("%s()::%d, err: %d pkey_reg: 0x%016llx"
                                " shadow: 0x%016llx\n",
                                __func__, __LINE__, err, __read_pkey_reg(),
                                shadow_pkey_reg);
                read_pkey_reg(); /* for shadow checking */
                dprintf2("%s() errno: %d ENOSPC: %d\n", __func__, errno, ENOSPC);
                if ((new_pkey == -1) && (errno == ENOSPC)) {
                        dprintf2("%s() failed to allocate pkey after %d tries\n",
                                __func__, nr_allocated_pkeys);
                } else {
                        /*
                         * Ensure the number of successes never
                         * exceeds the number of keys supported
                         * in the hardware.
                         */
                        pkey_assert(nr_allocated_pkeys < NR_PKEYS);
                        allocated_pkeys[nr_allocated_pkeys++] = new_pkey;
                }

                /*
                 * Make sure that allocation state is properly
                 * preserved across fork().
                 */
                if (i == NR_PKEYS*2)
                        become_child();
        }

        dprintf3("%s()::%d\n", __func__, __LINE__);

        /*
         * On x86:
         * There are 16 pkeys supported in hardware.  Three are
         * allocated by the time we get here:
         *   1. The default key (0)
         *   2. One possibly consumed by an execute-only mapping.
         *   3. One allocated by the test code and passed in via
         *      'pkey' to this function.
         * Ensure that we can allocate at least another 13 (16-3).
         *
         * On powerpc:
         * There are either 5, 28, 29 or 32 pkeys supported in
         * hardware depending on the page size (4K or 64K) and
         * platform (powernv or powervm). Four are allocated by
         * the time we get here. These include pkey-0, pkey-1,
         * exec-only pkey and the one allocated by the test code.
         * Ensure that we can allocate the remaining.
         */
        pkey_assert(i >= (NR_PKEYS - get_arch_reserved_keys() - 1));

        for (i = 0; i < nr_allocated_pkeys; i++) {
                err = sys_pkey_free(allocated_pkeys[i]);
                pkey_assert(!err);
                read_pkey_reg(); /* for shadow checking */
        }
}

void arch_force_pkey_reg_init(void)
{
#if defined(__i386__) || defined(__x86_64__) /* arch */
        u64 *buf;

        /*
         * All keys should be allocated and set to allow reads and
         * writes, so the register should be all 0.  If not, just
         * skip the test.
         */
        if (read_pkey_reg())
                return;

        /*
         * Just allocate an absurd about of memory rather than
         * doing the XSAVE size enumeration dance.
         */
        buf = mmap(NULL, 1*MB, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);

        /* These __builtins require compiling with -mxsave */

        /* XSAVE to build a valid buffer: */
        __builtin_ia32_xsave(buf, XSTATE_PKEY);
        /* Clear XSTATE_BV[PKRU]: */
        buf[XSTATE_BV_OFFSET/sizeof(u64)] &= ~XSTATE_PKEY;
        /* XRSTOR will likely get PKRU back to the init state: */
        __builtin_ia32_xrstor(buf, XSTATE_PKEY);

        munmap(buf, 1*MB);
#endif
}


/*
 * This is mostly useless on ppc for now.  But it will not
 * hurt anything and should give some better coverage as
 * a long-running test that continually checks the pkey
 * register.
 */
void test_pkey_init_state(int *ptr, u16 pkey)
{
        int err;
        int allocated_pkeys[NR_PKEYS] = {0};
        int nr_allocated_pkeys = 0;
        int i;

        for (i = 0; i < NR_PKEYS; i++) {
                int new_pkey = alloc_pkey();

                if (new_pkey < 0)
                        continue;
                allocated_pkeys[nr_allocated_pkeys++] = new_pkey;
        }

        dprintf3("%s()::%d\n", __func__, __LINE__);

        arch_force_pkey_reg_init();

        /*
         * Loop for a bit, hoping to get exercise the kernel
         * context switch code.
         */
        for (i = 0; i < 1000000; i++)
                read_pkey_reg();

        for (i = 0; i < nr_allocated_pkeys; i++) {
                err = sys_pkey_free(allocated_pkeys[i]);
                pkey_assert(!err);
                read_pkey_reg(); /* for shadow checking */
        }
}

/*
 * pkey 0 is special.  It is allocated by default, so you do not
 * have to call pkey_alloc() to use it first.  Make sure that it
 * is usable.
 */
void test_mprotect_with_pkey_0(int *ptr, u16 pkey)
{
        long size;
        int prot;

        assert(pkey_last_malloc_record);
        size = pkey_last_malloc_record->size;
        /*
         * This is a bit of a hack.  But mprotect() requires
         * huge-page-aligned sizes when operating on hugetlbfs.
         * So, make sure that we use something that's a multiple
         * of a huge page when we can.
         */
        if (size >= HPAGE_SIZE)
                size = HPAGE_SIZE;
        prot = pkey_last_malloc_record->prot;

        /* Use pkey 0 */
        mprotect_pkey(ptr, size, prot, 0);

        /* Make sure that we can set it back to the original pkey. */
        mprotect_pkey(ptr, size, prot, pkey);
}

void test_ptrace_of_child(int *ptr, u16 pkey)
{
        __attribute__((__unused__)) int peek_result;
        pid_t child_pid;
        void *ignored = 0;
        long ret;
        int status;
        /*
         * This is the "control" for our little expermient.  Make sure
         * we can always access it when ptracing.
         */
        int *plain_ptr_unaligned = malloc(HPAGE_SIZE);
        int *plain_ptr = ALIGN_PTR_UP(plain_ptr_unaligned, PAGE_SIZE);

        /*
         * Fork a child which is an exact copy of this process, of course.
         * That means we can do all of our tests via ptrace() and then plain
         * memory access and ensure they work differently.
         */
        child_pid = fork_lazy_child();
        dprintf1("[%d] child pid: %d\n", getpid(), child_pid);

        ret = ptrace(PTRACE_ATTACH, child_pid, ignored, ignored);
        if (ret)
                perror("attach");
        dprintf1("[%d] attach ret: %ld %d\n", getpid(), ret, __LINE__);
        pkey_assert(ret != -1);
        ret = waitpid(child_pid, &status, WUNTRACED);
        if ((ret != child_pid) || !(WIFSTOPPED(status))) {
                fprintf(stderr, "weird waitpid result %ld stat %x\n",
                                ret, status);
                pkey_assert(0);
        }
        dprintf2("waitpid ret: %ld\n", ret);
        dprintf2("waitpid status: %d\n", status);

        pkey_access_deny(pkey);
        pkey_write_deny(pkey);

        /* Write access, untested for now:
        ret = ptrace(PTRACE_POKEDATA, child_pid, peek_at, data);
        pkey_assert(ret != -1);
        dprintf1("poke at %p: %ld\n", peek_at, ret);
        */

        /*
         * Try to access the pkey-protected "ptr" via ptrace:
         */
        ret = ptrace(PTRACE_PEEKDATA, child_pid, ptr, ignored);
        /* expect it to work, without an error: */
        pkey_assert(ret != -1);
        /* Now access from the current task, and expect an exception: */
        peek_result = read_ptr(ptr);
        expected_pkey_fault(pkey);

        /*
         * Try to access the NON-pkey-protected "plain_ptr" via ptrace:
         */
        ret = ptrace(PTRACE_PEEKDATA, child_pid, plain_ptr, ignored);
        /* expect it to work, without an error: */
        pkey_assert(ret != -1);
        /* Now access from the current task, and expect NO exception: */
        peek_result = read_ptr(plain_ptr);
        do_not_expect_pkey_fault("read plain pointer after ptrace");

        ret = ptrace(PTRACE_DETACH, child_pid, ignored, 0);
        pkey_assert(ret != -1);

        ret = kill(child_pid, SIGKILL);
        pkey_assert(ret != -1);

        wait(&status);

        free(plain_ptr_unaligned);
}

void *get_pointer_to_instructions(void)
{
        void *p1;

        p1 = ALIGN_PTR_UP(&lots_o_noops_around_write, PAGE_SIZE);
        dprintf3("&lots_o_noops: %p\n", &lots_o_noops_around_write);
        /* lots_o_noops_around_write should be page-aligned already */
        assert(p1 == &lots_o_noops_around_write);

        /* Point 'p1' at the *second* page of the function: */
        p1 += PAGE_SIZE;

        /*
         * Try to ensure we fault this in on next touch to ensure
         * we get an instruction fault as opposed to a data one
         */
        madvise(p1, PAGE_SIZE, MADV_DONTNEED);

        return p1;
}

void test_executing_on_unreadable_memory(int *ptr, u16 pkey)
{
        void *p1;
        int scratch;
        int ptr_contents;
        int ret;

        p1 = get_pointer_to_instructions();
        lots_o_noops_around_write(&scratch);
        ptr_contents = read_ptr(p1);
        dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);

        ret = mprotect_pkey(p1, PAGE_SIZE, PROT_EXEC, (u64)pkey);
        pkey_assert(!ret);
        pkey_access_deny(pkey);

        dprintf2("pkey_reg: %016llx\n", read_pkey_reg());

        /*
         * Make sure this is an *instruction* fault
         */
        madvise(p1, PAGE_SIZE, MADV_DONTNEED);
        lots_o_noops_around_write(&scratch);
        do_not_expect_pkey_fault("executing on PROT_EXEC memory");
        expect_fault_on_read_execonly_key(p1, pkey);
}

void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey)
{
        void *p1;
        int scratch;
        int ptr_contents;
        int ret;

        dprintf1("%s() start\n", __func__);

        p1 = get_pointer_to_instructions();
        lots_o_noops_around_write(&scratch);
        ptr_contents = read_ptr(p1);
        dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);

        /* Use a *normal* mprotect(), not mprotect_pkey(): */
        ret = mprotect(p1, PAGE_SIZE, PROT_EXEC);
        pkey_assert(!ret);

        /*
         * Reset the shadow, assuming that the above mprotect()
         * correctly changed PKRU, but to an unknown value since
         * the actual alllocated pkey is unknown.
         */
        shadow_pkey_reg = __read_pkey_reg();

        dprintf2("pkey_reg: %016llx\n", read_pkey_reg());

        /* Make sure this is an *instruction* fault */
        madvise(p1, PAGE_SIZE, MADV_DONTNEED);
        lots_o_noops_around_write(&scratch);
        do_not_expect_pkey_fault("executing on PROT_EXEC memory");
        expect_fault_on_read_execonly_key(p1, UNKNOWN_PKEY);

        /*
         * Put the memory back to non-PROT_EXEC.  Should clear the
         * exec-only pkey off the VMA and allow it to be readable
         * again.  Go to PROT_NONE first to check for a kernel bug
         * that did not clear the pkey when doing PROT_NONE.
         */
        ret = mprotect(p1, PAGE_SIZE, PROT_NONE);
        pkey_assert(!ret);

        ret = mprotect(p1, PAGE_SIZE, PROT_READ|PROT_EXEC);
        pkey_assert(!ret);
        ptr_contents = read_ptr(p1);
        do_not_expect_pkey_fault("plain read on recently PROT_EXEC area");
}

void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey)
{
        int size = PAGE_SIZE;
        int sret;

        if (cpu_has_pkeys()) {
                dprintf1("SKIP: %s: no CPU support\n", __func__);
                return;
        }

        sret = syscall(SYS_mprotect_key, ptr, size, PROT_READ, pkey);
        pkey_assert(sret < 0);
}

void (*pkey_tests[])(int *ptr, u16 pkey) = {
        test_read_of_write_disabled_region,
        test_read_of_access_disabled_region,
        test_read_of_access_disabled_region_with_page_already_mapped,
        test_write_of_write_disabled_region,
        test_write_of_write_disabled_region_with_page_already_mapped,
        test_write_of_access_disabled_region,
        test_write_of_access_disabled_region_with_page_already_mapped,
        test_kernel_write_of_access_disabled_region,
        test_kernel_write_of_write_disabled_region,
        test_kernel_gup_of_access_disabled_region,
        test_kernel_gup_write_to_write_disabled_region,
        test_executing_on_unreadable_memory,
        test_implicit_mprotect_exec_only_memory,
        test_mprotect_with_pkey_0,
        test_ptrace_of_child,
        test_pkey_init_state,
        test_pkey_syscalls_on_non_allocated_pkey,
        test_pkey_syscalls_bad_args,
        test_pkey_alloc_exhaust,
        test_pkey_alloc_free_attach_pkey0,
};

void run_tests_once(void)
{
        int *ptr;
        int prot = PROT_READ|PROT_WRITE;

        for (test_nr = 0; test_nr < ARRAY_SIZE(pkey_tests); test_nr++) {
                int pkey;
                int orig_pkey_faults = pkey_faults;

                dprintf1("======================\n");
                dprintf1("test %d preparing...\n", test_nr);

                tracing_on();
                pkey = alloc_random_pkey();
                dprintf1("test %d starting with pkey: %d\n", test_nr, pkey);
                ptr = malloc_pkey(PAGE_SIZE, prot, pkey);
                dprintf1("test %d starting...\n", test_nr);
                pkey_tests[test_nr](ptr, pkey);
                dprintf1("freeing test memory: %p\n", ptr);
                free_pkey_malloc(ptr);
                sys_pkey_free(pkey);

                dprintf1("pkey_faults: %d\n", pkey_faults);
                dprintf1("orig_pkey_faults: %d\n", orig_pkey_faults);

                tracing_off();
                close_test_fds();

                printf("test %2d PASSED (iteration %d)\n", test_nr, iteration_nr);
                dprintf1("======================\n\n");
        }
        iteration_nr++;
}

void pkey_setup_shadow(void)
{
        shadow_pkey_reg = __read_pkey_reg();
}

int main(void)
{
        int nr_iterations = 22;
        int pkeys_supported = is_pkeys_supported();

        srand((unsigned int)time(NULL));

        setup_handlers();

        printf("has pkeys: %d\n", pkeys_supported);

        if (!pkeys_supported) {
                int size = PAGE_SIZE;
                int *ptr;

                printf("running PKEY tests for unsupported CPU/OS\n");

                ptr  = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
                assert(ptr != (void *)-1);
                test_mprotect_pkey_on_unsupported_cpu(ptr, 1);
                exit(0);
        }

        pkey_setup_shadow();
        printf("startup pkey_reg: %016llx\n", read_pkey_reg());
        setup_hugetlbfs();

        while (nr_iterations-- > 0)
                run_tests_once();

        printf("done (all tests OK)\n");
        return 0;
}