// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Ptrace test for GPR/FPR registers
 *
 * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
 */
#include "ptrace.h"
#include "ptrace-gpr.h"
#include "reg.h"
#include <time.h>

/* Tracer and Tracee Shared Data */
int shm_id;
int *cptr, *pptr;

extern void gpr_child_loop(int *read_flag, int *write_flag,
                           unsigned long *gpr_buf, double *fpr_buf);

unsigned long child_gpr_val, parent_gpr_val;
double child_fpr_val, parent_fpr_val;

static int child(void)
{
        unsigned long gpr_buf[32];
        double fpr_buf[32];
        int i;

        cptr = (int *)shmat(shm_id, NULL, 0);
        memset(gpr_buf, 0, sizeof(gpr_buf));
        memset(fpr_buf, 0, sizeof(fpr_buf));

        for (i = 0; i < 32; i++) {
                gpr_buf[i] = child_gpr_val;
                fpr_buf[i] = child_fpr_val;
        }

        gpr_child_loop(&cptr[0], &cptr[1], gpr_buf, fpr_buf);

        shmdt((void *)cptr);

        FAIL_IF(validate_gpr(gpr_buf, parent_gpr_val));
        FAIL_IF(validate_fpr_double(fpr_buf, parent_fpr_val));

        return 0;
}

int trace_gpr(pid_t child)
{
        __u64 tmp, fpr[32], *peeked_fprs;
        unsigned long gpr[18];

        FAIL_IF(start_trace(child));

        // Check child GPRs match what we expect using GETREGS
        FAIL_IF(show_gpr(child, gpr));
        FAIL_IF(validate_gpr(gpr, child_gpr_val));

        // Check child FPRs match what we expect using GETFPREGS
        FAIL_IF(show_fpr(child, fpr));
        memcpy(&tmp, &child_fpr_val, sizeof(tmp));
        FAIL_IF(validate_fpr(fpr, tmp));

        // Check child FPRs match what we expect using PEEKUSR
        peeked_fprs = peek_fprs(child);
        FAIL_IF(!peeked_fprs);
        FAIL_IF(validate_fpr(peeked_fprs, tmp));
        free(peeked_fprs);

        // Write child GPRs using SETREGS
        FAIL_IF(write_gpr(child, parent_gpr_val));

        // Write child FPRs using SETFPREGS
        memcpy(&tmp, &parent_fpr_val, sizeof(tmp));
        FAIL_IF(write_fpr(child, tmp));

        // Check child FPRs match what we just set, using PEEKUSR
        peeked_fprs = peek_fprs(child);
        FAIL_IF(!peeked_fprs);
        FAIL_IF(validate_fpr(peeked_fprs, tmp));

        // Write child FPRs using POKEUSR
        FAIL_IF(poke_fprs(child, (unsigned long *)peeked_fprs));

        // Child will check its FPRs match before exiting
        FAIL_IF(stop_trace(child));

        return TEST_PASS;
}

#ifndef __LONG_WIDTH__
#define __LONG_WIDTH__ (sizeof(long) * 8)
#endif

static uint64_t rand_reg(void)
{
        uint64_t result;
        long r;

        r = random();

        // Small values are typical
        result = r & 0xffff;
        if (r & 0x10000)
                return result;

        // Pointers tend to have high bits set
        result |= random() << (__LONG_WIDTH__ - 31);
        if (r & 0x100000)
                return result;

        // And sometimes we want a full 64-bit value
        result ^= random() << 16;

        return result;
}

int ptrace_gpr(void)
{
        unsigned long seed;
        int ret, status;
        pid_t pid;

        seed = getpid() ^ time(NULL);
        printf("srand(%lu)\n", seed);
        srand(seed);

        child_gpr_val = rand_reg();
        child_fpr_val = rand_reg();
        parent_gpr_val = rand_reg();
        parent_fpr_val = rand_reg();

        shm_id = shmget(IPC_PRIVATE, sizeof(int) * 2, 0777|IPC_CREAT);
        pid = fork();
        if (pid < 0) {
                perror("fork() failed");
                return TEST_FAIL;
        }
        if (pid == 0)
                exit(child());

        if (pid) {
                pptr = (int *)shmat(shm_id, NULL, 0);
                while (!pptr[1])
                        asm volatile("" : : : "memory");

                ret = trace_gpr(pid);
                if (ret) {
                        kill(pid, SIGTERM);
                        shmdt((void *)pptr);
                        shmctl(shm_id, IPC_RMID, NULL);
                        return TEST_FAIL;
                }

                pptr[0] = 1;
                shmdt((void *)pptr);

                ret = wait(&status);
                shmctl(shm_id, IPC_RMID, NULL);
                if (ret != pid) {
                        printf("Child's exit status not captured\n");
                        return TEST_FAIL;
                }

                return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
                        TEST_PASS;
        }

        return TEST_PASS;
}

int main(int argc, char *argv[])
{
        return test_harness(ptrace_gpr, "ptrace_gpr");
}