// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2016, Cyril Bur, IBM Corp.
 *
 * Test the kernel's signal frame code.
 *
 * The kernel sets up two sets of ucontexts if the signal was to be
 * delivered while the thread was in a transaction (referred too as
 * first and second contexts).
 * Expected behaviour is that the checkpointed state is in the user
 * context passed to the signal handler (first context). The speculated
 * state can be accessed with the uc_link pointer (second context).
 *
 * The rationale for this is that if TM unaware code (which linked
 * against TM libs) installs a signal handler it will not know of the
 * speculative nature of the 'live' registers and may infer the wrong
 * thing.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>

#include <altivec.h>

#include "utils.h"
#include "tm.h"

#define MAX_ATTEMPT 500000

#define NV_VMX_REGS 12 /* Number of non-volatile VMX registers */
#define VMX20 20 /* First non-volatile register to check in vr20-31 subset */

long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);

static sig_atomic_t fail, broken;

/* Test only non-volatile registers, i.e. 12 vmx registers from vr20 to vr31 */
vector int vms[] = {
        /* First context will be set with these values, i.e. non-speculative */
        /* VMX20     ,  VMX21      , ... */
        { 1, 2, 3, 4},{ 5, 6, 7, 8},{ 9,10,11,12},
        {13,14,15,16},{17,18,19,20},{21,22,23,24},
        {25,26,27,28},{29,30,31,32},{33,34,35,36},
        {37,38,39,40},{41,42,43,44},{45,46,47,48},
        /* Second context will be set with these values, i.e. speculative */
        /* VMX20        , VMX21            , ... */
        { -1, -2, -3, -4},{ -5, -6, -7, -8},{ -9,-10,-11,-12},
        {-13,-14,-15,-16},{-17,-18,-19,-20},{-21,-22,-23,-24},
        {-25,-26,-27,-28},{-29,-30,-31,-32},{-33,-34,-35,-36},
        {-37,-38,-39,-40},{-41,-42,-43,-44},{-45,-46,-47,-48}
};

static void signal_usr1(int signum, siginfo_t *info, void *uc)
{
        int i, j;
        ucontext_t *ucp = uc;
        ucontext_t *tm_ucp = ucp->uc_link;

        for (i = 0; i < NV_VMX_REGS; i++) {
                /* Check first context. Print all mismatches. */
                fail = memcmp(ucp->uc_mcontext.v_regs->vrregs[VMX20 + i],
                                &vms[i], sizeof(vector int));
                if (fail) {
                        broken = 1;
                        printf("VMX%d (1st context) == 0x", VMX20 + i);
                        /* Print actual value in first context. */
                        for (j = 0; j < 4; j++)
                                printf("%08x", ucp->uc_mcontext.v_regs->vrregs[VMX20 + i][j]);
                        printf(" instead of 0x");
                        /* Print expected value. */
                        for (j = 0; j < 4; j++)
                                printf("%08x", vms[i][j]);
                        printf(" (expected)\n");
                }
        }

        for (i = 0; i < NV_VMX_REGS; i++)  {
                /* Check second context. Print all mismatches. */
                fail = memcmp(tm_ucp->uc_mcontext.v_regs->vrregs[VMX20 + i],
                                &vms[NV_VMX_REGS + i], sizeof (vector int));
                if (fail) {
                        broken = 1;
                        printf("VMX%d (2nd context) == 0x", NV_VMX_REGS + i);
                        /* Print actual value in second context. */
                        for (j = 0; j < 4; j++)
                                printf("%08x", tm_ucp->uc_mcontext.v_regs->vrregs[VMX20 + i][j]);
                        printf(" instead of 0x");
                        /* Print expected value. */
                        for (j = 0; j < 4; j++)
                                printf("%08x", vms[NV_VMX_REGS + i][j]);
                        printf(" (expected)\n");
                }
        }
}

static int tm_signal_context_chk()
{
        struct sigaction act;
        int i;
        long rc;
        pid_t pid = getpid();

        SKIP_IF(!have_htm());
        SKIP_IF(htm_is_synthetic());

        act.sa_sigaction = signal_usr1;
        sigemptyset(&act.sa_mask);
        act.sa_flags = SA_SIGINFO;
        if (sigaction(SIGUSR1, &act, NULL) < 0) {
                perror("sigaction sigusr1");
                exit(1);
        }

        i = 0;
        while (i < MAX_ATTEMPT && !broken) {
                /*
                 * tm_signal_self_context_load will set both first and second
                 * contexts accordingly to the values passed through non-NULL
                 * array pointers to it, in that case 'vms', and invoke the
                 * signal handler installed for SIGUSR1.
                 */
                rc = tm_signal_self_context_load(pid, NULL, NULL, vms, NULL);
                FAIL_IF(rc != pid);
                i++;
        }

        return (broken);
}

int main(void)
{
        return test_harness(tm_signal_context_chk, "tm_signal_context_chk_vmx");
}