/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <libgen.h>

#include <dt_impl.h>
#include <dt_pid.h>

#define OP(x)           ((x) >> 30)
#define OP2(x)          (((x) >> 22) & 0x07)
#define COND(x)         (((x) >> 25) & 0x0f)
#define A(x)            (((x) >> 29) & 0x01)

#define OP_BRANCH       0

#define OP2_BPcc        0x1
#define OP2_Bicc        0x2
#define OP2_BPr         0x3
#define OP2_FBPfcc      0x5
#define OP2_FBfcc       0x6

/*ARGSUSED*/
int
dt_pid_create_entry_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
    fasttrap_probe_spec_t *ftp, const GElf_Sym *symp)
{
        ftp->ftps_type = DTFTP_ENTRY;
        ftp->ftps_pc = (uintptr_t)symp->st_value;
        ftp->ftps_size = (size_t)symp->st_size;
        ftp->ftps_noffs = 1;
        ftp->ftps_offs[0] = 0;

        if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
                dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
                    strerror(errno));
                return (dt_set_errno(dtp, errno));
        }

        return (1);
}

int
dt_pid_create_return_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
    fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, uint64_t *stret)
{

        uint32_t *text;
        int i;
        int srdepth = 0;

        if ((text = malloc(symp->st_size + 4)) == NULL) {
                dt_dprintf("mr sparkle: malloc() failed\n");
                return (DT_PROC_ERR);
        }

        if (Pread(P, text, symp->st_size, symp->st_value) != symp->st_size) {
                dt_dprintf("mr sparkle: Pread() failed\n");
                free(text);
                return (DT_PROC_ERR);
        }

        /*
         * Leave a dummy instruction in the last slot to simplify edge
         * conditions.
         */
        text[symp->st_size / 4] = 0;

        ftp->ftps_type = DTFTP_RETURN;
        ftp->ftps_pc = symp->st_value;
        ftp->ftps_size = symp->st_size;
        ftp->ftps_noffs = 0;

        for (i = 0; i < symp->st_size / 4; i++) {
                /*
                 * If we encounter an existing tracepoint, query the
                 * kernel to find out the instruction that was
                 * replaced at this spot.
                 */
                while (text[i] == FASTTRAP_INSTR) {
                        fasttrap_instr_query_t instr;

                        instr.ftiq_pid = Pstatus(P)->pr_pid;
                        instr.ftiq_pc = symp->st_value + i * 4;

                        if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_GETINSTR,
                            &instr) != 0) {

                                if (errno == ESRCH || errno == ENOENT) {
                                        if (Pread(P, &text[i], 4,
                                            instr.ftiq_pc) != 4) {
                                                dt_dprintf("mr sparkle: "
                                                    "Pread() failed\n");
                                                free(text);
                                                return (DT_PROC_ERR);
                                        }
                                        continue;
                                }

                                free(text);
                                dt_dprintf("mr sparkle: getinstr query "
                                    "failed: %s\n", strerror(errno));
                                return (DT_PROC_ERR);
                        }

                        text[i] = instr.ftiq_instr;
                        break;
                }

                /* save */
                if ((text[i] & 0xc1f80000) == 0x81e00000) {
                        srdepth++;
                        continue;
                }

                /* restore */
                if ((text[i] & 0xc1f80000) == 0x81e80000) {
                        srdepth--;
                        continue;
                }

                if (srdepth > 0) {
                        /* ret */
                        if (text[i] == 0x81c7e008)
                                goto is_ret;

                        /* return */
                        if (text[i] == 0x81cfe008)
                                goto is_ret;

                        /* call or jmpl w/ restore in the slot */
                        if (((text[i] & 0xc0000000) == 0x40000000 ||
                            (text[i] & 0xc1f80000) == 0x81c00000) &&
                            (text[i + 1] & 0xc1f80000) == 0x81e80000)
                                goto is_ret;

                        /* call to one of the stret routines */
                        if ((text[i] & 0xc0000000) == 0x40000000) {
                                int32_t disp = text[i] << 2;
                                uint64_t dest = ftp->ftps_pc + i * 4 + disp;

                                dt_dprintf("dest = %llx\n", (u_longlong_t)dest);

                                if (dest == stret[0] || dest == stret[1] ||
                                    dest == stret[2] || dest == stret[3])
                                        goto is_ret;
                        }
                } else {
                        /* external call */
                        if ((text[i] & 0xc0000000) == 0x40000000) {
                                int32_t dst = text[i] << 2;

                                dst += i * 4;

                                if ((uintptr_t)dst >= (uintptr_t)symp->st_size)
                                        goto is_ret;
                        }

                        /* jmpl into %g0 -- this includes the retl pseudo op */
                        if ((text[i] & 0xfff80000) == 0x81c00000)
                                goto is_ret;

                        /* external branch -- possible return site */
                        if (OP(text[i]) == OP_BRANCH) {
                                int32_t dst;
                                int baa;

                                switch (OP2(text[i])) {
                                case OP2_BPcc:
                                        dst = text[i] & 0x7ffff;
                                        dst <<= 13;
                                        dst >>= 11;

                                        baa = COND(text[i]) == 8 && A(text[i]);
                                        break;
                                case OP2_Bicc:
                                        dst = text[i] & 0x3fffff;
                                        dst <<= 10;
                                        dst >>= 8;

                                        baa = COND(text[i]) == 8 && A(text[i]);
                                        break;
                                case OP2_BPr:
                                        dst = (((text[i]) >> 6) & 0xc000) |
                                            ((text[i]) & 0x3fff);
                                        dst <<= 16;
                                        dst >>= 14;

                                        baa = 0;
                                        break;
                                case OP2_FBPfcc:
                                        dst = text[i] & 0x7ffff;
                                        dst <<= 13;
                                        dst >>= 11;

                                        baa = COND(text[i]) == 8 && A(text[i]);
                                        break;
                                case OP2_FBfcc:
                                        dst = text[i] & 0x3fffff;
                                        dst <<= 10;
                                        dst >>= 8;

                                        baa = COND(text[i]) == 8 && A(text[i]);
                                        break;
                                default:
                                        continue;
                                }

                                dst += i * 4;

                                /*
                                 * Interpret branches outside of the function's
                                 * bounds as potential return sites. If the
                                 * branch is a ba,a don't skip the instruction
                                 * in the delay slot.
                                 */
                                if ((uintptr_t)dst >=
                                    (uintptr_t)symp->st_size) {
                                        if (baa)
                                                goto is_ret_baa;
                                        else
                                                goto is_ret;
                                }
                        }
                }

                continue;
is_ret:
                i++;
is_ret_baa:
                dt_dprintf("return at offset %x\n", i * 4);
                ftp->ftps_offs[ftp->ftps_noffs++] = i * 4;
        }

        free(text);
        if (ftp->ftps_noffs > 0) {
                if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
                        dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
                            strerror(errno));
                        return (dt_set_errno(dtp, errno));
                }
        }


        return (ftp->ftps_noffs);
}

/*ARGSUSED*/
int
dt_pid_create_offset_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
    fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, ulong_t off)
{
        if (off & 0x3)
                return (DT_PROC_ALIGN);

        ftp->ftps_type = DTFTP_OFFSETS;
        ftp->ftps_pc = (uintptr_t)symp->st_value;
        ftp->ftps_size = (size_t)symp->st_size;
        ftp->ftps_noffs = 1;
        ftp->ftps_offs[0] = off;

        if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
                dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
                    strerror(errno));
                return (dt_set_errno(dtp, errno));
        }

        return (1);
}

/*ARGSUSED*/
int
dt_pid_create_glob_offset_probes(struct ps_prochandle *P, dtrace_hdl_t *dtp,
    fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, const char *pattern)
{
        ulong_t i;

        ftp->ftps_type = DTFTP_OFFSETS;
        ftp->ftps_pc = (uintptr_t)symp->st_value;
        ftp->ftps_size = (size_t)symp->st_size;
        ftp->ftps_noffs = 0;

        /*
         * If we're matching against everything, just iterate through each
         * instruction in the function, otherwise look for matching offset
         * names by constructing the string and comparing it against the
         * pattern.
         */
        if (strcmp("*", pattern) == 0) {
                for (i = 0; i < symp->st_size; i += 4) {
                        ftp->ftps_offs[ftp->ftps_noffs++] = i;
                }
        } else {
                char name[sizeof (i) * 2 + 1];

                for (i = 0; i < symp->st_size; i += 4) {
                        (void) sprintf(name, "%lx", i);
                        if (gmatch(name, pattern))
                                ftp->ftps_offs[ftp->ftps_noffs++] = i;
                }
        }

        if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
                dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
                    strerror(errno));
                return (dt_set_errno(dtp, errno));
        }

        return (ftp->ftps_noffs);
}