/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <errno.h>

// not available on macosx #include <gelf.h>

#include "libjvm_db.h"

#include "JvmOffsets.h"

#define LIBJVM_SO "libjvm.so"

#if defined(i386) || defined(__i386) || defined(__amd64)

#ifdef COMPILER2

#define X86_COMPILER2

#endif /* COMPILER2 */

#endif /* i386 */

typedef struct {

    short     vf_cnt; /* number of recognized java vframes */

    short     bci;    /* current frame method byte code index */

    int       line;   /* current frame method source line */

    uint64_t new_fp; /* fp for the next frame */

    uint64_t new_pc; /* pc for the next frame */

    uint64_t new_sp; /* "raw" sp for the next frame (includes extension by interpreter/adapter */

    char      locinf; /* indicates there is valid location info */

} Jframe_t;

int Jlookup_by_regs(jvm_agent_t* J, const prgregset_t regs, char *name,

                    size_t size, Jframe_t *jframe);

int main(int arg) { return arg; }

static int debug = 0;

static void failed(int err, const char * file, int line) {

  if (debug) {

    fprintf(stderr, "failed %d at %s:%d\n", err, file, line);

  }

}

static void warn(const char * file, int line, const char * msg) {

  if (debug) {

    fprintf(stderr, "warning: %s at %s:%d\n", msg, file, line);

  }

}

static void warn1(const char * file, int line, const char * msg, intptr_t arg1) {

  if (debug) {

    fprintf(stderr, "warning: ");

    fprintf(stderr, msg, arg1);

    fprintf(stderr, " at %s:%d\n", file, line);

  }

}

#define CHECK_FAIL(err) \

        if (err != PS_OK) { failed(err, __FILE__, __LINE__); goto fail; }

#define WARN(msg)  warn(__FILE__, __LINE__, msg)

#define WARN1(msg, arg1)  warn1(__FILE__, __LINE__, msg, arg1)

typedef struct VMStructEntry {

  const char * typeName;           /* The type name containing the given field (example: "Klass") */

  const char * fieldName;          /* The field name within the type           (example: "_name") */

  uint64_t address;                /* Address of field; only used for static fields */

                                   /* ("offset" can not be reused because of apparent SparcWorks compiler bug */

                                   /* in generation of initializer data) */

} VMStructEntry;

/* Prototyping inlined methods */

int sprintf(char *s, const char *format, ...);

#define SZ16  sizeof(int16_t)

#define SZ32  sizeof(int32_t)

#define COMP_METHOD_SIGN '*'

#define MAX_VFRAMES_CNT 256

typedef struct vframe {

  uint64_t method;

  int32_t  sender_decode_offset;

  int32_t  methodIdx;

  int32_t  bci;

  int32_t  line;

} Vframe_t;

typedef struct frame {

  uintptr_t fp;

  uintptr_t pc;

  uintptr_t sp;

  uintptr_t sender_sp; // The unextended sp of the caller

} Frame_t;

typedef struct Nmethod_t {

  struct jvm_agent* J;

  Jframe_t *jframe;

  uint64_t nm;                  /* _nmethod */

  uint64_t pc;

  uint64_t pc_desc;

  int32_t  orig_pc_offset;      /* _orig_pc_offset */

  int32_t  instrs_beg;          /* _code_offset */

  int32_t  instrs_end;

  int32_t  deopt_beg;           /* _deoptimize_offset */

  int32_t  scopes_data_beg;     /* _scopes_data_offset */

  int32_t  scopes_data_end;

  int32_t  metadata_beg;        /* _metadata_offset */

  int32_t  metadata_end;

  int32_t  scopes_pcs_beg;      /* _scopes_pcs_offset */

  int32_t  scopes_pcs_end;

  int      vf_cnt;

  Vframe_t vframes[MAX_VFRAMES_CNT];

} Nmethod_t;

struct jvm_agent {

  struct ps_prochandle* P;

  uint64_t nmethod_vtbl;

  uint64_t CodeBlob_vtbl;

  uint64_t BufferBlob_vtbl;

  uint64_t RuntimeStub_vtbl;

  uint64_t Method_vtbl;

  uint64_t Use_Compressed_Oops_address;

  uint64_t Universe_narrow_oop_base_address;

  uint64_t Universe_narrow_oop_shift_address;

  uint64_t CodeCache_heap_address;

  /* Volatiles */

  uint8_t  Use_Compressed_Oops;

  uint64_t Universe_narrow_oop_base;

  uint32_t Universe_narrow_oop_shift;

  uint64_t CodeCache_low;

  uint64_t CodeCache_high;

  uint64_t CodeCache_segmap_low;

  uint64_t CodeCache_segmap_high;

  int32_t  SIZE_CodeCache_log2_segment;

  uint64_t methodPtr;

  Nmethod_t *N;                 /*Inlined methods support */

  Frame_t   prev_fr;

  Frame_t   curr_fr;

};

static int

read_string(struct ps_prochandle *P,

        char *buf,              /* caller's buffer */

        size_t size,            /* upper limit on bytes to read */

        uintptr_t addr)         /* address in process */

{

  int err = PS_OK;

  while (size-- > 1 && err == PS_OK) {

    err = ps_pread(P, addr, buf, 1);

    if (*buf == '\0') {

      return PS_OK;

    }

    addr += 1;

    buf += 1;

  }

  return -1;

}

static int read_compressed_pointer(jvm_agent_t* J, uint64_t base, uint32_t *ptr) {

  int err = -1;

  uint32_t ptr32;

  err = ps_pread(J->P, base, &ptr32, sizeof(uint32_t));

  *ptr = ptr32;

  return err;

}

static int read_pointer(jvm_agent_t* J, uint64_t base, uint64_t* ptr) {

  int err = -1;

  uint32_t ptr32;

  switch (DATA_MODEL) {

  case PR_MODEL_LP64:

    err = ps_pread(J->P, base, ptr, sizeof(uint64_t));

    break;

  case PR_MODEL_ILP32:

    err = ps_pread(J->P, base, &ptr32, sizeof(uint32_t));

    *ptr = ptr32;

    break;

  }

  return err;

}

static int read_string_pointer(jvm_agent_t* J, uint64_t base, const char ** stringp) {

  uint64_t ptr;

  int err;

  char buffer[1024];

  *stringp = NULL;

  err = read_pointer(J, base, &ptr);

  CHECK_FAIL(err);

  if (ptr != 0) {

    err = read_string(J->P, buffer, sizeof(buffer), ptr);

    CHECK_FAIL(err);

    *stringp = strdup(buffer);

  }

  return PS_OK;

 fail:

  return err;

}

static int parse_vmstruct_entry(jvm_agent_t* J, uint64_t base, VMStructEntry* vmp) {

  uint64_t ptr;

  int err;

  err = read_string_pointer(J, base + OFFSET_VMStructEntrytypeName, &vmp->typeName);

  CHECK_FAIL(err);

  err = read_string_pointer(J, base + OFFSET_VMStructEntryfieldName, &vmp->fieldName);

  CHECK_FAIL(err);

  err = read_pointer(J, base + OFFSET_VMStructEntryaddress, &vmp->address);

  CHECK_FAIL(err);

  return PS_OK;

 fail:

  if (vmp->typeName != NULL) free((void*)vmp->typeName);

  if (vmp->fieldName != NULL) free((void*)vmp->fieldName);

  return err;

}

static int parse_vmstructs(jvm_agent_t* J) {

  VMStructEntry  vmVar;

  VMStructEntry* vmp = &vmVar;

  uint64_t gHotSpotVMStructs;

  psaddr_t sym_addr;

  uint64_t base;

  int err;

  err = ps_pglobal_lookup(J->P, LIBJVM_SO, "gHotSpotVMStructs", &sym_addr);

  CHECK_FAIL(err);

  err = read_pointer(J, sym_addr, &gHotSpotVMStructs);

  CHECK_FAIL(err);

  base = gHotSpotVMStructs;

  err = PS_OK;

  while (err == PS_OK) {

    memset(vmp, 0, sizeof(VMStructEntry));

    err = parse_vmstruct_entry(J, base, vmp);

    if (err != PS_OK || vmp->typeName == NULL) {

      break;

    }

    if (vmp->typeName[0] == 'C' && strcmp("CodeCache", vmp->typeName) == 0) {

      if (strcmp("_heap", vmp->fieldName) == 0) {

        err = read_pointer(J, vmp->address, &J->CodeCache_heap_address);

      }

    } else if (vmp->typeName[0] == 'U' && strcmp("Universe", vmp->typeName) == 0) {

      if (strcmp("_narrow_oop._base", vmp->fieldName) == 0) {

        J->Universe_narrow_oop_base_address = vmp->address;

      }

      if (strcmp("_narrow_oop._shift", vmp->fieldName) == 0) {

        J->Universe_narrow_oop_shift_address = vmp->address;

      }

    }

    CHECK_FAIL(err);

    base += SIZE_VMStructEntry;

    if (vmp->typeName != NULL) free((void*)vmp->typeName);

    if (vmp->fieldName != NULL) free((void*)vmp->fieldName);

  }

  return PS_OK;

 fail:

  if (vmp->typeName != NULL) free((void*)vmp->typeName);

  if (vmp->fieldName != NULL) free((void*)vmp->fieldName);

  return -1;

}

static int find_symbol(jvm_agent_t* J, const char *name, uint64_t* valuep) {

  psaddr_t sym_addr;

  int err;

  err = ps_pglobal_lookup(J->P, LIBJVM_SO, name, &sym_addr);

  if (err != PS_OK) goto fail;

  *valuep = sym_addr;

  return PS_OK;

 fail:

  return err;

}

static int read_volatiles(jvm_agent_t* J) {

  uint64_t ptr;

  int err;

  err = find_symbol(J, "UseCompressedOops", &J->Use_Compressed_Oops_address);

  if (err == PS_OK) {

    err = ps_pread(J->P,  J->Use_Compressed_Oops_address, &J->Use_Compressed_Oops, sizeof(uint8_t));

    CHECK_FAIL(err);

  } else {

    J->Use_Compressed_Oops = 0;

  }

  err = read_pointer(J, J->Universe_narrow_oop_base_address, &J->Universe_narrow_oop_base);

  CHECK_FAIL(err);

  err = ps_pread(J->P,  J->Universe_narrow_oop_shift_address, &J->Universe_narrow_oop_shift, sizeof(uint32_t));

  CHECK_FAIL(err);

  err = read_pointer(J, J->CodeCache_heap_address + OFFSET_CodeHeap_memory +

                     OFFSET_VirtualSpace_low, &J->CodeCache_low);

  CHECK_FAIL(err);

  err = read_pointer(J, J->CodeCache_heap_address + OFFSET_CodeHeap_memory +

                     OFFSET_VirtualSpace_high, &J->CodeCache_high);

  CHECK_FAIL(err);

  err = read_pointer(J, J->CodeCache_heap_address + OFFSET_CodeHeap_segmap +

                     OFFSET_VirtualSpace_low, &J->CodeCache_segmap_low);

  CHECK_FAIL(err);

  err = read_pointer(J, J->CodeCache_heap_address + OFFSET_CodeHeap_segmap +

                     OFFSET_VirtualSpace_high, &J->CodeCache_segmap_high);

  CHECK_FAIL(err);

  err = ps_pread(J->P, J->CodeCache_heap_address + OFFSET_CodeHeap_log2_segment_size,

                 &J->SIZE_CodeCache_log2_segment, sizeof(J->SIZE_CodeCache_log2_segment));

  CHECK_FAIL(err);

  return PS_OK;

 fail:

  return err;

}

static int codecache_contains(jvm_agent_t* J, uint64_t ptr) {

  /* make sure the code cache is up to date */

  return (J->CodeCache_low <= ptr && ptr < J->CodeCache_high);

}

static uint64_t segment_for(jvm_agent_t* J, uint64_t p) {

  return (p - J->CodeCache_low) >> J->SIZE_CodeCache_log2_segment;

}

static uint64_t block_at(jvm_agent_t* J, int i) {

  return J->CodeCache_low + (i << J->SIZE_CodeCache_log2_segment);

}

static int find_start(jvm_agent_t* J, uint64_t ptr, uint64_t *startp) {

  int err;

  *startp = 0;

  if (J->CodeCache_low <= ptr && ptr < J->CodeCache_high) {

    int32_t used;

    uint64_t segment = segment_for(J, ptr);

    uint64_t block = J->CodeCache_segmap_low;

    uint8_t tag;

    err = ps_pread(J->P, block + segment, &tag, sizeof(tag));

    CHECK_FAIL(err);

    if (tag == 0xff)

      return PS_OK;

    while (tag > 0) {

      err = ps_pread(J->P, block + segment, &tag, sizeof(tag));

      CHECK_FAIL(err);

      segment -= tag;

    }

    block = block_at(J, segment);

    err = ps_pread(J->P, block + OFFSET_HeapBlockHeader_used, &used, sizeof(used));

    CHECK_FAIL(err);

    if (used) {

      *startp = block + SIZE_HeapBlockHeader;

    }

  }

  return PS_OK;

 fail:

  return -1;

}

static int find_jlong_constant(jvm_agent_t* J, const char *name, uint64_t* valuep) {

  psaddr_t sym_addr;

  int err = ps_pglobal_lookup(J->P, LIBJVM_SO, name, &sym_addr);

  if (err == PS_OK) {

    err = ps_pread(J->P, sym_addr, valuep, sizeof(uint64_t));

    return err;

  }

  *valuep = -1;

  return -1;

}

jvm_agent_t *Jagent_create(struct ps_prochandle *P, int vers) {

  jvm_agent_t* J;

  int err;

  if (vers != JVM_DB_VERSION) {

    errno = ENOTSUP;

    return NULL;

  }

  J = (jvm_agent_t*)calloc(sizeof(struct jvm_agent), 1);

  debug = getenv("LIBJVMDB_DEBUG") != NULL;

  if (debug) debug = 3;

  if (debug) {

      fprintf(stderr, "Jagent_create: debug=%d\n", debug);

#ifdef X86_COMPILER2

      fprintf(stderr, "Jagent_create: R_SP=%d, R_FP=%d, POINTER_SIZE=%d\n", R_SP, R_FP, POINTER_SIZE);

#endif  /* X86_COMPILER2 */

  }

  J->P = P;

  // Initialize the initial previous frame

  J->prev_fr.fp = 0;

  J->prev_fr.pc = 0;

  J->prev_fr.sp = 0;

  J->prev_fr.sender_sp = 0;

  err = find_symbol(J, "__1cHnmethodG__vtbl_", &J->nmethod_vtbl);

  CHECK_FAIL(err);

  err = find_symbol(J, "__1cKBufferBlobG__vtbl_", &J->BufferBlob_vtbl);

  if (err != PS_OK) J->BufferBlob_vtbl = 0;

  err = find_symbol(J, "__1cICodeBlobG__vtbl_", &J->CodeBlob_vtbl);

  CHECK_FAIL(err);

  err = find_symbol(J, "__1cLRuntimeStubG__vtbl_", &J->RuntimeStub_vtbl);

  CHECK_FAIL(err);

  err = find_symbol(J, "__1cNMethodG__vtbl_", &J->Method_vtbl);

  CHECK_FAIL(err);

  err = parse_vmstructs(J);

  CHECK_FAIL(err);

  err = read_volatiles(J);

  CHECK_FAIL(err);

  return J;

 fail:

  Jagent_destroy(J);

  return NULL;

}

void Jagent_destroy(jvm_agent_t *J) {

  if (J != NULL) {

    free(J);

  }

}

static int is_method(jvm_agent_t* J, uint64_t methodPtr) {

  uint64_t klass;

  int err = read_pointer(J, methodPtr, &klass);

  if (err != PS_OK) goto fail;

  return klass == J->Method_vtbl;

 fail:

  return 0;

}

static int

name_for_methodPtr(jvm_agent_t* J, uint64_t methodPtr, char * result, size_t size)

{

  short nameIndex;

  short signatureIndex;

  uint64_t constantPool;

  uint64_t constMethod;

  uint64_t nameSymbol;

  uint64_t signatureSymbol;

  uint64_t klassPtr;

  uint64_t klassSymbol;

  short klassSymbolLength;

  short nameSymbolLength;

  short signatureSymbolLength;

  char * nameString = NULL;

  char * klassString = NULL;

  char * signatureString = NULL;

  int err;

  err = read_pointer(J, methodPtr + OFFSET_Method_constMethod, &constMethod);

  CHECK_FAIL(err);

  err = read_pointer(J, constMethod + OFFSET_ConstMethod_constants, &constantPool);

  CHECK_FAIL(err);

  /* To get name string */

  err = ps_pread(J->P, constMethod + OFFSET_ConstMethod_name_index, &nameIndex, 2);

  CHECK_FAIL(err);

  err = read_pointer(J, constantPool + nameIndex * POINTER_SIZE + SIZE_ConstantPool, &nameSymbol);

  CHECK_FAIL(err);

  // The symbol is a CPSlot and has lower bit set to indicate metadata

  nameSymbol &= (~1); // remove metadata lsb

  err = ps_pread(J->P, nameSymbol + OFFSET_Symbol_length, &nameSymbolLength, 2);

  CHECK_FAIL(err);

  nameString = (char*)calloc(nameSymbolLength + 1, 1);

  err = ps_pread(J->P, nameSymbol + OFFSET_Symbol_body, nameString, nameSymbolLength);

  CHECK_FAIL(err);

  /* To get signature string */

  err = ps_pread(J->P, constMethod + OFFSET_ConstMethod_signature_index, &signatureIndex, 2);

  CHECK_FAIL(err);

  err = read_pointer(J, constantPool + signatureIndex * POINTER_SIZE + SIZE_ConstantPool, &signatureSymbol);

  CHECK_FAIL(err);

  signatureSymbol &= (~1);  // remove metadata lsb

  err = ps_pread(J->P, signatureSymbol + OFFSET_Symbol_length, &signatureSymbolLength, 2);