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  1. /*
  2.  * Copyright (c) 2008 Jiri Svoboda
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup debug
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. #include <stdio.h>
  36. #include <stdlib.h>
  37. #include <assert.h>
  38. #include <sys/types.h>
  39. #include <errno.h>
  40. #include <udebug.h>
  41.  
  42. #include "../../../cons.h"
  43. #include "../../../main.h"
  44. #include "../../../breakpoint.h"
  45. #include "../../../include/arch.h"
  46.  
  47. #define OPCODE_BREAK        0x0000000d
  48.  
  49. static istate_t istate;
  50.  
  51. typedef enum {
  52.     /* Branches (conditional) */
  53.     OP_BCzF,
  54.     OP_BCzFL,
  55.     OP_BCzT,
  56.     OP_BCzTL,
  57.     OP_BEQ,
  58.     OP_BEQL,
  59.     OP_BGEZ,
  60.     OP_BGEZAL,
  61.     OP_BGEZALL,
  62.     OP_BGEZL,
  63.     OP_BGTZ,
  64.     OP_BGTZL,
  65.     OP_BLEZ,
  66.     OP_BLEZL,
  67.     OP_BLTZ,
  68.     OP_BLTZAL,
  69.     OP_BLTZALL,
  70.     OP_BLTZL,
  71.     OP_BNE,
  72.     OP_BNEL,
  73.  
  74.     /* Jumps (unconditional) */
  75.     OP_J,
  76.     OP_JAL,
  77.     OP_JALR,
  78.     OP_JR
  79. } op_t;
  80.  
  81. typedef struct {
  82.     uint32_t mask;
  83.     uint32_t value;
  84.     op_t op;
  85. } instr_desc_t;
  86.  
  87. static instr_desc_t decoding_table[] = {
  88.     { 0xf3ff0000, 0x41000000, OP_BCzF },
  89.     { 0xf3ff0000, 0x41020000, OP_BCzFL },
  90.     { 0xf3ff0000, 0x41010000, OP_BCzT },
  91.     { 0xf3ff0000, 0x41030000, OP_BCzTL },
  92.     { 0xfc000000, 0x10000000, OP_BEQ },
  93.     { 0xfc000000, 0x50000000, OP_BEQL },
  94.     { 0xfc1f0000, 0x04010000, OP_BGEZ },
  95.     { 0xfc1f0000, 0x04110000, OP_BGEZAL },
  96.     { 0xfc1f0000, 0x04130000, OP_BGEZALL },
  97.     { 0xfc1f0000, 0x04030000, OP_BGEZL },
  98.     { 0xfc1f0000, 0x1c000000, OP_BGTZ },
  99.     { 0xfc1f0000, 0x5c000000, OP_BGTZL },
  100.     { 0xfc1f0000, 0x18000000, OP_BLEZ },
  101.     { 0xfc1f0000, 0x58000000, OP_BLEZL },
  102.     { 0xfc1f0000, 0x04000000, OP_BLTZ },
  103.     { 0xfc1f0000, 0x04100000, OP_BLTZAL },
  104.     { 0xfc1f0000, 0x04120000, OP_BLTZALL },
  105.     { 0xfc1f0000, 0x04020000, OP_BLTZL },
  106.     { 0xfc000000, 0x14000000, OP_BNE },
  107.     { 0xfc000000, 0x54000000, OP_BNEL },
  108.  
  109.     { 0xfc000000, 0x08000000, OP_J },
  110.     { 0xfc000000, 0x0c000000, OP_JAL },
  111.     { 0xfc1f07ff, 0x00000009, OP_JALR },
  112.     { 0xfc1fffff, 0x00000008, OP_JR },
  113.  
  114.     { 0, 0, -1 }
  115. };
  116.  
  117. void arch_dthread_initialize(dthread_t *dt)
  118. {
  119.     dt->arch.singlestep = false;
  120.  
  121.     bstore_initialize(&dt->arch.cur);
  122.     bstore_initialize(&dt->arch.next[0]);
  123.     bstore_initialize(&dt->arch.next[1]);
  124. }
  125.  
  126. int arch_breakpoint_set(breakpoint_t *b)
  127. {
  128.     bstore_initialize(&b->arch.bs);
  129.     bstore_initialize(&b->arch.next_bs[0]);
  130.     bstore_initialize(&b->arch.next_bs[1]);
  131.  
  132.     return bstore_push(&b->arch.bs, b->addr, OPCODE_BREAK);
  133. }
  134.  
  135. int arch_breakpoint_remove(breakpoint_t *b)
  136. {
  137.     return bstore_pop(&b->arch.bs);
  138. }
  139.  
  140. static int islot_read(uintptr_t addr, uint32_t *instr)
  141. {
  142.     int rc;
  143.  
  144.     rc = udebug_mem_read(app_phone, instr, addr, sizeof(uint32_t));
  145.     if (rc != EOK) {
  146.         cons_printf("Error reading memory address 0x%zx\n", addr);
  147.     }
  148.  
  149.     return rc;
  150. }
  151.  
  152. static op_t instr_decode(uint32_t instr)
  153. {
  154.     instr_desc_t *idesc;
  155.  
  156.     idesc = &decoding_table[0];
  157.     while (idesc->op >= 0) {
  158.         if ((instr & idesc->mask) == idesc->value)
  159.             return idesc->op;
  160.         ++idesc;
  161.     }
  162.  
  163.     return -1;
  164. }
  165.  
  166. static int get_reg(int reg_no, uint32_t *value)
  167. {
  168.     cons_printf("get_reg...\n");
  169.  
  170.     if (reg_no == 0) {
  171.         *value = 0;
  172.         return 0;
  173.     }
  174.  
  175.     /* FIXME: ugly */
  176.     *value = ((uint32_t *)&istate)[reg_no - 1];
  177.     printf("get_reg ok (0x%08x)\n", *value);
  178.  
  179.     return 0;
  180. }
  181.  
  182. /** Get address of the instruction that will be executed after the current one.
  183.  *
  184.  * Assumptions: addr == PC, *addr is not covered by a BREAK.
  185.  *
  186.  * @param addr      Address of an instruction.
  187.  * @param buffer    Buffer for storing up to 2 addresses.
  188.  * @return      Number of stored addresses or negative error code.
  189.  */
  190. static int get_next_addr(uintptr_t addr, uintptr_t *buffer)
  191. {
  192.     /* TODO: J[AL]R, branches and delay slots */
  193.     uint32_t instr;
  194.     int32_t offset;
  195.     op_t op;
  196.     int rc;
  197.     int n;
  198.  
  199.     rc = islot_read(addr, &instr);
  200.     if (rc != 0) return rc;
  201.  
  202.     op = instr_decode(instr);
  203.  
  204.     switch (op) {
  205.     case OP_BCzF:
  206.     case OP_BCzFL:
  207.     case OP_BCzT:
  208.     case OP_BCzTL:
  209.     case OP_BEQ:
  210.     case OP_BEQL:
  211.     case OP_BGEZ:
  212.     case OP_BGEZAL:
  213.     case OP_BGEZALL:
  214.     case OP_BGEZL:
  215.     case OP_BGTZ:
  216.     case OP_BGTZL:
  217.     case OP_BLEZ:
  218.     case OP_BLTZ:
  219.     case OP_BLTZAL:
  220.     case OP_BLTZALL:
  221.     case OP_BLTZL:
  222.     case OP_BNE:
  223.     case OP_BNEL:
  224.         /* Branch */
  225.         offset = (int32_t)(int16_t)(instr & 0x0000ffff) << 2;
  226.         buffer[0] = (addr + 4) + offset;    /* taken */
  227.         buffer[1] = addr + 8;           /* not taken */
  228.         n = 2;
  229.         break;
  230.  
  231.     case OP_J:
  232.     case OP_JAL:
  233.         /* Immediate jump */
  234.         buffer[0] =
  235.             ((addr + 4) & 0xf0000000) |
  236.             ((instr & 0x03ffffff) << 2);
  237.         n = 1;
  238.         break;
  239.     case OP_JR:
  240.     case OP_JALR:
  241.         /* Register jump */
  242.         rc = get_reg((instr >> 21) & 0x1f, &buffer[0]);
  243.         n = 1;
  244.         break;
  245.     default:
  246.         /* Regular instruction */  
  247.         buffer[0] = addr + 4;
  248.         n = 1;
  249.         break;
  250.     }
  251.  
  252.     return n;
  253. }
  254.  
  255. static void _ev_breakpoint(thash_t thread_hash)
  256. {
  257.     breakpoint_t *b;
  258.     dthread_t *dt;
  259.     int rc, n_next, i;
  260.     uint32_t epc;
  261.     uintptr_t brk_addr;
  262.     uintptr_t next_addr[2];
  263.     uint32_t brkp;
  264.  
  265.     brkp = OPCODE_BREAK;
  266.  
  267.     cons_printf("arch_event_breakpoint\n");
  268.  
  269.     rc = udebug_regs_read(app_phone, thread_hash, &istate);
  270.     cons_printf("udebug_regs_read -> %d\n", rc);
  271.     epc = istate_get_pc(&istate);
  272.     cons_printf("EPC was 0x%08x\n", epc);
  273.     brk_addr = epc;
  274.  
  275.     dt = dthread_get();
  276.  
  277.     if (active_bkpt != NULL) {
  278.         assert(active_bkpt->arch.bs.address == brk_addr);
  279.         b = active_bkpt;
  280.  
  281.         /* A breakpoint-restoring BRK has been hit */
  282.         cons_printf("restoring breakpoint %d\n", b->id);
  283.         for (i = 0; i < b->arch.n_next; ++i) {
  284.             rc = bstore_pop(&b->arch.next_bs[i]);
  285.             if (rc != 0) return;
  286.         }
  287.  
  288.         rc = bstore_push(&b->arch.bs, b->addr, OPCODE_BREAK);
  289.         if (rc != 0) return;
  290.         active_bkpt = NULL;
  291.         return;
  292.     }
  293.  
  294.     b = breakpoint_find_by_addr(brk_addr);
  295.     if (b == NULL) {
  296.         cons_printf("Unrecognized breakpoint at 0x%lx\n", brk_addr);
  297.     }
  298.  
  299.     /* A breakpoint has been hit */
  300.     cons_printf("breakpoint_hit...\n");
  301.     breakpoint_hit(b);
  302.  
  303.     /* While in breakpoint_hit(), singlestep was activated */
  304.     if (dt->arch.singlestep) return;
  305.  
  306.     cons_printf("move breakpoint\b");
  307.     rc = bstore_pop(&b->arch.bs);
  308.     if (rc != 0) return;
  309.  
  310.     n_next = get_next_addr(brk_addr, next_addr);
  311.     if (n_next < 0) return;
  312.  
  313.     /*
  314.      * There could be another breakpoint at next_addr,
  315.      * but that's okay. We'll pop the active breakpoint bs
  316.      * before doing anything else.
  317.      */
  318.     for (i = 0; i < n_next; ++i) {
  319.         rc = bstore_push(&b->arch.next_bs[i], next_addr[i],
  320.             OPCODE_BREAK);
  321.         if (rc != 0) return;
  322.     }
  323.     b->arch.n_next = n_next;
  324.  
  325.     active_bkpt = b;
  326.     b->active = true;
  327.  
  328.     cons_printf("end_hit...\n");
  329. }
  330.  
  331.  
  332. static void _ev_singlestep(thash_t thread_hash)
  333. {
  334.     dthread_t *dt;
  335.     int rc, i;
  336.     uint32_t epc;
  337.     int brk_addr;
  338.     uint32_t brkp;
  339.  
  340.     dt = dthread_get();
  341.  
  342.     assert(active_bkpt == NULL);
  343.     assert(dt->arch.singlestep);
  344.     brkp = OPCODE_BREAK;
  345.  
  346.     cons_printf("arch_event_breakpoint\n");
  347.  
  348.     rc = udebug_regs_read(app_phone, thread_hash, &istate);
  349.     cons_printf("udebug_regs_read -> %d\n", rc);
  350.     epc = istate_get_pc(&istate);
  351.     cons_printf("EPC was 0x%08x\n", epc);
  352.     brk_addr = epc;
  353.  
  354.     if (dt->arch.cur.valid) {
  355.         cons_printf("restore breakpoint BREAK\n");
  356.         rc = bstore_pop(&dt->arch.cur);
  357.     }
  358.  
  359.     cons_printf("\nclear singlestep BREAKs\n");
  360.     for (i = 0; i < dt->arch.n_next; ++i) {
  361.         rc = bstore_pop(&dt->arch.next[i]);
  362.         if (rc != 0) return;
  363.     }
  364.  
  365.     dt->arch.singlestep = false;
  366.  
  367.     singlestep_hit();
  368. }
  369.  
  370.  
  371. void arch_event_breakpoint(thash_t thread_hash)
  372. {
  373.     dthread_t *dt;
  374.  
  375.     dt = dthread_get();
  376.     if (dt->arch.singlestep) {
  377.         _ev_singlestep(thread_hash);
  378.     } else {
  379.         _ev_breakpoint(thread_hash);
  380.     }
  381. }
  382.  
  383. void arch_event_trap(dthread_t *dt)
  384. {
  385.     /* Unused */
  386.     (void)dt;
  387. }
  388.  
  389. void arch_dump_regs(thash_t thash)
  390. {
  391.     /* TODO */
  392. }
  393.  
  394. void arch_singlestep(dthread_t *dt)
  395. {
  396.     int rc, i;
  397.     uint32_t epc;
  398.     breakpoint_t *b;
  399.     uint32_t old_instr;
  400.     uintptr_t next_addr[2];
  401.     int n_next;
  402.  
  403.     assert(active_bkpt == NULL);
  404.     assert(dt->arch.singlestep == false);
  405.  
  406.     cons_printf("arch_singlestep(dt)\n");
  407.     rc = udebug_regs_read(app_phone, dt->hash, &istate);
  408.     cons_printf("udebug_regs_read -> %d\n", rc);
  409.     epc = istate_get_pc(&istate);
  410.     cons_printf("EPC was 0x%08x\n", epc);
  411.  
  412.     cons_printf("initial set singlestep\n");
  413.     b = breakpoint_find_by_addr(epc);
  414.     if (b != NULL) {
  415.         /* Cover breakpoint with old instruction */
  416.         old_instr = b->arch.bs.value;
  417.         rc = bstore_push(&dt->arch.cur, epc, old_instr);
  418.         if (rc < 0) return;
  419.     }
  420.  
  421.     n_next = get_next_addr(epc, next_addr);
  422.     if (n_next < 0) return;
  423.  
  424.     /* Cover next instruction(s) with BREAK */
  425.     for (i = 0; i < n_next; ++i) {
  426.         rc = bstore_push(&dt->arch.next[i], next_addr[i], OPCODE_BREAK);
  427.         if (rc != 0) return;
  428.     }
  429.     dt->arch.n_next = n_next;
  430.  
  431.     dt->arch.singlestep = true;
  432.     dthread_resume(dt);
  433. }
  434.  
  435. /** @}
  436.  */
  437.