[MIPS] debuggerd and libcorkscrew support

Change-Id: I5a241dc2e470148be0ad2c138e31f1aba5ab8812
diff --git a/debuggerd/mips/machine.c b/debuggerd/mips/machine.c
new file mode 100644
index 0000000..dba1711
--- /dev/null
+++ b/debuggerd/mips/machine.c
@@ -0,0 +1,178 @@
+/* system/debuggerd/debuggerd.c
+**
+** Copyright 2012, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/ptrace.h>
+
+#include <corkscrew/ptrace.h>
+
+#include <linux/user.h>
+
+#include "../utility.h"
+#include "../machine.h"
+
+/* enable to dump memory pointed to by every register */
+#define DUMP_MEMORY_FOR_ALL_REGISTERS 1
+
+#define R(x) ((unsigned int)(x))
+
+static void dump_memory(log_t* log, pid_t tid, uintptr_t addr, bool at_fault) {
+    char code_buffer[64];       /* actual 8+1+((8+1)*4) + 1 == 45 */
+    char ascii_buffer[32];      /* actual 16 + 1 == 17 */
+    uintptr_t p, end;
+
+    p = addr & ~3;
+    p -= 32;
+    if (p > addr) {
+        /* catch underflow */
+        p = 0;
+    }
+    end = p + 80;
+    /* catch overflow; 'end - p' has to be multiples of 16 */
+    while (end < p)
+        end -= 16;
+
+    /* Dump the code around PC as:
+     *  addr     contents                             ascii
+     *  00008d34 ef000000 e8bd0090 e1b00000 512fff1e  ............../Q
+     *  00008d44 ea00b1f9 e92d0090 e3a070fc ef000000  ......-..p......
+     */
+    while (p < end) {
+        char* asc_out = ascii_buffer;
+
+        sprintf(code_buffer, "%08x ", p);
+
+        int i;
+        for (i = 0; i < 4; i++) {
+            /*
+             * If we see (data == -1 && errno != 0), we know that the ptrace
+             * call failed, probably because we're dumping memory in an
+             * unmapped or inaccessible page.  I don't know if there's
+             * value in making that explicit in the output -- it likely
+             * just complicates parsing and clarifies nothing for the
+             * enlightened reader.
+             */
+            long data = ptrace(PTRACE_PEEKTEXT, tid, (void*)p, NULL);
+            sprintf(code_buffer + strlen(code_buffer), "%08lx ", data);
+
+            int j;
+            for (j = 0; j < 4; j++) {
+                /*
+                 * Our isprint() allows high-ASCII characters that display
+                 * differently (often badly) in different viewers, so we
+                 * just use a simpler test.
+                 */
+                char val = (data >> (j*8)) & 0xff;
+                if (val >= 0x20 && val < 0x7f) {
+                    *asc_out++ = val;
+                } else {
+                    *asc_out++ = '.';
+                }
+            }
+            p += 4;
+        }
+        *asc_out = '\0';
+        _LOG(log, !at_fault, "    %s %s\n", code_buffer, ascii_buffer);
+    }
+}
+
+/*
+ * If configured to do so, dump memory around *all* registers
+ * for the crashing thread.
+ */
+void dump_memory_and_code(const ptrace_context_t* context __attribute((unused)),
+        log_t* log, pid_t tid, bool at_fault) {
+    pt_regs_mips_t r;
+    if(ptrace(PTRACE_GETREGS, tid, 0, &r)) {
+        return;
+    }
+
+    if (at_fault && DUMP_MEMORY_FOR_ALL_REGISTERS) {
+        static const char REG_NAMES[] = "$0atv0v1a0a1a2a3t0t1t2t3t4t5t6t7s0s1s2s3s4s5s6s7t8t9k0k1gpsps8ra";
+
+        for (int reg = 0; reg < 32; reg++) {
+            /* skip uninteresting registers */
+            if (reg == 0 /* $0 */
+                || reg == 26 /* $k0 */
+                || reg == 27 /* $k1 */
+                || reg == 31 /* $ra (done below) */
+               )
+               continue;
+
+            uintptr_t addr = R(r.regs[reg]);
+
+            /*
+             * Don't bother if it looks like a small int or ~= null, or if
+             * it's in the kernel area.
+             */
+            if (addr < 4096 || addr >= 0x80000000) {
+                continue;
+            }
+
+            _LOG(log, false, "\nmemory near %.2s:\n", &REG_NAMES[reg * 2]);
+            dump_memory(log, tid, addr, at_fault);
+        }
+    }
+
+    unsigned int pc = R(r.cp0_epc);
+    unsigned int ra = R(r.regs[31]);
+
+    _LOG(log, !at_fault, "\ncode around pc:\n");
+    dump_memory(log, tid, (uintptr_t)pc, at_fault);
+
+    if (pc != ra) {
+        _LOG(log, !at_fault, "\ncode around ra:\n");
+        dump_memory(log, tid, (uintptr_t)ra, at_fault);
+    }
+}
+
+void dump_registers(const ptrace_context_t* context __attribute((unused)),
+        log_t* log, pid_t tid, bool at_fault)
+{
+    pt_regs_mips_t r;
+    bool only_in_tombstone = !at_fault;
+
+    if(ptrace(PTRACE_GETREGS, tid, 0, &r)) {
+        _LOG(log, only_in_tombstone, "cannot get registers: %s\n", strerror(errno));
+        return;
+    }
+
+    _LOG(log, only_in_tombstone, " zr %08x  at %08x  v0 %08x  v1 %08x\n",
+     R(r.regs[0]), R(r.regs[1]), R(r.regs[2]), R(r.regs[3]));
+    _LOG(log, only_in_tombstone, " a0 %08x  a1 %08x  a2 %08x  a3 %08x\n",
+     R(r.regs[4]), R(r.regs[5]), R(r.regs[6]), R(r.regs[7]));
+    _LOG(log, only_in_tombstone, " t0 %08x  t1 %08x  t2 %08x  t3 %08x\n",
+     R(r.regs[8]), R(r.regs[9]), R(r.regs[10]), R(r.regs[11]));
+    _LOG(log, only_in_tombstone, " t4 %08x  t5 %08x  t6 %08x  t7 %08x\n",
+     R(r.regs[12]), R(r.regs[13]), R(r.regs[14]), R(r.regs[15]));
+    _LOG(log, only_in_tombstone, " s0 %08x  s1 %08x  s2 %08x  s3 %08x\n",
+     R(r.regs[16]), R(r.regs[17]), R(r.regs[18]), R(r.regs[19]));
+    _LOG(log, only_in_tombstone, " s4 %08x  s5 %08x  s6 %08x  s7 %08x\n",
+     R(r.regs[20]), R(r.regs[21]), R(r.regs[22]), R(r.regs[23]));
+    _LOG(log, only_in_tombstone, " t8 %08x  t9 %08x  k0 %08x  k1 %08x\n",
+     R(r.regs[24]), R(r.regs[25]), R(r.regs[26]), R(r.regs[27]));
+    _LOG(log, only_in_tombstone, " gp %08x  sp %08x  s8 %08x  ra %08x\n",
+     R(r.regs[28]), R(r.regs[29]), R(r.regs[30]), R(r.regs[31]));
+    _LOG(log, only_in_tombstone, " hi %08x  lo %08x bva %08x epc %08x\n",
+     R(r.hi), R(r.lo), R(r.cp0_badvaddr), R(r.cp0_epc));
+}