DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (5b81998bb7ab)

VCS Links

Line Code
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 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "jscrashreport.h"

#include <time.h>

#include "jsapi.h"
#include "jscrashformat.h"
#include "jsutil.h"

using namespace js;
using namespace js::crash;

const static int stack_snapshot_max_size = 32768;

#if defined(XP_WIN)

#include <windows.h>

static bool
GetStack(uint64_t *stack, uint64_t *stack_len, CrashRegisters *regs, char *buffer, size_t size)
{
    /* Try to figure out how big the stack is. */
    char dummy;
    MEMORY_BASIC_INFORMATION info;
    if (VirtualQuery(reinterpret_cast<LPCVOID>(&dummy), &info, sizeof(info)) == 0)
        return false;
    if (info.State != MEM_COMMIT)
        return false;

    /* 256 is a fudge factor to account for the rest of GetStack's frame. */
    uint64_t p = uint64_t(&dummy) - 256;
    uint64_t len = stack_snapshot_max_size;

    if (p + len > uint64_t(info.BaseAddress) + info.RegionSize)
        len = uint64_t(info.BaseAddress) + info.RegionSize - p;

    if (len > size)
        len = size;

    *stack = p;
    *stack_len = len;

    /* Get the register state. */
#if defined(_MSC_VER) && JS_BITS_PER_WORD == 32
    /* ASM version for win2k that doesn't support RtlCaptureContext */
    uint32_t vip, vsp, vbp;
    __asm {
    Label:
        mov [vbp], ebp;
        mov [vsp], esp;
        mov eax, [Label];
        mov [vip], eax;
    }
    regs->ip = vip;
    regs->sp = vsp;
    regs->bp = vbp;
#else
    CONTEXT context;
    RtlCaptureContext(&context);
#if JS_BITS_PER_WORD == 32
    regs->ip = context.Eip;
    regs->sp = context.Esp;
    regs->bp = context.Ebp;
#else
    regs->ip = context.Rip;
    regs->sp = context.Rsp;
    regs->bp = context.Rbp;
#endif
#endif

    js_memcpy(buffer, (void *)p, len);

    return true;
}

#elif 0

#include <unistd.h>
#include <ucontext.h>
#include <sys/mman.h>

static bool
GetStack(uint64_t *stack, uint64_t *stack_len, CrashRegisters *regs, char *buffer, size_t size)
{
    /* 256 is a fudge factor to account for the rest of GetStack's frame. */
    char dummy;
    uint64_t p = uint64_t(&dummy) - 256;
    uint64_t pgsz = getpagesize();
    uint64_t len = stack_snapshot_max_size;
    p &= ~(pgsz - 1);

    /* Try to figure out how big the stack is. */
    while (len > 0) {
	if (mlock((const void *)p, len) == 0) {
	    munlock((const void *)p, len);
	    break;
	}
	len -= pgsz;
    }

    if (len > size)
        len = size;

    *stack = p;
    *stack_len = len;

    /* Get the register state. */
    ucontext_t context;
    if (getcontext(&context) != 0)
	return false;

#if JS_BITS_PER_WORD == 64
    regs->sp = (uint64_t)context.uc_mcontext.gregs[REG_RSP];
    regs->bp = (uint64_t)context.uc_mcontext.gregs[REG_RBP];
    regs->ip = (uint64_t)context.uc_mcontext.gregs[REG_RIP];
#elif JS_BITS_PER_WORD == 32
    regs->sp = (uint64_t)context.uc_mcontext.gregs[REG_ESP];
    regs->bp = (uint64_t)context.uc_mcontext.gregs[REG_EBP];
    regs->ip = (uint64_t)context.uc_mcontext.gregs[REG_EIP];
#endif

    js_memcpy(buffer, (void *)p, len);

    return true;
}

#else

static bool
GetStack(uint64_t *stack, uint64_t *stack_len, CrashRegisters *regs, char *buffer, size_t size)
{
    return false;
}

#endif

namespace js {
namespace crash {

class Stack : private CrashStack
{
public:
    Stack(uint64_t id);

    bool snapshot();
};

Stack::Stack(uint64_t id)
  : CrashStack(id)
{
}

bool
Stack::snapshot()
{
    snaptime = time(NULL);
    return GetStack(&stack_base, &stack_len, &regs, stack, sizeof(stack));
}

class Ring : private CrashRing
{
public:
    Ring(uint64_t id);

    void push(uint64_t tag, void *data, size_t size);

private:
    size_t bufferSize() { return crash_buffer_size; }
    void copyBytes(void *data, size_t size);
};

Ring::Ring(uint64_t id)
  : CrashRing(id)
{
}

void
Ring::push(uint64_t tag, void *data, size_t size)
{
    uint64_t t = time(NULL);

    copyBytes(&tag, sizeof(uint64_t));
    copyBytes(&t, sizeof(uint64_t));
    copyBytes(data, size);
    uint64_t mysize = size;
    copyBytes(&mysize, sizeof(uint64_t));
}

void
Ring::copyBytes(void *data, size_t size)
{
    if (size >= bufferSize())
        size = bufferSize();

    if (offset + size > bufferSize()) {
        size_t first = bufferSize() - offset;
        size_t second = size - first;
        js_memcpy(&buffer[offset], data, first);
        js_memcpy(buffer, (char *)data + first, second);
        offset = second;
    } else {
        js_memcpy(&buffer[offset], data, size);
        offset += size;
    }
}

} /* namespace crash */
} /* namespace js */

static bool gInitialized;

static Stack gGCStack(JS_CRASH_STACK_GC);
static Stack gErrorStack(JS_CRASH_STACK_ERROR);
static Ring gRingBuffer(JS_CRASH_RING);

void
js::crash::SnapshotGCStack()
{
    if (gInitialized)
        gGCStack.snapshot();
}

void
js::crash::SnapshotErrorStack()
{
    if (gInitialized)
        gErrorStack.snapshot();
}

void
js::crash::SaveCrashData(uint64_t tag, void *ptr, size_t size)
{
    if (gInitialized)
        gRingBuffer.push(tag, ptr, size);
}

JS_PUBLIC_API(void)
JS_EnumerateDiagnosticMemoryRegions(JSEnumerateDiagnosticMemoryCallback callback)
{
#ifdef JS_CRASH_DIAGNOSTICS
    if (!gInitialized) {
        gInitialized = true;
        (*callback)(&gGCStack, sizeof(gGCStack));
        (*callback)(&gErrorStack, sizeof(gErrorStack));
        (*callback)(&gRingBuffer, sizeof(gRingBuffer));
    }
#endif
}