michael@0: 
michael@0: /* libunwind - a platform-independent unwind library
michael@0:    Copyright 2011 Linaro Limited
michael@0: 
michael@0: This file is part of libunwind.
michael@0: 
michael@0: Permission is hereby granted, free of charge, to any person obtaining
michael@0: a copy of this software and associated documentation files (the
michael@0: "Software"), to deal in the Software without restriction, including
michael@0: without limitation the rights to use, copy, modify, merge, publish,
michael@0: distribute, sublicense, and/or sell copies of the Software, and to
michael@0: permit persons to whom the Software is furnished to do so, subject to
michael@0: the following conditions:
michael@0: 
michael@0: The above copyright notice and this permission notice shall be
michael@0: included in all copies or substantial portions of the Software.
michael@0: 
michael@0: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
michael@0: EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
michael@0: MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
michael@0: NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
michael@0: LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
michael@0: OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
michael@0: WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
michael@0: 
michael@0: // Copyright (c) 2010 Google Inc.
michael@0: // All rights reserved.
michael@0: //
michael@0: // Redistribution and use in source and binary forms, with or without
michael@0: // modification, are permitted provided that the following conditions are
michael@0: // met:
michael@0: //
michael@0: //     * Redistributions of source code must retain the above copyright
michael@0: // notice, this list of conditions and the following disclaimer.
michael@0: //     * Redistributions in binary form must reproduce the above
michael@0: // copyright notice, this list of conditions and the following disclaimer
michael@0: // in the documentation and/or other materials provided with the
michael@0: // distribution.
michael@0: //     * Neither the name of Google Inc. nor the names of its
michael@0: // contributors may be used to endorse or promote products derived from
michael@0: // this software without specific prior written permission.
michael@0: //
michael@0: // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0: // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0: // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0: // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
michael@0: // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
michael@0: // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
michael@0: // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0: // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0: // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0: // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0: // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0: 
michael@0: 
michael@0: // Derived from libunwind, with extensive modifications.
michael@0: 
michael@0: #include "common/unique_string.h"
michael@0: #include "common/arm_ex_to_module.h"
michael@0: 
michael@0: #include <stdio.h>
michael@0: #include <assert.h>
michael@0: 
michael@0: // For big-picture comments on how the EXIDX reader works, 
michael@0: // see arm_ex_reader.cc.
michael@0: 
michael@0: #define ARM_EXBUF_START(x) (((x) >> 4) & 0x0f)
michael@0: #define ARM_EXBUF_COUNT(x) ((x) & 0x0f)
michael@0: #define ARM_EXBUF_END(x)   (ARM_EXBUF_START(x) + ARM_EXBUF_COUNT(x))
michael@0: 
michael@0: using google_breakpad::ustr__pc;
michael@0: using google_breakpad::ustr__lr;
michael@0: using google_breakpad::ustr__sp;
michael@0: using google_breakpad::ustr__ZDra;
michael@0: using google_breakpad::ustr__ZDcfa;
michael@0: using google_breakpad::Module;
michael@0: using google_breakpad::ToUniqueString;
michael@0: using google_breakpad::UniqueString;
michael@0: 
michael@0: namespace arm_ex_to_module {
michael@0: 
michael@0: // Translate command from extab_data to command for Module.
michael@0: int ARMExToModule::TranslateCmd(const struct extab_data* edata,
michael@0:                                 Module::StackFrameEntry* entry,
michael@0:                                 Module::Expr& vsp) {
michael@0:   int ret = 0;
michael@0:   switch (edata->cmd) {
michael@0:     case ARM_EXIDX_CMD_FINISH:
michael@0:       /* Copy LR to PC if there isn't currently a rule for PC in force. */
michael@0:       if (entry->initial_rules.find(ustr__pc())
michael@0:           == entry->initial_rules.end()) {
michael@0:         if (entry->initial_rules.find(ustr__lr())
michael@0:             == entry->initial_rules.end()) {
michael@0:           entry->initial_rules[ustr__pc()] = Module::Expr(ustr__lr(),
michael@0:                                                           0, false); // "lr"
michael@0:         } else {
michael@0:           entry->initial_rules[ustr__pc()] = entry->initial_rules[ustr__lr()];
michael@0:         }
michael@0:       }
michael@0:       break;
michael@0:     case ARM_EXIDX_CMD_SUB_FROM_VSP:
michael@0:       vsp = vsp.add_delta(- static_cast<long>(edata->data));
michael@0:       break;
michael@0:     case ARM_EXIDX_CMD_ADD_TO_VSP:
michael@0:       vsp = vsp.add_delta(static_cast<long>(edata->data));
michael@0:       break;
michael@0:     case ARM_EXIDX_CMD_REG_POP:
michael@0:       for (unsigned int i = 0; i < 16; i++) {
michael@0:         if (edata->data & (1 << i)) {
michael@0:           entry->initial_rules[ToUniqueString(regnames[i])] = vsp.deref();
michael@0:           vsp = vsp.add_delta(4);
michael@0:         }
michael@0:       }
michael@0:       /* Set cfa in case the SP got popped. */
michael@0:       if (edata->data & (1 << 13)) {
michael@0:         vsp = entry->initial_rules[ustr__sp()];
michael@0:       }
michael@0:       break;
michael@0:     case ARM_EXIDX_CMD_REG_TO_SP: {
michael@0:       assert (edata->data < 16);
michael@0:       const char* const regname = regnames[edata->data];
michael@0:       const UniqueString* regname_us = ToUniqueString(regname);
michael@0:       if (entry->initial_rules.find(regname_us) == entry->initial_rules.end()) {
michael@0:         entry->initial_rules[ustr__sp()] = Module::Expr(regname_us,
michael@0:                                                         0, false); // "regname"
michael@0:       } else {
michael@0:         entry->initial_rules[ustr__sp()] = entry->initial_rules[regname_us];
michael@0:       }
michael@0:       vsp = entry->initial_rules[ustr__sp()];
michael@0:       break;
michael@0:     }
michael@0:     case ARM_EXIDX_CMD_VFP_POP:
michael@0:       /* Don't recover VFP registers, but be sure to adjust the stack
michael@0:          pointer. */
michael@0:       for (unsigned int i = ARM_EXBUF_START(edata->data);
michael@0:            i <= ARM_EXBUF_END(edata->data); i++) {
michael@0:         vsp = vsp.add_delta(8);
michael@0:       }
michael@0:       if (!(edata->data & ARM_EXIDX_VFP_FSTMD)) {
michael@0:         vsp = vsp.add_delta(4);
michael@0:       }
michael@0:       break;
michael@0:     case ARM_EXIDX_CMD_WREG_POP:
michael@0:       for (unsigned int i = ARM_EXBUF_START(edata->data);
michael@0:            i <= ARM_EXBUF_END(edata->data); i++) {
michael@0:         vsp = vsp.add_delta(8);
michael@0:       }
michael@0:       break;
michael@0:     case ARM_EXIDX_CMD_WCGR_POP:
michael@0:       // Pop wCGR registers under mask {wCGR3,2,1,0}, hence "i < 4"
michael@0:       for (unsigned int i = 0; i < 4; i++) {
michael@0:         if (edata->data & (1 << i)) {
michael@0:           vsp = vsp.add_delta(4);
michael@0:         }
michael@0:       }
michael@0:       break;
michael@0:     case ARM_EXIDX_CMD_REFUSED:
michael@0:     case ARM_EXIDX_CMD_RESERVED:
michael@0:       ret = -1;
michael@0:       break;
michael@0:   }
michael@0:   return ret;
michael@0: }
michael@0: 
michael@0: void ARMExToModule::AddStackFrame(uintptr_t addr, size_t size) {
michael@0:   stack_frame_entry_ = new Module::StackFrameEntry;
michael@0:   stack_frame_entry_->address = addr;
michael@0:   stack_frame_entry_->size = size;
michael@0:   Module::Expr sp_expr = Module::Expr(ustr__sp(), 0, false); // "sp"
michael@0:   stack_frame_entry_->initial_rules[ustr__ZDcfa()] = sp_expr; // ".cfa"
michael@0:   vsp_ = sp_expr;
michael@0: }
michael@0: 
michael@0: int ARMExToModule::ImproveStackFrame(const struct extab_data* edata) {
michael@0:   return TranslateCmd(edata, stack_frame_entry_, vsp_) ;
michael@0: }
michael@0: 
michael@0: void ARMExToModule::DeleteStackFrame() {
michael@0:   delete stack_frame_entry_;
michael@0: }
michael@0: 
michael@0: void ARMExToModule::SubmitStackFrame() {
michael@0:   // return address always winds up in pc
michael@0:   stack_frame_entry_->initial_rules[ustr__ZDra()] // ".ra"
michael@0:     = stack_frame_entry_->initial_rules[ustr__pc()];
michael@0:   // the final value of vsp is the new value of sp
michael@0:   stack_frame_entry_->initial_rules[ustr__sp()] = vsp_;
michael@0:   module_->AddStackFrameEntry(stack_frame_entry_);
michael@0: }
michael@0: 
michael@0: } // namespace arm_ex_to_module