lldb/source/Plugins/Process/Utility/NativeRegisterContextDBReg_arm64.cpp

   1 //===-- NativeRegisterContextDBReg_arm64.cpp ------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "NativeRegisterContextDBReg_arm64.h"
  10
  11 #include "lldb/Utility/LLDBLog.h"
  12 #include "lldb/Utility/Log.h"
  13 #include "lldb/Utility/RegisterValue.h"
  14
  15 using namespace lldb_private;
  16
  17 uint32_t
  18 NativeRegisterContextDBReg_arm64::GetWatchpointSize(uint32_t wp_index) {
  19   Log *log = GetLog(LLDBLog::Watchpoints);
  20   LLDB_LOG(log, "wp_index: {0}", wp_index);
  21
  22   switch ((m_hwp_regs[wp_index].control >> 5) & 0xff) {
  23   case 0x01:
  24     return 1;
  25   case 0x03:
  26     return 2;
  27   case 0x0f:
  28     return 4;
  29   case 0xff:
  30     return 8;
  31   default:
  32     return 0;
  33   }
  34 }
  35
  36 std::optional<NativeRegisterContextDBReg::WatchpointDetails>
  37 NativeRegisterContextDBReg_arm64::AdjustWatchpoint(
  38     const WatchpointDetails &details) {
  39   size_t size = details.size;
  40   lldb::addr_t addr = details.addr;
  41   // Check if size has a valid hardware watchpoint length.
  42   if (size != 1 && size != 2 && size != 4 && size != 8)
  43     return std::nullopt;
  44
  45   // Check 8-byte alignment for hardware watchpoint target address. Below is a
  46   // hack to recalculate address and size in order to make sure we can watch
  47   // non 8-byte aligned addresses as well.
  48   if (addr & 0x07) {
  49     uint8_t watch_mask = (addr & 0x07) + size;
  50
  51     if (watch_mask > 0x08)
  52       return std::nullopt;
  53
  54     if (watch_mask <= 0x02)
  55       size = 2;
  56     else if (watch_mask <= 0x04)
  57       size = 4;
  58     else
  59       size = 8;
  60
  61     addr = addr & (~0x07);
  62   }
  63   return WatchpointDetails{size, addr};
  64 }
  65
  66 uint32_t NativeRegisterContextDBReg_arm64::MakeBreakControlValue(size_t size) {
  67   // PAC (bits 2:1): 0b10
  68   const uint32_t pac_bits = 2 << 1;
  69
  70   // BAS (bits 12:5) hold a bit-mask of addresses to watch
  71   // e.g. 0b00000001 means 1 byte at address
  72   //      0b00000011 means 2 bytes (addr..addr+1)
  73   //      ...
  74   //      0b11111111 means 8 bytes (addr..addr+7)
  75   size_t encoded_size = ((1 << size) - 1) << 5;
  76
  77   // Return encoded hardware breakpoint control value.
  78   return m_hw_dbg_enable_bit | pac_bits | encoded_size;
  79 }
  80
  81 uint32_t
  82 NativeRegisterContextDBReg_arm64::MakeWatchControlValue(size_t size,
  83                                                         uint32_t watch_flags) {
  84   // PAC (bits 2:1): 0b10
  85   const uint32_t pac_bits = 2 << 1;
  86
  87   // BAS (bits 12:5) hold a bit-mask of addresses to watch
  88   // e.g. 0b00000001 means 1 byte at address
  89   //      0b00000011 means 2 bytes (addr..addr+1)
  90   //      ...
  91   //      0b11111111 means 8 bytes (addr..addr+7)
  92   size_t encoded_size = ((1 << size) - 1) << 5;
  93
  94   // Return encoded hardware watchpoint control value.
  95   return m_hw_dbg_enable_bit | pac_bits | encoded_size | (watch_flags << 3);
  96 }