diff options
5 files changed, 136 insertions, 7 deletions
diff --git a/lldb/include/lldb/Host/common/NativeProcessProtocol.h b/lldb/include/lldb/Host/common/NativeProcessProtocol.h index b574e57f80c..77bcf788bbd 100644 --- a/lldb/include/lldb/Host/common/NativeProcessProtocol.h +++ b/lldb/include/lldb/Host/common/NativeProcessProtocol.h @@ -84,6 +84,31 @@ public: Status ReadMemoryWithoutTrap(lldb::addr_t addr, void *buf, size_t size, size_t &bytes_read); + /// Reads a null terminated string from memory. + /// + /// Reads up to \p max_size bytes of memory until it finds a '\0'. + /// If a '\0' is not found then it reads max_size-1 bytes as a string and a + /// '\0' is added as the last character of the \p buffer. + /// + /// \param[in] addr + /// The address in memory to read from. + /// + /// \param[in] buffer + /// An allocated buffer with at least \p max_size size. + /// + /// \param[in] max_size + /// The maximum number of bytes to read from memory until it reads the + /// string. + /// + /// \param[out] total_bytes_read + /// The number of bytes read from memory into \p buffer. + /// + /// \return + /// Returns a StringRef backed up by the \p buffer passed in. + llvm::Expected<llvm::StringRef> + ReadCStringFromMemory(lldb::addr_t addr, char *buffer, size_t max_size, + size_t &total_bytes_read); + virtual Status WriteMemory(lldb::addr_t addr, const void *buf, size_t size, size_t &bytes_written) = 0; diff --git a/lldb/source/Host/common/NativeProcessProtocol.cpp b/lldb/source/Host/common/NativeProcessProtocol.cpp index 90272cb8d0b..476ab97a490 100644 --- a/lldb/source/Host/common/NativeProcessProtocol.cpp +++ b/lldb/source/Host/common/NativeProcessProtocol.cpp @@ -16,6 +16,8 @@ #include "lldb/Utility/State.h" #include "lldb/lldb-enumerations.h" +#include "llvm/Support/Process.h" + using namespace lldb; using namespace lldb_private; @@ -659,6 +661,58 @@ Status NativeProcessProtocol::ReadMemoryWithoutTrap(lldb::addr_t addr, return Status(); } +llvm::Expected<llvm::StringRef> +NativeProcessProtocol::ReadCStringFromMemory(lldb::addr_t addr, char *buffer, + size_t max_size, + size_t &total_bytes_read) { + static const size_t cache_line_size = + llvm::sys::Process::getPageSizeEstimate(); + size_t bytes_read = 0; + size_t bytes_left = max_size; + addr_t curr_addr = addr; + size_t string_size; + char *curr_buffer = buffer; + total_bytes_read = 0; + Status status; + + while (bytes_left > 0 && status.Success()) { + addr_t cache_line_bytes_left = + cache_line_size - (curr_addr % cache_line_size); + addr_t bytes_to_read = std::min<addr_t>(bytes_left, cache_line_bytes_left); + status = ReadMemory(curr_addr, reinterpret_cast<void *>(curr_buffer), + bytes_to_read, bytes_read); + + if (bytes_read == 0) + break; + + void *str_end = std::memchr(curr_buffer, '\0', bytes_read); + if (str_end != nullptr) { + total_bytes_read = + (size_t)(reinterpret_cast<char *>(str_end) - buffer + 1); + status.Clear(); + break; + } + + total_bytes_read += bytes_read; + curr_buffer += bytes_read; + curr_addr += bytes_read; + bytes_left -= bytes_read; + } + + string_size = total_bytes_read - 1; + + // Make sure we return a null terminated string. + if (bytes_left == 0 && max_size > 0 && buffer[max_size - 1] != '\0') { + buffer[max_size - 1] = '\0'; + total_bytes_read--; + } + + if (!status.Success()) + return status.ToError(); + + return llvm::StringRef(buffer, string_size); +} + lldb::StateType NativeProcessProtocol::GetState() const { std::lock_guard<std::recursive_mutex> guard(m_state_mutex); return m_state; diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp index b40b70104ea..7637237aa16 100644 --- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp +++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp @@ -2076,4 +2076,4 @@ Status NativeProcessLinux::StopProcessorTracingOnThread(lldb::user_id_t traceid, m_processor_trace_monitor.erase(iter); return error; -}
\ No newline at end of file +} diff --git a/lldb/source/Plugins/Process/POSIX/NativeProcessELF.cpp b/lldb/source/Plugins/Process/POSIX/NativeProcessELF.cpp index 50b2d05df3e..6470eca7746 100644 --- a/lldb/source/Plugins/Process/POSIX/NativeProcessELF.cpp +++ b/lldb/source/Plugins/Process/POSIX/NativeProcessELF.cpp @@ -118,14 +118,13 @@ NativeProcessELF::ReadSVR4LibraryInfo(lldb::addr_t link_map_addr) { return error.ToError(); char name_buffer[PATH_MAX]; - error = ReadMemory(link_map.l_name, &name_buffer, sizeof(name_buffer), - bytes_read); - if (bytes_read == 0) - return error.ToError(); - name_buffer[PATH_MAX - 1] = '\0'; + llvm::Expected<llvm::StringRef> string_or_error = ReadCStringFromMemory( + link_map.l_name, &name_buffer[0], sizeof(name_buffer), bytes_read); + if (!string_or_error) + return string_or_error.takeError(); SVR4LibraryInfo info; - info.name = std::string(name_buffer); + info.name = string_or_error->str(); info.link_map = link_map_addr; info.base_addr = link_map.l_addr; info.ld_addr = link_map.l_ld; diff --git a/lldb/unittests/Host/NativeProcessProtocolTest.cpp b/lldb/unittests/Host/NativeProcessProtocolTest.cpp index bf61951be60..c5516b1b1d3 100644 --- a/lldb/unittests/Host/NativeProcessProtocolTest.cpp +++ b/lldb/unittests/Host/NativeProcessProtocolTest.cpp @@ -9,6 +9,7 @@ #include "TestingSupport/Host/NativeProcessTestUtils.h" #include "lldb/Host/common/NativeProcessProtocol.h" +#include "llvm/Support/Process.h" #include "llvm/Testing/Support/Error.h" #include "gmock/gmock.h" @@ -96,3 +97,53 @@ TEST(NativeProcessProtocolTest, ReadMemoryWithoutTrap) { EXPECT_THAT_EXPECTED(Process.ReadMemoryWithoutTrap(4, 2), llvm::HasValue(std::vector<uint8_t>{4, 5})); } + +TEST(NativeProcessProtocolTest, ReadCStringFromMemory) { + NiceMock<MockDelegate> DummyDelegate; + MockProcess<NativeProcessProtocol> Process(DummyDelegate, + ArchSpec("aarch64-pc-linux")); + FakeMemory M({'h', 'e', 'l', 'l', 'o', 0, 'w', 'o'}); + EXPECT_CALL(Process, ReadMemory(_, _)) + .WillRepeatedly(Invoke(&M, &FakeMemory::Read)); + + char string[1024]; + size_t bytes_read; + EXPECT_THAT_EXPECTED(Process.ReadCStringFromMemory( + 0x0, &string[0], sizeof(string), bytes_read), + llvm::HasValue(llvm::StringRef("hello"))); + EXPECT_EQ(bytes_read, 6UL); +} + +TEST(NativeProcessProtocolTest, ReadCStringFromMemory_MaxSize) { + NiceMock<MockDelegate> DummyDelegate; + MockProcess<NativeProcessProtocol> Process(DummyDelegate, + ArchSpec("aarch64-pc-linux")); + FakeMemory M({'h', 'e', 'l', 'l', 'o', 0, 'w', 'o'}); + EXPECT_CALL(Process, ReadMemory(_, _)) + .WillRepeatedly(Invoke(&M, &FakeMemory::Read)); + + char string[4]; + size_t bytes_read; + EXPECT_THAT_EXPECTED(Process.ReadCStringFromMemory( + 0x0, &string[0], sizeof(string), bytes_read), + llvm::HasValue(llvm::StringRef("hel"))); + EXPECT_EQ(bytes_read, 3UL); +} + +TEST(NativeProcessProtocolTest, ReadCStringFromMemory_CrossPageBoundary) { + NiceMock<MockDelegate> DummyDelegate; + MockProcess<NativeProcessProtocol> Process(DummyDelegate, + ArchSpec("aarch64-pc-linux")); + unsigned string_start = llvm::sys::Process::getPageSizeEstimate() - 3; + FakeMemory M({'h', 'e', 'l', 'l', 'o', 0, 'w', 'o'}, string_start); + EXPECT_CALL(Process, ReadMemory(_, _)) + .WillRepeatedly(Invoke(&M, &FakeMemory::Read)); + + char string[1024]; + size_t bytes_read; + EXPECT_THAT_EXPECTED(Process.ReadCStringFromMemory(string_start, &string[0], + sizeof(string), + bytes_read), + llvm::HasValue(llvm::StringRef("hello"))); + EXPECT_EQ(bytes_read, 6UL); +}
\ No newline at end of file |
