implemented core functionality required to work on issue #484

eteran · May 24, 2017 · b211a8d · b211a8d
1 parent 2f1388e
commit b211a8d
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Showing 3 changed files with 34 additions and 4 deletions.
diff --git a/include/IProcess.h b/include/IProcess.h
@@ -55,6 +55,7 @@ class IProcess {
 	virtual QList<std::shared_ptr<IThread>> threads() const = 0;
 	virtual std::shared_ptr<IThread>        current_thread() const = 0;
 	virtual std::size_t                     write_bytes(edb::address_t address, const void *buf, size_t len) = 0;
+	virtual std::size_t                     patch_bytes(edb::address_t address, const void *buf, size_t len) = 0;
 	virtual std::size_t                     read_bytes(edb::address_t address, void *buf, size_t len) const = 0;
 	virtual std::size_t                     read_pages(edb::address_t address, void *buf, size_t count) const = 0;
 	virtual void                            pause() = 0;

diff --git a/plugins/DebuggerCore/unix/linux/PlatformProcess.cpp b/plugins/DebuggerCore/unix/linux/PlatformProcess.cpp
@@ -317,6 +317,33 @@ std::size_t PlatformProcess::read_bytes(edb::address_t address, void* buf, std::
 	return read;
 }
 
+//------------------------------------------------------------------------------
+// Name: patch_bytes
+// Desc: same as write_bytes, except that it also records the original data
+//       that was found at the address being written to.
+// Note: unlike the read_bytes, write_bytes functions, this will not apply the
+//       write if we could not properly backup <len> bytes as requested.
+// Note: on the off chance that we can READ <len> bytes, but can't WRITE <len>
+//       bytes, we will return the number of bytes written, but record <len>
+//       bytes of patch data.
+//------------------------------------------------------------------------------
+std::size_t PlatformProcess::patch_bytes(edb::address_t address, const void *buf, size_t len) {
+	Q_ASSERT(buf);
+	Q_ASSERT(core_->process_ == this);
+
+	QByteArray orig_bytes;
+	orig_bytes.resize(len);
+
+	size_t read_ret = read_bytes(address, orig_bytes.data(), len);
+	if(read_ret != len) {
+		return 0;
+	}
+
+	patches_.insert(address, orig_bytes);
+
+	return write_bytes(address, buf, len);
+}
+
 //------------------------------------------------------------------------------
 // Name: write_bytes
 // Desc: writes <len> bytes from <buf> starting at <address>

diff --git a/plugins/DebuggerCore/unix/linux/PlatformProcess.h b/plugins/DebuggerCore/unix/linux/PlatformProcess.h
@@ -63,6 +63,7 @@ class PlatformProcess : public IProcess {
 
 public:
 	virtual std::size_t write_bytes(edb::address_t address, const void *buf, size_t len) override;
+	virtual std::size_t patch_bytes(edb::address_t address, const void *buf, size_t len) override;
 	virtual std::size_t read_bytes(edb::address_t address, void *buf, size_t len) const override;
 	virtual std::size_t read_pages(edb::address_t address, void *buf, size_t count) const override;
 
@@ -73,10 +74,11 @@ class PlatformProcess : public IProcess {
 	void write_byte_via_ptrace(edb::address_t address, quint8 value, bool *ok);
 
 private:
-	DebuggerCore* core_;
-	edb::pid_t    pid_;
-	QFile*        ro_mem_file_;
-	QFile*        rw_mem_file_;
+	DebuggerCore*                    core_;
+	edb::pid_t                       pid_;
+	QFile*                           ro_mem_file_;
+	QFile*                           rw_mem_file_;
+	QMap<edb::address_t, QByteArray> patches_;
 };
 
 }