Add a new library for collecting stack traces.
Supports collecting the stack trace of the current thread,
another thread in the same process, or a thread in a
different process (using ptrace).
Change-Id: Ica2594e4436edde4ceb7bcc3d78e6c31a7902cbf
diff --git a/include/corkscrew/ptrace.h b/include/corkscrew/ptrace.h
new file mode 100644
index 0000000..6acf9eb
--- /dev/null
+++ b/include/corkscrew/ptrace.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* Useful ptrace() utility functions. */
+
+#ifndef _CORKSCREW_PTRACE_H
+#define _CORKSCREW_PTRACE_H
+
+#include <corkscrew/map_info.h>
+#include <corkscrew/symbol_table.h>
+
+#include <sys/types.h>
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Stores information about a process that is used for several different
+ * ptrace() based operations. */
+typedef struct {
+ map_info_t* map_info_list;
+} ptrace_context_t;
+
+#if __i386__
+/* ptrace() register context. */
+typedef struct pt_regs_x86 {
+ uint32_t ebx;
+ uint32_t ecx;
+ uint32_t edx;
+ uint32_t esi;
+ uint32_t edi;
+ uint32_t ebp;
+ uint32_t eax;
+ uint32_t xds;
+ uint32_t xes;
+ uint32_t xfs;
+ uint32_t xgs;
+ uint32_t orig_eax;
+ uint32_t eip;
+ uint32_t xcs;
+ uint32_t eflags;
+ uint32_t esp;
+ uint32_t xss;
+} pt_regs_x86_t;
+#endif
+
+/*
+ * Reads a word of memory safely.
+ * Uses ptrace() if tid >= 0, local memory otherwise.
+ * Returns false if the word could not be read.
+ */
+bool try_get_word(pid_t tid, uintptr_t ptr, uint32_t* out_value);
+
+/*
+ * Loads information needed for examining a remote process using ptrace().
+ * The caller must already have successfully attached to the process
+ * using ptrace().
+ *
+ * The context can be used for any threads belonging to that process
+ * assuming ptrace() is attached to them before performing the actual
+ * unwinding. The context can continue to be used to decode backtraces
+ * even after ptrace() has been detached from the process.
+ */
+ptrace_context_t* load_ptrace_context(pid_t pid);
+
+/*
+ * Frees a ptrace context.
+ */
+void free_ptrace_context(ptrace_context_t* context);
+
+/*
+ * Finds a symbol using ptrace.
+ * Returns the containing map and information about the symbol, or
+ * NULL if one or the other is not available.
+ */
+void find_symbol_ptrace(const ptrace_context_t* context,
+ uintptr_t addr, const map_info_t** out_map_info, const symbol_t** out_symbol);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _CORKSCREW_PTRACE_H