*
* Copyright 2009 VMware, Inc.
* All Rights Reserved.
- *
+ *
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
- *
+ *
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
- *
+ *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- *
+ *
**************************************************************************/
/**
* @file
* Stack backtracing.
- *
+ *
* @author Jose Fonseca <jfonseca@vmware.com>
*/
#include "u_debug_symbol.h"
#include "u_debug_stack.h"
+#if defined(HAVE_LIBUNWIND)
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <dlfcn.h>
+
+#include "os/os_thread.h"
+#include "u_hash_table.h"
+
+struct util_hash_table* symbols_hash;
+static mtx_t symbols_mutex = _MTX_INITIALIZER_NP;
+
+static unsigned hash_ptr(void* p)
+{
+ return (unsigned)(uintptr_t)p;
+}
+
+static int compare_ptr(void* a, void* b)
+{
+ if(a == b)
+ return 0;
+ else if(a < b)
+ return -1;
+ else
+ return 1;
+}
+
+/* TODO with some refactoring we might be able to re-use debug_symbol_name_cached()
+ * instead.. otoh if using libunwind I think u_debug_symbol could just be excluded
+ * from build?
+ */
+static const char *
+symbol_name_cached(unw_cursor_t *cursor, unw_proc_info_t *pip)
+{
+ void *addr = (void *)(uintptr_t)pip->start_ip;
+ char *name;
+
+ mtx_lock(&symbols_mutex);
+ if(!symbols_hash)
+ symbols_hash = util_hash_table_create(hash_ptr, compare_ptr);
+ name = util_hash_table_get(symbols_hash, addr);
+ if(!name)
+ {
+ char procname[256];
+ unw_word_t off;
+ int ret;
+
+ ret = unw_get_proc_name(cursor, procname, sizeof(procname), &off);
+ if (ret && ret != -UNW_ENOMEM) {
+ procname[0] = '?';
+ procname[1] = 0;
+ }
+
+ asprintf(&name, "%s%s", procname, ret == -UNW_ENOMEM ? "..." : "");
+
+ util_hash_table_set(symbols_hash, addr, (void*)name);
+ }
+ mtx_unlock(&symbols_mutex);
+
+ return name;
+}
void
debug_backtrace_capture(struct debug_stack_frame *backtrace,
- unsigned start_frame,
+ unsigned start_frame,
+ unsigned nr_frames)
+{
+ unw_cursor_t cursor;
+ unw_context_t context;
+ unw_proc_info_t pip;
+ unsigned i = 0;
+
+ pip.unwind_info = NULL;
+
+ unw_getcontext(&context);
+ unw_init_local(&cursor, &context);
+
+ while ((start_frame > 0) && (unw_step(&cursor) > 0))
+ start_frame--;
+
+ while ((i < nr_frames) && (unw_step(&cursor) > 0)) {
+ unw_word_t ip;
+
+ unw_get_reg(&cursor, UNW_REG_IP, &ip);
+ unw_get_proc_info(&cursor, &pip);
+
+ backtrace[i].start_ip = pip.start_ip;
+ backtrace[i].off = ip - pip.start_ip;
+ backtrace[i].procname = symbol_name_cached(&cursor, &pip);
+
+ i++;
+ }
+
+ while (i < nr_frames) {
+ backtrace[i].start_ip = 0;
+ i++;
+ }
+}
+
+static const void *
+frame_ip(const struct debug_stack_frame *frame)
+{
+ return (void *)(uintptr_t)(frame->start_ip + frame->off);
+}
+
+static const char *
+frame_info(const struct debug_stack_frame *frame, unsigned *offset)
+{
+ Dl_info dlinfo;
+ const void *addr = frame_ip(frame);
+
+
+ if (dladdr(addr, &dlinfo) && dlinfo.dli_fname &&
+ *dlinfo.dli_fname) {
+ *offset = (unsigned)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase);
+ return dlinfo.dli_fname;
+ }
+
+ *offset = 0;
+ return "?";
+}
+
+void
+debug_backtrace_dump(const struct debug_stack_frame *backtrace,
+ unsigned nr_frames)
+{
+ unsigned i, offset;
+ const char *filename;
+
+ for (i = 0; i < nr_frames; ++i) {
+ if (!backtrace[i].start_ip)
+ break;
+ filename = frame_info(&backtrace[i], &offset);
+ debug_printf("\t%s(+0x%x) (%s+0x%x) [%p]\n", filename, offset,
+ backtrace[i].procname, backtrace[i].off,
+ frame_ip(&backtrace[i]));
+ }
+}
+
+void
+debug_backtrace_print(FILE *f,
+ const struct debug_stack_frame *backtrace,
+ unsigned nr_frames)
+{
+ unsigned i, offset;
+ const char *filename;
+
+ for (i = 0; i < nr_frames; ++i) {
+ if (!backtrace[i].start_ip)
+ break;
+ filename = frame_info(&backtrace[i], &offset);
+ fprintf(f, "\t%s(+0x%x) (%s+0x%x) [%p]\n", filename, offset,
+ backtrace[i].procname, backtrace[i].off,
+ frame_ip(&backtrace[i]));
+ }
+}
+
+#else /* ! HAVE_LIBUNWIND */
+
+#if defined(PIPE_OS_WINDOWS)
+#include <windows.h>
+#endif
+
+
+/**
+ * Capture stack backtrace.
+ *
+ * NOTE: The implementation of this function is quite big, but it is important
+ * not to break it down in smaller functions to avoid adding new frames to the
+ * calling stack.
+ */
+void
+debug_backtrace_capture(struct debug_stack_frame *backtrace,
+ unsigned start_frame,
unsigned nr_frames)
{
const void **frame_pointer = NULL;
unsigned i = 0;
- if(!nr_frames)
+ if (!nr_frames) {
return;
+ }
+
+ /*
+ * On Windows try obtaining the stack backtrace via CaptureStackBackTrace.
+ *
+ * It works reliably both for x86 for x86_64.
+ */
+#if defined(PIPE_OS_WINDOWS)
+ {
+ typedef USHORT (WINAPI *PFNCAPTURESTACKBACKTRACE)(ULONG, ULONG,
+ PVOID *, PULONG);
+ static PFNCAPTURESTACKBACKTRACE pfnCaptureStackBackTrace = NULL;
+
+ if (!pfnCaptureStackBackTrace) {
+ static HMODULE hModule = NULL;
+ if (!hModule) {
+ hModule = LoadLibraryA("kernel32");
+ assert(hModule);
+ }
+ if (hModule) {
+ pfnCaptureStackBackTrace =
+ (PFNCAPTURESTACKBACKTRACE)GetProcAddress(hModule,
+ "RtlCaptureStackBackTrace");
+ }
+ }
+ if (pfnCaptureStackBackTrace) {
+ /*
+ * Skip this (debug_backtrace_capture) function's frame.
+ */
+
+ start_frame += 1;
+
+ assert(start_frame + nr_frames < 63);
+ i = pfnCaptureStackBackTrace(start_frame, nr_frames,
+ (PVOID *) &backtrace->function, NULL);
+
+ /* Pad remaing requested frames with NULL */
+ while (i < nr_frames) {
+ backtrace[i++].function = NULL;
+ }
+
+ return;
+ }
+ }
+#endif
#if defined(PIPE_CC_GCC)
frame_pointer = ((const void **)__builtin_frame_address(1));
#else
frame_pointer = NULL;
#endif
-
-
+
#ifdef PIPE_ARCH_X86
- while(nr_frames) {
- if(!frame_pointer)
+ while (nr_frames) {
+ const void **next_frame_pointer;
+
+ if (!frame_pointer)
break;
-
- if(start_frame)
+
+ if (start_frame)
--start_frame;
else {
backtrace[i++].function = frame_pointer[1];
--nr_frames;
}
-
- frame_pointer = (const void **)frame_pointer[0];
+
+ next_frame_pointer = (const void **)frame_pointer[0];
+
+ /* Limit the stack walk to avoid referencing undefined memory */
+ if ((uintptr_t)next_frame_pointer <= (uintptr_t)frame_pointer ||
+ (uintptr_t)next_frame_pointer > (uintptr_t)frame_pointer + 64*1024)
+ break;
+
+ frame_pointer = next_frame_pointer;
}
+#else
+ (void) frame_pointer;
#endif
-
- while(nr_frames) {
+
+ while (nr_frames) {
backtrace[i++].function = NULL;
--nr_frames;
}
}
-
+
void
-debug_backtrace_dump(const struct debug_stack_frame *backtrace,
+debug_backtrace_dump(const struct debug_stack_frame *backtrace,
unsigned nr_frames)
{
unsigned i;
-
- for(i = 0; i < nr_frames; ++i) {
- if(!backtrace[i].function)
+
+ for (i = 0; i < nr_frames; ++i) {
+ if (!backtrace[i].function)
break;
debug_symbol_print(backtrace[i].function);
}
}
+
+void
+debug_backtrace_print(FILE *f,
+ const struct debug_stack_frame *backtrace,
+ unsigned nr_frames)
+{
+ unsigned i;
+
+ for (i = 0; i < nr_frames; ++i) {
+ const char *symbol;
+ if (!backtrace[i].function)
+ break;
+ symbol = debug_symbol_name_cached(backtrace[i].function);
+ if (symbol)
+ fprintf(f, "%s\n", symbol);
+ }
+}
+
+#endif /* HAVE_LIBUNWIND */