From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
Add platform-specific interface to log information about the current
process.
On Windows, this interface is used to indicate whether the git process
is running under a debugger and list names of the process ancestors.
Information for other platforms is left for a future effort.
Signed-off-by: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
---
common-main.c | 1 +
compat/win32/trace2_win32_process_info.c | 101 +++++++++++++++++++++++
config.mak.uname | 2 +
trace2.h | 14 ++++
4 files changed, 118 insertions(+)
create mode 100644 compat/win32/trace2_win32_process_info.c
diff --git a/common-main.c b/common-main.c
index 6dbdc4adf2..d484aec209 100644
--- a/common-main.c
+++ b/common-main.c
@@ -37,6 +37,7 @@ int main(int argc, const char **argv)
trace2_initialize();
trace2_cmd_start(argv);
+ trace2_collect_process_info();
git_resolve_executable_dir(argv[0]);
diff --git a/compat/win32/trace2_win32_process_info.c b/compat/win32/trace2_win32_process_info.c
new file mode 100644
index 0000000000..253199f812
--- /dev/null
+++ b/compat/win32/trace2_win32_process_info.c
@@ -0,0 +1,101 @@
+#include "../../cache.h"
+#include "../../json-writer.h"
+#include <Psapi.h>
+#include <tlHelp32.h>
+
+/*
+ * Find the process data for the given PID in the given snapshot
+ * and update the PROCESSENTRY32 data.
+ */
+static int find_pid(DWORD pid, HANDLE hSnapshot, PROCESSENTRY32 *pe32)
+{
+ pe32->dwSize = sizeof(PROCESSENTRY32);
+
+ if (Process32First(hSnapshot, pe32)) {
+ do {
+ if (pe32->th32ProcessID == pid)
+ return 1;
+ } while (Process32Next(hSnapshot, pe32));
+ }
+ return 0;
+}
+
+/*
+ * Accumulate JSON array:
+ * [
+ * exe-name-parent,
+ * exe-name-grand-parent,
+ * ...
+ * ]
+ *
+ * Note: we only report the filename of the process executable; the
+ * only way to get its full pathname is to use OpenProcess()
+ * and GetModuleFileNameEx() or QueryfullProcessImageName()
+ * and that seems rather expensive (on top of the cost of
+ * getting the snapshot).
+ */
+static void get_processes(struct json_writer *jw, HANDLE hSnapshot)
+{
+ PROCESSENTRY32 pe32;
+ DWORD pid;
+
+ pid = GetCurrentProcessId();
+
+ /* We only want parent processes, so skip self. */
+ if (!find_pid(pid, hSnapshot, &pe32))
+ return;
+ pid = pe32.th32ParentProcessID;
+
+ while (find_pid(pid, hSnapshot, &pe32)) {
+ jw_array_string(jw, pe32.szExeFile);
+
+ pid = pe32.th32ParentProcessID;
+ }
+}
+
+/*
+ * Emit JSON data for the current and parent processes. Individual
+ * trace2 targets can decide how to actually print it.
+ */
+static void get_ancestry(void)
+{
+ HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
+
+ if (hSnapshot != INVALID_HANDLE_VALUE) {
+ struct json_writer jw = JSON_WRITER_INIT;
+
+ jw_array_begin(&jw, 0);
+ get_processes(&jw, hSnapshot);
+ jw_end(&jw);
+
+ trace2_data_json("process", the_repository, "windows/ancestry",
+ &jw);
+
+ jw_release(&jw);
+ CloseHandle(hSnapshot);
+ }
+}
+
+/*
+ * Is a debugger attached to the current process?
+ *
+ * This will catch debug runs (where the debugger started the process).
+ * This is the normal case. Since this code is called during our startup,
+ * it will not report instances where a debugger is attached dynamically
+ * to a running git process, but that is relatively rare.
+ */
+static void get_is_being_debugged(void)
+{
+ if (IsDebuggerPresent())
+ trace2_data_intmax("process", the_repository,
+ "windows/debugger_present", 1);
+}
+
+void trace2_collect_process_info(void)
+{
+ if (!trace2_is_enabled())
+ return;
+
+ get_is_being_debugged();
+ get_ancestry();
+}
diff --git a/config.mak.uname b/config.mak.uname
index 7b36a1dfe7..a3c03ce2ae 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -391,6 +391,7 @@ ifeq ($(uname_S),Windows)
BASIC_CFLAGS = -nologo -I. -I../zlib -Icompat/vcbuild -Icompat/vcbuild/include -DWIN32 -D_CONSOLE -DHAVE_STRING_H -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE
COMPAT_OBJS = compat/msvc.o compat/winansi.o \
compat/win32/pthread.o compat/win32/syslog.o \
+ compat/win32/trace2_win32_process_info.o \
compat/win32/dirent.o
COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -Icompat -Icompat/regex -Icompat/win32 -DSTRIP_EXTENSION=\".exe\"
BASIC_LDFLAGS = -IGNORE:4217 -IGNORE:4049 -NOLOGO -SUBSYSTEM:CONSOLE
@@ -545,6 +546,7 @@ ifneq (,$(findstring MINGW,$(uname_S)))
COMPAT_CFLAGS += -DNOGDI -Icompat -Icompat/win32
COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
COMPAT_OBJS += compat/mingw.o compat/winansi.o \
+ compat/win32/trace2_win32_process_info.o \
compat/win32/path-utils.o \
compat/win32/pthread.o compat/win32/syslog.o \
compat/win32/dirent.o
diff --git a/trace2.h b/trace2.h
index fce9891f53..ae5020d0e6 100644
--- a/trace2.h
+++ b/trace2.h
@@ -368,4 +368,18 @@ void trace2_printf(const char *fmt, ...);
/* clang-format on */
#endif
+/*
+ * Optional platform-specific code to dump information about the
+ * current and any parent process(es). This is intended to allow
+ * post-processors to know who spawned this git instance and anything
+ * else the platform may be able to tell us about the current process.
+ */
+#if defined(GIT_WINDOWS_NATIVE)
+void trace2_collect_process_info(void);
+#else
+#define trace2_collect_process_info() \
+ do { \
+ } while (0)
+#endif
+
#endif /* TRACE2_H */
--
gitgitgadget
