Make LD_DEBUG more user-friendly.
This is more self-explanatory than arbitrary integers, actually does
explain itself if you typo or say LD_DEBUG=help, and makes statistics
and timing available without recompilation.
Some of the groups could probably use a little tweaking, and we could
probably use some more groups, but I think this is already better than
what we have, and the initial change moving LD_DEBUG from integers to
names should probably minimize the amount of change that regard.
There's also the continuing question of whether statistics and timing
should just be deleted. They're not super useful as-is, and we should
think about whether we want to make them more useful or just remove them.
The timing stuff in particular is probably questionable, because
systrace is probably a better way to do anything like that? But that too
sounds like a question for another day.
Bug: http://b/309528372
Test: adb shell LD_DEBUG=<various things> date
Change-Id: I52b96c4892a41f9d24873122aebe5c272f39cdae
diff --git a/linker/linker_debug.cpp b/linker/linker_debug.cpp
index e6211f7..430a151 100644
--- a/linker/linker_debug.cpp
+++ b/linker/linker_debug.cpp
@@ -30,19 +30,76 @@
#include <unistd.h>
-void linker_log_va_list(int prio, const char* fmt, va_list ap) {
+#include <android-base/strings.h>
+
+LinkerDebugConfig g_linker_debug_config;
+
+void init_LD_DEBUG(const std::string& value) {
+ if (value.empty()) return;
+ std::vector<std::string> options = android::base::Split(value, ",");
+ for (const auto& o : options) {
+ if (o == "calls") g_linker_debug_config.calls = true;
+ else if (o == "cfi") g_linker_debug_config.cfi = true;
+ else if (o == "dynamic") g_linker_debug_config.dynamic = true;
+ else if (o == "lookup") g_linker_debug_config.lookup = true;
+ else if (o == "props") g_linker_debug_config.props = true;
+ else if (o == "reloc") g_linker_debug_config.reloc = true;
+ else if (o == "statistics") g_linker_debug_config.statistics = true;
+ else if (o == "timing") g_linker_debug_config.timing = true;
+ else if (o == "all") {
+ g_linker_debug_config.calls = true;
+ g_linker_debug_config.cfi = true;
+ g_linker_debug_config.dynamic = true;
+ g_linker_debug_config.lookup = true;
+ g_linker_debug_config.props = true;
+ g_linker_debug_config.reloc = true;
+ g_linker_debug_config.statistics = true;
+ g_linker_debug_config.timing = true;
+ } else {
+ __linker_error("$LD_DEBUG is a comma-separated list of:\n"
+ "\n"
+ " calls ctors/dtors/ifuncs\n"
+ " cfi control flow integrity messages\n"
+ " dynamic dynamic section processing\n"
+ " lookup symbol lookup\n"
+ " props ELF property processing\n"
+ " reloc relocation resolution\n"
+ " statistics relocation statistics\n"
+ " timing timing information\n"
+ "\n"
+ "or 'all' for all of the above.\n");
+ }
+ }
+ if (g_linker_debug_config.calls || g_linker_debug_config.cfi ||
+ g_linker_debug_config.dynamic || g_linker_debug_config.lookup ||
+ g_linker_debug_config.props || g_linker_debug_config.reloc ||
+ g_linker_debug_config.statistics || g_linker_debug_config.timing) {
+ g_linker_debug_config.any = true;
+ }
+}
+
+static void linker_log_va_list(int prio, const char* fmt, va_list ap) {
va_list ap2;
va_copy(ap2, ap);
- async_safe_format_log_va_list(5 - prio, "linker", fmt, ap2);
+ async_safe_format_log_va_list(prio, "linker", fmt, ap2);
va_end(ap2);
async_safe_format_fd_va_list(STDERR_FILENO, fmt, ap);
write(STDERR_FILENO, "\n", 1);
}
-void linker_log(int prio, const char* fmt, ...) {
+void __linker_log(int prio, const char* fmt, ...) {
va_list ap;
va_start(ap, fmt);
linker_log_va_list(prio, fmt, ap);
va_end(ap);
}
+
+void __linker_error(const char* fmt, ...) {
+ va_list ap;
+ va_start(ap, fmt);
+ linker_log_va_list(ANDROID_LOG_FATAL, fmt, ap);
+ va_end(ap);
+
+ _exit(EXIT_FAILURE);
+}