Refactor syscall logging

 * Syscall logging has its own translation unit(s).
 * The syscall argument formats are stored in a table, which
makes them easier to maintain.
 * Removed some libc usages, just to make sure syscall_intercept
is not surprised by something unexpected going on in sprintf calls
(such as libc opening a file to read locales, other tracing, or whatnot).
 * Interpreting error codes returned by syscalls.

CMakeLists.txt

@@ -69,9 +69,11 @@ set(SOURCES_C
 	src/disasm_wrapper.c
 	src/intercept.c
 	src/intercept_desc.c
+	src/intercept_log.c
 	src/intercept_util.c
 	src/patcher.c
-	src/magic_syscalls.c)
+	src/magic_syscalls.c
+	src/syscall_formats.c)
 
 set(SOURCES_ASM
 	src/intercept_template.s

src/intercept.c

@@ -54,6 +54,7 @@
 #include <sys/auxv.h>
 
 #include "intercept.h"
+#include "intercept_log.h"
 #include "intercept_util.h"
 #include "libsyscall_intercept_hook_point.h"
 #include "disasm_wrapper.h"