diff --git a/arch/arm64/kernel/cpu.c b/arch/arm64/kernel/cpu.c
index ba1600b2..ded67e8c 100644
--- a/arch/arm64/kernel/cpu.c
+++ b/arch/arm64/kernel/cpu.c
@@ -30,6 +30,7 @@
 #include <debug-monitors.h>
 #include <sysreg.h>
 #include <cpufeature.h>
+#include <debug.h>
 #ifdef POSTK_DEBUG_ARCH_DEP_65
 #include <hwcap.h>
 #endif /* POSTK_DEBUG_ARCH_DEP_65 */
@@ -39,11 +40,8 @@
 #include "postk_print_sysreg.c"
 
 #ifdef DEBUG_PRINT_CPU
-#define dkprintf kprintf
-#define ekprintf kprintf
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf kprintf
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #define BUG_ON(condition) do { if (condition) { kprintf("PANIC: %s: %s(line:%d)\n",\
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index a32e7d78..5f6c9c69 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -9,15 +9,13 @@
 #include <prctl.h>
 #include <cpufeature.h>
 #include <kmalloc.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_FPSIMD
 
 #ifdef DEBUG_PRINT_FPSIMD
-#define dkprintf kprintf
-#define ekprintf kprintf
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf kprintf
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #define BUG_ON(condition) do { if (condition) { kprintf("PANIC: %s: %s(line:%d)\n",\
diff --git a/arch/arm64/kernel/gencore.c b/arch/arm64/kernel/gencore.c
index 77e33a53..ec621e49 100644
--- a/arch/arm64/kernel/gencore.c
+++ b/arch/arm64/kernel/gencore.c
@@ -7,6 +7,7 @@
 #include <process.h>
 #include <string.h>
 #include <elfcore.h>
+#include <debug.h>
 
 #define	align32(x) ((((x) + 3) / 4) * 4)
 #define	alignpage(x) ((((x) + (PAGE_SIZE) - 1) / (PAGE_SIZE)) * (PAGE_SIZE))
@@ -14,11 +15,8 @@
 //#define DEBUG_PRINT_GENCORE
 
 #ifdef DEBUG_PRINT_GENCORE
-#define	dkprintf(...)	kprintf(__VA_ARGS__)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 /*
diff --git a/arch/arm64/kernel/irq-gic-v2.c b/arch/arm64/kernel/irq-gic-v2.c
index d29b45ca..995b3bb4 100644
--- a/arch/arm64/kernel/irq-gic-v2.c
+++ b/arch/arm64/kernel/irq-gic-v2.c
@@ -7,15 +7,13 @@
 #include <arch/cpu.h>
 #include <memory.h>
 #include <syscall.h>
+#include <debug.h>
 
 // #define DEBUG_GICV2
 
 #ifdef DEBUG_GICV2
-#define	dkprintf(...)	kprintf(__VA_ARGS__)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 void *dist_base;
diff --git a/arch/arm64/kernel/irq-gic-v3.c b/arch/arm64/kernel/irq-gic-v3.c
index 6550eee8..99a352bc 100644
--- a/arch/arm64/kernel/irq-gic-v3.c
+++ b/arch/arm64/kernel/irq-gic-v3.c
@@ -7,17 +7,15 @@
 #include <cputype.h>
 #include <process.h>
 #include <syscall.h>
+#include <debug.h>
 
 //#define DEBUG_GICV3
 
 #define USE_CAVIUM_THUNDER_X
 
 #ifdef DEBUG_GICV3
-#define	dkprintf(...)	kprintf(__VA_ARGS__)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #ifdef USE_CAVIUM_THUNDER_X
diff --git a/arch/arm64/kernel/memory.c b/arch/arm64/kernel/memory.c
index cee0ceea..7c6c9c02 100644
--- a/arch/arm64/kernel/memory.c
+++ b/arch/arm64/kernel/memory.c
@@ -14,9 +14,7 @@
 #include <context.h>
 #include <kmalloc.h>
 #include <vdso.h>
-
-#define	dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#include <debug.h>
 
 #define NOT_IMPLEMENTED()  do { kprintf("%s is not implemented\n", __func__); while(1);} while(0)
 
diff --git a/arch/arm64/kernel/perfctr_armv8pmu.c b/arch/arm64/kernel/perfctr_armv8pmu.c
index 2aea7343..87f919e7 100644
--- a/arch/arm64/kernel/perfctr_armv8pmu.c
+++ b/arch/arm64/kernel/perfctr_armv8pmu.c
@@ -4,16 +4,14 @@
 #include <ihk/perfctr.h>
 #include <errno.h>
 #include <ihk/debug.h>
+#include <debug.h>
 
 #define BIT(nr) (1UL << (nr))
 
 //#define DEBUG_PRINT_PMU
 #ifdef DEBUG_PRINT_PMU
-#define	dkprintf(...) kprintf(__VA_ARGS__)
-#define	ekprintf(...) kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...) kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index db092998..b264fdb2 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -21,15 +21,13 @@
 #include <ihk/debug.h>
 #include <compiler.h>
 #include <lwk/compiler.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_PSCI
 
 #ifdef DEBUG_PRINT_PSCI
-#define dkprintf(...) kprintf(__VA_ARGS__)
-#define ekprintf(...) kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #define PSCI_POWER_STATE_TYPE_POWER_DOWN	1
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 1795eb5f..f6572a0e 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -11,15 +11,13 @@
 #include <hwcap.h>
 #include <string.h>
 #include <thread_info.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_SC
 
 #ifdef DEBUG_PRINT_SC
-#define dkprintf kprintf
-#define ekprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #define NOT_IMPLEMENTED()  do { kprintf("%s is not implemented\n", __func__); while(1);} while(0)
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index b325e15a..8e4a362f 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -14,6 +14,7 @@
 #include <prctl.h>
 #include <limits.h>
 #include <syscall.h>
+#include <debug.h>
 
 extern void ptrace_report_signal(struct thread *thread, int sig);
 extern void clear_single_step(struct thread *thread);
@@ -27,11 +28,8 @@ static void __check_signal(unsigned long rc, void *regs, int num, int irq_disabl
 //#define DEBUG_PRINT_SC
 
 #ifdef DEBUG_PRINT_SC
-#define dkprintf kprintf
-#define ekprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #define NOT_IMPLEMENTED()  do { kprintf("%s is not implemented\n", __func__); while(1);} while(0)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 92b12949..bc2329e8 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -14,15 +14,13 @@
 #include <ihk/debug.h>
 #include <ikc/queue.h>
 #include <vdso.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_VDSO
 
 #ifdef DEBUG_PRINT_VDSO
-#define	dkprintf(...)	kprintf(__VA_ARGS__)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #ifdef POSTK_DEBUG_ARCH_DEP_52
diff --git a/arch/x86_64/elfboot/raw.lds b/arch/x86_64/elfboot/raw.lds
index 798395a0..fa026190 100644
--- a/arch/x86_64/elfboot/raw.lds
+++ b/arch/x86_64/elfboot/raw.lds
@@ -9,29 +9,29 @@ PHDRS
 SECTIONS
 {
 	. = SIZEOF_HEADERS;
-    . = ALIGN(4096);
+	. = ALIGN(4096);
 	.text :	{
-	      *(.text)
+		*(.text)
 	} :text
 	.data : {
-	      *(.data)
-	      *(.data.*)
+		*(.data)
+		*(.data.*)
 	} :data
 	.rodata : {
-	      *(.rodata .rodata.*)
+		*(.rodata .rodata.*)
 	} :data
 
 	. = ALIGN(8);
 	.bss : {
-	     _bss_start = .;
-	     *(.bss .bss.*)
-	     _bss_end = .;
-         . = ALIGN(4096);
-         _stack_end = .;
-    } :data
+		_bss_start = .;
+		*(.bss .bss.*)
+		_bss_end = .;
+		. = ALIGN(4096);
+		_stack_end = .;
+	} :data
 
 	/DISCARD/ : {
-	     *(.eh_frame)
-         *(.note.gnu.build-id)
+		*(.eh_frame)
+		*(.note.gnu.build-id)
 	}
-}
\ No newline at end of file
+}
diff --git a/arch/x86_64/kernel/cpu.c b/arch/x86_64/kernel/cpu.c
index f7464d6e..91c93a61 100644
--- a/arch/x86_64/kernel/cpu.c
+++ b/arch/x86_64/kernel/cpu.c
@@ -31,6 +31,7 @@
 #include <prctl.h>
 #include <page.h>
 #include <kmalloc.h>
+#include <debug.h>
 
 #define LAPIC_ID            0x020
 #define LAPIC_TIMER         0x320
@@ -69,11 +70,8 @@
 //#define DEBUG_PRINT_CPU
 
 #ifdef DEBUG_PRINT_CPU
-#define dkprintf kprintf
-#define ekprintf kprintf
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf kprintf
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 static void *lapic_vp;
diff --git a/arch/x86_64/kernel/gencore.c b/arch/x86_64/kernel/gencore.c
index 7ad03f06..100f857b 100644
--- a/arch/x86_64/kernel/gencore.c
+++ b/arch/x86_64/kernel/gencore.c
@@ -6,6 +6,7 @@
 #include <process.h>
 #include <string.h>
 #include <elfcore.h>
+#include <debug.h>
 
 #define	align32(x) ((((x) + 3) / 4) * 4)
 #define	alignpage(x) ((((x) + (PAGE_SIZE) - 1) / (PAGE_SIZE)) * (PAGE_SIZE))
@@ -13,11 +14,8 @@
 //#define DEBUG_PRINT_GENCORE
 
 #ifdef DEBUG_PRINT_GENCORE
-#define	dkprintf(...)	kprintf(__VA_ARGS__)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 /*
diff --git a/arch/x86_64/kernel/memory.c b/arch/x86_64/kernel/memory.c
index a25c3b1f..2c454511 100644
--- a/arch/x86_64/kernel/memory.c
+++ b/arch/x86_64/kernel/memory.c
@@ -25,15 +25,13 @@
 #include <cls.h>
 #include <kmalloc.h>
 #include <rusage_private.h>
+#include <debug.h>
 
 //#define DEBUG
 
 #ifdef DEBUG
-#define	dkprintf(...)	do { kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	do { kprintf(__VA_ARGS__); } while (0)
-#else
-#define dkprintf(...) do { } while (0)
-#define ekprintf(...) do { kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 static char *last_page;
diff --git a/arch/x86_64/kernel/perfctr.c b/arch/x86_64/kernel/perfctr.c
index 4f33939d..01aab0f6 100644
--- a/arch/x86_64/kernel/perfctr.c
+++ b/arch/x86_64/kernel/perfctr.c
@@ -16,6 +16,7 @@
 #include <registers.h>
 #include <mc_perf_event.h>
 #include <config.h>
+#include <debug.h>
 
 extern unsigned int *x86_march_perfmap;
 extern int running_on_kvm(void);
@@ -25,11 +26,8 @@ int ihk_mc_perfctr_fixed_init(int counter, int mode);
 
 //#define PERFCTR_DEBUG
 #ifdef PERFCTR_DEBUG
-#define	dkprintf(...)	do { kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	do { kprintf(__VA_ARGS__); } while (0)
-#else
-#define	dkprintf(...)	do { } while (0)
-#define	ekprintf(...)	do { kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #define X86_CR4_PCE     0x00000100
diff --git a/arch/x86_64/kernel/syscall.c b/arch/x86_64/kernel/syscall.c
index 366e6130..2a5af272 100644
--- a/arch/x86_64/kernel/syscall.c
+++ b/arch/x86_64/kernel/syscall.c
@@ -31,6 +31,7 @@
 #include <page.h>
 #include <limits.h>
 #include <syscall.h>
+#include <debug.h>
 
 void terminate_mcexec(int, int);
 extern long do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact);
@@ -45,11 +46,8 @@ extern uint64_t get_xsave_mask();
 //#define DEBUG_PRINT_SC
 
 #ifdef DEBUG_PRINT_SC
-#define dkprintf kprintf
-#define ekprintf(...) kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 uintptr_t debug_constants[] = {
diff --git a/kernel/ap.c b/kernel/ap.c
index 0323e707..131efe4a 100644
--- a/kernel/ap.c
+++ b/kernel/ap.c
@@ -29,15 +29,13 @@
 #include <time.h>
 #include <syscall.h>
 #include <rusage_private.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_AP
 
 #ifdef DEBUG_PRINT_AP
-#define dkprintf(...) do { kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) do { kprintf(__VA_ARGS__); } while (0)
-#else
-#define dkprintf(...) do { } while (0)
-#define ekprintf(...) do { kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 int num_processors = 1;
diff --git a/kernel/config/attached-mic.lds b/kernel/config/attached-mic.lds
index 4da8397a..c826cc17 100644
--- a/kernel/config/attached-mic.lds
+++ b/kernel/config/attached-mic.lds
@@ -1,24 +1,28 @@
 PHDRS 
 {
 	text PT_LOAD FLAGS(5);
-    data PT_LOAD FLAGS(7);
+	data PT_LOAD FLAGS(7);
 }
 SECTIONS
 {
 	. = 0xffffffff80001000;
-    _head = .;
+	_head = .;
 
-    .text : {
-        *(.text);
-    } : text
+	.text : {
+		*(.text);
+	} : text
 
-    . = ALIGN(4096);
+	. = ALIGN(4096);
 	.data : {
-	      *(.data)
-	      *(.data.*)
+		*(.data)
+		*(.data.*)
+		. = ALIGN(8);
+		__start___verbose = .;
+		*(__verbose);
+		__stop___verbose = .;
 	} :data
 	.rodata : {
-	      *(.rodata .rodata.*)
+		*(.rodata .rodata.*)
 	} :data
 
 	.vsyscall : ALIGN(0x1000) {
@@ -37,14 +41,14 @@ SECTIONS
 		. = ALIGN(4096);
 	} : data = 0xf4
 
-    .bss : {
-          *(.bss .bss.*)
-    }
-    . = ALIGN(4096);
-    _end = .;
+	.bss : {
+		*(.bss .bss.*)
+	}
+	. = ALIGN(4096);
+	_end = .;
 
 	/DISCARD/ : {
-	     *(.eh_frame)
-         *(.note.gnu.build-id)
+		*(.eh_frame)
+		*(.note.gnu.build-id)
 	}
 }
diff --git a/kernel/config/builtin-mic.lds b/kernel/config/builtin-mic.lds
index 4da8397a..c826cc17 100644
--- a/kernel/config/builtin-mic.lds
+++ b/kernel/config/builtin-mic.lds
@@ -1,24 +1,28 @@
 PHDRS 
 {
 	text PT_LOAD FLAGS(5);
-    data PT_LOAD FLAGS(7);
+	data PT_LOAD FLAGS(7);
 }
 SECTIONS
 {
 	. = 0xffffffff80001000;
-    _head = .;
+	_head = .;
 
-    .text : {
-        *(.text);
-    } : text
+	.text : {
+		*(.text);
+	} : text
 
-    . = ALIGN(4096);
+	. = ALIGN(4096);
 	.data : {
-	      *(.data)
-	      *(.data.*)
+		*(.data)
+		*(.data.*)
+		. = ALIGN(8);
+		__start___verbose = .;
+		*(__verbose);
+		__stop___verbose = .;
 	} :data
 	.rodata : {
-	      *(.rodata .rodata.*)
+		*(.rodata .rodata.*)
 	} :data
 
 	.vsyscall : ALIGN(0x1000) {
@@ -37,14 +41,14 @@ SECTIONS
 		. = ALIGN(4096);
 	} : data = 0xf4
 
-    .bss : {
-          *(.bss .bss.*)
-    }
-    . = ALIGN(4096);
-    _end = .;
+	.bss : {
+		*(.bss .bss.*)
+	}
+	. = ALIGN(4096);
+	_end = .;
 
 	/DISCARD/ : {
-	     *(.eh_frame)
-         *(.note.gnu.build-id)
+		*(.eh_frame)
+		*(.note.gnu.build-id)
 	}
 }
diff --git a/kernel/config/builtin-x86.lds b/kernel/config/builtin-x86.lds
index bae71899..8f33262d 100644
--- a/kernel/config/builtin-x86.lds
+++ b/kernel/config/builtin-x86.lds
@@ -1,24 +1,28 @@
 PHDRS 
 {
 	text PT_LOAD FLAGS(5);
-    data PT_LOAD FLAGS(7);
+	data PT_LOAD FLAGS(7);
 }
 SECTIONS
 {
 	. = 0xffffffff80001000;
-    _head = .;
+	_head = .;
 
-    .text : {
-        *(.text);
-    } : text
+	.text : {
+		*(.text);
+	} : text
 
-    . = ALIGN(4096);
+	. = ALIGN(4096);
 	.data : {
-	      *(.data)
-	      *(.data.*)
+		*(.data)
+		*(.data.*)
+		. = ALIGN(8);
+		__start___verbose = .;
+		*(__verbose);
+		__stop___verbose = .;
 	} :data
 	.rodata : {
-	      *(.rodata .rodata.*)
+		*(.rodata .rodata.*)
 	} :data
 
 	.vsyscall : ALIGN(0x1000) {
@@ -37,10 +41,10 @@ SECTIONS
 		. = ALIGN(4096);
 	} : data = 0xf4
 
-    .bss : {
-          *(.bss .bss.*)
-    }
-    . = ALIGN(4096);
-    _end = .;
+	.bss : {
+		*(.bss .bss.*)
+	}
+	. = ALIGN(4096);
+	_end = .;
 
 }
diff --git a/kernel/config/smp-arm64_type1.lds b/kernel/config/smp-arm64_type1.lds
index 1a5969e6..86c7f658 100644
--- a/kernel/config/smp-arm64_type1.lds
+++ b/kernel/config/smp-arm64_type1.lds
@@ -16,6 +16,10 @@ SECTIONS
 	.data : {
 		*(.data)
 		*(.data.*)
+		. = ALIGN(8);
+		__start___verbose = .;
+		*(__verbose);
+		__stop___verbose = .;
 	} :data
 	.rodata : {
 		*(.rodata .rodata.*)
diff --git a/kernel/config/smp-arm64_type2.lds b/kernel/config/smp-arm64_type2.lds
index 32be18ba..481e139e 100644
--- a/kernel/config/smp-arm64_type2.lds
+++ b/kernel/config/smp-arm64_type2.lds
@@ -16,6 +16,10 @@ SECTIONS
 	.data : {
 		*(.data)
 		*(.data.*)
+		. = ALIGN(8);
+		__start___verbose = .;
+		*(__verbose);
+		__stop___verbose = .;
 	} :data
 	.rodata : {
 		*(.rodata .rodata.*)
diff --git a/kernel/config/smp-arm64_type3.lds b/kernel/config/smp-arm64_type3.lds
index 8a39b1ee..6186d926 100644
--- a/kernel/config/smp-arm64_type3.lds
+++ b/kernel/config/smp-arm64_type3.lds
@@ -16,6 +16,10 @@ SECTIONS
 	.data : {
 		*(.data)
 		*(.data.*)
+		. = ALIGN(8);
+		__start___verbose = .;
+		*(__verbose);
+		__stop___verbose = .;
 	} :data
 	.rodata : {
 		*(.rodata .rodata.*)
diff --git a/kernel/config/smp-arm64_type4.lds b/kernel/config/smp-arm64_type4.lds
index 11843c44..0ef7d5ac 100644
--- a/kernel/config/smp-arm64_type4.lds
+++ b/kernel/config/smp-arm64_type4.lds
@@ -16,6 +16,10 @@ SECTIONS
 	.data : {
 		*(.data)
 		*(.data.*)
+		. = ALIGN(8);
+		__start___verbose = .;
+		*(__verbose);
+		__stop___verbose = .;
 	} :data
 	.rodata : {
 		*(.rodata .rodata.*)
diff --git a/kernel/config/smp-x86.lds b/kernel/config/smp-x86.lds
index 9f4b0832..0e322d13 100644
--- a/kernel/config/smp-x86.lds
+++ b/kernel/config/smp-x86.lds
@@ -1,24 +1,28 @@
 PHDRS 
 {
 	text PT_LOAD FLAGS(5);
-    data PT_LOAD FLAGS(7);
+	data PT_LOAD FLAGS(7);
 }
 SECTIONS
 {
 	. = 0xffffffff80001000;
-    _head = .;
+	_head = .;
 
-    .text : {
-        *(.text);
-    } : text
+	.text : {
+		*(.text);
+	} : text
 
-    . = ALIGN(4096);
+	. = ALIGN(4096);
 	.data : {
-	      *(.data)
-	      *(.data.*)
+		*(.data)
+		*(.data.*)
+		. = ALIGN(8);
+		__start___verbose = .;
+		*(__verbose);
+		__stop___verbose = .;
 	} :data
 	.rodata : {
-	      *(.rodata .rodata.*)
+		*(.rodata .rodata.*)
 	} :data
 
 	.vsyscall : ALIGN(0x1000) {
@@ -37,9 +41,9 @@ SECTIONS
 		. = ALIGN(4096);
 	} : data = 0xf4
 
-    .bss : {
-          *(.bss .bss.*)
-    }
-    . = ALIGN(4096);
-    _end = .;
+	.bss : {
+		*(.bss .bss.*)
+	}
+	. = ALIGN(4096);
+	_end = .;
 }
diff --git a/kernel/debug.c b/kernel/debug.c
index 64e90cfe..0328eb93 100644
--- a/kernel/debug.c
+++ b/kernel/debug.c
@@ -18,6 +18,9 @@
 #include <ihk/lock.h>
 #include <ihk/monitor.h>
 #include <errno.h>
+#include <sysfs.h>
+#include <debug.h>
+#include <limits.h>
 
 struct ihk_kmsg_buf *kmsg_buf;
 
@@ -180,3 +183,147 @@ void kmsg_init()
 {
 	ihk_mc_spinlock_init(&kmsg_lock);
 }
+
+extern struct ddebug __start___verbose[];
+extern struct ddebug __stop___verbose[];
+
+static ssize_t dynamic_debug_sysfs_show(struct sysfs_ops *ops,
+		void *instance, void *buf, size_t size)
+{
+	struct ddebug *dbg;
+	ssize_t n = 0;
+
+	n = snprintf(buf, size, "# filename:lineno function flags format\n");
+
+	for (dbg = __start___verbose; dbg < __stop___verbose; dbg++) {
+		n += snprintf(buf + n, size - n, "%s:%d %s =%s\n",
+				dbg->file, dbg->line, dbg->func,
+				dbg->flags ? "p" : "_");
+
+		if (n >= size)
+			break;
+	}
+
+	return n;
+}
+
+static ssize_t dynamic_debug_sysfs_store(struct sysfs_ops *ops,
+		void *instance, void *buf, size_t size)
+{
+	char *cur = buf;
+	char *file = NULL, *func = NULL;
+	long int line_start = 0, line_end = INT_MAX;
+	int set_flag = -1;
+	struct ddebug *dbg;
+
+
+	// assume line was new-line terminated and squash last newline
+	cur[size-1] = '\0';
+
+	/* basic line parsing, combinaisons of:
+	 *   file <file>
+	 *   func <func>
+	 *   line <line|line-line|line-|-line>
+	 *   and must end with [+-=][p_] (set/clear print flag)
+	 */
+again:
+	while (cur && cur < ((char *)buf) + size && *cur) {
+		dkprintf("looking at %.*s, size left %d\n",
+			size - (cur - (char *)buf), cur,
+			(char *)buf - cur + size);
+
+		if (strncmp(cur, "func ", 5) == 0) {
+			cur += 5;
+			func = cur;
+		} else if (strncmp(cur, "file ", 5) == 0) {
+			cur += 5;
+			file = cur;
+		} else if (strncmp(cur, "line ", 5) == 0) {
+			cur += 5;
+			if (*cur != '-') {
+				line_start = strtol(cur, &cur, 0);
+			}
+			if (*cur != '-') {
+				line_end = line_start;
+			} else {
+				cur++;
+				if (*cur == ' ' || *cur == '\0') {
+					line_end = INT_MAX;
+				} else {
+					line_end = strtol(cur, &cur, 0);
+				}
+			}
+		} else if (strchr("+-=", *cur)) {
+			switch ((*cur) + 256 * (*(cur+1))) {
+			case '+' + 256*'p':
+			case '=' + 256*'p':
+				set_flag = DDEBUG_PRINT;
+				break;
+			case '-' + 256*'p':
+			case '=' + 256*'_':
+				set_flag = DDEBUG_NONE;
+				break;
+			default:
+				kprintf("invalid flag: %.*s\n",
+					size - (cur - (char *)buf), cur);
+				return -EINVAL;
+			}
+			/* XXX check 3rd char is end of input or \n or ; */
+			cur += 3;
+			break;
+
+		} else {
+			kprintf("dynamic debug control: unrecognized keyword: %.*s\n",
+				size - (cur - (char *)buf), cur);
+			return -EINVAL;
+		}
+		cur = strpbrk(cur, " \n");
+		if (cur) {
+			*cur = '\0';
+			cur++;
+		}
+	}
+	dkprintf("func %s, file %s, lines %d-%d, flag %x\n",
+		func, file, line_start, line_end, set_flag);
+
+	if (set_flag < 0) {
+		kprintf("dynamic debug control: no flag set?\n");
+		return -EINVAL;
+	}
+	if (!func && !file) {
+		kprintf("at least file or func should be set\n");
+		return -EINVAL;
+	}
+
+	for (dbg = __start___verbose; dbg < __stop___verbose; dbg++) {
+		/* TODO: handle wildcards */
+		if ((!func || strcmp(func, dbg->func) == 0) &&
+		    (!file || strcmp(file, dbg->file) == 0) &&
+		    dbg->line >= line_start &&
+		    dbg->line <= line_end) {
+			dbg->flags = set_flag;
+		}
+	}
+
+	if (cur && cur < ((char *)buf) + size && *cur)
+		goto again;
+
+	return size;
+}
+
+static struct sysfs_ops dynamic_debug_sysfs_ops = {
+	.show = &dynamic_debug_sysfs_show,
+	.store = &dynamic_debug_sysfs_store,
+};
+
+void dynamic_debug_sysfs_setup(void)
+{
+	int error;
+
+	error = sysfs_createf(&dynamic_debug_sysfs_ops, NULL, 0644,
+			      "/sys/kernel/debug/dynamic_debug/control");
+	if (error) {
+		kprintf("%s: ERROR: creating dynamic_debug/control sysfs file",
+			__func__);
+	}
+}
diff --git a/kernel/devobj.c b/kernel/devobj.c
index 3b3267e3..2b0b7b4a 100644
--- a/kernel/devobj.c
+++ b/kernel/devobj.c
@@ -36,15 +36,13 @@
 #include <syscall.h>
 #include <process.h>
 #include <rusage_private.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_DEVOBJ
 
 #ifdef DEBUG_PRINT_DEVOBJ
-#define	dkprintf(...) kprintf(__VA_ARGS__)
-#define	ekprintf(...) kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...) kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 
diff --git a/kernel/fileobj.c b/kernel/fileobj.c
index 2eb21b03..37d2c9d6 100644
--- a/kernel/fileobj.c
+++ b/kernel/fileobj.c
@@ -27,15 +27,13 @@
 #include <string.h>
 #include <syscall.h>
 #include <rusage_private.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_FILEOBJ
 
 #ifdef DEBUG_PRINT_FILEOBJ
-#define	dkprintf(...)	do { if (1) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#else
-#define	dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 mcs_lock_t fileobj_list_lock;
diff --git a/kernel/futex.c b/kernel/futex.c
index ee728d1c..1522a836 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -70,13 +70,13 @@
 #include <cls.h>
 #include <kmsg.h>
 #include <timer.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_FUTEX
 
 #ifdef DEBUG_PRINT_FUTEX
-#define dkprintf kprintf
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 int futex_cmpxchg_enabled;
diff --git a/kernel/host.c b/kernel/host.c
index b1c90da4..0942b240 100644
--- a/kernel/host.c
+++ b/kernel/host.c
@@ -34,13 +34,13 @@
 #include <sysfs.h>
 #include <ihk/perfctr.h>
 #include <rusage_private.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_HOST
 
 #ifdef DEBUG_PRINT_HOST
-#define dkprintf kprintf
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 /* Linux channel table, indexec by Linux CPU id */
diff --git a/kernel/include/debug.h b/kernel/include/debug.h
new file mode 100644
index 00000000..4a512942
--- /dev/null
+++ b/kernel/include/debug.h
@@ -0,0 +1,40 @@
+#ifndef DEBUG_H
+#define DEBUG_H
+
+#include <lwk/compiler.h>
+
+struct ddebug {
+	const char *file;
+	const char *func;
+	const char *fmt;
+	unsigned int line:24;
+	unsigned int flags:8;
+} __aligned(8);
+
+#define DDEBUG_NONE  0x0
+#define DDEBUG_PRINT 0x1
+
+#define DDEBUG_DEFAULT DDEBUG_NONE
+
+#define DDEBUG_SYMBOL()                                  \
+	static struct ddebug __aligned(8)                \
+	__attribute__((section("__verbose"))) ddebug = { \
+		.file = __FILE__,                        \
+		.func = __func__,                        \
+		.line = __LINE__,                        \
+		.flags = DDEBUG_DEFAULT,                 \
+	}
+
+#define DDEBUG_TEST ddebug.flags
+
+
+
+#define dkprintf(fmt, args...)        \
+do {                                  \
+	DDEBUG_SYMBOL();              \
+	if (DDEBUG_TEST)              \
+		kprintf(fmt, ##args); \
+} while (0)
+#define ekprintf(fmt, args...) kprintf(fmt, ##args)
+
+#endif
diff --git a/kernel/include/init.h b/kernel/include/init.h
index 874a7cbc..400438c2 100644
--- a/kernel/include/init.h
+++ b/kernel/include/init.h
@@ -33,6 +33,7 @@ extern void cpu_sysfs_setup(void);
 extern void numa_sysfs_setup(void);
 extern void rusage_sysfs_setup(void);
 extern void status_sysfs_setup(void);
+extern void dynamic_debug_sysfs_setup(void);
 
 extern char *find_command_line(char *name);
 
diff --git a/kernel/include/xpmem_private.h b/kernel/include/xpmem_private.h
index 23d76f10..a12c406a 100644
--- a/kernel/include/xpmem_private.h
+++ b/kernel/include/xpmem_private.h
@@ -26,20 +26,17 @@
 
 #include <mc_xpmem.h>
 #include <xpmem.h>
+#include <debug.h>
 
 #define XPMEM_CURRENT_VERSION           0x00026003
 
 //#define DEBUG_PRINT_XPMEM
 
 #ifdef DEBUG_PRINT_XPMEM
-#define dkprintf(...) kprintf(__VA_ARGS__)
-#define ekprintf(...) kprintf(__VA_ARGS__)
-#define XPMEM_DEBUG(format, a...) kprintf("[%d] %s: "format"\n", cpu_local_var(current)->proc->rgid, __func__, ##a)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) kprintf(__VA_ARGS__)
-#define XPMEM_DEBUG(format, a...) do { if (0) kprintf("\n"); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
+#define XPMEM_DEBUG(format, a...) dkprintf("[%d] %s: "format"\n", cpu_local_var(current)->proc->rgid, __func__, ##a)
 
 //#define USE_DBUG_ON
 
diff --git a/kernel/init.c b/kernel/init.c
index 88d11682..c38a6941 100644
--- a/kernel/init.c
+++ b/kernel/init.c
@@ -32,6 +32,7 @@
 #include <syscall.h>
 #include <sysfs.h>
 #include <ihk/monitor.h>
+#include <debug.h>
 
 //#define IOCTL_FUNC_EXTENSION
 #ifdef IOCTL_FUNC_EXTENSION
@@ -41,11 +42,8 @@
 //#define DEBUG_PRINT_INIT
 
 #ifdef DEBUG_PRINT_INIT
-#define dkprintf(...) do { kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) do { kprintf(__VA_ARGS__); } while (0)
-#else
-#define dkprintf(...) do { } while (0)
-#define ekprintf(...) do { kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #define DUMP_LEVEL_USER_UNUSED_EXCLUDE 24
@@ -331,6 +329,7 @@ static void populate_sysfs(void)
 {
 	cpu_sysfs_setup();
 	numa_sysfs_setup();
+	dynamic_debug_sysfs_setup();
 	//setup_remote_snooping_samples();
 } /* populate_sysfs() */
 
diff --git a/kernel/listeners.c b/kernel/listeners.c
index 5dd058e4..345f0655 100644
--- a/kernel/listeners.c
+++ b/kernel/listeners.c
@@ -19,15 +19,13 @@
 #include <ihk/ikc.h>
 #include <ikc/master.h>
 #include <arch/cpu.h>
+#include <debug.h>
 
 //#define DEBUG_LISTENERS
 
 #ifdef DEBUG_LISTENERS
-#define	dkprintf(...)	kprintf(__VA_ARGS__)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 void testmem(void *v, unsigned long size)
diff --git a/kernel/mem.c b/kernel/mem.c
index 1b361270..f6dc309b 100644
--- a/kernel/mem.c
+++ b/kernel/mem.c
@@ -44,15 +44,13 @@
 #include <process.h>
 #include <limits.h>
 #include <sysfs.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_MEM
 
 #ifdef DEBUG_PRINT_MEM
-#define	dkprintf(...)	kprintf(__VA_ARGS__)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 static unsigned long pa_start, pa_end;
diff --git a/kernel/pager.c b/kernel/pager.c
index 2fc1a725..f6b2cb0b 100644
--- a/kernel/pager.c
+++ b/kernel/pager.c
@@ -21,6 +21,7 @@
 #include <kmalloc.h>
 #include <process.h>
 #include <swapfmt.h>
+#include <debug.h>
 
 #define O_RDONLY	00000000
 #define O_WRONLY	00000001
@@ -44,11 +45,8 @@
 //#define DEBUG_PRINT_PROCESS
 
 #ifdef DEBUG_PRINT_PROCESS
-#define dkprintf(...) kprintf(__VA_ARGS__)
-#define ekprintf(...) kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 /*
diff --git a/kernel/process.c b/kernel/process.c
index 2f7cefaa..bb15608a 100644
--- a/kernel/process.c
+++ b/kernel/process.c
@@ -38,12 +38,13 @@
 #include <xpmem.h>
 #include <rusage_private.h>
 #include <ihk/monitor.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_PROCESS
 
 #ifdef DEBUG_PRINT_PROCESS
-#define dkprintf(...) kprintf(__VA_ARGS__)
-#define ekprintf(...) kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 static void dtree(struct rb_node *node, int l) {
 	struct vm_range *range;
 	if (!node)
@@ -60,8 +61,6 @@ static void dump_tree(struct process_vm *vm) {
 	dtree(vm->vm_range_tree.rb_node, 1);
 }
 #else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) kprintf(__VA_ARGS__)
 static void dump_tree(struct process_vm *vm) {}
 #endif
 
diff --git a/kernel/profile.c b/kernel/profile.c
index 4ebc0b4d..4f3e66fb 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -39,6 +39,7 @@
 #include <limits.h>
 #include <march.h>
 #include <process.h>
+#include <debug.h>
 
 extern char *syscall_name[];
 
@@ -47,11 +48,8 @@ extern char *syscall_name[];
 //#define DEBUG_PRINT_PROFILE
 
 #ifdef DEBUG_PRINT_PROFILE
-#define	dkprintf(...) kprintf(__VA_ARGS__)
-#define	ekprintf(...) kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...) kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 
diff --git a/kernel/shmobj.c b/kernel/shmobj.c
index 2d30a854..4da2194a 100644
--- a/kernel/shmobj.c
+++ b/kernel/shmobj.c
@@ -23,10 +23,8 @@
 #include <shm.h>
 #include <string.h>
 #include <rusage_private.h>
+#include <debug.h>
 
-#define	dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#define	fkprintf(...)	kprintf(__VA_ARGS__)
 
 static LIST_HEAD(shmobj_list_head);
 static ihk_spinlock_t shmobj_list_lock_body = SPIN_LOCK_UNLOCKED;
@@ -273,7 +271,7 @@ void shmobj_destroy(struct shmobj *obj)
 				page->mode, page->count);
 		count = ihk_atomic_sub_return(1, &page->count);
 		if (!((page->mode == PM_MAPPED) && (count == 0))) {
-			fkprintf("shmobj_destroy(%p): "
+			ekprintf("shmobj_destroy(%p): "
 					"page %p phys %#lx mode %#x"
 					" count %d off %#lx\n",
 					obj, page,
@@ -335,7 +333,7 @@ static void shmobj_release(struct memobj *memobj)
 	newref = --obj->ds.shm_nattch;
 	if (newref <= 0) {
 		if (newref < 0) {
-			fkprintf("shmobj_release(%p):ref %ld\n",
+			ekprintf("shmobj_release(%p):ref %ld\n",
 					memobj, newref);
 			panic("shmobj_release:freeing free shmobj");
 		}
@@ -430,7 +428,7 @@ static int shmobj_get_page(struct memobj *memobj, off_t off, int p2align,
 		   Add when setting the PTE for a page with count of one in ihk_mc_pt_set_range(). */
 
 		if (page->mode != PM_NONE) {
-			fkprintf("shmobj_get_page(%p,%#lx,%d,%p):"
+			ekprintf("shmobj_get_page(%p,%#lx,%d,%p):"
 					"page %p %#lx %d %d %#lx\n",
 					memobj, off, p2align, physp,
 					page, page_to_phys(page), page->mode,
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 9ad47661..d51cdeb1 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -59,6 +59,7 @@
 #include <rusage_private.h>
 #include <ihk/monitor.h>
 #include <profile.h>
+#include <debug.h>
 
 /* Headers taken from kitten LWK */
 #include <lwk/stddef.h>
@@ -69,11 +70,8 @@
 //#define DEBUG_PRINT_SC
 
 #ifdef DEBUG_PRINT_SC
-#define	dkprintf(...) kprintf(__VA_ARGS__)
-#define	ekprintf(...) kprintf(__VA_ARGS__)
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...) kprintf(__VA_ARGS__)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 //static ihk_atomic_t pid_cnt = IHK_ATOMIC_INIT(1024);
diff --git a/kernel/sysfs.c b/kernel/sysfs.c
index fc07cd32..670d4294 100644
--- a/kernel/sysfs.c
+++ b/kernel/sysfs.c
@@ -23,9 +23,7 @@
 #include <sysfs.h>
 #include <sysfs_msg.h>
 #include <vsprintf.h>
-
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define ekprintf(...) do { if (1) kprintf(__VA_ARGS__); } while (0)
+#include <debug.h>
 
 static size_t sysfs_data_bufsize;
 static void *sysfs_data_buf;
diff --git a/kernel/timer.c b/kernel/timer.c
index 031d15b7..1871ad43 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -32,13 +32,13 @@
 #include <futex.h>
 #include <bitops.h>
 #include <timer.h>
+#include <debug.h>
 
 //#define DEBUG_PRINT_TIMER
 
 #ifdef DEBUG_PRINT_TIMER
-#define dkprintf kprintf
-#else
-#define dkprintf(...) do { if (0) kprintf(__VA_ARGS__); } while (0)
+#undef DDEBUG_DEFAULT
+#define DDEBUG_DEFAULT DDEBUG_PRINT
 #endif
 
 #define LOOP_TIMEOUT 500
diff --git a/kernel/xpmem.c b/kernel/xpmem.c
index e2668b75..070b9e7d 100644
--- a/kernel/xpmem.c
+++ b/kernel/xpmem.c
@@ -283,7 +283,8 @@ static int xpmem_close(
 	int n_opened;
 
 	XPMEM_DEBUG("call: fd=%d, pid=%d, rgid=%d", 
-		mckfd->fd, proc->pid, proc->rgid);
+		mckfd->fd, cpu_local_var(current)->proc->pid,
+		cpu_local_var(current)->proc->rgid);
 
 	n_opened = ihk_atomic_dec_return(&xpmem_my_part->n_opened);
 	XPMEM_DEBUG("n_opened=%d", n_opened);
diff --git a/kernel/zeroobj.c b/kernel/zeroobj.c
index 1b0f78bb..5987cbee 100644
--- a/kernel/zeroobj.c
+++ b/kernel/zeroobj.c
@@ -21,10 +21,7 @@
 #include <memory.h>
 #include <page.h>
 #include <string.h>
-
-#define	dkprintf(...)	do { if (0) kprintf(__VA_ARGS__); } while (0)
-#define	ekprintf(...)	kprintf(__VA_ARGS__)
-#define	fkprintf(...)	kprintf(__VA_ARGS__)
+#include <debug.h>
 
 struct zeroobj {
 	struct memobj		memobj;		/* must be first */
@@ -117,7 +114,7 @@ static int alloc_zeroobj(void)
 	page = phys_to_page_insert_hash(phys);
 
 	if (page->mode != PM_NONE) {
-		fkprintf("alloc_zeroobj():"
+		ekprintf("alloc_zeroobj():"
 				"page %p %#lx %d %d %#lx\n",
 				page, page_to_phys(page), page->mode,
 				page->count, page->offset);
diff --git a/lib/include/string.h b/lib/include/string.h
index e26a13ab..ae537ef5 100644
--- a/lib/include/string.h
+++ b/lib/include/string.h
@@ -23,6 +23,7 @@ char *strncpy(char *dest, const char *src, size_t maxlen);
 int strcmp(const char *s1, const char *s2);
 int strncmp(const char *s1, const char *s2, size_t n);
 char *strstr(const char *haystack, const char *needle);
+char *strpbrk(const char *haystack, const char *accept);
 char *strchr(const char *s, int n);
 char *strrchr(const char *s, int n);
 void *memcpy(void *dest, const void *src, size_t n);
diff --git a/lib/string.c b/lib/string.c
index ab194e27..6089121e 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -112,6 +112,19 @@ strrchr(const char *s, int c)
 	return (char *)last;
 } /* strrchr() */
 
+char *strpbrk(const char *s, const char *accept)
+{
+	const char *a;
+
+	do {
+		for (a = accept; *a; a++)
+			if (*s == *a)
+				return (char *)s;
+	} while (*(s++));
+
+	return NULL;
+}
+
 char *strstr(const char *haystack, const char *needle)
 {
 	int len = strlen(needle);