Some cleanup and preparation for support for multiple architectures (both host and client) and OSes

Signed-off-by: Mattias Andrée <maandree@kth.se>

10 files changed, 237 insertions, 152 deletions

diff --git a/Makefile b/Makefile
index 44c177b..9c02102 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,8 @@ OBJ =\
 	util.o
 
 HDR =\
-	arch-x86-64.h\
+	linux/os.h\
+	linux/x86-64.h\
 	arg.h\
 	common.h\
 	list-errnos.h\
@@ -29,15 +30,13 @@ sctrace: $(OBJ)
 
 list-errnos.h:
 	printf '#define LIST_ERRNOS(_)\\\n\t' > $@
-	cat /usr/include/asm-generic/errno.h /usr/include/asm-generic/errno-base.h \
-		| sed 's/\/\/.*$$//' | tr -d '$$' | sed 's/\*\//\$$/g' | sed 's/\/\*[^$$]*\$$//g' \
+	cat $(ERRNO_HDRS) sed 's/\/\/.*$$//' | tr -d '$$' | sed 's/\*\//\$$/g' | sed 's/\/\*[^$$]*\$$//g' \
 		| sed -n '/^[ \t]*#[ \t]*define[ \t].*[ \t][0-9]*[ \t]*$$/s/^[ \t#]*define[ \t]*\([^ \t]*\).*$$/_(\1)/p' \
 		| sort | uniq | tr '\n' '#' | sed 's/#_/\\\n\t_/g' | tr '#' '\n' >> $@
 
 list-signums.h:
 	printf '#define LIST_SIGNUMS(_)\\\n\t' > $@
-	cat /usr/include/bits/signum.h /usr/include/bits/signum-generic.h \
-		| sed 's/\/\/.*$$//' | tr -d '$$' | sed 's/\*\//\$$/g' | sed 's/\/\*[^$$]*\$$//g' \
+	cat $(SIGNUM_HDRS) | sed 's/\/\/.*$$//' | tr -d '$$' | sed 's/\*\//\$$/g' | sed 's/\/\*[^$$]*\$$//g' \
 		| sed -n '/^[ \t]*#[ \t]*define[ \t][^_]*[ \t][0-9]*[ \t]*$$/s/^[ \t#]*define[ \t]*\([^ \t]*\).*$$/_(\1)/p' \
 		| sort | uniq | tr '\n' '#' | sed 's/#_/\\\n\t_/g' | tr '#' '\n' >> $@
 
diff --git a/arch-x86-64.h b/arch-x86-64.h
deleted file mode 100644
index 044b73f..0000000
--- a/arch-x86-64.h
+++ /dev/null
@@ -1,29 +0,0 @@
-struct i386_user_regs_struct
-{
-	uint32_t ebx;
-	uint32_t ecx;
-	uint32_t edx;
-	uint32_t esi;
-	uint32_t edi;
-	uint32_t ebp;
-	uint32_t eax;
-	uint32_t xds;
-	uint32_t xes;
-	uint32_t xfs;
-	uint32_t xgs;
-	uint32_t orig_eax;
-	uint32_t eip;
-	uint32_t xcs;
-	uint32_t eflags;
-	uint32_t esp;
-	uint32_t xss;
-};
-
-#define SYSCALL_NUM_REG orig_rax
-#define SYSCALL_ARG1_REG rdi
-#define SYSCALL_ARG2_REG rsi
-#define SYSCALL_ARG3_REG rdx
-#define SYSCALL_ARG4_REG r10
-#define SYSCALL_ARG5_REG r8
-#define SYSCALL_ARG6_REG r9
-#define SYSCALL_RET_REG rax
diff --git a/common.h b/common.h
index 0c9ff8f..125611e 100644
--- a/common.h
+++ b/common.h
@@ -1,10 +1,5 @@
 /* See LICENSE file for copyright and license details. */
-#include <linux/elf.h>
-#include <sys/ptrace.h>
-#include <linux/ptrace.h> /* After <sys/ptrace.h> */
-#include <sys/syscall.h>
 #include <sys/uio.h>
-#include <sys/user.h>
 #include <sys/wait.h>
 #include <ctype.h>
 #include <errno.h>
@@ -17,13 +12,9 @@
 #include <string.h>
 #include <unistd.h>
 
-#if defined(__x86_64__) && !defined(__IPL32__)
-# include "arch-x86-64.h"
+#if defined(__linux__)
+# include "linux/os.h"
 #else
-# error "This program is only implemented for x86-64"
-#endif
-
-#if !defined(__linux__)
 # error "This program is only implemented for Linux"
 #endif
 
@@ -32,24 +23,6 @@
 #include "list-signums.h"
 
 
-#ifndef ERESTARTSYS
-# define ERESTARTSYS    512
-# define ALSO_ERESTARTSYS
-#endif
-#ifndef ERESTARTNOINTR
-# define ERESTARTNOINTR 513
-# define ALSO_ERESTARTNOINTR
-#endif
-#ifndef ERESTARTNOHAND
-# define ERESTARTNOHAND 514
-# define ALSO_ERESTARTNOHAND
-#endif
-#ifndef ERESTART_RESTARTBLOCK
-# define ERESTART_RESTARTBLOCK 516
-# define ALSO_ERESTART_RESTARTBLOCK
-#endif
-
-
 struct process;
 
 enum type {
@@ -103,6 +76,11 @@ struct process {
 	unsigned long long int ret;
 	enum type ret_type;
 	struct output outputs[6];
+	/* multiarch support */
+	unsigned long long int scall_xor;
+	int long_is_int;
+	int ptr_is_int;
+	int mode;
 
 	/* vfork(2) data */
 	struct process *continue_on_exit;
@@ -119,6 +97,8 @@ char *get_string(pid_t pid, unsigned long int addr, size_t *lenp, const char **e
 int get_struct(pid_t pid, unsigned long int addr, void *out, size_t size, const char **errorp);
 char *get_memory(pid_t pid, unsigned long int addr, size_t n, const char **errorp);
 char *escape_memory(char *str, size_t m);
+char *get_escaped_string(pid_t pid, unsigned long int addr, size_t *lenp, const char **errorp);
+char *get_escaped_memory(pid_t pid, unsigned long int addr, size_t n, const char **errorp);
 
 /* print.c */
 void print_systemcall(struct process *proc);
diff --git a/config.mk b/config.mk
index 9d233fb..8825261 100644
--- a/config.mk
+++ b/config.mk
@@ -1,6 +1,11 @@
 PREFIX    = /usr
 MANPREFIX = $(PREFIX)/share/man
 
+CC = cc
+
+ERRNO_HDRS  = /usr/include/asm-generic/errno.h /usr/include/asm-generic/errno-base.h
+SIGNUM_HDRS = /usr/include/bits/signum.h /usr/include/bits/signum-generic.h
+
 CPPFLAGS = -D_XOPEN_SOURCE=700 -D_GNU_SOURCE
 CFLAGS   = -std=c11 -Wall -Og -g
 LDFLAGS  =
diff --git a/consts.c b/consts.c
index 4e68230..8f6e4d9 100644
--- a/consts.c
+++ b/consts.c
@@ -9,6 +9,7 @@ get_errno_name(int err)
 
 #define X(N) if (err == N) return #N;
 	LIST_ERRNOS(X)
+
 #ifdef ALSO_ERESTARTSYS
 	X(ERESTARTSYS)
 #endif
@@ -21,6 +22,7 @@ get_errno_name(int err)
 #ifdef ALSO_ERESTART_RESTARTBLOCK
 	X(ERESTART_RESTARTBLOCK)
 #endif
+
 #undef X
 
 	sprintf(buf, "%i", err);
diff --git a/linux/os.h b/linux/os.h
new file mode 100644
index 0000000..db22f10
--- /dev/null
+++ b/linux/os.h
@@ -0,0 +1,32 @@
+/* See LICENSE file for copyright and license details. */
+#include <linux/elf.h>
+#include <sys/ptrace.h>
+#include <linux/ptrace.h> /* after <sys/ptrace.h> */
+#include <sys/syscall.h>
+#include <sys/user.h>
+
+#ifndef ERESTARTSYS
+# define ERESTARTSYS 512
+# define ALSO_ERESTARTSYS
+#endif
+#ifndef ERESTARTNOINTR
+# define ERESTARTNOINTR 513
+# define ALSO_ERESTARTNOINTR
+#endif
+#ifndef ERESTARTNOHAND
+# define ERESTARTNOHAND 514
+# define ALSO_ERESTARTNOHAND
+#endif
+#ifndef ERESTART_RESTARTBLOCK
+# define ERESTART_RESTARTBLOCK 516
+# define ALSO_ERESTART_RESTARTBLOCK
+#endif
+
+#define RETURN_IS_ERROR(RET)\
+	((RET) > -(unsigned long long int)PAGE_SIZE) /* Don't know the actual limit, but this seems safe */
+
+#if defined(__x86_64__) && !defined(__IPL32__)
+# include "x86-64.h"
+#else
+# error "This program is only implemented for x86-64 on Linux"
+#endif
diff --git a/linux/x86-64.h b/linux/x86-64.h
new file mode 100644
index 0000000..16ff32f
--- /dev/null
+++ b/linux/x86-64.h
@@ -0,0 +1,86 @@
+/* See LICENSE file for copyright and license details. */
+struct i386_user_regs_struct
+{
+	uint32_t ebx;
+	uint32_t ecx;
+	uint32_t edx;
+	uint32_t esi;
+	uint32_t edi;
+	uint32_t ebp;
+	uint32_t eax;
+	uint32_t xds;
+	uint32_t xes;
+	uint32_t xfs;
+	uint32_t xgs;
+	uint32_t orig_eax;
+	uint32_t eip;
+	uint32_t xcs;
+	uint32_t eflags;
+	uint32_t esp;
+	uint32_t xss;
+};
+
+#define SYSCALL_NUM_REG orig_rax
+#define SYSCALL_RET_REG rax
+
+enum {
+      x86_64 = 0,
+      x32,
+      i386
+};
+
+#define CHECK_ARCHITECTURE(proc, regsp)\
+	do {\
+		struct iovec iov = {\
+			.iov_base = (regsp),\
+			.iov_len = sizeof(*(regsp)),\
+		};\
+		if (ptrace(PTRACE_GETREGSET, (proc)->pid, NT_PRSTATUS, &iov)) {\
+			eprintf("ptrace PTRACE_GETREGSET %ju NT_PRSTATUS {.iov_base=<buffer>, .iov_len=%zu}:",\
+			        (uintmax_t)(proc)->pid, sizeof(*(regsp)));\
+		} else if (iov.iov_len != sizeof(*(regsp))) {\
+			if ((proc)->mode != i386) {\
+				(proc)->mode = i386;\
+				(proc)->long_is_int = 1;\
+				(proc)->ptr_is_int = 1;\
+				(proc)->scall_xor = 0;\
+				tprintf(proc, "Process is running in i386 mode, this is not yet supported\n"); /* TODO */\
+				exit(1);\
+			}\
+		} else if ((proc)->scall & __X32_SYSCALL_BIT) {\
+			if ((proc)->mode != x32) {\
+				(proc)->mode = x32;\
+				(proc)->long_is_int = 0;\
+				(proc)->ptr_is_int = 1;\
+				(proc)->scall_xor = __X32_SYSCALL_BIT;\
+				tprintf(proc, "Process is running in x32 mode (support is untested)\n");\
+			}\
+		} else {\
+			if ((proc)->mode != x86_64) {\
+				(proc)->mode = x86_64;\
+				(proc)->long_is_int = 0;\
+				(proc)->ptr_is_int = 0;\
+				(proc)->scall_xor = 0;\
+				tprintf(proc, "Process is running in x86-64 mode\n");\
+			}\
+		}\
+	} while (0)
+
+#define GET_SYSCALL_ARGUMENTS(proc, regsp)\
+	do {\
+		if ((proc)->mode != i386) {\
+			(proc)->args[0] = (regsp)->rdi;\
+			(proc)->args[1] = (regsp)->rsi;\
+			(proc)->args[2] = (regsp)->rdx;\
+			(proc)->args[3] = (regsp)->r10;\
+			(proc)->args[4] = (regsp)->r8;\
+			(proc)->args[5] = (regsp)->r9;\
+		} else {\
+			(proc)->args[0] = ((const struct i386_user_regs_struct *)(regsp))->ebx;\
+			(proc)->args[1] = ((const struct i386_user_regs_struct *)(regsp))->ecx;\
+			(proc)->args[2] = ((const struct i386_user_regs_struct *)(regsp))->edx;\
+			(proc)->args[3] = ((const struct i386_user_regs_struct *)(regsp))->esi;\
+			(proc)->args[4] = ((const struct i386_user_regs_struct *)(regsp))->edi;\
+			(proc)->args[5] = ((const struct i386_user_regs_struct *)(regsp))->ebp;\
+		}\
+	} while (0)
diff --git a/memory.c b/memory.c
index c721268..6262c61 100644
--- a/memory.c
+++ b/memory.c
@@ -5,6 +5,9 @@
 char *
 get_string(pid_t pid, unsigned long int addr, size_t *lenp, const char **errorp)
 {
+#if defined(__x86_64__) && defined(__IPL32__)
+# error "x32 is not supported, would not be able to read memory from 64-bit applications with current method"
+#endif
 	struct iovec inv, outv;
 	size_t off = 0, size = 0, page_off, read_size;
 	char *out = NULL, *in = (char *)addr, *p;
@@ -39,14 +42,21 @@ int
 get_struct(pid_t pid, unsigned long int addr, void *out, size_t size, const char **errorp)
 {
 	struct iovec inv, outv;
+	if (!addr) {
+		*errorp = "NULL";
+		return -1;
+	}
 	*errorp = NULL;
+#if defined(__x86_64__) && defined(__IPL32__)
+# error "x32 is not supported, would not be able to read memory from 64-bit applications with current method"
+#endif
 	inv.iov_base  = (void *)addr;
 	inv.iov_len   = size;
 	outv.iov_base = out;
 	outv.iov_len  = size;
 	if (process_vm_readv(pid, &outv, 1, &inv, 1, 0) == (ssize_t)size)
 		return 0;
-	*errorp = errno == EFAULT ? "<invalid address>" : "<an error occured during reading of string>";
+	*errorp = errno == EFAULT ? "<invalid address>" : "<an error occured during reading of memory>";
 	return -1;
 }
 
@@ -65,7 +75,6 @@ get_memory(pid_t pid, unsigned long int addr, size_t n, const char **errorp)
 }
 
 
-
 static void
 add_char(char **strp, size_t *sizep, size_t *lenp, char c)
 {
@@ -188,3 +197,29 @@ escape_memory(char *str, size_t m)
 	free(str);
 	return ret;
 }
+
+
+char *
+get_escaped_string(pid_t pid, unsigned long int addr, size_t *lenp, const char **errorp)
+{
+	char *r;
+	if (!addr) {
+		*errorp = "NULL";
+		return NULL;
+	}
+	r = get_string(pid, addr, lenp, errorp);
+	return escape_memory(r, *lenp);
+}
+
+
+char *
+get_escaped_memory(pid_t pid, unsigned long int addr, size_t n, const char **errorp)
+{
+	char *r;
+	if (!addr) {
+		*errorp = "NULL";
+		return NULL;
+	}
+	r = get_memory(pid, addr, n, errorp);
+	return escape_memory(r, n);
+}
diff --git a/print.c b/print.c
index 8c572a8..ddd5a7c 100644
--- a/print.c
+++ b/print.c
@@ -13,48 +13,15 @@
 #include <sched.h>
 #include <time.h>
 
-#ifndef CLONE_NEWTIME
-# define CLONE_NEWTIME 0x00000080
+#if defined(__linux__)
+# ifndef CLONE_NEWTIME
+#  define CLONE_NEWTIME 0x00000080
+# endif
 #endif
 
 
-static char *
-get_escaped_string_or_null(pid_t pid, unsigned long int addr, size_t *lenp, const char **errorp)
-{
-	char *r;
-	if (!addr) {
-		*errorp = "NULL";
-		return NULL;
-	}
-	r = get_string(pid, addr, lenp, errorp);
-	return escape_memory(r, *lenp);
-}
-
-static char *
-get_escaped_memory_or_null(pid_t pid, unsigned long int addr, size_t n, const char **errorp)
-{
-	char *r;
-	if (!addr) {
-		*errorp = "NULL";
-		return NULL;
-	}
-	r = get_memory(pid, addr, n, errorp);
-	return escape_memory(r, n);
-}
-
-static int
-get_struct_or_null(pid_t pid, unsigned long int addr, void *out, size_t size, const char **errorp)
-{
-	if (!addr) {
-		*errorp = "NULL";
-		return -1;
-	}
-	return get_struct(pid, addr, out, size, errorp);
-}
-
-
-
-#define CASE(N) if (proc->args[arg_index] == N) return tprintf(proc, "%s", #N)
+#define CASE(N)\
+	if (proc->args[arg_index] == N) return tprintf(proc, "%s", #N)
 
 #define FLAGS_BEGIN\
 	do {\
@@ -146,7 +113,7 @@ print_timespec(struct process *proc, size_t arg_index)
 {
 	struct timespec ts;
 	const char *err;
-	if (get_struct_or_null(proc->pid, proc->args[arg_index], &ts, sizeof(ts), &err)) {
+	if (get_struct(proc->pid, proc->args[arg_index], &ts, sizeof(ts), &err)) {
 		tprintf(proc, "%s", err);
 		return;
 	}
@@ -270,7 +237,7 @@ print_int_pair(struct process *proc, size_t arg_index)
 {
 	int pair[2];
 	const char *err;
-	if (get_struct_or_null(proc->pid, proc->args[arg_index], pair, sizeof(pair), &err)) {
+	if (get_struct(proc->pid, proc->args[arg_index], pair, sizeof(pair), &err)) {
 		tprintf(proc, "%s", err);
 		return;
 	}
@@ -473,15 +440,26 @@ printf_systemcall(struct process *proc, const char *scall, const char *fmt, ...)
 
 		if (*fmt == 'p') {
 		p_fmt:
+			if (proc->ptr_is_int)
+				arg = (unsigned int)arg;
 			if (input) {
-				if (get_struct_or_null(proc->pid, arg, &arg, sizeof(void *), &err)) {
-					tprintf(proc, "%s", err);
-					goto next;
+				if (proc->ptr_is_int) {
+					if (get_struct(proc->pid, arg, &arg, sizeof(int), &err)) {
+						tprintf(proc, "%s", err);
+						goto next;
+					}
+					arg = *(unsigned int *)&arg;
+				} else {
+					if (get_struct(proc->pid, arg, &arg, sizeof(long int), &err)) {
+						tprintf(proc, "%s", err);
+						goto next;
+					}
+					arg = *(unsigned long int *)&arg;
 				}
 				tprintf(proc, "&");
 			}
 			if (arg)
-				tprintf(proc, "%p", (void *)arg);
+				tprintf(proc, "%#llu", arg);
 			else
 				tprintf(proc, "NULL");
 		} else if (*fmt >= '1' && *fmt <= '6') {
@@ -490,16 +468,16 @@ printf_systemcall(struct process *proc, const char *scall, const char *fmt, ...)
 				funcs[nfuncs++] = va_arg(ap, Function);
 			funcs[func - 1](proc, i);
 		} else if (*fmt == 's') {
-			str = get_escaped_string_or_null(proc->pid, arg, &len, &err);
+			str = get_escaped_string(proc->pid, arg, &len, &err);
 			tprintf(proc, "%s", str ? str : err);
 			free(str);
 		} else if (*fmt == 'm') {
-			str = get_escaped_memory_or_null(proc->pid, arg, (size_t)args[i + 1], &err);
+			str = get_escaped_memory(proc->pid, arg, (size_t)args[i + 1], &err);
 			tprintf(proc, "%s", str ? str : err);
 			free(str);
 		} else if (*fmt == 'F') {
 			if (input) {
-				if (get_struct_or_null(proc->pid, arg, &arg, sizeof(int), &err)) {
+				if (get_struct(proc->pid, arg, &arg, sizeof(int), &err)) {
 					tprintf(proc, "%s", err);
 					goto next;
 				}
@@ -510,6 +488,8 @@ printf_systemcall(struct process *proc, const char *scall, const char *fmt, ...)
 			else
 				tprintf(proc, "%i", (int)arg);
 		} else {
+			if (ells == 1 && proc->long_is_int)
+				ells = 0;
 			if (ells == 1)
 				size = sizeof(long int);
 			else if (ells > 1)
@@ -521,7 +501,7 @@ printf_systemcall(struct process *proc, const char *scall, const char *fmt, ...)
 			else
 				size = sizeof(int);
 			if (input) {
-				if (get_struct_or_null(proc->pid, arg, &arg, size, &err)) {
+				if (get_struct(proc->pid, arg, &arg, size, &err)) {
 					tprintf(proc, "%s", err);
 					goto next;
 				}
@@ -942,13 +922,13 @@ print_systemcall_exit(struct process *proc)
 	char *str, buf[32];
 	const char *err;
 
-	if (proc->ret_type == Int)
+	if (proc->ret_type == Int || (proc->long_is_int && proc->ret_type == Long))
 		tprintf(proc, "= %i", (int)proc->ret);
-	else if (proc->ret_type == UInt)
+	else if (proc->ret_type == UInt || (proc->long_is_int && proc->ret_type == ULong))
 		tprintf(proc, "= %u", (unsigned int)proc->ret);
-	else if (proc->ret_type == OInt)
+	else if (proc->ret_type == OInt || (proc->long_is_int && proc->ret_type == OLong))
 		tprintf(proc, "= %#o", (unsigned int)proc->ret);
-	else if (proc->ret_type == XInt)
+	else if (proc->ret_type == XInt || (proc->long_is_int && proc->ret_type == XLong))
 		tprintf(proc, "= %#x", (unsigned int)proc->ret);
 	else if (proc->ret_type == Long)
 		tprintf(proc, "= %li", (long int)proc->ret);
@@ -966,12 +946,14 @@ print_systemcall_exit(struct process *proc)
 		tprintf(proc, "= %#llo", (unsigned long long int)proc->ret);
 	else if (proc->ret_type == XLLong)
 		tprintf(proc, "= %#llx", (unsigned long long int)proc->ret);
+	else if (proc->ret_type == Ptr && (long long int)proc->ret >= 0 && proc->ptr_is_int)
+		tprintf(proc, "= %#u", (unsigned int)proc->ret);
 	else if (proc->ret_type == Ptr && (long long int)proc->ret >= 0)
-		tprintf(proc, "= %p", (void *)proc->ret);
+		tprintf(proc, "= %#llu", proc->ret);
 	else
-		tprintf(proc, "= %li", (long int)proc->ret);
+		tprintf(proc, "= %lli", (long long int)proc->ret);
 
-	if ((unsigned long long int)proc->ret > -(unsigned long long int)PAGE_SIZE) {
+	if (RETURN_IS_ERROR(proc->ret)) {
 		tprintf(proc, " (%s: %s)", get_errno_name(-(int)proc->ret), strerror(-(int)proc->ret));
 		tprintf(proc, "\n");
 
@@ -984,17 +966,26 @@ print_systemcall_exit(struct process *proc)
 			switch (proc->outputs[i].fmt) {
 
 			case 'p':
-				if (get_struct_or_null(proc->pid, proc->args[i], buf, sizeof(void *), &err))
-					tprintf(proc, "%s\n", err);
-				else if (*(void **)buf)
-					tprintf(proc, "%p\n", *(void **)buf);
-				else
-					tprintf(proc, "NULL\n");
+				if (proc->ptr_is_int) {
+					if (get_struct(proc->pid, proc->args[i], buf, sizeof(int), &err))
+						tprintf(proc, "%s\n", err);
+					else if (*(unsigned int *)buf)
+						tprintf(proc, "%#u\n", *(unsigned int *)buf);
+					else
+						tprintf(proc, "NULL\n");
+				} else {
+					if (get_struct(proc->pid, proc->args[i], buf, sizeof(long int), &err))
+						tprintf(proc, "%s\n", err);
+					else if (*(unsigned long int *)buf)
+						tprintf(proc, "%#lu\n", *(unsigned long int *)buf);
+					else
+						tprintf(proc, "NULL\n");
+				}
 				break;
 
 			case 'm':
 				value = proc->args[i + 1] < proc->ret ? proc->args[i + 1] : proc->ret;
-				str = get_escaped_memory_or_null(proc->pid, proc->args[i], (size_t)value, &err);
+				str = get_escaped_memory(proc->pid, proc->args[i], (size_t)value, &err);
 				tprintf(proc, "%s\n", str ? str : err);
 				free(str);
 				break;
@@ -1005,6 +996,7 @@ print_systemcall_exit(struct process *proc)
 				break;
 
 			default:
+				/* .ells is adjust for .long_is_int when set */
 				if (proc->outputs[i].ells == 1)
 					size = sizeof(unsigned long int);
 				else if (proc->outputs[i].ells > 1)
@@ -1015,7 +1007,7 @@ print_systemcall_exit(struct process *proc)
 					size = sizeof(unsigned char);
 				else
 					size = sizeof(unsigned int);
-				if (get_struct_or_null(proc->pid, proc->args[i], buf, size, &err)) {
+				if (get_struct(proc->pid, proc->args[i], buf, size, &err)) {
 					tprintf(proc, "%s\n", err);
 					break;
 				}
diff --git a/sctrace.c b/sctrace.c
index 9bab8ff..3d2669a 100644
--- a/sctrace.c
+++ b/sctrace.c
@@ -18,10 +18,6 @@ static void
 handle_syscall(struct process *proc)
 {
 	struct user_regs_struct regs;
-	struct iovec iov = {
-		.iov_base = &regs,
-		.iov_len = sizeof(regs),
-	};
 
 	switch ((int)proc->state) {
 	default:
@@ -29,24 +25,11 @@ handle_syscall(struct process *proc)
 		if (ptrace(PTRACE_GETREGS, proc->pid, NULL, &regs))
 			eprintf("ptrace PTRACE_GETREGS %ju NULL <buffer>:", (uintmax_t)proc->pid);
 		proc->scall = regs.SYSCALL_NUM_REG;
-		proc->args[0] = regs.SYSCALL_ARG1_REG;
-		proc->args[1] = regs.SYSCALL_ARG2_REG;
-		proc->args[2] = regs.SYSCALL_ARG3_REG;
-		proc->args[3] = regs.SYSCALL_ARG4_REG;
-		proc->args[4] = regs.SYSCALL_ARG5_REG;
-		proc->args[5] = regs.SYSCALL_ARG6_REG;
-
-		/* Check architecture */
-		if (ptrace(PTRACE_GETREGSET, proc->pid, NT_PRSTATUS, &iov)) {
-			eprintf("ptrace PTRACE_GETREGSET %ju NT_PRSTATUS {.iov_base=<buffer>, .iov_len=%zu}:",
-			        (uintmax_t)proc->pid, sizeof(regs));
-		} else if (iov.iov_len != sizeof(regs)) {
-			tprintf(proc, "Process is running as i386, this is not yet supported\n");
-			exit(1);
-		} else if (proc->scall & __X32_SYSCALL_BIT) {
-			tprintf(proc, "Process is running as x32, this is not yet supported\n");
-			exit(1);
-		}
+#ifdef CHECK_ARCHITECTURE
+		CHECK_ARCHITECTURE(proc, &regs);
+		proc->scall ^= proc->scall_xor;
+#endif
+		GET_SYSCALL_ARGUMENTS(proc, &regs);
 
 		/* Print system call */
 		print_systemcall(proc);
@@ -115,7 +98,7 @@ handle_event(struct process *proc, int status)
 	struct process *proc2;
 
 	sig = WSTOPSIG(status);
-	trace_event = ((status >> 8) ^ SIGTRAP) >> 8;
+	trace_event = status >> 16;
 	switch (trace_event) {
 
 	case PTRACE_EVENT_VFORK: