cleanup: make get_syscall_args.c files more readable

Make get_syscall_args.c files more self-contained.  While they are
still being included by syscall.c, the latter no longer defines
get_syscall_args function.

* linux/aarch64/get_syscall_args.c: Include "arm/get_syscall_args.c"
with get_syscall_args temporarily defined to arm_get_syscall_args.
(get_syscall_args): Define.
* linux/alpha/get_syscall_args.c (get_syscall_args): Define.
* linux/arc/get_syscall_args.c: Likewise.
* linux/arm/get_syscall_args.c: Likewise.
* linux/avr32/get_syscall_args.c: Likewise.
* linux/bfin/get_syscall_args.c: Likewise.
* linux/crisv10/get_syscall_args.c: Likewise.
* linux/hppa/get_syscall_args.c: Likewise.
* linux/i386/get_syscall_args.c: Likewise.
* linux/ia64/get_syscall_args.c: Likewise.
* linux/m68k/get_syscall_args.c: Likewise.
* linux/metag/get_syscall_args.c: Likewise.
* linux/microblaze/get_syscall_args.c: Likewise.
* linux/mips/get_syscall_args.c: Likewise.
* linux/nios2/get_syscall_args.c: Likewise.
* linux/or1k/get_syscall_args.c: Likewise.
* linux/powerpc/get_syscall_args.c: Likewise.
* linux/s390/get_syscall_args.c: Likewise.
* linux/sh/get_syscall_args.c: Likewise.
* linux/sh64/get_syscall_args.c: Likewise.
* linux/sparc/get_syscall_args.c: Likewise.
* linux/tile/get_syscall_args.c: Likewise.
* linux/x86_64/get_syscall_args.c: Likewise.
* linux/xtensa/get_syscall_args.c: Likewise.
* syscall.c (get_syscall_args): Remove.
Include "get_syscall_args.c" in file scope.

Requested-by: Denys Vlasenko <dvlasenk@redhat.com>

24 files changed, 324 insertions, 163 deletions

diff --git a/linux/aarch64/get_syscall_args.c b/linux/aarch64/get_syscall_args.c
index 41ce8b448..b92130130 100644
--- a/linux/aarch64/get_syscall_args.c
+++ b/linux/aarch64/get_syscall_args.c
@@ -1,10 +1,18 @@
-if (tcp->currpers == 1) {
+#define get_syscall_args arm_get_syscall_args
+#include "arm/get_syscall_args.c"
+#undef get_syscall_args
+
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	if (tcp->currpers == 0)
+		return arm_get_syscall_args(tcp);
 	tcp->u_arg[0] = aarch64_regs.regs[0];
 	tcp->u_arg[1] = aarch64_regs.regs[1];
 	tcp->u_arg[2] = aarch64_regs.regs[2];
 	tcp->u_arg[3] = aarch64_regs.regs[3];
 	tcp->u_arg[4] = aarch64_regs.regs[4];
 	tcp->u_arg[5] = aarch64_regs.regs[5];
-} else {
-#include "arm/get_syscall_args.c"
+	return 1;
 }
diff --git a/linux/alpha/get_syscall_args.c b/linux/alpha/get_syscall_args.c
index 7f7d493a7..a3857263d 100644
--- a/linux/alpha/get_syscall_args.c
+++ b/linux/alpha/get_syscall_args.c
@@ -1,5 +1,11 @@
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	unsigned int i;
 
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, REG_A0+i, &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, REG_A0+i, &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}
diff --git a/linux/arc/get_syscall_args.c b/linux/arc/get_syscall_args.c
index bb003c8d5..4d6ace5c3 100644
--- a/linux/arc/get_syscall_args.c
+++ b/linux/arc/get_syscall_args.c
@@ -1,5 +1,11 @@
-long *arc_args = &arc_regs.scratch.r0;
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	long *arc_args = &arc_regs.scratch.r0;
+	unsigned int i;
 
-for (i = 0; i < MAX_ARGS; ++i)
-	tcp->u_arg[i] = *arc_args--;
+	for (i = 0; i < MAX_ARGS; ++i)
+		tcp->u_arg[i] = *arc_args--;
+	return 1;
+}
diff --git a/linux/arm/get_syscall_args.c b/linux/arm/get_syscall_args.c
index 1bd4faf20..6be175019 100644
--- a/linux/arm/get_syscall_args.c
+++ b/linux/arm/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = arm_regs.uregs[0];
-tcp->u_arg[1] = arm_regs.uregs[1];
-tcp->u_arg[2] = arm_regs.uregs[2];
-tcp->u_arg[3] = arm_regs.uregs[3];
-tcp->u_arg[4] = arm_regs.uregs[4];
-tcp->u_arg[5] = arm_regs.uregs[5];
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = arm_regs.uregs[0];
+	tcp->u_arg[1] = arm_regs.uregs[1];
+	tcp->u_arg[2] = arm_regs.uregs[2];
+	tcp->u_arg[3] = arm_regs.uregs[3];
+	tcp->u_arg[4] = arm_regs.uregs[4];
+	tcp->u_arg[5] = arm_regs.uregs[5];
+	return 1;
+}
diff --git a/linux/avr32/get_syscall_args.c b/linux/avr32/get_syscall_args.c
index 2e3cd3b6e..e8c41198b 100644
--- a/linux/avr32/get_syscall_args.c
+++ b/linux/avr32/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = avr32_regs.r12;
-tcp->u_arg[1] = avr32_regs.r11;
-tcp->u_arg[2] = avr32_regs.r10;
-tcp->u_arg[3] = avr32_regs.r9;
-tcp->u_arg[4] = avr32_regs.r5;
-tcp->u_arg[5] = avr32_regs.r3;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = avr32_regs.r12;
+	tcp->u_arg[1] = avr32_regs.r11;
+	tcp->u_arg[2] = avr32_regs.r10;
+	tcp->u_arg[3] = avr32_regs.r9;
+	tcp->u_arg[4] = avr32_regs.r5;
+	tcp->u_arg[5] = avr32_regs.r3;
+	return 1;
+}
diff --git a/linux/bfin/get_syscall_args.c b/linux/bfin/get_syscall_args.c
index ac6e6cd2c..13d58bd7e 100644
--- a/linux/bfin/get_syscall_args.c
+++ b/linux/bfin/get_syscall_args.c
@@ -1,6 +1,13 @@
-static const int argreg[MAX_ARGS] = { PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5 };
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	static const int argreg[MAX_ARGS] =
+		{ PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5 };
+	unsigned int i;
 
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, argreg[i], &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, argreg[i], &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}
diff --git a/linux/crisv10/get_syscall_args.c b/linux/crisv10/get_syscall_args.c
index 66b5ac7e2..bdd05746e 100644
--- a/linux/crisv10/get_syscall_args.c
+++ b/linux/crisv10/get_syscall_args.c
@@ -1,9 +1,15 @@
-static const int crisregs[MAX_ARGS] = {
-	4*PT_ORIG_R10, 4*PT_R11, 4*PT_R12,
-	4*PT_R13     , 4*PT_MOF, 4*PT_SRP
-};
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	static const int crisregs[MAX_ARGS] = {
+		4*PT_ORIG_R10, 4*PT_R11, 4*PT_R12,
+		4*PT_R13     , 4*PT_MOF, 4*PT_SRP
+	};
+	unsigned int i;
 
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, crisregs[i], &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, crisregs[i], &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}
diff --git a/linux/hppa/get_syscall_args.c b/linux/hppa/get_syscall_args.c
index 117b68b91..2258ea87c 100644
--- a/linux/hppa/get_syscall_args.c
+++ b/linux/hppa/get_syscall_args.c
@@ -1,5 +1,11 @@
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	unsigned int i;
 
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, PT_GR26-4*i, &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, PT_GR26-4*i, &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}
diff --git a/linux/i386/get_syscall_args.c b/linux/i386/get_syscall_args.c
index 30cce6a45..d5de1d959 100644
--- a/linux/i386/get_syscall_args.c
+++ b/linux/i386/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = i386_regs.ebx;
-tcp->u_arg[1] = i386_regs.ecx;
-tcp->u_arg[2] = i386_regs.edx;
-tcp->u_arg[3] = i386_regs.esi;
-tcp->u_arg[4] = i386_regs.edi;
-tcp->u_arg[5] = i386_regs.ebp;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = i386_regs.ebx;
+	tcp->u_arg[1] = i386_regs.ecx;
+	tcp->u_arg[2] = i386_regs.edx;
+	tcp->u_arg[3] = i386_regs.esi;
+	tcp->u_arg[4] = i386_regs.edi;
+	tcp->u_arg[5] = i386_regs.ebp;
+	return 1;
+}
diff --git a/linux/ia64/get_syscall_args.c b/linux/ia64/get_syscall_args.c
index 95273965d..2295d08dc 100644
--- a/linux/ia64/get_syscall_args.c
+++ b/linux/ia64/get_syscall_args.c
@@ -1,22 +1,29 @@
-if (!ia64_ia32mode) {
-	unsigned long *rbs_end =
-		(unsigned long *) ia64_regs.ar[PT_AUR_BSP];
-	unsigned long sof = (ia64_regs.cfm >> 0) & 0x7f;
-	unsigned long sol = (ia64_regs.cfm >> 7) & 0x7f;
-	unsigned long *out0 = ia64_rse_skip_regs(rbs_end, -sof + sol);
-	unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	if (!ia64_ia32mode) {
+		unsigned long *rbs_end =
+			(unsigned long *) ia64_regs.ar[PT_AUR_BSP];
+		unsigned long sof = (ia64_regs.cfm >> 0) & 0x7f;
+		unsigned long sol = (ia64_regs.cfm >> 7) & 0x7f;
+		unsigned long *out0 = ia64_rse_skip_regs(rbs_end, -sof + sol);
+		unsigned int i;
 
-	for (i = 0; i < tcp->s_ent->nargs; ++i) {
-		if (umoven(tcp, (unsigned long) ia64_rse_skip_regs(out0, i),
-			   sizeof(long), &tcp->u_arg[i]) < 0)
-			return -1;
+		for (i = 0; i < tcp->s_ent->nargs; ++i) {
+			if (umoven(tcp,
+				   (unsigned long) ia64_rse_skip_regs(out0, i),
+				   sizeof(long), &tcp->u_arg[i]) < 0)
+				return -1;
+		}
+	} else {
+		/* truncate away IVE sign-extension */
+		tcp->u_arg[0] = 0xffffffff & ia64_regs.gr[11]; /* EBX */
+		tcp->u_arg[1] = 0xffffffff & ia64_regs.gr[ 9]; /* ECX */
+		tcp->u_arg[2] = 0xffffffff & ia64_regs.gr[10]; /* EDX */
+		tcp->u_arg[3] = 0xffffffff & ia64_regs.gr[14]; /* ESI */
+		tcp->u_arg[4] = 0xffffffff & ia64_regs.gr[15]; /* EDI */
+		tcp->u_arg[5] = 0xffffffff & ia64_regs.gr[13]; /* EBP */
 	}
-} else {
-	/* truncate away IVE sign-extension */
-	tcp->u_arg[0] = 0xffffffff & ia64_regs.gr[11]; /* EBX */
-	tcp->u_arg[1] = 0xffffffff & ia64_regs.gr[ 9]; /* ECX */
-	tcp->u_arg[2] = 0xffffffff & ia64_regs.gr[10]; /* EDX */
-	tcp->u_arg[3] = 0xffffffff & ia64_regs.gr[14]; /* ESI */
-	tcp->u_arg[4] = 0xffffffff & ia64_regs.gr[15]; /* EDI */
-	tcp->u_arg[5] = 0xffffffff & ia64_regs.gr[13]; /* EBP */
+	return 1;
 }
diff --git a/linux/m68k/get_syscall_args.c b/linux/m68k/get_syscall_args.c
index bdffcb1d9..bc69a1957 100644
--- a/linux/m68k/get_syscall_args.c
+++ b/linux/m68k/get_syscall_args.c
@@ -1,5 +1,11 @@
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	unsigned int i;
 
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, (i < 5 ? i : i + 2)*4, &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, (i < 5 ? i : i + 2)*4, &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}
diff --git a/linux/metag/get_syscall_args.c b/linux/metag/get_syscall_args.c
index 269f4eb8e..b7c10f45f 100644
--- a/linux/metag/get_syscall_args.c
+++ b/linux/metag/get_syscall_args.c
@@ -1,5 +1,12 @@
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	unsigned int i;
 
-for (i = 0; i < MAX_ARGS; i++)
-	/* arguments go backwards from D1Ar1 (D1.3) */
-	tcp->u_arg[i] = ((unsigned long *)&metag_regs.dx[3][1])[-i];
+	for (i = 0; i < MAX_ARGS; i++) {
+		/* arguments go backwards from D1Ar1 (D1.3) */
+		tcp->u_arg[i] = ((unsigned long *)&metag_regs.dx[3][1])[-i];
+	}
+	return 1;
+}
diff --git a/linux/microblaze/get_syscall_args.c b/linux/microblaze/get_syscall_args.c
index 373911c1c..830c8c321 100644
--- a/linux/microblaze/get_syscall_args.c
+++ b/linux/microblaze/get_syscall_args.c
@@ -1,5 +1,11 @@
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	unsigned int i;
 
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, (5 + i) * 4, &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, (5 + i) * 4, &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}
diff --git a/linux/mips/get_syscall_args.c b/linux/mips/get_syscall_args.c
index 4e4a22b77..a20be8dee 100644
--- a/linux/mips/get_syscall_args.c
+++ b/linux/mips/get_syscall_args.c
@@ -1,3 +1,7 @@
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
 #if defined LINUX_MIPSN64
 	tcp->u_arg[0] = mips_REG_A0;
 	tcp->u_arg[1] = mips_REG_A1;
@@ -18,10 +22,13 @@
 	tcp->u_arg[2] = mips_REG_A2;
 	tcp->u_arg[3] = mips_REG_A3;
 	if (tcp->s_ent->nargs > 4) {
-		umoven(tcp, mips_REG_SP + 4 * 4,
-		       (tcp->s_ent->nargs - 4) * sizeof(tcp->u_arg[0]),
-		       &tcp->u_arg[4]);
+		if (umoven(tcp, mips_REG_SP + 4 * 4,
+			   (tcp->s_ent->nargs - 4) * sizeof(tcp->u_arg[0]),
+			   &tcp->u_arg[4]) < 0)
+			return -1;
 	}
 #else
 # error unsupported mips abi
 #endif
+	return 1;
+}
diff --git a/linux/nios2/get_syscall_args.c b/linux/nios2/get_syscall_args.c
index d12c2f7e2..707f594a6 100644
--- a/linux/nios2/get_syscall_args.c
+++ b/linux/nios2/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = nios2_regs.regs[4];
-tcp->u_arg[1] = nios2_regs.regs[5];
-tcp->u_arg[2] = nios2_regs.regs[6];
-tcp->u_arg[3] = nios2_regs.regs[7];
-tcp->u_arg[4] = nios2_regs.regs[8];
-tcp->u_arg[5] = nios2_regs.regs[9];
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = nios2_regs.regs[4];
+	tcp->u_arg[1] = nios2_regs.regs[5];
+	tcp->u_arg[2] = nios2_regs.regs[6];
+	tcp->u_arg[3] = nios2_regs.regs[7];
+	tcp->u_arg[4] = nios2_regs.regs[8];
+	tcp->u_arg[5] = nios2_regs.regs[9];
+	return 1;
+}
diff --git a/linux/or1k/get_syscall_args.c b/linux/or1k/get_syscall_args.c
index 751cba05b..b72e01f09 100644
--- a/linux/or1k/get_syscall_args.c
+++ b/linux/or1k/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = or1k_regs.gpr[3 + 0];
-tcp->u_arg[1] = or1k_regs.gpr[3 + 1];
-tcp->u_arg[2] = or1k_regs.gpr[3 + 2];
-tcp->u_arg[3] = or1k_regs.gpr[3 + 3];
-tcp->u_arg[4] = or1k_regs.gpr[3 + 4];
-tcp->u_arg[5] = or1k_regs.gpr[3 + 5];
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = or1k_regs.gpr[3 + 0];
+	tcp->u_arg[1] = or1k_regs.gpr[3 + 1];
+	tcp->u_arg[2] = or1k_regs.gpr[3 + 2];
+	tcp->u_arg[3] = or1k_regs.gpr[3 + 3];
+	tcp->u_arg[4] = or1k_regs.gpr[3 + 4];
+	tcp->u_arg[5] = or1k_regs.gpr[3 + 5];
+	return 1;
+}
diff --git a/linux/powerpc/get_syscall_args.c b/linux/powerpc/get_syscall_args.c
index 237cf77fe..66bcae31f 100644
--- a/linux/powerpc/get_syscall_args.c
+++ b/linux/powerpc/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = ppc_regs.orig_gpr3;
-tcp->u_arg[1] = ppc_regs.gpr[4];
-tcp->u_arg[2] = ppc_regs.gpr[5];
-tcp->u_arg[3] = ppc_regs.gpr[6];
-tcp->u_arg[4] = ppc_regs.gpr[7];
-tcp->u_arg[5] = ppc_regs.gpr[8];
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = ppc_regs.orig_gpr3;
+	tcp->u_arg[1] = ppc_regs.gpr[4];
+	tcp->u_arg[2] = ppc_regs.gpr[5];
+	tcp->u_arg[3] = ppc_regs.gpr[6];
+	tcp->u_arg[4] = ppc_regs.gpr[7];
+	tcp->u_arg[5] = ppc_regs.gpr[8];
+	return 1;
+}
diff --git a/linux/s390/get_syscall_args.c b/linux/s390/get_syscall_args.c
index 85f258511..ebf6c6c4a 100644
--- a/linux/s390/get_syscall_args.c
+++ b/linux/s390/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = s390_regset.orig_gpr2;
-tcp->u_arg[1] = s390_regset.gprs[3];
-tcp->u_arg[2] = s390_regset.gprs[4];
-tcp->u_arg[3] = s390_regset.gprs[5];
-tcp->u_arg[4] = s390_regset.gprs[6];
-tcp->u_arg[5] = s390_regset.gprs[7];
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = s390_regset.orig_gpr2;
+	tcp->u_arg[1] = s390_regset.gprs[3];
+	tcp->u_arg[2] = s390_regset.gprs[4];
+	tcp->u_arg[3] = s390_regset.gprs[5];
+	tcp->u_arg[4] = s390_regset.gprs[6];
+	tcp->u_arg[5] = s390_regset.gprs[7];
+	return 1;
+}
diff --git a/linux/sh/get_syscall_args.c b/linux/sh/get_syscall_args.c
index 7c94f4885..0b6c8819d 100644
--- a/linux/sh/get_syscall_args.c
+++ b/linux/sh/get_syscall_args.c
@@ -1,10 +1,19 @@
-static const int syscall_regs[MAX_ARGS] = {
-	4 * (REG_REG0+4), 4 * (REG_REG0+5), 4 * (REG_REG0+6),
-	4 * (REG_REG0+7), 4 * (REG_REG0  ), 4 * (REG_REG0+1)
-};
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	static const int syscall_regs[MAX_ARGS] = {
+		4 * (REG_REG0+4),
+		4 * (REG_REG0+5),
+		4 * (REG_REG0+6),
+		4 * (REG_REG0+7),
+		4 * (REG_REG0  ),
+		4 * (REG_REG0+1)
+	};
+	unsigned int i;
 
-unsigned int i;
-
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, syscall_regs[i], &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, syscall_regs[i], &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}
diff --git a/linux/sh64/get_syscall_args.c b/linux/sh64/get_syscall_args.c
index dcc8967ac..3970df8f7 100644
--- a/linux/sh64/get_syscall_args.c
+++ b/linux/sh64/get_syscall_args.c
@@ -1,7 +1,14 @@
-/* Registers used by SH5 Linux system calls for parameters */
-static const int syscall_regs[MAX_ARGS] = { 2, 3, 4, 5, 6, 7 };
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	/* Registers used by SH5 Linux system calls for parameters */
+	static const int syscall_regs[MAX_ARGS] = { 2, 3, 4, 5, 6, 7 };
+	unsigned int i;
 
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, REG_GENERAL(syscall_regs[i]), &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, REG_GENERAL(syscall_regs[i]),
+			  &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}
diff --git a/linux/sparc/get_syscall_args.c b/linux/sparc/get_syscall_args.c
index 14bce8f95..57b5488e4 100644
--- a/linux/sparc/get_syscall_args.c
+++ b/linux/sparc/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = sparc_regs.u_regs[U_REG_O0 + 0];
-tcp->u_arg[1] = sparc_regs.u_regs[U_REG_O0 + 1];
-tcp->u_arg[2] = sparc_regs.u_regs[U_REG_O0 + 2];
-tcp->u_arg[3] = sparc_regs.u_regs[U_REG_O0 + 3];
-tcp->u_arg[4] = sparc_regs.u_regs[U_REG_O0 + 4];
-tcp->u_arg[5] = sparc_regs.u_regs[U_REG_O0 + 5];
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = sparc_regs.u_regs[U_REG_O0 + 0];
+	tcp->u_arg[1] = sparc_regs.u_regs[U_REG_O0 + 1];
+	tcp->u_arg[2] = sparc_regs.u_regs[U_REG_O0 + 2];
+	tcp->u_arg[3] = sparc_regs.u_regs[U_REG_O0 + 3];
+	tcp->u_arg[4] = sparc_regs.u_regs[U_REG_O0 + 4];
+	tcp->u_arg[5] = sparc_regs.u_regs[U_REG_O0 + 5];
+	return 1;
+}
diff --git a/linux/tile/get_syscall_args.c b/linux/tile/get_syscall_args.c
index 33371d5c4..b2043d394 100644
--- a/linux/tile/get_syscall_args.c
+++ b/linux/tile/get_syscall_args.c
@@ -1,6 +1,12 @@
-tcp->u_arg[0] = tile_regs.regs[0];
-tcp->u_arg[1] = tile_regs.regs[1];
-tcp->u_arg[2] = tile_regs.regs[2];
-tcp->u_arg[3] = tile_regs.regs[3];
-tcp->u_arg[4] = tile_regs.regs[4];
-tcp->u_arg[5] = tile_regs.regs[5];
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	tcp->u_arg[0] = tile_regs.regs[0];
+	tcp->u_arg[1] = tile_regs.regs[1];
+	tcp->u_arg[2] = tile_regs.regs[2];
+	tcp->u_arg[3] = tile_regs.regs[3];
+	tcp->u_arg[4] = tile_regs.regs[4];
+	tcp->u_arg[5] = tile_regs.regs[5];
+	return 1;
+}
diff --git a/linux/x86_64/get_syscall_args.c b/linux/x86_64/get_syscall_args.c
index 0ccecdf07..fa591fb63 100644
--- a/linux/x86_64/get_syscall_args.c
+++ b/linux/x86_64/get_syscall_args.c
@@ -1,29 +1,35 @@
-if (x86_io.iov_len != sizeof(i386_regs)) {
-	/* x86-64 or x32 ABI */
-	tcp->u_arg[0] = x86_64_regs.rdi;
-	tcp->u_arg[1] = x86_64_regs.rsi;
-	tcp->u_arg[2] = x86_64_regs.rdx;
-	tcp->u_arg[3] = x86_64_regs.r10;
-	tcp->u_arg[4] = x86_64_regs.r8;
-	tcp->u_arg[5] = x86_64_regs.r9;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	if (x86_io.iov_len != sizeof(i386_regs)) {
+		/* x86-64 or x32 ABI */
+		tcp->u_arg[0] = x86_64_regs.rdi;
+		tcp->u_arg[1] = x86_64_regs.rsi;
+		tcp->u_arg[2] = x86_64_regs.rdx;
+		tcp->u_arg[3] = x86_64_regs.r10;
+		tcp->u_arg[4] = x86_64_regs.r8;
+		tcp->u_arg[5] = x86_64_regs.r9;
 #ifdef X32
-	tcp->ext_arg[0] = x86_64_regs.rdi;
-	tcp->ext_arg[1] = x86_64_regs.rsi;
-	tcp->ext_arg[2] = x86_64_regs.rdx;
-	tcp->ext_arg[3] = x86_64_regs.r10;
-	tcp->ext_arg[4] = x86_64_regs.r8;
-	tcp->ext_arg[5] = x86_64_regs.r9;
+		tcp->ext_arg[0] = x86_64_regs.rdi;
+		tcp->ext_arg[1] = x86_64_regs.rsi;
+		tcp->ext_arg[2] = x86_64_regs.rdx;
+		tcp->ext_arg[3] = x86_64_regs.r10;
+		tcp->ext_arg[4] = x86_64_regs.r8;
+		tcp->ext_arg[5] = x86_64_regs.r9;
 #endif
-} else {
-	/* i386 ABI */
-	/* Zero-extend from 32 bits */
-	/* Use widen_to_long(tcp->u_arg[N]) in syscall handlers
-	 * if you need to use *sign-extended* parameter.
-	 */
-	tcp->u_arg[0] = (long)(uint32_t)i386_regs.ebx;
-	tcp->u_arg[1] = (long)(uint32_t)i386_regs.ecx;
-	tcp->u_arg[2] = (long)(uint32_t)i386_regs.edx;
-	tcp->u_arg[3] = (long)(uint32_t)i386_regs.esi;
-	tcp->u_arg[4] = (long)(uint32_t)i386_regs.edi;
-	tcp->u_arg[5] = (long)(uint32_t)i386_regs.ebp;
+	} else {
+		/* i386 ABI */
+		/* Zero-extend from 32 bits */
+		/* Use widen_to_long(tcp->u_arg[N]) in syscall handlers
+		 * if you need to use *sign-extended* parameter.
+		 */
+		tcp->u_arg[0] = (long)(uint32_t)i386_regs.ebx;
+		tcp->u_arg[1] = (long)(uint32_t)i386_regs.ecx;
+		tcp->u_arg[2] = (long)(uint32_t)i386_regs.edx;
+		tcp->u_arg[3] = (long)(uint32_t)i386_regs.esi;
+		tcp->u_arg[4] = (long)(uint32_t)i386_regs.edi;
+		tcp->u_arg[5] = (long)(uint32_t)i386_regs.ebp;
+	}
+	return 1;
 }
diff --git a/linux/xtensa/get_syscall_args.c b/linux/xtensa/get_syscall_args.c
index dca8788e9..a9c933a9f 100644
--- a/linux/xtensa/get_syscall_args.c
+++ b/linux/xtensa/get_syscall_args.c
@@ -1,7 +1,20 @@
-/* arg0: a6, arg1: a3, arg2: a4, arg3: a5, arg4: a8, arg5: a9 */
-static const int xtensaregs[MAX_ARGS] = { 6, 3, 4, 5, 8, 9 };
-unsigned int i;
+/* Return -1 on error or 1 on success (never 0!). */
+static int
+get_syscall_args(struct tcb *tcp)
+{
+	/* arg0: a6, arg1: a3, arg2: a4, arg3: a5, arg4: a8, arg5: a9 */
+	static const int xtensaregs[MAX_ARGS] = {
+		REG_A_BASE + 6,
+		REG_A_BASE + 3,
+		REG_A_BASE + 4,
+		REG_A_BASE + 5,
+		REG_A_BASE + 8,
+		REG_A_BASE + 9
+	};
+	unsigned int i;
 
-for (i = 0; i < tcp->s_ent->nargs; ++i)
-	if (upeek(tcp->pid, REG_A_BASE + xtensaregs[i], &tcp->u_arg[i]) < 0)
-		return -1;
+	for (i = 0; i < tcp->s_ent->nargs; ++i)
+		if (upeek(tcp->pid, xtensaregs[i], &tcp->u_arg[i]) < 0)
+			return -1;
+	return 1;
+}