Fix pread/pwrite display for SH and MIPS

[Daniel Jacobowitz]

Both SH and MIPS calling conventions mandate a blank padding register before
the 64-bit off_t argument to pread or pwrite.  How's this patch?

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

--- strace-4.4/io.c.orig	2003-07-16 14:30:56.000000000 -0400
+++ strace-4.4/io.c	2003-07-16 14:33:59.000000000 -0400
@@ -231,6 +231,14 @@ struct tcb *tcp;
 #endif /* FREEBSD */
 
 #ifdef LINUX
+
+/* On MIPS and SH (as of 2.4.20) there is a padding word before the off_t.  */
+#if defined(MIPS) || defined(SH)
+#define PREAD_OFF_ARG 4
+#else
+#define PREAD_OFF_ARG 3
+#endif
+
 int
 sys_pread(tcp)
 struct tcb *tcp;
@@ -243,7 +251,7 @@ struct tcb *tcp;
 		else
 			printstr(tcp, tcp->u_arg[1], tcp->u_rval);
 		tprintf(", %lu, %llu", tcp->u_arg[2],
-			*(unsigned long long *)&tcp->u_arg[3]);
+			*(unsigned long long *)&tcp->u_arg[PREAD_OFF_ARG]);
 	}
 	return 0;
 }
@@ -256,7 +264,7 @@ struct tcb *tcp;
 		tprintf("%ld, ", tcp->u_arg[0]);
 		printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 		tprintf(", %lu, %llu", tcp->u_arg[2],
-			*(unsigned long long *)&tcp->u_arg[3]);
+			*(unsigned long long *)&tcp->u_arg[PREAD_OFF_ARG]);
 	}
 	return 0;
 }
--- strace-4.4/linux/syscallent.h.orig	2003-07-16 14:34:20.000000000 -0400
+++ strace-4.4/linux/syscallent.h	2003-07-16 14:36:22.000000000 -0400
@@ -221,7 +221,12 @@
 	{ 3,	TS,	sys_rt_sigqueueinfo,    "rt_sigqueueinfo"}, /* 178 */
 	{ 2,	TS,	sys_rt_sigsuspend,	"rt_sigsuspend"	}, /* 179 */
 
+#ifdef SH
+	{ 6,	TF,	sys_pread,		"pread"		}, /* 180 */
+	{ 6,	TF,	sys_pwrite,		"pwrite"	}, /* 181 */
+#else
 	{ 5,	TF,	sys_pread,		"pread"		}, /* 180 */
 	{ 5,	TF,	sys_pwrite,		"pwrite"	}, /* 181 */
+#endif
 #ifdef M68K
 	{ 3,	TF,	sys_chown,		"lchown"	}, /* 182 */
--- strace-4.4/linux/mips/syscallent.h.orig	2003-07-16 14:34:24.000000000 -0400
+++ strace-4.4/linux/mips/syscallent.h	2003-07-16 14:34:32.000000000 -0400
@@ -4198,7 +4198,7 @@
 	{ 4,	TS,	sys_rt_sigtimedwait,	"rt_sigtimedwait"},/* 4197 */
 	{ 3,	TS,	sys_rt_sigqueueinfo,	"rt_sigqueueinfo"},/* 4198 */
 	{ 2,	TS,	sys_rt_sigsuspend,	"rt_siguspend"	}, /* 4199 */
-	{ 5,	TF,	sys_pread,		"pread"		}, /* 4200 */
-	{ 5,	TF,	sys_pwrite,		"pwrite"	}, /* 4201 */
+	{ 6,	TF,	sys_pread,		"pread"		}, /* 4200 */
+	{ 6,	TF,	sys_pwrite,		"pwrite"	}, /* 4201 */
 	{ 3,	TF,	sys_chown,		"chown"		}, /* 4202 */
 	{ 2,	TF,	sys_getcwd,		"getcwd"	}, /* 4203 */