From 3ab6693971d7fe8eb1131f33de80260ee7cad3be Mon Sep 17 00:00:00 2001
From: jhb <jhb@FreeBSD.org>
Date: Sat, 1 Oct 2016 22:01:41 +0000
Subject: [PATCH] Handle 64-bit system call arguments (off_t, id_t).

In particular, 64-bit system call arguments use up two register_t
arguments for 32-bit processes.  They must also be aligned on a 64-bit
boundary on 32-bit powerpc processes.  This fixes the decoding of
lseek(), procctl(), and wait6() arguments for 32-bit processes (both
native and via freebsd32).

Note that the ktrace system call return record only returns a single
register, so the return value of lseek is always truncated to the low
32-bits for 32-bit processes.
---
 usr.bin/kdump/kdump.c | 44 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 37 insertions(+), 7 deletions(-)

diff --git a/usr.bin/kdump/kdump.c b/usr.bin/kdump/kdump.c
index 776909a13a3..be9f7f6102a 100644
--- a/usr.bin/kdump/kdump.c
+++ b/usr.bin/kdump/kdump.c
@@ -74,6 +74,7 @@ extern int errno;
 #include <netdb.h>
 #include <nl_types.h>
 #include <pwd.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -132,6 +133,27 @@ static struct ktr_header ktr_header;
 #define TIME_FORMAT	"%b %e %T %Y"
 #define eqs(s1, s2)	(strcmp((s1), (s2)) == 0)
 
+#define	print_number64(first,i,n,c) do {				\
+	uint64_t __v;							\
+									\
+	if (quad_align && (((ptrdiff_t)((i) - (first))) & 1) == 1) {	\
+		(i)++;							\
+		(n)--;							\
+	}								\
+	if (quad_slots == 2)						\
+		__v = (uint64_t)(uint32_t)(i)[0] |			\
+		    ((uint64_t)(uint32_t)(i)[1]) << 32;			\
+	else								\
+		__v = (uint64_t)*(i);					\
+	if (decimal)							\
+		printf("%c%jd", (c), (intmax_t)__v);			\
+	else								\
+		printf("%c%#jx", (c), (uintmax_t)__v);			\
+	(i) += quad_slots;						\
+	(n) -= quad_slots;						\
+	(c) = ',';							\
+} while (0)
+
 #define print_number(i,n,c) do {					\
 	if (decimal)							\
 		printf("%c%jd", c, (intmax_t)*i);			\
@@ -705,16 +727,25 @@ void
 ktrsyscall(struct ktr_syscall *ktr, u_int sv_flags)
 {
 	int narg = ktr->ktr_narg;
-	register_t *ip;
+	register_t *ip, *first;
 	intmax_t arg;
+	int quad_align, quad_slots;
 
 	syscallname(ktr->ktr_code, sv_flags);
-	ip = &ktr->ktr_args[0];
+	ip = first = &ktr->ktr_args[0];
 	if (narg) {
 		char c = '(';
 		if (fancy &&
 		    (sv_flags == 0 ||
 		    (sv_flags & SV_ABI_MASK) == SV_ABI_FREEBSD)) {
+			quad_align = 0;
+			if (sv_flags & SV_ILP32) {
+#ifdef __powerpc__
+				quad_align = 1;
+#endif
+				quad_slots = 2;
+			} else
+				quad_slots = 1;
 			switch (ktr->ktr_code) {
 			case SYS_bindat:
 			case SYS_connectat:
@@ -796,7 +827,7 @@ ktrsyscall(struct ktr_syscall *ktr, u_int sv_flags)
 				c = ',';
 				ip++;
 				narg--;
-				print_number(ip, narg, c);
+				print_number64(first, ip, narg, c);
 				print_number(ip, narg, c);
 				putchar(',');
 				wait6optname(*ip);
@@ -996,7 +1027,7 @@ ktrsyscall(struct ktr_syscall *ktr, u_int sv_flags)
 				print_number(ip, narg, c);
 				/* Hidden 'pad' argument, not in lseek(2) */
 				print_number(ip, narg, c);
-				print_number(ip, narg, c);
+				print_number64(first, ip, narg, c);
 				putchar(',');
 				whencename(*ip);
 				ip++;
@@ -1005,8 +1036,7 @@ ktrsyscall(struct ktr_syscall *ktr, u_int sv_flags)
 #endif
 			case SYS_lseek:
 				print_number(ip, narg, c);
-				/* Hidden 'pad' argument, not in lseek(2) */
-				print_number(ip, narg, c);
+				print_number64(first, ip, narg, c);
 				putchar(',');
 				whencename(*ip);
 				ip++;
@@ -1285,7 +1315,7 @@ ktrsyscall(struct ktr_syscall *ktr, u_int sv_flags)
 				c = ',';
 				ip++;
 				narg--;
-				print_number(ip, narg, c);
+				print_number64(first, ip, narg, c);
 				putchar(',');
 				procctlcmdname(*ip);
 				ip++;
-- 
2.45.0