Module Name: src
Committed By: uwe
Date: Fri Sep 8 21:45:08 UTC 2017
Modified Files:
src/usr.bin/kdump: kdump.c
Log Message:
Print negative time offsets correctly. Provide an exegetical quote
from riastradh@, slightly edited to fit the metre.
To generate a diff of this commit:
cvs rdiff -u -r1.127 -r1.128 src/usr.bin/kdump/kdump.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/kdump/kdump.c
diff -u src/usr.bin/kdump/kdump.c:1.127 src/usr.bin/kdump/kdump.c:1.128
--- src/usr.bin/kdump/kdump.c:1.127 Fri Sep 8 21:09:29 2017
+++ src/usr.bin/kdump/kdump.c Fri Sep 8 21:45:08 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: kdump.c,v 1.127 2017/09/08 21:09:29 uwe Exp $ */
+/* $NetBSD: kdump.c,v 1.128 2017/09/08 21:45:08 uwe Exp $ */
/*-
* Copyright (c) 1988, 1993
@@ -39,7 +39,7 @@ __COPYRIGHT("@(#) Copyright (c) 1988, 19
#if 0
static char sccsid[] = "@(#)kdump.c 8.4 (Berkeley) 4/28/95";
#else
-__RCSID("$NetBSD: kdump.c,v 1.127 2017/09/08 21:09:29 uwe Exp $");
+__RCSID("$NetBSD: kdump.c,v 1.128 2017/09/08 21:45:08 uwe Exp $");
#endif
#endif /* not lint */
@@ -109,6 +109,7 @@ static const char * const linux_ptrace_o
static int fread_tail(void *, size_t, size_t);
static int dumpheader(struct ktr_header *);
+static int output_ts(const struct timespec *);
static void output_long(u_long, int);
static void ioctldecode(u_long);
static void ktrsyscall(struct ktr_syscall *);
@@ -399,8 +400,7 @@ dumpheader(struct ktr_header *kth)
if (timestamp & TIMESTAMP_ABSOLUTE) {
temp.tv_sec = kth->ktr_ts.tv_sec;
temp.tv_nsec = kth->ktr_ts.tv_nsec;
- col += printf("%lld.%09ld ",
- (long long)temp.tv_sec, (long)temp.tv_nsec);
+ col += output_ts(&temp);
}
if (timestamp & TIMESTAMP_ELAPSED) {
@@ -410,8 +410,7 @@ dumpheader(struct ktr_header *kth)
temp.tv_sec = temp.tv_nsec = 0;
} else
timespecsub(&kth->ktr_ts, &starttime, &temp);
- col += printf("%lld.%09ld ",
- (long long)temp.tv_sec, (long)temp.tv_nsec);
+ col += output_ts(&temp);
}
if (timestamp & TIMESTAMP_RELATIVE) {
@@ -421,14 +420,42 @@ dumpheader(struct ktr_header *kth)
timespecsub(&kth->ktr_ts, &prevtime, &temp);
prevtime.tv_sec = kth->ktr_ts.tv_sec;
prevtime.tv_nsec = kth->ktr_ts.tv_nsec;
- col += printf("%lld.%09ld ",
- (long long)temp.tv_sec, (long)temp.tv_nsec);
+ col += output_ts(&temp);
}
}
col += printf("%-4s ", type);
return col;
}
+static int
+output_ts(const struct timespec *ts)
+{
+ int col;
+
+ if (__predict_true(ts->tv_sec >= 0))
+ col = printf("%lld.%09ld ",
+ (long long)ts->tv_sec, (long)ts->tv_nsec);
+ else {
+ /*
+ * The time represented by a timespec object ts is always
+ *
+ * ts.tv_sec + ts.tv_nsec * 1e-9
+ *
+ * where ts.tv_sec may be negative but ts.tv_nsec is
+ * always in [0, 1e9). So, for example, -1/4 second is
+ * represented by the struct timespec object
+ *
+ * { .tv_sec = -1, .tv_nsec = 750000000 }
+ */
+ const struct timespec zero_ts = { 0, 0 };
+ struct timespec abs_ts;
+ timespecsub(&zero_ts, ts, &abs_ts);
+ col = printf("-%lld.%09ld ",
+ (long long)abs_ts.tv_sec, (long)abs_ts.tv_nsec);
+ }
+ return col;
+}
+
static void
output_long(u_long it, int as_x)
{
