Author: scottl
Date: Tue Feb 28 18:25:06 2017
New Revision: 314397
URL: https://svnweb.freebsd.org/changeset/base/314397
Log:
Implement sbuf_prf(), which takes an sbuf and outputs it
to stdout in the non-kernel case and to the console+log
in the kernel case. For the kernel case it hooks the
putbuf() machinery underneath printf(9) so that the buffer
is written completely atomically and without a copy into
another temporary buffer. This is useful for fixing
compound console/log messages that become broken and
interleaved when multiple threads are competing for the
console.
Reviewed by: ken, imp
Sponsored by: Netflix
Modified:
head/share/man/man9/sbuf.9
head/sys/kern/subr_prf.c
Modified: head/share/man/man9/sbuf.9
==============================================================================
--- head/share/man/man9/sbuf.9 Tue Feb 28 18:10:03 2017 (r314396)
+++ head/share/man/man9/sbuf.9 Tue Feb 28 18:25:06 2017 (r314397)
@@ -57,7 +57,8 @@
.Nm sbuf_delete ,
.Nm sbuf_start_section ,
.Nm sbuf_end_section ,
-.Nm sbuf_hexdump
+.Nm sbuf_hexdump ,
+.Nm sbuf_putbuf
.Nd safe string composition
.Sh SYNOPSIS
.In sys/types.h
@@ -124,6 +125,8 @@
.Fa "const char *hdr"
.Fa "int flags"
.Fc
+.Ft void
+.Fn sbuf_putbuf "struct sbuf *s"
.In sys/sysctl.h
.Ft struct sbuf *
.Fn sbuf_new_for_sysctl "struct sbuf *s" "char *buf" "int length" "struct
sysctl_req *req"
@@ -472,6 +475,12 @@ representation of the bytes if possible.
See the
.Xr hexdump 3
man page for more details on the interface.
+.Pp
+The
+.Fn sbuf_putbuf
+function printfs the sbuf to stdout if in userland, and to the console
+and log if in the kernel.
+It does not drain the buffer or update any pointers.
.Sh NOTES
If an operation caused an
.Fa sbuf
Modified: head/sys/kern/subr_prf.c
==============================================================================
--- head/sys/kern/subr_prf.c Tue Feb 28 18:10:03 2017 (r314396)
+++ head/sys/kern/subr_prf.c Tue Feb 28 18:25:06 2017 (r314397)
@@ -411,6 +411,23 @@ vprintf(const char *fmt, va_list ap)
}
static void
+prf_putbuf(char *bufr, int flags, int pri)
+{
+
+ if (flags & TOLOG)
+ msglogstr(bufr, pri, /*filter_cr*/1);
+
+ if (flags & TOCONS) {
+ if ((panicstr == NULL) && (constty != NULL))
+ msgbuf_addstr(&consmsgbuf, -1,
+ bufr, /*filter_cr*/ 0);
+
+ if ((constty == NULL) ||(always_console_output))
+ cnputs(bufr);
+ }
+}
+
+static void
putbuf(int c, struct putchar_arg *ap)
{
/* Check if no console output buffer was provided. */
@@ -431,18 +448,7 @@ putbuf(int c, struct putchar_arg *ap)
/* Check if the buffer needs to be flushed. */
if (ap->remain == 2 || c == '\n') {
-
- if (ap->flags & TOLOG)
- msglogstr(ap->p_bufr, ap->pri, /*filter_cr*/1);
-
- if (ap->flags & TOCONS) {
- if ((panicstr == NULL) && (constty != NULL))
- msgbuf_addstr(&consmsgbuf, -1,
- ap->p_bufr, /*filter_cr*/ 0);
-
- if ((constty == NULL) ||(always_console_output))
- cnputs(ap->p_bufr);
- }
+ prf_putbuf(ap->p_bufr, ap->flags, ap->pri);
ap->p_next = ap->p_bufr;
ap->remain = ap->n_bufr;
@@ -1221,3 +1227,19 @@ counted_warning(unsigned *counter, const
}
}
#endif
+
+#ifdef _KERNEL
+void
+sbuf_putbuf(struct sbuf *sb)
+{
+
+ prf_putbuf(sbuf_data(sb), TOLOG | TOCONS, -1);
+}
+#else
+void
+sbuf_putbuf(struct sbuf *sb)
+{
+
+ printf("%s", sbuf_data(sb));
+}
+#endif
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