Author: gallatin
Date: Mon Jul 31 14:56:35 2017
New Revision: 321790
URL:
https://urldefense.proofpoint.com/v2/url?u=https-3A__svnweb.freebsd.org_changeset_base_321790&d=DwICAg&c=imBPVzF25OnBgGmVOlcsiEgHoG1i6YHLR0Sj_gZ4adc&r=Ed-falealxPeqc22ehgAUCLh8zlZbibZLSMWJeZro4A&m=6pTZhALOHVMuNxvC0RsuEoG4j_dKwjmuXgxC_aZLwj4&s=iX60l0OLjrKSEAZM1J0IrtmCEX_ZvHr2sMgDd4SdHxg&e=
Log:
Don't request CTLTYPE_OPAQUE if we can't print them.
The intent is to skip expensive opaque sysctls like tcp_pcblist unless
they are explicitly requested. Sysctl nodes like this don't show up in
sysctl -a, but they do generate output that winds up being dropped,
unless the user specifically requested binary/hex output or opaques.
This reduces the runtime of sysctl in many circumstances on a loaded
system. It also reduces the likelihood that simply gathering
diagnostics on a sick machine (stuck lock, etc) via sysctl -a might
push it over the edge into a total lockup.
Reviewed by: jtl
Sponsored by: Netflix
Differential Revision:
https://urldefense.proofpoint.com/v2/url?u=https-3A__reviews.freebsd.org_D11461&d=DwICAg&c=imBPVzF25OnBgGmVOlcsiEgHoG1i6YHLR0Sj_gZ4adc&r=Ed-falealxPeqc22ehgAUCLh8zlZbibZLSMWJeZro4A&m=6pTZhALOHVMuNxvC0RsuEoG4j_dKwjmuXgxC_aZLwj4&s=b-hXEv1EHJwVhKxSsmgugUz3RBcGHN7oxcMcI3Dbp_c&e=
Modified:
head/sbin/sysctl/sysctl.c
Modified: head/sbin/sysctl/sysctl.c
==============================================================================
--- head/sbin/sysctl/sysctl.c Mon Jul 31 14:53:03 2017 (r321789)
+++ head/sbin/sysctl/sysctl.c Mon Jul 31 14:56:35 2017 (r321790)
@@ -925,6 +925,32 @@ show_var(int *oid, int nlen)
printf("%s", buf);
return (0);
}
+
+ /* don't fetch opaques that we don't know how to print */
+ if (ctltype == CTLTYPE_OPAQUE) {
+ if (strcmp(fmt, "S,clockinfo") == 0)
+ func = S_clockinfo;
+ else if (strcmp(fmt, "S,timeval") == 0)
+ func = S_timeval;
+ else if (strcmp(fmt, "S,loadavg") == 0)
+ func = S_loadavg;
+ else if (strcmp(fmt, "S,vmtotal") == 0)
+ func = S_vmtotal;
+#ifdef __amd64__
+ else if (strcmp(fmt, "S,efi_map_header") == 0)
+ func = S_efi_map;
+#endif
+#if defined(__amd64__) || defined(__i386__)
+ else if (strcmp(fmt, "S,bios_smap_xattr") == 0)
+ func = S_bios_smap_xattr;
+#endif
+ else {
+ func = NULL;
+ if (!bflag && !oflag && !xflag)
+ return (1);
+ }
+ }
+
/* find an estimate of how much we need for this var */
if (Bflag)
j = Bflag;
@@ -1045,24 +1071,6 @@ show_var(int *oid, int nlen)
case CTLTYPE_OPAQUE:
i = 0;
- if (strcmp(fmt, "S,clockinfo") == 0)
- func = S_clockinfo;
- else if (strcmp(fmt, "S,timeval") == 0)
- func = S_timeval;
- else if (strcmp(fmt, "S,loadavg") == 0)
- func = S_loadavg;
- else if (strcmp(fmt, "S,vmtotal") == 0)
- func = S_vmtotal;
-#ifdef __amd64__
- else if (strcmp(fmt, "S,efi_map_header") == 0)
- func = S_efi_map;
-#endif
-#if defined(__amd64__) || defined(__i386__)
- else if (strcmp(fmt, "S,bios_smap_xattr") == 0)
- func = S_bios_smap_xattr;
-#endif
- else
- func = NULL;
if (func) {
