Author: rlibby Date: Mon Nov 25 07:38:27 2019 New Revision: 355083 URL: https://svnweb.freebsd.org/changeset/base/355083
Log: sysctl sysctls: wire old buf before output with sysctl lock Several sysctl sysctls output to a user buffer while holding a non-sleepable lock that protects the sysctl topology. They need to wire the output buffer, or else they may try to sleep on a page fault. Reviewed by: cem, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22528 Modified: head/sys/kern/kern_sysctl.c Modified: head/sys/kern/kern_sysctl.c ============================================================================== --- head/sys/kern/kern_sysctl.c Mon Nov 25 07:13:05 2019 (r355082) +++ head/sys/kern/kern_sysctl.c Mon Nov 25 07:38:27 2019 (r355083) @@ -1023,12 +1023,16 @@ sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) { int *name = (int *) arg1; u_int namelen = arg2; - int error = 0; + int error; struct sysctl_oid *oid; struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; struct rm_priotracker tracker; char buf[10]; + error = sysctl_wire_old_buffer(req, 0); + if (error) + return (error); + SYSCTL_RLOCK(&tracker); while (namelen) { if (!lsp) { @@ -1265,6 +1269,10 @@ sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) struct rm_priotracker tracker; int error; + error = sysctl_wire_old_buffer(req, 0); + if (error) + return (error); + SYSCTL_RLOCK(&tracker); error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); if (error) @@ -1294,6 +1302,10 @@ sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) struct rm_priotracker tracker; int error; + error = sysctl_wire_old_buffer(req, 0); + if (error) + return (error); + SYSCTL_RLOCK(&tracker); error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); if (error) @@ -1318,6 +1330,10 @@ sysctl_sysctl_oidlabel(SYSCTL_HANDLER_ARGS) struct sysctl_oid *oid; struct rm_priotracker tracker; int error; + + error = sysctl_wire_old_buffer(req, 0); + if (error) + return (error); SYSCTL_RLOCK(&tracker); error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
