The branch main has been updated by netchild: URL: https://cgit.FreeBSD.org/src/commit/?id=c8db6d4b63f18c81557628ad0d3f715bea46cc99
commit c8db6d4b63f18c81557628ad0d3f715bea46cc99 Author: Alexander Leidinger <[email protected]> AuthorDate: 2026-07-21 20:39:56 +0000 Commit: Alexander Leidinger <[email protected]> CommitDate: 2026-07-21 20:50:37 +0000 exterror: advertise error strings via kern.features.exterr_strings Allow userland, in particular test cases for EXTERROR conversions, to detect at run time whether extended errors include the descriptive message strings, which depends on the EXTERR_STRINGS kernel option and cannot be probed in any other way. Reviewed by: kib MFC after: 1 week Assisted-by: Claude Code (Fable 5) Differential Revision: https://reviews.freebsd.org/D58321 --- share/man/man9/exterror.9 | 13 ++++++++++++- sys/kern/sys_generic.c | 4 ++++ 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/share/man/man9/exterror.9 b/share/man/man9/exterror.9 index 47ffda065d43..2c9dc73f7616 100644 --- a/share/man/man9/exterror.9 +++ b/share/man/man9/exterror.9 @@ -6,7 +6,7 @@ .\" Konstantin Belousov <[email protected]> under sponsorship .\" from the FreeBSD Foundation. .\" -.Dd November 5, 2025 +.Dd July 21, 2026 .Dt EXTERROR 9 .Os .Sh NAME @@ -171,6 +171,17 @@ were modified to print the extended information if it is available in addition to the usual .Va errno decoding. +.Pp +Kernels built with the +.Cd option EXTERR_STRINGS +advertise the +.Va kern.features.exterr_strings +.Xr sysctl 8 +variable, see +.Xr feature_present 3 , +indicating that the reported errors include the descriptive message strings. +Without it, only the numeric information (error code, category, +source line number and parameters) is available. .Sh ASYNCHRONOUS INPUT/OUTPUT Due to the nature of the .Fx diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c index c16e806e0bd7..5d356a26359b 100644 --- a/sys/kern/sys_generic.c +++ b/sys/kern/sys_generic.c @@ -112,6 +112,10 @@ static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); MALLOC_DEFINE(M_IOV, "iov", "large iov's"); +#ifdef EXTERR_STRINGS +FEATURE(exterr_strings, "Extended error reporting includes message strings"); +#endif + static int pollout(struct thread *, struct pollfd *, struct pollfd *, u_int); static int pollscan(struct thread *, struct pollfd *, u_int);
