The manpage claims that kcmp() is now available unconditionally. That's
not true; from kernel/Makefile:
obj-$(CONFIG_KCMP) += kcmp.o
This new Kconfig flag is forced on by CONFIG_CHECKPOINT_RESTORE as
before, but also by CONFIG_DRM, which means that pretty much any kernel
built to support desktop systems will implicitly have it available.
But if you compiled some kind of server/embedded kernel without DRM and
without CHECKPOINT_RESTORE, you'd have to flip on the expert config
option to get KCMP.
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
---
man2/kcmp.2 | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/man2/kcmp.2 b/man2/kcmp.2
index 7acfa8ef8b47..2e4495539645 100644
--- a/man2/kcmp.2
+++ b/man2/kcmp.2
@@ -317,7 +317,9 @@ checkpoint/restore in user space (CRIU) feature.
process information via the
.BR proc (5)
filesystem; this was deemed to be unsuitable for security reasons.)
-Since Linux 5.12, this system call is made available unconditionally.
+Since Linux 5.12, this system call is also available if the kernel is configured
+with
+.BR CONFIG_KCMP .
.PP
See
.BR clone (2)
base-commit: ae6b221882ce71ba82fcdbe02419a225111502f0
--
2.34.1.400.ga245620fadb-goog
