The branch main has been updated by kevans:
URL:
https://cgit.FreeBSD.org/src/commit/?id=58c92776d1580717934e29ca2c0ef9bf2fbb7397
commit 58c92776d1580717934e29ca2c0ef9bf2fbb7397
Author: Kyle Evans <kev...@freebsd.org>
AuthorDate: 2025-08-08 04:26:51 +0000
Commit: Kyle Evans <kev...@freebsd.org>
CommitDate: 2025-08-08 04:26:51 +0000
jail: separate "statically valid allow flags" from "prison0 allow flags"
The current setup means that we can't add an allow flag in sys/jail.h
that's disabled by default without removing it from the pr_flags
assignment in kern_jail.c. That's technically fine, but I think it's
better to make it more prevalent at the PR_ALLOW_* definition site so
that it's top-of-mind when adding a new flag.
This is a preparatory change for adding an allow flag that prison0 will
also have disabled by default, but with an allow.* knob and sysctl to
enable it.
Reviewed by: jamie
Differential Revision: https://reviews.freebsd.org/D51656
---
sys/kern/kern_jail.c | 5 ++++-
sys/sys/jail.h | 8 ++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
index 7ef1d19f0ea8..14e6e735f8e7 100644
--- a/sys/kern/kern_jail.c
+++ b/sys/kern/kern_jail.c
@@ -115,8 +115,11 @@ struct prison prison0 = {
#else
.pr_flags = PR_HOST|_PR_IP_SADDRSEL,
#endif
- .pr_allow = PR_ALLOW_ALL_STATIC,
+ .pr_allow = PR_ALLOW_PRISON0,
};
+_Static_assert((PR_ALLOW_PRISON0 & ~PR_ALLOW_ALL_STATIC) == 0,
+ "Bits enabled in PR_ALLOW_PRISON0 that are not statically reserved");
+
MTX_SYSINIT(prison0, &prison0.pr_mtx, "jail mutex", MTX_DEF);
struct bool_flags {
diff --git a/sys/sys/jail.h b/sys/sys/jail.h
index 24c420e2c976..efe5e3ee8db7 100644
--- a/sys/sys/jail.h
+++ b/sys/sys/jail.h
@@ -260,7 +260,15 @@ struct prison_racct {
#define PR_ALLOW_ADJTIME 0x00080000
#define PR_ALLOW_SETTIME 0x00100000
#define PR_ALLOW_ROUTING 0x00200000
+
+/*
+ * PR_ALLOW_PRISON0 are the allow flags that we apply by default to prison0,
+ * while PR_ALLOW_ALL_STATIC are all of the allow bits that we have allocated
at
+ * build time. PR_ALLOW_ALL_STATIC should contain any bit above that we expect
+ * to be used on the system, while PR_ALLOW_PRISON0 will be some subset of
that.
+ */
#define PR_ALLOW_ALL_STATIC 0x003f87ff
+#define PR_ALLOW_PRISON0 (PR_ALLOW_ALL_STATIC)
/*
* PR_ALLOW_DIFFERENCES determines which flags are able to be
