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-rw-r--r--Documentation/admin-guide/LSM/SafeSetID.rst29
-rw-r--r--Documentation/admin-guide/cpu-load.rst63
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt7
-rw-r--r--Documentation/admin-guide/sysctl/vm.rst2
4 files changed, 62 insertions, 39 deletions
diff --git a/Documentation/admin-guide/LSM/SafeSetID.rst b/Documentation/admin-guide/LSM/SafeSetID.rst
index 7bff07ce4fdd..17996c9070e2 100644
--- a/Documentation/admin-guide/LSM/SafeSetID.rst
+++ b/Documentation/admin-guide/LSM/SafeSetID.rst
@@ -3,9 +3,9 @@ SafeSetID
=========
SafeSetID is an LSM module that gates the setid family of syscalls to restrict
UID/GID transitions from a given UID/GID to only those approved by a
-system-wide whitelist. These restrictions also prohibit the given UIDs/GIDs
+system-wide allowlist. These restrictions also prohibit the given UIDs/GIDs
from obtaining auxiliary privileges associated with CAP_SET{U/G}ID, such as
-allowing a user to set up user namespace UID mappings.
+allowing a user to set up user namespace UID/GID mappings.
Background
@@ -98,10 +98,21 @@ Directions for use
==================
This LSM hooks the setid syscalls to make sure transitions are allowed if an
applicable restriction policy is in place. Policies are configured through
-securityfs by writing to the safesetid/add_whitelist_policy and
-safesetid/flush_whitelist_policies files at the location where securityfs is
-mounted. The format for adding a policy is '<UID>:<UID>', using literal
-numbers, such as '123:456'. To flush the policies, any write to the file is
-sufficient. Again, configuring a policy for a UID will prevent that UID from
-obtaining auxiliary setid privileges, such as allowing a user to set up user
-namespace UID mappings.
+securityfs by writing to the safesetid/uid_allowlist_policy and
+safesetid/gid_allowlist_policy files at the location where securityfs is
+mounted. The format for adding a policy is '<UID>:<UID>' or '<GID>:<GID>',
+using literal numbers, and ending with a newline character such as '123:456\n'.
+Writing an empty string "" will flush the policy. Again, configuring a policy
+for a UID/GID will prevent that UID/GID from obtaining auxiliary setid
+privileges, such as allowing a user to set up user namespace UID/GID mappings.
+
+Note on GID policies and setgroups()
+==================
+In v5.9 we are adding support for limiting CAP_SETGID privileges as was done
+previously for CAP_SETUID. However, for compatibility with common sandboxing
+related code conventions in userspace, we currently allow arbitrary
+setgroups() calls for processes with CAP_SETGID restrictions. Until we add
+support in a future release for restricting setgroups() calls, these GID
+policies add no meaningful security. setgroups() restrictions will be enforced
+once we have the policy checking code in place, which will rely on GID policy
+configuration code added in v5.9.
diff --git a/Documentation/admin-guide/cpu-load.rst b/Documentation/admin-guide/cpu-load.rst
index ebdecf864080..f3ada90e9ca8 100644
--- a/Documentation/admin-guide/cpu-load.rst
+++ b/Documentation/admin-guide/cpu-load.rst
@@ -61,43 +61,46 @@ will lead to quite erratic information inside ``/proc/stat``::
static volatile sig_atomic_t stop;
- static void sighandler (int signr)
+ static void sighandler(int signr)
{
- (void) signr;
- stop = 1;
+ (void) signr;
+ stop = 1;
}
+
static unsigned long hog (unsigned long niters)
{
- stop = 0;
- while (!stop && --niters);
- return niters;
+ stop = 0;
+ while (!stop && --niters);
+ return niters;
}
+
int main (void)
{
- int i;
- struct itimerval it = { .it_interval = { .tv_sec = 0, .tv_usec = 1 },
- .it_value = { .tv_sec = 0, .tv_usec = 1 } };
- sigset_t set;
- unsigned long v[HIST];
- double tmp = 0.0;
- unsigned long n;
- signal (SIGALRM, &sighandler);
- setitimer (ITIMER_REAL, &it, NULL);
-
- hog (ULONG_MAX);
- for (i = 0; i < HIST; ++i) v[i] = ULONG_MAX - hog (ULONG_MAX);
- for (i = 0; i < HIST; ++i) tmp += v[i];
- tmp /= HIST;
- n = tmp - (tmp / 3.0);
-
- sigemptyset (&set);
- sigaddset (&set, SIGALRM);
-
- for (;;) {
- hog (n);
- sigwait (&set, &i);
- }
- return 0;
+ int i;
+ struct itimerval it = {
+ .it_interval = { .tv_sec = 0, .tv_usec = 1 },
+ .it_value = { .tv_sec = 0, .tv_usec = 1 } };
+ sigset_t set;
+ unsigned long v[HIST];
+ double tmp = 0.0;
+ unsigned long n;
+ signal(SIGALRM, &sighandler);
+ setitimer(ITIMER_REAL, &it, NULL);
+
+ hog (ULONG_MAX);
+ for (i = 0; i < HIST; ++i) v[i] = ULONG_MAX - hog(ULONG_MAX);
+ for (i = 0; i < HIST; ++i) tmp += v[i];
+ tmp /= HIST;
+ n = tmp - (tmp / 3.0);
+
+ sigemptyset(&set);
+ sigaddset(&set, SIGALRM);
+
+ for (;;) {
+ hog(n);
+ sigwait(&set, &i);
+ }
+ return 0;
}
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 02d4adbf98d2..526d65d8573a 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5978,6 +5978,13 @@
After which time (jiffies) the event handling loop
should start to delay EOI handling. Default is 2.
+ xen.fifo_events= [XEN]
+ Boolean parameter to disable using fifo event handling
+ even if available. Normally fifo event handling is
+ preferred over the 2-level event handling, as it is
+ fairer and the number of possible event channels is
+ much higher. Default is on (use fifo events).
+
nopv= [X86,XEN,KVM,HYPER_V,VMWARE]
Disables the PV optimizations forcing the guest to run
as generic guest with no PV drivers. Currently support
diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst
index 4b9d2e8e9142..f455fa00c00f 100644
--- a/Documentation/admin-guide/sysctl/vm.rst
+++ b/Documentation/admin-guide/sysctl/vm.rst
@@ -27,6 +27,7 @@ Currently, these files are in /proc/sys/vm:
- admin_reserve_kbytes
- block_dump
- compact_memory
+- compaction_proactiveness
- compact_unevictable_allowed
- dirty_background_bytes
- dirty_background_ratio
@@ -37,6 +38,7 @@ Currently, these files are in /proc/sys/vm:
- dirty_writeback_centisecs
- drop_caches
- extfrag_threshold
+- highmem_is_dirtyable
- hugetlb_shm_group
- laptop_mode
- legacy_va_layout