Rust-for-Linux
diff --git a/‎Documentation/PCI/pci-error-recovery.rst
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diff --git a/‎Documentation/bpf/bpf_design_QA.rst
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diff --git a/‎Documentation/bpf/bpf_devel_QA.rst
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diff --git a/‎Documentation/bpf/clang-notes.rst
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diff --git a/‎Documentation/bpf/cpumasks.rst
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@@ -418,7 +418,6 @@ That is, the recovery API only requires that:
    - drivers/next/e100.c
    - drivers/net/e1000
    - drivers/net/e1000e
-   - drivers/net/ixgb
    - drivers/net/ixgbe
    - drivers/net/cxgb3
    - drivers/net/s2io.c
 
@@ -314,7 +314,7 @@ Q: What is the compatibility story for special BPF types in map values?
 Q: Users are allowed to embed bpf_spin_lock, bpf_timer fields in their BPF map
 values (when using BTF support for BPF maps). This allows to use helpers for
 such objects on these fields inside map values. Users are also allowed to embed
-pointers to some kernel types (with __kptr and __kptr_ref BTF tags). Will the
+pointers to some kernel types (with __kptr_untrusted and __kptr BTF tags). Will the
 kernel preserve backwards compatibility for these features?
 
 A: It depends. For bpf_spin_lock, bpf_timer: YES, for kptr and everything else:
@@ -324,7 +324,7 @@ For struct types that have been added already, like bpf_spin_lock and bpf_timer,
 the kernel will preserve backwards compatibility, as they are part of UAPI.
 
 For kptrs, they are also part of UAPI, but only with respect to the kptr
-mechanism. The types that you can use with a __kptr and __kptr_ref tagged
+mechanism. The types that you can use with a __kptr_untrusted and __kptr tagged
 pointer in your struct are NOT part of the UAPI contract. The supported types can
 and will change across kernel releases. However, operations like accessing kptr
 fields and bpf_kptr_xchg() helper will continue to be supported across kernel
 
@@ -128,7 +128,8 @@ into the bpf-next tree will make their way into net-next tree. net and
 net-next are both run by David S. Miller. From there, they will go
 into the kernel mainline tree run by Linus Torvalds. To read up on the
 process of net and net-next being merged into the mainline tree, see
-the :ref:`netdev-FAQ`
+the documentation on netdev subsystem at
+Documentation/process/maintainer-netdev.rst.
 
 
 
@@ -147,7 +148,8 @@ request)::
 Q: How do I indicate which tree (bpf vs. bpf-next) my patch should be applied to?
 ---------------------------------------------------------------------------------
 
-A: The process is the very same as described in the :ref:`netdev-FAQ`,
+A: The process is the very same as described in the netdev subsystem
+documentation at Documentation/process/maintainer-netdev.rst,
 so please read up on it. The subject line must indicate whether the
 patch is a fix or rather "next-like" content in order to let the
 maintainers know whether it is targeted at bpf or bpf-next.
@@ -206,8 +208,9 @@ ii) run extensive BPF test suite and
 Once the BPF pull request was accepted by David S. Miller, then
 the patches end up in net or net-next tree, respectively, and
 make their way from there further into mainline. Again, see the
-:ref:`netdev-FAQ` for additional information e.g. on how often they are
-merged to mainline.
+documentation for netdev subsystem at
+Documentation/process/maintainer-netdev.rst for additional information
+e.g. on how often they are merged to mainline.
 
 Q: How long do I need to wait for feedback on my BPF patches?
 -------------------------------------------------------------
@@ -230,7 +233,8 @@ Q: Are patches applied to bpf-next when the merge window is open?
 -----------------------------------------------------------------
 A: For the time when the merge window is open, bpf-next will not be
 processed. This is roughly analogous to net-next patch processing,
-so feel free to read up on the :ref:`netdev-FAQ` about further details.
+so feel free to read up on the netdev docs at
+Documentation/process/maintainer-netdev.rst about further details.
 
 During those two weeks of merge window, we might ask you to resend
 your patch series once bpf-next is open again. Once Linus released
@@ -394,7 +398,8 @@ netdev kernel mailing list in Cc and ask for the fix to be queued up:
   [email protected]
 
 The process in general is the same as on netdev itself, see also the
-:ref:`netdev-FAQ`.
+the documentation on networking subsystem at
+Documentation/process/maintainer-netdev.rst.
 
 Q: Do you also backport to kernels not currently maintained as stable?
 ----------------------------------------------------------------------
@@ -410,7 +415,7 @@ Q: The BPF patch I am about to submit needs to go to stable as well
 What should I do?
 
 A: The same rules apply as with netdev patch submissions in general, see
-the :ref:`netdev-FAQ`.
+the netdev docs at Documentation/process/maintainer-netdev.rst.
 
 Never add "``Cc: [email protected]``" to the patch description, but
 ask the BPF maintainers to queue the patches instead. This can be done
@@ -684,7 +689,6 @@ when:
 
 
 .. Links
-.. _netdev-FAQ: Documentation/process/maintainer-netdev.rst
 .. _selftests:
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/testing/selftests/bpf/
 
 
@@ -20,6 +20,12 @@ Arithmetic instructions
 For CPU versions prior to 3, Clang v7.0 and later can enable ``BPF_ALU`` support with
 ``-Xclang -target-feature -Xclang +alu32``.  In CPU version 3, support is automatically included.
 
+Jump instructions
+=================
+
+If ``-O0`` is used, Clang will generate the ``BPF_CALL | BPF_X | BPF_JMP`` (0x8d)
+instruction, which is not supported by the Linux kernel verifier.
+
 Atomic operations
 =================
 
 
@@ -51,7 +51,7 @@ For example:
 .. code-block:: c
 
         struct cpumask_map_value {
-                struct bpf_cpumask __kptr_ref * cpumask;
+                struct bpf_cpumask __kptr * cpumask;
         };
 
         struct array_map {
@@ -117,18 +117,13 @@ For example:
 As mentioned and illustrated above, these ``struct bpf_cpumask *`` objects can
 also be stored in a map and used as kptrs. If a ``struct bpf_cpumask *`` is in
 a map, the reference can be removed from the map with bpf_kptr_xchg(), or
-opportunistically acquired with bpf_cpumask_kptr_get():
-
-.. kernel-doc:: kernel/bpf/cpumask.c
-  :identifiers: bpf_cpumask_kptr_get
-
-Here is an example of a ``struct bpf_cpumask *`` being retrieved from a map:
+opportunistically acquired using RCU:
 
 .. code-block:: c
 
 	/* struct containing the struct bpf_cpumask kptr which is stored in the map. */
 	struct cpumasks_kfunc_map_value {
-		struct bpf_cpumask __kptr_ref * bpf_cpumask;
+		struct bpf_cpumask __kptr * bpf_cpumask;
 	};
 
 	/* The map containing struct cpumasks_kfunc_map_value entries. */
@@ -144,7 +139,7 @@ Here is an example of a ``struct bpf_cpumask *`` being retrieved from a map:
 	/**
 	 * A simple example tracepoint program showing how a
 	 * struct bpf_cpumask * kptr that is stored in a map can
-	 * be acquired using the bpf_cpumask_kptr_get() kfunc.
+	 * be passed to kfuncs using RCU protection.
 	 */
 	SEC("tp_btf/cgroup_mkdir")
 	int BPF_PROG(cgrp_ancestor_example, struct cgroup *cgrp, const char *path)
@@ -158,26 +153,21 @@ Here is an example of a ``struct bpf_cpumask *`` being retrieved from a map:
 		if (!v)
 			return -ENOENT;
 
+		bpf_rcu_read_lock();
 		/* Acquire a reference to the bpf_cpumask * kptr that's already stored in the map. */
-		kptr = bpf_cpumask_kptr_get(&v->cpumask);
-		if (!kptr)
+		kptr = v->cpumask;
+		if (!kptr) {
 			/* If no bpf_cpumask was present in the map, it's because
 			 * we're racing with another CPU that removed it with
 			 * bpf_kptr_xchg() between the bpf_map_lookup_elem()
-			 * above, and our call to bpf_cpumask_kptr_get().
-			 * bpf_cpumask_kptr_get() internally safely handles this
-			 * race, and will return NULL if the cpumask is no longer
-			 * present in the map by the time we invoke the kfunc.
+			 * above, and our load of the pointer from the map.
 			 */
+			bpf_rcu_read_unlock();
 			return -EBUSY;
+		}
 
-		/* Free the reference we just took above. Note that the
-		 * original struct bpf_cpumask * kptr is still in the map. It will
-		 * be freed either at a later time if another context deletes
-		 * it from the map, or automatically by the BPF subsystem if
-		 * it's still present when the map is destroyed.
-		 */
-		bpf_cpumask_release(kptr);
+		bpf_cpumask_setall(kptr);
+		bpf_rcu_read_unlock();
 
 		return 0;
 	}