Commit 31674900 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 

Daniel Borkmann says:

====================
pull-request: bpf 2021-08-19

We've added 3 non-merge commits during the last 3 day(s) which contain
a total of 3 files changed, 29 insertions(+), 6 deletions(-).

The main changes are:

1) Fix to clear zext_dst for dead instructions which was causing invalid program
   rejections on JITs with bpf_jit_needs_zext such as s390x, from Ilya Leoshkevich.

2) Fix RCU splat in bpf_get_current_{ancestor_,}cgroup_id() helpers when they are
   invoked from sleepable programs, from Yonghong Song.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests, bpf: Test that dead ldx_w insns are accepted
  bpf: Clear zext_dst of dead insns
  bpf: Add rcu_read_lock in bpf_get_current_[ancestor_]cgroup_id() helpers
====================

Link: https://lore.kernel.org/r/20210819144904.20069-1-daniel@iogearbox.net


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents c15128c9 3776f351

kernel/bpf/helpers.c

+16 −6
Original line number Diff line number Diff line
@@ -353,9 +353,15 @@ const struct bpf_func_proto bpf_jiffies64_proto = { 
#ifdef CONFIG_CGROUPS

BPF_CALL_0(bpf_get_current_cgroup_id)

{

	struct cgroup *cgrp = task_dfl_cgroup(current);

	struct cgroup *cgrp;

	u64 cgrp_id;



	return cgroup_id(cgrp);

	rcu_read_lock();

	cgrp = task_dfl_cgroup(current);

	cgrp_id = cgroup_id(cgrp);

	rcu_read_unlock();



	return cgrp_id;

}



const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
@@ -366,13 +372,17 @@ const struct bpf_func_proto bpf_get_current_cgroup_id_proto = { 


BPF_CALL_1(bpf_get_current_ancestor_cgroup_id, int, ancestor_level)

{

	struct cgroup *cgrp = task_dfl_cgroup(current);

	struct cgroup *cgrp;

	struct cgroup *ancestor;

	u64 cgrp_id;



	rcu_read_lock();

	cgrp = task_dfl_cgroup(current);

	ancestor = cgroup_ancestor(cgrp, ancestor_level);

	if (!ancestor)

		return 0;

	return cgroup_id(ancestor);

	cgrp_id = ancestor ? cgroup_id(ancestor) : 0;

	rcu_read_unlock();



	return cgrp_id;

}



const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {

kernel/bpf/verifier.c

+1 −0
Original line number Diff line number Diff line
@@ -11663,6 +11663,7 @@ static void sanitize_dead_code(struct bpf_verifier_env *env) 
		if (aux_data[i].seen)

			continue;

		memcpy(insn + i, &trap, sizeof(trap));

		aux_data[i].zext_dst = false;

	}

}

tools/testing/selftests/bpf/verifier/dead_code.c

+12 −0
Original line number Diff line number Diff line
@@ -159,3 +159,15 @@ 
	.result = ACCEPT,

	.retval = 2,

},

{

	"dead code: zero extension",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4),

	BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),

	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),

	BPF_EXIT_INSN(),

	},

	.result = ACCEPT,

	.retval = 0,

},