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authorDavid S. Miller <davem@davemloft.net>2018-06-17 07:54:24 +0900
committerDavid S. Miller <davem@davemloft.net>2018-06-17 07:54:24 +0900
commit0841d98641bdb9c7f873adf7f6865ab0880ddfc7 (patch)
treeca7beb6acb47518f53c3e5591a5b1c8ccabcbcc5 /kernel
parent35773c93817c5f2df264d013978e7551056a063a (diff)
parent6d5fc1957989266006db6ef3dfb9159b42cf0189 (diff)
downloadop-kernel-dev-0841d98641bdb9c7f873adf7f6865ab0880ddfc7.zip
op-kernel-dev-0841d98641bdb9c7f873adf7f6865ab0880ddfc7.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says: ==================== pull-request: bpf 2018-06-16 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix a panic in devmap handling in generic XDP where return type of __devmap_lookup_elem() got changed recently but generic XDP code missed the related update, from Toshiaki. 2) Fix a freeze when BPF progs are loaded that include BPF to BPF calls when JIT is enabled where we would later bail out via error path w/o dropping kallsyms, and another one to silence syzkaller splats from locking prog read-only, from Daniel. 3) Fix a bug in test_offloads.py BPF selftest which must not assume that the underlying system have no BPF progs loaded prior to test, and one in bpftool to fix accuracy of program load time, from Jakub. 4) Fix a bug in bpftool's probe for availability of the bpf(2) BPF_TASK_FD_QUERY subcommand, from Yonghong. 5) Fix a regression in AF_XDP's XDP_SKB receive path where queue id check got erroneously removed, from Björn. 6) Fix missing state cleanup in BPF's xfrm tunnel test, from William. 7) Check tunnel type more accurately in BPF's tunnel collect metadata kselftest, from Jian. 8) Fix missing Kconfig fragments for BPF kselftests, from Anders. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/core.c69
-rw-r--r--kernel/bpf/devmap.c14
-rw-r--r--kernel/bpf/syscall.c12
3 files changed, 79 insertions, 16 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 9f14937..a9e6c04 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -350,6 +350,20 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
return prog_adj;
}
+void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
+{
+ int i;
+
+ for (i = 0; i < fp->aux->func_cnt; i++)
+ bpf_prog_kallsyms_del(fp->aux->func[i]);
+}
+
+void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
+{
+ bpf_prog_kallsyms_del_subprogs(fp);
+ bpf_prog_kallsyms_del(fp);
+}
+
#ifdef CONFIG_BPF_JIT
/* All BPF JIT sysctl knobs here. */
int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON);
@@ -584,6 +598,8 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
bpf_fill_ill_insns(hdr, size);
hdr->pages = size / PAGE_SIZE;
+ hdr->locked = 0;
+
hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
PAGE_SIZE - sizeof(*hdr));
start = (get_random_int() % hole) & ~(alignment - 1);
@@ -1434,6 +1450,33 @@ static int bpf_check_tail_call(const struct bpf_prog *fp)
return 0;
}
+static int bpf_prog_check_pages_ro_locked(const struct bpf_prog *fp)
+{
+#ifdef CONFIG_ARCH_HAS_SET_MEMORY
+ int i, err;
+
+ for (i = 0; i < fp->aux->func_cnt; i++) {
+ err = bpf_prog_check_pages_ro_single(fp->aux->func[i]);
+ if (err)
+ return err;
+ }
+
+ return bpf_prog_check_pages_ro_single(fp);
+#endif
+ return 0;
+}
+
+static void bpf_prog_select_func(struct bpf_prog *fp)
+{
+#ifndef CONFIG_BPF_JIT_ALWAYS_ON
+ u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
+
+ fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
+#else
+ fp->bpf_func = __bpf_prog_ret0_warn;
+#endif
+}
+
/**
* bpf_prog_select_runtime - select exec runtime for BPF program
* @fp: bpf_prog populated with internal BPF program
@@ -1444,13 +1487,13 @@ static int bpf_check_tail_call(const struct bpf_prog *fp)
*/
struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
{
-#ifndef CONFIG_BPF_JIT_ALWAYS_ON
- u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
+ /* In case of BPF to BPF calls, verifier did all the prep
+ * work with regards to JITing, etc.
+ */
+ if (fp->bpf_func)
+ goto finalize;
- fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
-#else
- fp->bpf_func = __bpf_prog_ret0_warn;
-#endif
+ bpf_prog_select_func(fp);
/* eBPF JITs can rewrite the program in case constant
* blinding is active. However, in case of error during
@@ -1471,6 +1514,8 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
if (*err)
return fp;
}
+
+finalize:
bpf_prog_lock_ro(fp);
/* The tail call compatibility check can only be done at
@@ -1479,7 +1524,17 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
* all eBPF JITs might immediately support all features.
*/
*err = bpf_check_tail_call(fp);
-
+ if (*err)
+ return fp;
+
+ /* Checkpoint: at this point onwards any cBPF -> eBPF or
+ * native eBPF program is read-only. If we failed to change
+ * the page attributes (e.g. allocation failure from
+ * splitting large pages), then reject the whole program
+ * in order to guarantee not ending up with any W+X pages
+ * from BPF side in kernel.
+ */
+ *err = bpf_prog_check_pages_ro_locked(fp);
return fp;
}
EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index a7cc7b3..642c97f 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -345,6 +345,20 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
return bq_enqueue(dst, xdpf, dev_rx);
}
+int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
+ struct bpf_prog *xdp_prog)
+{
+ int err;
+
+ err = __xdp_generic_ok_fwd_dev(skb, dst->dev);
+ if (unlikely(err))
+ return err;
+ skb->dev = dst->dev;
+ generic_xdp_tx(skb, xdp_prog);
+
+ return 0;
+}
+
static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
{
struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0fa2062..35dc466 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1034,14 +1034,9 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu)
static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
{
if (atomic_dec_and_test(&prog->aux->refcnt)) {
- int i;
-
/* bpf_prog_free_id() must be called first */
bpf_prog_free_id(prog, do_idr_lock);
-
- for (i = 0; i < prog->aux->func_cnt; i++)
- bpf_prog_kallsyms_del(prog->aux->func[i]);
- bpf_prog_kallsyms_del(prog);
+ bpf_prog_kallsyms_del_all(prog);
call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
}
@@ -1358,9 +1353,7 @@ static int bpf_prog_load(union bpf_attr *attr)
if (err < 0)
goto free_used_maps;
- /* eBPF program is ready to be JITed */
- if (!prog->bpf_func)
- prog = bpf_prog_select_runtime(prog, &err);
+ prog = bpf_prog_select_runtime(prog, &err);
if (err < 0)
goto free_used_maps;
@@ -1384,6 +1377,7 @@ static int bpf_prog_load(union bpf_attr *attr)
return err;
free_used_maps:
+ bpf_prog_kallsyms_del_subprogs(prog);
free_used_maps(prog->aux);
free_prog:
bpf_prog_uncharge_memlock(prog);
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