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authorJakub Kicinski <kuba@kernel.org>2020-11-07 04:49:31 +0300
committerJakub Kicinski <kuba@kernel.org>2020-11-07 04:49:34 +0300
commit86bbf01977b4fdfffc8cab46e398ff279380b194 (patch)
tree79016c30f90f34b95d29cfbd0f6df99ca7547e6a /kernel
parentbf3e76289cd28b87f679cd53e26d67fd708d718a (diff)
parent6f64e477830000746c1f992050fbd45c03c89429 (diff)
downloadlinux-86bbf01977b4fdfffc8cab46e398ff279380b194.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says: ==================== pull-request: bpf 2020-11-06 1) Pre-allocated per-cpu hashmap needs to zero-fill reused element, from David. 2) Tighten bpf_lsm function check, from KP. 3) Fix bpftool attaching to flow dissector, from Lorenz. 4) Use -fno-gcse for the whole kernel/bpf/core.c instead of function attribute, from Ard. * git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Update verification logic for LSM programs bpf: Zero-fill re-used per-cpu map element bpf: BPF_PRELOAD depends on BPF_SYSCALL tools/bpftool: Fix attaching flow dissector libbpf: Fix possible use after free in xsk_socket__delete libbpf: Fix null dereference in xsk_socket__delete libbpf, hashmap: Fix undefined behavior in hash_bits bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE tools, bpftool: Remove two unused variables. tools, bpftool: Avoid array index warnings. xsk: Fix possible memory leak at socket close bpf: Add struct bpf_redir_neigh forward declaration to BPF helper defs samples/bpf: Set rlimit for memlock to infinity in all samples bpf: Fix -Wshadow warnings selftest/bpf: Fix profiler test using CO-RE relocation for enums ==================== Link: https://lore.kernel.org/r/20201106221759.24143-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/Makefile6
-rw-r--r--kernel/bpf/bpf_lsm.c10
-rw-r--r--kernel/bpf/core.c2
-rw-r--r--kernel/bpf/hashtab.c30
-rw-r--r--kernel/bpf/preload/Kconfig1
5 files changed, 42 insertions, 7 deletions
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index bdc8cd1b6767..c1b9f71ee6aa 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -1,6 +1,10 @@
# SPDX-License-Identifier: GPL-2.0
obj-y := core.o
-CFLAGS_core.o += $(call cc-disable-warning, override-init)
+ifneq ($(CONFIG_BPF_JIT_ALWAYS_ON),y)
+# ___bpf_prog_run() needs GCSE disabled on x86; see 3193c0836f203 for details
+cflags-nogcse-$(CONFIG_X86)$(CONFIG_CC_IS_GCC) := -fno-gcse
+endif
+CFLAGS_core.o += $(call cc-disable-warning, override-init) $(cflags-nogcse-yy)
obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o bpf_iter.o map_iter.o task_iter.o prog_iter.o
obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index 78ea8a7bd27f..56cc5a915f67 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -13,6 +13,7 @@
#include <linux/bpf_verifier.h>
#include <net/bpf_sk_storage.h>
#include <linux/bpf_local_storage.h>
+#include <linux/btf_ids.h>
/* For every LSM hook that allows attachment of BPF programs, declare a nop
* function where a BPF program can be attached.
@@ -26,7 +27,11 @@ noinline RET bpf_lsm_##NAME(__VA_ARGS__) \
#include <linux/lsm_hook_defs.h>
#undef LSM_HOOK
-#define BPF_LSM_SYM_PREFX "bpf_lsm_"
+#define LSM_HOOK(RET, DEFAULT, NAME, ...) BTF_ID(func, bpf_lsm_##NAME)
+BTF_SET_START(bpf_lsm_hooks)
+#include <linux/lsm_hook_defs.h>
+#undef LSM_HOOK
+BTF_SET_END(bpf_lsm_hooks)
int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog,
const struct bpf_prog *prog)
@@ -37,8 +42,7 @@ int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog,
return -EINVAL;
}
- if (strncmp(BPF_LSM_SYM_PREFX, prog->aux->attach_func_name,
- sizeof(BPF_LSM_SYM_PREFX) - 1)) {
+ if (!btf_id_set_contains(&bpf_lsm_hooks, prog->aux->attach_btf_id)) {
bpf_log(vlog, "attach_btf_id %u points to wrong type name %s\n",
prog->aux->attach_btf_id, prog->aux->attach_func_name);
return -EINVAL;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 9268d77898b7..55454d2278b1 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1369,7 +1369,7 @@ u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
*
* Decode and execute eBPF instructions.
*/
-static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
+static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
{
#define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y
#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 1815e97d4c9c..1fccba6e88c4 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -821,6 +821,32 @@ static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr,
}
}
+static void pcpu_init_value(struct bpf_htab *htab, void __percpu *pptr,
+ void *value, bool onallcpus)
+{
+ /* When using prealloc and not setting the initial value on all cpus,
+ * zero-fill element values for other cpus (just as what happens when
+ * not using prealloc). Otherwise, bpf program has no way to ensure
+ * known initial values for cpus other than current one
+ * (onallcpus=false always when coming from bpf prog).
+ */
+ if (htab_is_prealloc(htab) && !onallcpus) {
+ u32 size = round_up(htab->map.value_size, 8);
+ int current_cpu = raw_smp_processor_id();
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ if (cpu == current_cpu)
+ bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value,
+ size);
+ else
+ memset(per_cpu_ptr(pptr, cpu), 0, size);
+ }
+ } else {
+ pcpu_copy_value(htab, pptr, value, onallcpus);
+ }
+}
+
static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab)
{
return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS &&
@@ -891,7 +917,7 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
}
}
- pcpu_copy_value(htab, pptr, value, onallcpus);
+ pcpu_init_value(htab, pptr, value, onallcpus);
if (!prealloc)
htab_elem_set_ptr(l_new, key_size, pptr);
@@ -1183,7 +1209,7 @@ static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
value, onallcpus);
} else {
- pcpu_copy_value(htab, htab_elem_get_ptr(l_new, key_size),
+ pcpu_init_value(htab, htab_elem_get_ptr(l_new, key_size),
value, onallcpus);
hlist_nulls_add_head_rcu(&l_new->hash_node, head);
l_new = NULL;
diff --git a/kernel/bpf/preload/Kconfig b/kernel/bpf/preload/Kconfig
index ace49111d3a3..26bced262473 100644
--- a/kernel/bpf/preload/Kconfig
+++ b/kernel/bpf/preload/Kconfig
@@ -6,6 +6,7 @@ config USERMODE_DRIVER
menuconfig BPF_PRELOAD
bool "Preload BPF file system with kernel specific program and map iterators"
depends on BPF
+ depends on BPF_SYSCALL
# The dependency on !COMPILE_TEST prevents it from being enabled
# in allmodconfig or allyesconfig configurations
depends on !COMPILE_TEST