]> asedeno.scripts.mit.edu Git - linux.git/blobdiff - kernel/bpf/core.c
Merge tag 'linux-kselftest-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel...
[linux.git] / kernel / bpf / core.c
index ef0e1e3e66f4a50308819a332812fa5e88488afe..49e32acad7d80e310376c137453fffd97ac234c6 100644 (file)
@@ -30,7 +30,8 @@
 #include <linux/kallsyms.h>
 #include <linux/rcupdate.h>
 #include <linux/perf_event.h>
-
+#include <linux/extable.h>
+#include <linux/log2.h>
 #include <asm/unaligned.h>
 
 /* Registers */
@@ -255,6 +256,7 @@ void __bpf_prog_free(struct bpf_prog *fp)
 {
        if (fp->aux) {
                free_percpu(fp->aux->stats);
+               kfree(fp->aux->poke_tab);
                kfree(fp->aux);
        }
        vfree(fp);
@@ -668,9 +670,6 @@ static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
 {
        struct latch_tree_node *n;
 
-       if (!bpf_jit_kallsyms_enabled())
-               return NULL;
-
        n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
        return n ?
               container_of(n, struct bpf_prog_aux, ksym_tnode)->prog :
@@ -712,6 +711,24 @@ bool is_bpf_text_address(unsigned long addr)
        return ret;
 }
 
+const struct exception_table_entry *search_bpf_extables(unsigned long addr)
+{
+       const struct exception_table_entry *e = NULL;
+       struct bpf_prog *prog;
+
+       rcu_read_lock();
+       prog = bpf_prog_kallsyms_find(addr);
+       if (!prog)
+               goto out;
+       if (!prog->aux->num_exentries)
+               goto out;
+
+       e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
+out:
+       rcu_read_unlock();
+       return e;
+}
+
 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
                    char *sym)
 {
@@ -740,6 +757,39 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
        return ret;
 }
 
+int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
+                               struct bpf_jit_poke_descriptor *poke)
+{
+       struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
+       static const u32 poke_tab_max = 1024;
+       u32 slot = prog->aux->size_poke_tab;
+       u32 size = slot + 1;
+
+       if (size > poke_tab_max)
+               return -ENOSPC;
+       if (poke->ip || poke->ip_stable || poke->adj_off)
+               return -EINVAL;
+
+       switch (poke->reason) {
+       case BPF_POKE_REASON_TAIL_CALL:
+               if (!poke->tail_call.map)
+                       return -EINVAL;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
+       if (!tab)
+               return -ENOMEM;
+
+       memcpy(&tab[slot], poke, sizeof(*poke));
+       prog->aux->size_poke_tab = size;
+       prog->aux->poke_tab = tab;
+
+       return slot;
+}
+
 static atomic_long_t bpf_jit_current;
 
 /* Can be overridden by an arch's JIT compiler if it has a custom,
@@ -800,6 +850,9 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
        struct bpf_binary_header *hdr;
        u32 size, hole, start, pages;
 
+       WARN_ON_ONCE(!is_power_of_2(alignment) ||
+                    alignment > BPF_IMAGE_ALIGNMENT);
+
        /* Most of BPF filters are really small, but if some of them
         * fill a page, allow at least 128 extra bytes to insert a
         * random section of illegal instructions.
@@ -1291,6 +1344,12 @@ bool bpf_opcode_in_insntable(u8 code)
 }
 
 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
+u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
+{
+       memset(dst, 0, size);
+       return -EFAULT;
+}
+
 /**
  *     __bpf_prog_run - run eBPF program on a given context
  *     @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
@@ -1310,6 +1369,10 @@ static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u6
                /* Non-UAPI available opcodes. */
                [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
                [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
+               [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
+               [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
+               [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
+               [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
        };
 #undef BPF_INSN_3_LBL
 #undef BPF_INSN_2_LBL
@@ -1542,6 +1605,16 @@ static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u6
        LDST(W,  u32)
        LDST(DW, u64)
 #undef LDST
+#define LDX_PROBE(SIZEOP, SIZE)                                                        \
+       LDX_PROBE_MEM_##SIZEOP:                                                 \
+               bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off));      \
+               CONT;
+       LDX_PROBE(B,  1)
+       LDX_PROBE(H,  2)
+       LDX_PROBE(W,  4)
+       LDX_PROBE(DW, 8)
+#undef LDX_PROBE
+
        STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
                atomic_add((u32) SRC, (atomic_t *)(unsigned long)
                           (DST + insn->off));
@@ -1652,18 +1725,17 @@ bool bpf_prog_array_compatible(struct bpf_array *array,
        if (fp->kprobe_override)
                return false;
 
-       if (!array->owner_prog_type) {
+       if (!array->aux->type) {
                /* There's no owner yet where we could check for
                 * compatibility.
                 */
-               array->owner_prog_type = fp->type;
-               array->owner_jited = fp->jited;
-
+               array->aux->type  = fp->type;
+               array->aux->jited = fp->jited;
                return true;
        }
 
-       return array->owner_prog_type == fp->type &&
-              array->owner_jited == fp->jited;
+       return array->aux->type  == fp->type &&
+              array->aux->jited == fp->jited;
 }
 
 static int bpf_check_tail_call(const struct bpf_prog *fp)
@@ -1964,18 +2036,47 @@ int bpf_prog_array_copy_info(struct bpf_prog_array *array,
                                                                     : 0;
 }
 
+static void bpf_free_cgroup_storage(struct bpf_prog_aux *aux)
+{
+       enum bpf_cgroup_storage_type stype;
+
+       for_each_cgroup_storage_type(stype) {
+               if (!aux->cgroup_storage[stype])
+                       continue;
+               bpf_cgroup_storage_release(aux->prog,
+                                          aux->cgroup_storage[stype]);
+       }
+}
+
+static void bpf_free_used_maps(struct bpf_prog_aux *aux)
+{
+       struct bpf_map *map;
+       int i;
+
+       bpf_free_cgroup_storage(aux);
+       for (i = 0; i < aux->used_map_cnt; i++) {
+               map = aux->used_maps[i];
+               if (map->ops->map_poke_untrack)
+                       map->ops->map_poke_untrack(map, aux);
+               bpf_map_put(map);
+       }
+       kfree(aux->used_maps);
+}
+
 static void bpf_prog_free_deferred(struct work_struct *work)
 {
        struct bpf_prog_aux *aux;
        int i;
 
        aux = container_of(work, struct bpf_prog_aux, work);
+       bpf_free_used_maps(aux);
        if (bpf_prog_is_dev_bound(aux))
                bpf_prog_offload_destroy(aux->prog);
 #ifdef CONFIG_PERF_EVENTS
        if (aux->prog->has_callchain_buf)
                put_callchain_buffers();
 #endif
+       bpf_trampoline_put(aux->trampoline);
        for (i = 0; i < aux->func_cnt; i++)
                bpf_jit_free(aux->func[i]);
        if (aux->func_cnt) {
@@ -1991,6 +2092,8 @@ void bpf_prog_free(struct bpf_prog *fp)
 {
        struct bpf_prog_aux *aux = fp->aux;
 
+       if (aux->linked_prog)
+               bpf_prog_put(aux->linked_prog);
        INIT_WORK(&aux->work, bpf_prog_free_deferred);
        schedule_work(&aux->work);
 }
@@ -2105,6 +2208,12 @@ int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
        return -EFAULT;
 }
 
+int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
+                             void *addr1, void *addr2)
+{
+       return -ENOTSUPP;
+}
+
 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 EXPORT_SYMBOL(bpf_stats_enabled_key);