1 files changed, 78 insertions, 2 deletions

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 7f0dbcbb34af..b54bb2c2e494 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -22,6 +22,7 @@
  */
 #include <linux/filter.h>
 #include <linux/skbuff.h>
+#include <linux/vmalloc.h>
 #include <asm/unaligned.h>
 
 /* Registers */
@@ -63,6 +64,67 @@ void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, uns
         return NULL;
 }
 
+struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
+{
+        gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
+                          gfp_extra_flags;
+        struct bpf_work_struct *ws;
+        struct bpf_prog *fp;
+
+        size = round_up(size, PAGE_SIZE);
+        fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
+        if (fp == NULL)
+                return NULL;
+
+        ws = kmalloc(sizeof(*ws), GFP_KERNEL | gfp_extra_flags);
+        if (ws == NULL) {
+                vfree(fp);
+                return NULL;
+        }
+
+        fp->pages = size / PAGE_SIZE;
+        fp->work = ws;
+
+        return fp;
+}
+EXPORT_SYMBOL_GPL(bpf_prog_alloc);
+
+struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
+                                  gfp_t gfp_extra_flags)
+{
+        gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
+                          gfp_extra_flags;
+        struct bpf_prog *fp;
+
+        BUG_ON(fp_old == NULL);
+
+        size = round_up(size, PAGE_SIZE);
+        if (size <= fp_old->pages * PAGE_SIZE)
+                return fp_old;
+
+        fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
+        if (fp != NULL) {
+                memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
+                fp->pages = size / PAGE_SIZE;
+
+                /* We keep fp->work from fp_old around in the new
+                 * reallocated structure.
+                 */
+                fp_old->work = NULL;
+                __bpf_prog_free(fp_old);
+        }
+
+        return fp;
+}
+EXPORT_SYMBOL_GPL(bpf_prog_realloc);
+
+void __bpf_prog_free(struct bpf_prog *fp)
+{
+        kfree(fp->work);
+        vfree(fp);
+}
+EXPORT_SYMBOL_GPL(__bpf_prog_free);
+
 /* Base function for offset calculation. Needs to go into .text section,
  * therefore keeping it non-static as well; will also be used by JITs
  * anyway later on, so do not let the compiler omit it.
@@ -523,12 +585,26 @@ void bpf_prog_select_runtime(struct bpf_prog *fp)
 
         /* Probe if internal BPF can be JITed */
         bpf_int_jit_compile(fp);
+        /* Lock whole bpf_prog as read-only */
+        bpf_prog_lock_ro(fp);
 }
 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
 
-/* free internal BPF program */
+static void bpf_prog_free_deferred(struct work_struct *work)
+{
+        struct bpf_work_struct *ws;
+
+        ws = container_of(work, struct bpf_work_struct, work);
+        bpf_jit_free(ws->prog);
+}
+
+/* Free internal BPF program */
 void bpf_prog_free(struct bpf_prog *fp)
 {
-        bpf_jit_free(fp);
+        struct bpf_work_struct *ws = fp->work;
+
+        INIT_WORK(&ws->work, bpf_prog_free_deferred);
+        ws->prog = fp;
+        schedule_work(&ws->work);
 }
 EXPORT_SYMBOL_GPL(bpf_prog_free);