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-rw-r--r--kernel/bpf/core.c127
1 files changed, 125 insertions, 2 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 7f0dbcbb34af..f0c30c59b317 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -20,9 +20,14 @@
* Andi Kleen - Fix a few bad bugs and races.
* Kris Katterjohn - Added many additional checks in bpf_check_classic()
*/
+
#include <linux/filter.h>
#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
+#include <linux/random.h>
+#include <linux/moduleloader.h>
#include <asm/unaligned.h>
+#include <linux/bpf.h>
/* Registers */
#define BPF_R0 regs[BPF_REG_0]
@@ -63,6 +68,105 @@ 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_prog_aux *aux;
+ struct bpf_prog *fp;
+
+ size = round_up(size, PAGE_SIZE);
+ fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
+ if (fp == NULL)
+ return NULL;
+
+ aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
+ if (aux == NULL) {
+ vfree(fp);
+ return NULL;
+ }
+
+ fp->pages = size / PAGE_SIZE;
+ fp->aux = aux;
+
+ 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->aux from fp_old around in the new
+ * reallocated structure.
+ */
+ fp_old->aux = NULL;
+ __bpf_prog_free(fp_old);
+ }
+
+ return fp;
+}
+EXPORT_SYMBOL_GPL(bpf_prog_realloc);
+
+void __bpf_prog_free(struct bpf_prog *fp)
+{
+ kfree(fp->aux);
+ vfree(fp);
+}
+EXPORT_SYMBOL_GPL(__bpf_prog_free);
+
+#ifdef CONFIG_BPF_JIT
+struct bpf_binary_header *
+bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
+ unsigned int alignment,
+ bpf_jit_fill_hole_t bpf_fill_ill_insns)
+{
+ struct bpf_binary_header *hdr;
+ unsigned int size, hole, start;
+
+ /* 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.
+ */
+ size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
+ hdr = module_alloc(size);
+ if (hdr == NULL)
+ return NULL;
+
+ /* Fill space with illegal/arch-dep instructions. */
+ bpf_fill_ill_insns(hdr, size);
+
+ hdr->pages = size / PAGE_SIZE;
+ hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
+ PAGE_SIZE - sizeof(*hdr));
+ start = (prandom_u32() % hole) & ~(alignment - 1);
+
+ /* Leave a random number of instructions before BPF code. */
+ *image_ptr = &hdr->image[start];
+
+ return hdr;
+}
+
+void bpf_jit_binary_free(struct bpf_binary_header *hdr)
+{
+ module_free(NULL, hdr);
+}
+#endif /* CONFIG_BPF_JIT */
+
/* 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.
@@ -180,6 +284,7 @@ static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn)
[BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W,
[BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H,
[BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B,
+ [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW,
};
void *ptr;
int off;
@@ -239,6 +344,10 @@ select_insn:
ALU64_MOV_K:
DST = IMM;
CONT;
+ LD_IMM_DW:
+ DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
+ insn++;
+ CONT;
ALU64_ARSH_X:
(*(s64 *) &DST) >>= SRC;
CONT;
@@ -523,12 +632,26 @@ 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_prog_aux *aux;
+
+ aux = container_of(work, struct bpf_prog_aux, work);
+ bpf_jit_free(aux->prog);
+}
+
+/* Free internal BPF program */
void bpf_prog_free(struct bpf_prog *fp)
{
- bpf_jit_free(fp);
+ struct bpf_prog_aux *aux = fp->aux;
+
+ INIT_WORK(&aux->work, bpf_prog_free_deferred);
+ aux->prog = fp;
+ schedule_work(&aux->work);
}
EXPORT_SYMBOL_GPL(bpf_prog_free);