1 files changed, 12 insertions, 72 deletions

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 61e45b7c04d7..c52ac77408ca 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -5,11 +5,9 @@
  *
  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
-#include <linux/moduleloader.h>
 #include <linux/netdevice.h>
 #include <linux/if_vlan.h>
 #include <linux/filter.h>
-#include <linux/random.h>
 #include <linux/init.h>
 #include <asm/cacheflush.h>
 #include <asm/facility.h>
@@ -148,6 +146,12 @@ struct bpf_jit {
         ret;                                            \
 })
 
+static void bpf_jit_fill_hole(void *area, unsigned int size)
+{
+        /* Fill whole space with illegal instructions */
+        memset(area, 0, size);
+}
+
 static void bpf_jit_prologue(struct bpf_jit *jit)
 {
         /* Save registers and create stack frame if necessary */
@@ -223,37 +227,6 @@ static void bpf_jit_epilogue(struct bpf_jit *jit)
         EMIT2(0x07fe);
 }
 
-/* Helper to find the offset of pkt_type in sk_buff
- * Make sure its still a 3bit field starting at the MSBs within a byte.
- */
-#define PKT_TYPE_MAX 0xe0
-static int pkt_type_offset;
-
-static int __init bpf_pkt_type_offset_init(void)
-{
-        struct sk_buff skb_probe = {
-                .pkt_type = ~0,
-        };
-        char *ct = (char *)&skb_probe;
-        int off;
-
-        pkt_type_offset = -1;
-        for (off = 0; off < sizeof(struct sk_buff); off++) {
-                if (!ct[off])
-                        continue;
-                if (ct[off] == PKT_TYPE_MAX)
-                        pkt_type_offset = off;
-                else {
-                        /* Found non matching bit pattern, fix needed. */
-                        WARN_ON_ONCE(1);
-                        pkt_type_offset = -1;
-                        return -1;
-                }
-        }
-        return 0;
-}
-device_initcall(bpf_pkt_type_offset_init);
-
 /*
  * make sure we dont leak kernel information to user
  */
@@ -753,12 +726,10 @@ call_fn:	/* lg %r1,<d(function)>(%r13) */
                 }
                 break;
         case BPF_ANC | SKF_AD_PKTTYPE:
-                if (pkt_type_offset < 0)
-                        goto out;
                 /* lhi %r5,0 */
                 EMIT4(0xa7580000);
                 /* ic %r5,<d(pkt_type_offset)>(%r2) */
-                EMIT4_DISP(0x43502000, pkt_type_offset);
+                EMIT4_DISP(0x43502000, PKT_TYPE_OFFSET());
                 /* srl %r5,5 */
                 EMIT4_DISP(0x88500000, 5);
                 break;
@@ -780,38 +751,6 @@ out:
         return -1;
 }
 
-/*
- * Note: for security reasons, bpf code will follow a randomly
- *       sized amount of illegal instructions.
- */
-struct bpf_binary_header {
-        unsigned int pages;
-        u8 image[];
-};
-
-static struct bpf_binary_header *bpf_alloc_binary(unsigned int bpfsize,
-                                                  u8 **image_ptr)
-{
-        struct bpf_binary_header *header;
-        unsigned int sz, hole;
-
-        /* Most BPF filters are really small, but if some of them fill a page,
-         * allow at least 128 extra bytes for illegal instructions.
-         */
-        sz = round_up(bpfsize + sizeof(*header) + 128, PAGE_SIZE);
-        header = module_alloc(sz);
-        if (!header)
-                return NULL;
-        memset(header, 0, sz);
-        header->pages = sz / PAGE_SIZE;
-        hole = min(sz - (bpfsize + sizeof(*header)), PAGE_SIZE - sizeof(*header));
-        /* Insert random number of illegal instructions before BPF code
-         * and make sure the first instruction starts at an even address.
-         */
-        *image_ptr = &header->image[(prandom_u32() % hole) & -2];
-        return header;
-}
-
 void bpf_jit_compile(struct bpf_prog *fp)
 {
         struct bpf_binary_header *header = NULL;
@@ -850,7 +789,8 @@ void bpf_jit_compile(struct bpf_prog *fp)
                         size = prg_len + lit_len;
                         if (size >= BPF_SIZE_MAX)
                                 goto out;
-                        header = bpf_alloc_binary(size, &jit.start);
+                        header = bpf_jit_binary_alloc(size, &jit.start,
+                                                      2, bpf_jit_fill_hole);
                         if (!header)
                                 goto out;
                         jit.prg = jit.mid = jit.start + prg_len;
@@ -869,7 +809,7 @@ void bpf_jit_compile(struct bpf_prog *fp)
         if (jit.start) {
                 set_memory_ro((unsigned long)header, header->pages);
                 fp->bpf_func = (void *) jit.start;
-                fp->jited = 1;
+                fp->jited = true;
         }
 out:
         kfree(addrs);
@@ -884,8 +824,8 @@ void bpf_jit_free(struct bpf_prog *fp)
                 goto free_filter;
 
         set_memory_rw(addr, header->pages);
-        module_free(NULL, header);
+        bpf_jit_binary_free(header);
 
 free_filter:
-        kfree(fp);
+        bpf_prog_unlock_free(fp);
 }