Commit b954d834 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

net: bpf: only build bpf_jit_binary_{alloc, free}() when jit selected 



Since BPF JIT depends on the availability of module_alloc() and
module_free() helpers (HAVE_BPF_JIT and MODULES), we better build
that code only in case we have BPF_JIT in our config enabled, just
like with other JIT code. Fixes builds for arm/marzen_defconfig
and sh/rsk7269_defconfig.

====================
kernel/built-in.o: In function `bpf_jit_binary_alloc':
/home/cwang/linux/kernel/bpf/core.c:144: undefined reference to `module_alloc'
kernel/built-in.o: In function `bpf_jit_binary_free':
/home/cwang/linux/kernel/bpf/core.c:164: undefined reference to `module_free'
make: *** [vmlinux] Error 1
====================

Reported-by: default avatarFengguang Wu <fengguang.wu@intel.com>
Fixes: 738cbe72 ("net: bpf: consolidate JIT binary allocator")
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 17fa1f98

include/linux/filter.h

+39 −39
Original line number Diff line number Diff line
@@ -4,12 +4,18 @@ 
#ifndef __LINUX_FILTER_H__

#define __LINUX_FILTER_H__



#include <stdarg.h>



#include <linux/atomic.h>

#include <linux/compat.h>

#include <linux/skbuff.h>

#include <linux/linkage.h>

#include <linux/printk.h>

#include <linux/workqueue.h>

#include <uapi/linux/filter.h>



#include <asm/cacheflush.h>



#include <uapi/linux/filter.h>

#include <uapi/linux/bpf.h>



struct sk_buff;
@@ -363,14 +369,6 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 
				  gfp_t gfp_extra_flags);

void __bpf_prog_free(struct bpf_prog *fp);



typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);



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);

void bpf_jit_binary_free(struct bpf_binary_header *hdr);



static inline void bpf_prog_unlock_free(struct bpf_prog *fp)

{

	bpf_prog_unlock_ro(fp);
@@ -393,6 +391,38 @@ void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); 
u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);

void bpf_int_jit_compile(struct bpf_prog *fp);



#ifdef CONFIG_BPF_JIT

typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);



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);

void bpf_jit_binary_free(struct bpf_binary_header *hdr);



void bpf_jit_compile(struct bpf_prog *fp);

void bpf_jit_free(struct bpf_prog *fp);



static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,

				u32 pass, void *image)

{

	pr_err("flen=%u proglen=%u pass=%u image=%pK\n",

	       flen, proglen, pass, image);

	if (image)

		print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,

			       16, 1, image, proglen, false);

}

#else

static inline void bpf_jit_compile(struct bpf_prog *fp)

{

}



static inline void bpf_jit_free(struct bpf_prog *fp)

{

	bpf_prog_unlock_free(fp);

}

#endif /* CONFIG_BPF_JIT */



#define BPF_ANC		BIT(15)



static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
@@ -440,36 +470,6 @@ static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, 
	return bpf_internal_load_pointer_neg_helper(skb, k, size);

}



#ifdef CONFIG_BPF_JIT

#include <stdarg.h>

#include <linux/linkage.h>

#include <linux/printk.h>



void bpf_jit_compile(struct bpf_prog *fp);

void bpf_jit_free(struct bpf_prog *fp);



static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,

				u32 pass, void *image)

{

	pr_err("flen=%u proglen=%u pass=%u image=%pK\n",

	       flen, proglen, pass, image);

	if (image)

		print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,

			       16, 1, image, proglen, false);

}

#else

#include <linux/slab.h>



static inline void bpf_jit_compile(struct bpf_prog *fp)

{

}



static inline void bpf_jit_free(struct bpf_prog *fp)

{

	bpf_prog_unlock_free(fp);

}

#endif /* CONFIG_BPF_JIT */



static inline int bpf_tell_extensions(void)

{

	return SKF_AD_MAX;

kernel/bpf/core.c

+2 −0
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ void __bpf_prog_free(struct bpf_prog *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,
@@ -163,6 +164,7 @@ 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

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