Commit 79617801 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

filter: bpf_jit_comp: refactor and unify BPF JIT image dump output 



If bpf_jit_enable > 1, then we dump the emitted JIT compiled image
after creation. Currently, only SPARC and PowerPC has similar output
as in the reference implementation on x86_64. Make a small helper
function in order to reduce duplicated code and make the dump output
uniform across architectures x86_64, SPARC, PPC, ARM (e.g. on ARM
flen, pass and proglen are currently not shown, but would be
interesting to know as well), also for future BPF JIT implementations
on other archs.

Cc: Mircea Gherzan <mgherzan@gmail.com>
Cc: Matt Evans <matt@ozlabs.org>
Cc: Eric Dumazet <eric.dumazet@google.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d5e07e69

arch/arm/net/bpf_jit_32.c

+2 −3
Original line number Diff line number Diff line
@@ -918,9 +918,8 @@ void bpf_jit_compile(struct sk_filter *fp) 
#endif



	if (bpf_jit_enable > 1)

		print_hex_dump(KERN_INFO, "BPF JIT code: ",

			       DUMP_PREFIX_ADDRESS, 16, 4, ctx.target,

			       alloc_size, false);

		/* there are 2 passes here */

		bpf_jit_dump(fp->len, alloc_size, 2, ctx.target);



	fp->bpf_func = (void *)ctx.target;

out:

arch/powerpc/net/bpf_jit_comp.c

+4 −8
Original line number Diff line number Diff line
@@ -671,16 +671,12 @@ void bpf_jit_compile(struct sk_filter *fp) 
	}



	if (bpf_jit_enable > 1)

		pr_info("flen=%d proglen=%u pass=%d image=%p\n",

		       flen, proglen, pass, image);

		/* Note that we output the base address of the code_base

		 * rather than image, since opcodes are in code_base.

		 */

		bpf_jit_dump(flen, proglen, pass, code_base);



	if (image) {

		if (bpf_jit_enable > 1)

			print_hex_dump(KERN_ERR, "JIT code: ",

				       DUMP_PREFIX_ADDRESS,

				       16, 1, code_base,

				       proglen, false);



		bpf_flush_icache(code_base, code_base + (proglen/4));

		/* Function descriptor nastiness: Address + TOC */

		((u64 *)image)[0] = (u64)code_base;

arch/sparc/net/bpf_jit_comp.c

+1 −5
Original line number Diff line number Diff line
@@ -795,13 +795,9 @@ cond_branch: f_offset = addrs[i + filter[i].jf]; 
	}



	if (bpf_jit_enable > 1)

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

		       flen, proglen, pass, image);

		bpf_jit_dump(flen, proglen, pass, image);



	if (image) {

		if (bpf_jit_enable > 1)

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

				       16, 1, image, proglen, false);

		bpf_flush_icache(image, image + proglen);

		fp->bpf_func = (void *)image;

	}

arch/x86/net/bpf_jit_comp.c

+2 −7
Original line number Diff line number Diff line
@@ -725,17 +725,12 @@ cond_branch: f_offset = addrs[i + filter[i].jf] - addrs[i]; 
		}

		oldproglen = proglen;

	}

	if (bpf_jit_enable > 1)

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

		       flen, proglen, pass, image);



	if (image) {

	if (bpf_jit_enable > 1)

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

				       16, 1, image, proglen, false);

		bpf_jit_dump(flen, proglen, pass, image);



	if (image) {

		bpf_flush_icache(image, image + proglen);



		fp->bpf_func = (void *)image;

	}

out:

include/linux/filter.h

+10 −0
Original line number Diff line number Diff line
@@ -50,6 +50,16 @@ extern int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, uns 
#ifdef CONFIG_BPF_JIT

extern void bpf_jit_compile(struct sk_filter *fp);

extern void bpf_jit_free(struct sk_filter *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=%p\n",

	       flen, proglen, pass, image);

	if (image)

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

			       16, 1, image, proglen, false);

}

#define SK_RUN_FILTER(FILTER, SKB) (*FILTER->bpf_func)(SKB, FILTER->insns)

#else

static inline void bpf_jit_compile(struct sk_filter *fp)

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