Subject: Re: [PATCH v2] include/linux: printk is needed in filter.h when CONFIG_BPF_JIT is defined

From: Chen Gang <[email-masked]>
Date: Sat, 30 Mar 2013 11:10:55 +0800

On 2013年03月30日 03:34, David Miller wrote:
> From: Chen Gang <[email-masked]>
> Date: Fri, 29 Mar 2013 09:24:53 +0800
> 
>> > 
>> >   for make V=1 EXTRA_CFLAGS=-W ARCH=arm allmodconfig
>> >     printk is need when CONFIG_BPF_JIT is defined
>> >     or it will report pr_err and print_hex_dump are implicit declaration
>> > 
>> > Signed-off-by: Chen Gang <[email-masked]>
> There are no references to pr_err nor print_hex_dump in this
> filter.h header file.

  maybe we see the different tree.
  I find it in next-20130328.

  please help check, thanks.

commit 79617801ea0c0e6664cb497d4c1892c2ff407364
Author: Daniel Borkmann <[email-masked]>
Date:   Thu Mar 21 22:22:03 2013 +0100

    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 <[email-masked]>
    Cc: Matt Evans <[email-masked]>
    Cc: Eric Dumazet <[email-masked]>
    Cc: David S. Miller <[email-masked]>
    Signed-off-by: Daniel Borkmann <[email-masked]>
    Signed-off-by: David S. Miller <[email-masked]>

diff --git a/include/linux/filter.h b/include/linux/filter.h
index d2059cb..d7d2508 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -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)

-- 
Chen Gang

Asianux Corporation