lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 27 Aug 2015 22:27:38 -0700 From: David Ahern <dsa@...ulusnetworks.com> To: David Miller <davem@...emloft.net> Cc: netdev@...r.kernel.org Subject: Re: [PATCH net-next] net: FIB tracepoints On 8/27/15 10:16 PM, David Miller wrote: > From: David Ahern <dsa@...ulusnetworks.com> > Date: Thu, 27 Aug 2015 22:07:30 -0700 > >> On 8/27/15 10:05 PM, David Miller wrote: >>> From: David Ahern <dsa@...ulusnetworks.com> >>> Date: Thu, 27 Aug 2015 21:59:32 -0700 >>> >>>> + __array( __u8, src, 4 ) >>>> + __array( __u8, dst, 4 ) >>> ... >>>> + __array( __u8, src, 4 ) >>> >>> Maybe there is something I don't understand about tracing, but why not >>> use __u32? If endianness types are the issue, just force cast it as >>> needed. >>> >>> Using a memcpy() on a 4-byte array is kinda excessive. >>> >> >> Silly trick need to use %pI4. ie., printing the addresses as strings >> vs. hex. > > %pI4 doesn't care what kind of pointer you give it, &__entry->src will > work just fine if you used __u32. > $ git diff diff --git a/include/trace/events/fib.h b/include/trace/events/fib.h index 1fd7cfeb36ff..07687b93a4f0 100644 --- a/include/trace/events/fib.h +++ b/include/trace/events/fib.h @@ -22,7 +22,7 @@ TRACE_EVENT(fib_table_lookup, __field( __u8, tos ) __field( __u8, scope ) __field( __u8, flags ) - __array( __u8, src, 4 ) + __field( __u32, src ) __array( __u8, dst, 4 ) ), @@ -33,13 +33,13 @@ TRACE_EVENT(fib_table_lookup, __entry->tos = flp->flowi4_tos; __entry->scope = flp->flowi4_scope; __entry->flags = flp->flowi4_flags; - memcpy(&__entry->src, &flp->saddr, 4); + __entry->src = flp->saddr; memcpy(&__entry->dst, &flp->daddr, 4); ), TP_printk("table %d oif %d iif %d src %pI4 dst %pI4 tos %d scope %d flags %x", __entry->tb_id, __entry->oif, __entry->iif, - __entry->src, __entry->dst, __entry->tos, __entry->scope, + &__entry->src, __entry->dst, __entry->tos, __entry->scope, __entry->flags) ); and compiles fine but run time: $ perf record -e fib:* -a Warning: [fib:fib_table_lookup] bad op token & ^C[ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.089 MB perf.data (148 samples) ] $ perf script Warning: [fib:fib_table_lookup] bad op token & ... swapper 0 [000] 49.533997: fib:fib_table_lookup: [FAILED TO PARSE] tb_id=254 oif=0 iif=3 tos=0 scope=0 flags=0 src=16843096 dst=ARRA ... ie., it does matter. src was declared a u32 and trying to pass &src to the printk fails. Been down this road a lot. David -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists