From: Daniel Borkmann <daniel@iogearbox.net>
To: Quentin Monnet <quentin.monnet@netronome.com>
Cc: David Laight <David.Laight@aculab.com>,
Jakub Kicinski <jakub.kicinski@netronome.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"oss-drivers@netronome.com" <oss-drivers@netronome.com>
Subject: Re: [PATCH net-next 6/8] tools: bpftool: print all relevant byte opcodes for "load double word"
Date: Fri, 20 Oct 2017 18:12:39 +0200 [thread overview]
Message-ID: <59EA2077.7000901@iogearbox.net> (raw)
In-Reply-To: <CAH3iqT5vPnOCEm6wjavbpSyC4Md922Bts3ynxxVCT-1=MWsgKA@mail.gmail.com>
On 10/20/2017 05:50 PM, Quentin Monnet wrote:
[...]
> The remaining four bytes are taken from the "immediate" field of the second
> instruction, which leaves the first four fields (offset, source and destination
> registers, and in particular opcode) unused. As far as I know, these fields
> remain at zero, and this makes it the only “instruction” to have a null code
> (although I am not sure this is a strict requirement, because I did not find
> the code in the verifier that would reject a program having a non-null opcode
> right after a "load double word immediate" instruction).
It's in replace_map_fd_with_map_ptr(), invalid insns for the 2nd part
are rejected there, they have to be otherwise it's not extendable anymore
from abi pov; check also 'test1* ld_imm64' in the verifier test cases.
Cheers,
Daniel
next prev parent reply other threads:[~2017-10-20 16:12 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-19 22:46 [PATCH net-next 0/8] tools: bpftool: add a "version" command, and fix several items Jakub Kicinski
2017-10-19 22:46 ` [PATCH net-next 1/8] tools: bpftool: add pointer to file argument to print_hex() Jakub Kicinski
2017-10-20 10:55 ` Daniel Borkmann
2017-10-19 22:46 ` [PATCH net-next 2/8] tools: bpftool: fix return value when all eBPF programs have been shown Jakub Kicinski
2017-10-20 10:55 ` Daniel Borkmann
2017-10-19 22:46 ` [PATCH net-next 3/8] tools: bpftool: use err() instead of info() if there are too many insns Jakub Kicinski
2017-10-20 10:55 ` Daniel Borkmann
2017-10-19 22:46 ` [PATCH net-next 4/8] tools: bpftool: add `bpftool prog help` as real command i.r.t exit code Jakub Kicinski
2017-10-20 10:56 ` Daniel Borkmann
2017-10-19 22:46 ` [PATCH net-next 5/8] tools: bpftool: print only one error message on byte parsing failure Jakub Kicinski
2017-10-20 10:56 ` Daniel Borkmann
2017-10-19 22:46 ` [PATCH net-next 6/8] tools: bpftool: print all relevant byte opcodes for "load double word" Jakub Kicinski
2017-10-20 9:59 ` David Laight
2017-10-20 15:50 ` Quentin Monnet
2017-10-20 16:12 ` Daniel Borkmann [this message]
2017-10-20 16:41 ` Quentin Monnet
2017-10-20 10:56 ` Daniel Borkmann
2017-10-19 22:46 ` [PATCH net-next 7/8] tools: bpftool: show that `opcodes` or `file FILE` should be exclusive Jakub Kicinski
2017-10-20 10:56 ` Daniel Borkmann
2017-10-19 22:46 ` [PATCH net-next 8/8] tools: bpftool: add a command to display bpftool version Jakub Kicinski
2017-10-20 10:57 ` Daniel Borkmann
2017-10-19 23:42 ` [PATCH net-next 0/8] tools: bpftool: add a "version" command, and fix several items Alexei Starovoitov
2017-10-22 1:11 ` David Miller
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