From: Michael Matz <matz@suse.de>
To: Maxim Kuvyrkov <maxim.kuvyrkov@linaro.org>
Cc: Li Bin <huawei.libin@huawei.com>,
GCC Patches <gcc-patches@gcc.gnu.org>,
Marcus Shawcroft <marcus.shawcroft@arm.com>,
richard.earnshaw@arm.com, andrew.wafaa@arm.com,
szabolcs.nagy@arm.com, masami.hiramatsu.pt@hitachi.com,
geoff@infradead.org, takahiro.akashi@linaro.org,
guohanjun@huawei.com, felix.yang@huawei.com,
jiangjiji@huawei.com
Subject: Re: [PATCH] [AArch64] support -mfentry feature for arm64
Date: Fri, 15 Apr 2016 15:40:00 -0000 [thread overview]
Message-ID: <alpine.LSU.2.20.1604151739210.20277@wotan.suse.de> (raw)
In-Reply-To: <B6E2AECD-096C-489F-A217-8140E781E722@linaro.org>
Hi,
On Thu, 14 Apr 2016, Maxim Kuvyrkov wrote:
> It appears that implementing -fprolog-pad=N option in GCC will not
> enable kernel live-patching support for AArch64. The proposal for the
> option was to make GCC output a given number of NOPs at the beginning of
> each function, and then the kernel could use that NOP pad to insert
> whatever instructions it needs. The modification of kernel instruction
> stream needs to be done atomically, and, unfortunately, it seems the
> kernel can use only architecture-provided atomicity primitives -- i.e.,
> changing at most 8 bytes at a time.
Replace first nop with a breakpoint, handle rest of patching in breakpoint
handler, patch breakpoint insn last, no need to atomically patch multiple
instructions.
Ciao,
Michael.
next prev parent reply other threads:[~2016-04-15 15:40 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-14 8:13 Li Bin
2016-03-14 8:12 ` Li Bin
2016-04-14 13:08 ` Maxim Kuvyrkov
2016-04-14 13:15 ` Andrew Pinski
2016-04-14 15:58 ` Szabolcs Nagy
2016-04-18 13:26 ` Alexander Monakov
2016-04-18 13:34 ` Ramana Radhakrishnan
2016-04-18 13:44 ` Alexander Monakov
2016-04-18 13:57 ` Ramana Radhakrishnan
2016-04-18 14:03 ` Alexander Monakov
2016-04-18 14:31 ` Szabolcs Nagy
2016-04-18 15:54 ` Alexander Monakov
2016-04-19 6:46 ` AKASHI Takahiro
2016-04-19 6:13 ` AKASHI Takahiro
2016-04-19 6:44 ` Alexander Monakov
2016-04-20 0:33 ` AKASHI Takahiro
2016-04-20 10:02 ` Szabolcs Nagy
2016-04-15 15:40 ` Michael Matz [this message]
2016-04-15 17:29 ` Alexander Monakov
2016-04-17 15:06 ` Alexander Monakov
2016-04-18 12:12 ` Michael Matz
2016-04-19 6:26 ` AKASHI Takahiro
2016-04-19 6:39 ` Alexander Monakov
2016-04-20 1:23 ` AKASHI Takahiro
2016-04-20 16:45 ` Szabolcs Nagy
2016-04-19 16:03 ` Torsten Duwe
2016-04-18 14:32 ` Andrew Haley
2016-04-18 17:13 ` Michael Matz
2016-04-18 17:17 ` Andrew Haley
2016-04-18 17:34 ` Michael Matz
2016-04-19 8:00 ` Andrew Haley
2016-04-19 13:19 ` Michael Matz
2016-04-19 13:25 ` Andrew Haley
2016-04-19 14:38 ` Pedro Alves
2016-04-19 15:02 ` Andrew Haley
2016-04-19 6:08 ` AKASHI Takahiro
-- strict thread matches above, loose matches on Subject: below --
2015-10-22 13:24 Li Bin
2015-10-22 13:53 ` Marcus Shawcroft
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