Messages in this thread | | | From | Luis Araneda <> | Date | Wed, 31 Jul 2019 00:12:11 -0400 | Subject | Re: [RFC PATCH] ARM: zynq: Use memcpy_toio instead of memcpy on smp bring-up |
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Hi Russell,
Thanks for reviewing.
On Tue, Jul 30, 2019 at 6:47 AM Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote: > > On Tue, Jul 30, 2019 at 12:43:26AM -0400, Luis Araneda wrote: > > This fixes a kernel panic (read overflow) on memcpy when > > FORTIFY_SOURCE is enabled. [...] > > I'm not convinced that this is correct. It looks like > zynq_secondary_trampoline could be either ARM or Thumb code - there is > no .arm directive before it. If it's ARM code, then this is fine. If > Thumb code, then zynq_secondary_trampoline will be offset by one, and > we will miss copying the first byte of code.
You're right, I tested what happens if the zynq_secondary_trampoline is ARM or Thumb by editing the file where it's defined, headsmp.S
When the .arm directive is used, the CPU is brought-up correctly, but if I use .thumb, I get the following message (no panic): > CPU1: failed to come online
This seems unrelated to solving the panic, as the message even appears with memcpy and FORTIFY_SOURCE disabled.
I could add the .arm directive to headsmp.S Is that your expected solution? Should that change be on a separate commit?
I'd like to know Michal's opinion, as he wrote the code.
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