Messages in this thread | | | Date | Mon, 19 Feb 2018 10:36:35 +0100 | From | Ingo Molnar <> | Subject | Re: [tip:x86/pti] x86/speculation: Use IBRS if available before calling into firmware |
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* Peter Zijlstra <peterz@infradead.org> wrote:
> On Sat, Feb 17, 2018 at 11:26:16AM +0100, Ingo Molnar wrote: > > Note that PeterZ was struggling with intermittent boot hangs yesterday as well, > > which hangs came and went during severeal (fruitless) bisection attempts. Then at > > a certain point the hangs went away altogether. > > > > The symptoms for both his and your hangs are consistent with an alignment > > dependent bug. > > Mine would consistently hang right after > > "Freeing SMP alternatives memory: 44K" > > At one point I bisected it to commit: > > a06cc94f3f8d ("x86/build: Drop superfluous ALIGN from the linker script")
So, just to make sure this commit had no effect: I cannot really see anything wrong with that commit, it does a single substantial change, which is to remove this explicit alignment:
. = ALIGN(8); TEXT_TEXT
which seems fine to me, since it expanded to:
. = ALIGN(8); ALIGN_FUNCTION(); \ ...
which expanded to:
. = ALIGN(8); . = ALIGN(8); ...
... which duplication the commit removed.
... where all the relevant defitions of TEXT_TEXT and ALIGN_FUNCTION are unconditional and not overriden anywhere for arch/x86 builds.
I.e. the commit is a NOP AFAICS.
Thanks,
Ingo
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