[PATCH v6] powerpc/fadump: fix race between pstore write and fadump crash trigger

[Michael Ellerman]

On Mon, 13 Jul 2020 10:54:35 +0530, Sourabh Jain wrote:
> When we enter into fadump crash path via system reset we fail to update
> the pstore.
> 
> On the system reset path we first update the pstore then we go for fadump
> crash. But the problem here is when all the CPUs try to get the pstore
> lock to initiate the pstore write, only one CPUs will acquire the lock
> and proceed with the pstore write. Since it in NMI context CPUs that fail
> to get lock do not wait for their turn to write to the pstore and simply
> proceed with the next operation which is fadump crash. One of the CPU who
> proceeded with fadump crash path triggers the crash and does not wait for
> the CPU who gets the pstore lock to complete the pstore update.
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/fadump: fix race between pstore write and fadump crash trigger
      https://git.kernel.org/powerpc/c/ba608c4fa12cfd0cab0e153249c29441f4dd3312

cheers