Messages in this thread | | | From | Heiko Stübner <> | Subject | Re: [PATCH v8 01/14] riscv: prevent null-pointer dereference with sbi_remote_fence_i | Date | Thu, 07 Apr 2022 20:50:42 +0200 |
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Am Donnerstag, 31. März 2022, 14:33:22 CEST schrieb Christoph Hellwig: > On Thu, Mar 31, 2022 at 02:28:06PM +0200, Heiko Stübner wrote: > > so essentially flushes the _local_ icache first and then tries to flush > > caches on other cores, either via an ipi or via sbi. > > > > The remote-fence callback is set correctly during sbi_init(). > > The other cores are only brought up after sbi-init is done. > > > > So it's not really about error reporting but making sure that flush_icache_all() > > does something sane even when still running on the first core. > > As I assume the "all" means on all available cores (which would be the > > core the system booted on). > > > > Does this make it clearer what this tries to solve? > > A little. Whatever code calls this early still seems broken to me > and just just do a local flush, though.
Looking at this again made me realize that we don't need this patch anymore at all.
In a previous revision the "main" alternatives apply-point was earlier, triggering the issue when the generic patching-functions wanted to flush the cache, but with the alternatives getting applied where they are now, the issue is not triggered anymore.
And the "early" alternatives use a local flush anyway.
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