Re: [PATCH v9 44/44] kselftest/arm64: Check GCR_EL1 after context switch
From: Alexander Potapenko <glider@google.com>
Date: 2020-11-12 16:41:36
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On Thu, Nov 12, 2020 at 5:09 PM Marco Elver [off-list ref] wrote:
On Thu, 12 Nov 2020 at 16:59, Alexander Potapenko [off-list ref] wrote:quoted
On Tue, Nov 10, 2020 at 11:12 PM Andrey Konovalov [off-list ref] wrote:quoted
From: Vincenzo Frascino <vincenzo.frascino@arm.com> This test is specific to MTE and verifies that the GCR_EL1 register is context switched correctly. It spawn 1024 processes and each process spawns 5 threads. Each threadNit: "spawns"quoted
+ srand(time(NULL) ^ (pid << 16) ^ (tid << 16)); + + prctl_tag_mask = rand() % 0xffff;Nit: if you want values between 0 and 0xffff you probably want to use bitwise AND.Another question would be, is the max here meant to be 0xffff or 0xffff-1. Because, as-is now, it's 0xffff-1. Only one of them has a trivial conversion to bitwise AND ( x % 2^n == x & (2^n - 1) ).
Yes, that is basically what I meant, assuming that Vincenzo wanted the max to be 0xffff -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel