| From | "Edgecombe, Rick P" <> | Subject | Re: [PATCH V8 30/44] mm/pkeys: Test setting a PKS key in a custom fault callback | Date | Tue, 1 Feb 2022 00:55:47 +0000 |
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On Thu, 2022-01-27 at 09:54 -0800, ira.weiny@intel.com wrote: > Add a test which does this. > > $ echo 5 > /sys/kernel/debug/x86/run_pks > $ cat /sys/kernel/debug/x86/run_pks > PASS
Hmm, when I run this on qemu TCG, I get:
root@(none):/# echo 5 > /sys/kernel/debug/x86/run_pks [ 29.438159] pks_test: Failed to see the callback root@(none):/# cat /sys/kernel/debug/x86/run_pks FAIL
I think it's a problem with the test though. The generated code is not expecting fault_callback_ctx.callback_seen to get changed in the exception. The following fixed it for me:
diff --git a/lib/pks/pks_test.c b/lib/pks/pks_test.c index 1528df0bb283..d979d2afe921 100644 --- a/lib/pks/pks_test.c +++ b/lib/pks/pks_test.c @@ -570,6 +570,7 @@ static bool run_fault_clear_test(void) /* fault */ memcpy(test_page, ctx->data, 8); + barrier(); if (!fault_callback_ctx.callback_seen) { pr_err("Failed to see the callback\n"); rc = false; But, I wonder if volatile is also needed on the read to be fully correct. I usually have to consult the docs when I deal with that stuff...
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