Re: [PATCH v3 1/6] x86/bugs: Add asm helpers for executing VERW
From: Andrew Cooper <hidden>
Date: 2023-10-25 22:13:55
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On 25/10/2023 11:07 pm, Pawan Gupta wrote:
On Wed, Oct 25, 2023 at 10:10:41PM +0100, Andrew Cooper wrote:quoted
quoted
+.align L1_CACHE_BYTES, 0xcc +SYM_CODE_START_NOALIGN(mds_verw_sel) + UNWIND_HINT_UNDEFINED + ANNOTATE_NOENDBR + .word __KERNEL_DSYou need another .align here. Otherwise subsequent code will still start in this cacheline and defeat the purpose of trying to keep it separate.Right.quoted
quoted
+SYM_CODE_END(mds_verw_sel);Thinking about it, should this really be CODE and not a data entry?Would that require adding a data equivalent of .entry.text and update KPTI to keep it mapped? Or is there an easier option?
Leave it right here in .entry.text , but try using SYM_DATA() and friends. See whether objtool vomits over the result or not. And if objtool does vomit over the result, then leaving it as it is in this patch with SYM_CODE() is good enough.
quoted hunk ↗ jump to hunk
quoted
P.S. Please CC on the full series. Far less effort than fishing the rest off lore.I didn't realize get_maintainer.pl isn't doing that already. Proposing below update to MAINTAINERS: --- From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Date: Wed, 25 Oct 2023 14:50:41 -0700 Subject: [PATCH] MAINTAINERS: Update entry for X86 HARDWARE VULNERABILITIES Add Andrew Cooper to maintainers of hardware vulnerabilities mitigations. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> --- MAINTAINERS | 1 + 1 file changed, 1 insertion(+)diff --git a/MAINTAINERS b/MAINTAINERS index 2894f0777537..bf8c8707b8f8 100644 --- a/MAINTAINERS +++ b/MAINTAINERS@@ -23382,6 +23382,7 @@ M: Thomas Gleixner <tglx@linutronix.de> M: Borislav Petkov <bp@alien8.de> M: Peter Zijlstra <peterz@infradead.org> M: Josh Poimboeuf <jpoimboe@kernel.org> +M: Andrew Cooper <andrew.cooper3@citrix.com>
Oh, right. Perhaps R rather than M seeing as I can't make any time commitments, but sure. ~Andrew