From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4+Re0h911xzM6eUPq+9F/uBVKsLCFd+3/vjUBoKxHLs0PyOSkWBehm5hhFHatVMJKYzBhzN ARC-Seal: i=1; a=rsa-sha256; t=1523999803; cv=none; d=google.com; s=arc-20160816; b=KRt9Zh+7DGH2zTJCCh4kFFjZALus+qVo1GdWRuNcItD/eETGz7/GZKH/5DWiKaUDmu Pn6iEigrUQqiCkufJLJjI4acRVVta1hTLMoUxYFVsUKWOXFqp+O6sNnHxTmOIomCkhp1 GcKaV3IAIPlQlWqFRY62houYEYAcbU3gKRY4/KrovHpTp5KbOqBQaYgvG3u4kOM1aXzT 1vdZLaDVi1IV2f2ZFWQ6FimRDFCuVGU+sOzNQOoQllmYP9q5JrA2kowHZ80P6Q3QrS7o agRwX/5wzu9O2dnWveyuSDqN7n/OYiBpzjUyxEZcckTuBOFQyUzaP+xi1Hr1z0HXaUN0 3WFw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:date:from:cc:to:subject:arc-authentication-results; bh=eYtIb8pn51KryZ976App67e1S8flkH3zr63SlTSZeq4=; b=AHKR63A5m46FyEbCZgGbHuUmI8TAcrvP/RZKL7SboKbtC970qUvwKQV9PVQn5EbQ0e gPDA60VYYckNXF+2w58fu2Pbjh8n6GreNRdA5feTIzJWsyGzmi/mmDFKThERm3enIoqQ 2WDkGEdFnDHMGLxeuxxpTEEPuXLst/eD48FzDGOtcoxiO74vVhNRpOxABvGXz6MSs7kx kZ2bBonDe63z6cq/pbOD+VSFPsbULeGMJry/PxKrnbGu/2OtKXKB38t0iOAzE77cF37O bwQhYOuqOn0gQOFBfesf+pl8dBLiuc2+7Yo8Rll35FDVgrTOH2TLB42cGs8MqhzZLVtm 3e4g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of dave.hansen@linux.intel.com designates 192.55.52.115 as permitted sender) smtp.mailfrom=dave.hansen@linux.intel.com Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of dave.hansen@linux.intel.com designates 192.55.52.115 as permitted sender) smtp.mailfrom=dave.hansen@linux.intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,464,1517904000"; d="scan'208";a="35019219" Subject: [PATCH 1/2] x86, pti: fix boot problems from Global-bit setting To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org,Dave Hansen ,mceier@gmail.com,aaro.koskinen@nokia.com,aarcange@redhat.com,luto@kernel.org,arjan@linux.intel.com,bp@alien8.de,dan.j.williams@intel.com,dwmw2@infradead.org,gregkh@linuxfoundation.org,hughd@google.com,jpoimboe@redhat.com,jgross@suse.com,keescook@google.com,torvalds@linux-foundation.org,namit@vmware.com,peterz@infradead.org,tglx@linutronix.de From: Dave Hansen Date: Tue, 17 Apr 2018 14:13:02 -0700 Message-Id: <20180417211302.421F6442@viggo.jf.intel.com> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1598029618240044266?= X-GMAIL-MSGID: =?utf-8?q?1598029618240044266?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: These are _very_ lightly tested. I'm throwing them out there for folks are looking for a fix. --- From: Dave Hansen Part of the global bit _setting_ patches also includes clearing the Global bit when we do not want it. That is done with set_memory_nonglobal(), which uses change_page_attr_clear() in pageattr.c under the covers. However, it's pretty clear that change_page_attr_clear() has not been heavily used early in boot, or on kernel text. It has checks like BUG_ON(irqs_disabled()), looking for interrupt disabling but that also trip in early boot on certain preempt configurations. Just copy the existing BUG_ON() sequence to check for early boot. Signed-off-by: Dave Hansen Fixes: 39114b7a7 (x86/pti: Never implicitly clear _PAGE_GLOBAL for kernel image) Reported-by: Mariusz Ceier Reported-by: Aaro Koskinen Cc: Andrea Arcangeli Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kees Cook Cc: Linus Torvalds Cc: Nadav Amit Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org --- b/arch/x86/mm/pageattr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN arch/x86/mm/pageattr.c~pti-glb-boot-problem-fix arch/x86/mm/pageattr.c --- a/arch/x86/mm/pageattr.c~pti-glb-boot-problem-fix 2018-04-17 14:10:13.553395577 -0700 +++ b/arch/x86/mm/pageattr.c 2018-04-17 14:10:13.559395577 -0700 @@ -172,7 +172,7 @@ static void __cpa_flush_all(void *arg) static void cpa_flush_all(unsigned long cache) { - BUG_ON(irqs_disabled()); + BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); on_each_cpu(__cpa_flush_all, (void *) cache, 1); } @@ -236,7 +236,7 @@ static void cpa_flush_array(unsigned lon unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */ #endif - BUG_ON(irqs_disabled()); + BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1); _