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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Linus Torvalds <torvalds@linux-foundation.org>,
	Andy Lutomirsky <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Borislav Petkov <bpetkov@suse.de>,
	Greg KH <gregkh@linuxfoundation.org>,
	keescook@google.com, hughd@google.com,
	Brian Gerst <brgerst@gmail.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Denys Vlasenko <dvlasenk@redhat.com>,
	Rik van Riel <riel@redhat.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Juergen Gross <jgross@suse.com>,
	David Laight <David.Laight@aculab.com>,
	Eduardo Valentin <eduval@amazon.com>,
	aliguori@amazon.com, Will Deacon <will.deacon@arm.com>,
	daniel.gruss@iaik.tugraz.at
Subject: [patch V149 01/50] x86/mm/dump_pagetables: Check PAGE_PRESENT for real
Date: Sat, 16 Dec 2017 22:23:55 +0100	[thread overview]
Message-ID: <20171216213136.501622826@linutronix.de> (raw)
In-Reply-To: 20171216212354.120930222@linutronix.de

[-- Attachment #1: x86-mm-dump_pagetables--Check-PAGE_PRESENT-for-real.patch --]
[-- Type: text/plain, Size: 939 bytes --]

From: Thomas Gleixner <tglx@linutronix.de>

The check for a present page in printk_prot():

       if (!pgprot_val(prot)) {
                /* Not present */

is bogus. If a PTE is set to PAGE_NONE then the pgprot_val is not zero and
the entry is decoded in bogus ways, e.g. as RX GLB. That is confusing when
analyzing mapping correctness. Check for the present bit to make an
informed decision.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/mm/dump_pagetables.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -140,7 +140,7 @@ static void printk_prot(struct seq_file
 	static const char * const level_name[] =
 		{ "cr3", "pgd", "p4d", "pud", "pmd", "pte" };
 
-	if (!pgprot_val(prot)) {
+	if (!(pgprot_val(prot) & _PAGE_PRESENT)) {
 		/* Not present */
 		pt_dump_cont_printf(m, dmsg, "                              ");
 	} else {

  reply	other threads:[~2017-12-16 21:37 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-16 21:23 [patch V149 00/50] x86/pti: Updated and reshuffled patch queue Thomas Gleixner
2017-12-16 21:23 ` Thomas Gleixner [this message]
2017-12-16 21:23 ` [patch V149 02/50] x86/vsyscall/64: Explicitly set _PAGE_USER in the pagetable hierarchy Thomas Gleixner
2017-12-16 21:23 ` [patch V149 03/50] x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode Thomas Gleixner
2017-12-16 21:23 ` [patch V149 04/50] arch: Allow arch_dup_mmap() to fail Thomas Gleixner
2017-12-16 21:23 ` [patch V149 05/50] x86/ldt: Rework locking Thomas Gleixner
2017-12-16 21:24 ` [patch V149 06/50] x86/ldt: Prevent ldt inheritance on exec Thomas Gleixner
2017-12-16 21:24 ` [patch V149 07/50] x86/mm/64: Improve the memory map documentation Thomas Gleixner
2017-12-16 21:24 ` [patch V149 08/50] x86/doc: Remove obvious weirdness Thomas Gleixner
2017-12-16 21:24 ` [patch V149 09/50] x86/entry: Remove SYSENTER_stack naming Thomas Gleixner
2017-12-16 21:24 ` [patch V149 10/50] x86/uv: Use the right tlbflush API Thomas Gleixner
2017-12-16 21:24 ` [patch V149 11/50] x86/microcode: Dont abuse the tlbflush interface Thomas Gleixner
2017-12-16 21:24 ` [patch V149 12/50] x86/mm: Use __flush_tlb_one() for kernel memory Thomas Gleixner
2017-12-16 21:24 ` [patch V149 13/50] x86/mm: Remove superfluous barriers Thomas Gleixner
2017-12-16 21:24 ` [patch V149 14/50] x86/mm: Clarify which functions are supposed to flush what Thomas Gleixner
2017-12-16 21:24 ` [patch V149 15/50] x86/mm: Move the CR3 construction functions to tlbflush.h Thomas Gleixner
2017-12-16 21:24 ` [patch V149 16/50] x86/mm: Remove hard-coded ASID limit checks Thomas Gleixner
2017-12-16 21:24 ` [patch V149 17/50] x86/mm: Put MMU to hardware ASID translation in one place Thomas Gleixner
2017-12-16 21:24 ` [patch V149 18/50] x86/mm: Create asm/invpcid.h Thomas Gleixner
2017-12-16 21:24 ` [patch V149 19/50] x86/cpufeatures: Add X86_BUG_CPU_INSECURE Thomas Gleixner
2017-12-16 21:24 ` [patch V149 20/50] x86/mm/pti: Disable global pages if PAGE_TABLE_ISOLATION=y Thomas Gleixner
2017-12-16 21:24 ` [patch V149 21/50] x86/mm/pti: Prepare the x86/entry assembly code for entry/exit CR3 switching Thomas Gleixner
2017-12-16 21:24 ` [patch V149 22/50] x86/mm/pti: Add infrastructure for page table isolation Thomas Gleixner
2017-12-16 21:24 ` [patch V149 23/50] x86/mm/pti: Add mapping helper functions Thomas Gleixner
2017-12-16 21:24 ` [patch V149 24/50] x86/mm/pti: Allow NX poison to be set in p4d/pgd Thomas Gleixner
2017-12-16 21:24 ` [patch V149 25/50] x86/mm/pti: Allocate a separate user PGD Thomas Gleixner
2017-12-16 21:24 ` [patch V149 26/50] x86/mm/pti: Populate " Thomas Gleixner
2017-12-16 21:24 ` [patch V149 27/50] x86/mm/pti: Add functions to clone kernel PMDs Thomas Gleixner
2017-12-16 21:24 ` [patch V149 28/50] x86/mm/pti: Force entry through trampoline when PTI active Thomas Gleixner
2017-12-16 21:24 ` [patch V149 29/50] x86/fixmap: Move the CPU entry area into a separate PMD Thomas Gleixner
2017-12-16 21:24 ` [patch V149 30/50] x86/mm/pti: Share cpu_entry_area PMDs Thomas Gleixner
2017-12-16 21:24 ` [patch V149 31/50] x86/entry: Align entry text section to PMD boundary Thomas Gleixner
2017-12-16 21:24 ` [patch V149 32/50] x86/mm/pti: Share entry text PMD Thomas Gleixner
2017-12-16 21:24 ` [patch V149 33/50] x86/mm/pti: Map ESPFIX into user space Thomas Gleixner
2017-12-16 21:24 ` [patch V149 34/50] x86/fixmap: Move IDT fixmap into the cpu_entry_area range Thomas Gleixner
2017-12-16 21:24 ` [patch V149 35/50] x86/fixmap: Add debugstore entries to cpu_entry_area Thomas Gleixner
2017-12-16 21:24 ` [patch V149 36/50] x86/events/intel/ds: Map debug buffers in fixmap Thomas Gleixner
2017-12-16 21:24 ` [patch V149 37/50] x86/mm/64: Make a full PGD-entry size hole in the memory map Thomas Gleixner
2017-12-17 11:07   ` Kirill A. Shutemov
2017-12-16 21:24 ` [patch V149 38/50] x86/pti: Put the LDT in its own PGD if PTI is on Thomas Gleixner
2017-12-17 11:09   ` Kirill A. Shutemov
2017-12-16 21:24 ` [patch V149 39/50] x86/pti: Map the vsyscall page if needed Thomas Gleixner
2017-12-16 21:24 ` [patch V149 40/50] x86/mm: Allow flushing for future ASID switches Thomas Gleixner
2017-12-16 21:24 ` [patch V149 41/50] x86/mm: Abstract switching CR3 Thomas Gleixner
2017-12-16 21:24 ` [patch V149 42/50] x86/mm: Use/Fix PCID to optimize user/kernel switches Thomas Gleixner
2017-12-16 21:24 ` [patch V149 43/50] x86/mm: Optimize RESTORE_CR3 Thomas Gleixner
2017-12-16 21:24 ` [patch V149 44/50] x86/mm: Use INVPCID for __native_flush_tlb_single() Thomas Gleixner
2017-12-16 21:24 ` [patch V149 45/50] x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming Thomas Gleixner
2017-12-16 21:24 ` [patch V149 46/50] x86/mm/pti: Add Kconfig Thomas Gleixner
2017-12-16 21:24 ` [patch V149 47/50] x86/mm/dump_pagetables: Add page table directory Thomas Gleixner
2017-12-16 21:24 ` [patch V149 48/50] x86/mm/dump_pagetables: Check user space page table for WX pages Thomas Gleixner
2017-12-16 21:24 ` [patch V149 49/50] x86/mm/dump_pagetables: Allow dumping current pagetables Thomas Gleixner
2017-12-16 21:24 ` [patch V149 50/50] x86/ldt: Make the LDT mapping RO Thomas Gleixner

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