linux-kernel - [PATCH 12/36] HMM: add dirty range helper (to toggle dirty bit inside mirror page table).

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1432236705-4209-13-git-send-email-j.glisse@gmail.com>
Date:	Thu, 21 May 2015 15:31:21 -0400
From:	j.glisse@...il.com
To:	akpm@...ux-foundation.org
Cc:	<linux-kernel@...r.kernel.org>, linux-mm@...ck.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	<joro@...tes.org>, Mel Gorman <mgorman@...e.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Johannes Weiner <jweiner@...hat.com>,
	Larry Woodman <lwoodman@...hat.com>,
	Rik van Riel <riel@...hat.com>,
	Dave Airlie <airlied@...hat.com>,
	Brendan Conoboy <blc@...hat.com>,
	Joe Donohue <jdonohue@...hat.com>,
	Duncan Poole <dpoole@...dia.com>,
	Sherry Cheung <SCheung@...dia.com>,
	Subhash Gutti <sgutti@...dia.com>,
	John Hubbard <jhubbard@...dia.com>,
	Mark Hairgrove <mhairgrove@...dia.com>,
	Lucien Dunning <ldunning@...dia.com>,
	Cameron Buschardt <cabuschardt@...dia.com>,
	Arvind Gopalakrishnan <arvindg@...dia.com>,
	Haggai Eran <haggaie@...lanox.com>,
	Shachar Raindel <raindel@...lanox.com>,
	Liran Liss <liranl@...lanox.com>,
	Roland Dreier <roland@...estorage.com>,
	Ben Sander <ben.sander@....com>,
	Greg Stoner <Greg.Stoner@....com>,
	John Bridgman <John.Bridgman@....com>,
	Michael Mantor <Michael.Mantor@....com>,
	Paul Blinzer <Paul.Blinzer@....com>,
	Laurent Morichetti <Laurent.Morichetti@....com>,
	Alexander Deucher <Alexander.Deucher@....com>,
	Oded Gabbay <Oded.Gabbay@....com>,
	Jérôme Glisse <jglisse@...hat.com>
Subject: [PATCH 12/36] HMM: add dirty range helper (to toggle dirty bit inside mirror page table).

From: Jérôme Glisse <jglisse@...hat.com>

Device driver must properly toggle the dirty inside the mirror page table so
dirtyness is properly accounted when core mm code needs to know. Provide a
simple helper to toggle that bit for a range of address.

Signed-off-by: Jérôme Glisse <jglisse@...hat.com>
---
 include/linux/hmm.h |  3 +++
 mm/hmm.c            | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index ec05df8..186f497 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -253,6 +253,9 @@ int hmm_mirror_fault(struct hmm_mirror *mirror, struct hmm_event *event);
 void hmm_mirror_range_discard(struct hmm_mirror *mirror,
 			      unsigned long start,
 			      unsigned long end);
+void hmm_mirror_range_dirty(struct hmm_mirror *mirror,
+			    unsigned long start,
+			    unsigned long end);
 
 
 #endif /* CONFIG_HMM */
diff --git a/mm/hmm.c b/mm/hmm.c
index 4cab3f2..21fda9f 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -940,6 +940,53 @@ void hmm_mirror_range_discard(struct hmm_mirror *mirror,
 }
 EXPORT_SYMBOL(hmm_mirror_range_discard);
 
+/* hmm_mirror_range_dirty() - toggle dirty bit for a range of address.
+ *
+ * @mirror: The mirror struct.
+ * @start: Start address of the range to discard (inclusive).
+ * @end: End address of the range to discard (exclusive).
+ *
+ * Call when device driver want to toggle the dirty bit for a range of address.
+ * Usefull when the device driver just want to toggle the bit for whole range
+ * without walking the mirror page table itself.
+ *
+ * Note this function does not directly dirty the page behind an address, but
+ * this will happen once address is invalidated or discard by device driver or
+ * core mm code.
+ */
+void hmm_mirror_range_dirty(struct hmm_mirror *mirror,
+			    unsigned long start,
+			    unsigned long end)
+{
+	struct hmm_pt_iter iter;
+	unsigned long addr;
+
+	hmm_pt_iter_init(&iter);
+	for (addr = start; addr != end;) {
+		unsigned long cend, next;
+		dma_addr_t *hmm_pte;
+
+		hmm_pte = hmm_pt_iter_update(&iter, &mirror->pt, addr);
+		if (!hmm_pte) {
+			addr = hmm_pt_iter_next(&iter, &mirror->pt,
+						addr, end);
+			continue;
+		}
+		cend = hmm_pt_level_next(&mirror->pt, addr, end,
+					 mirror->pt.llevel - 1);
+		do {
+			next = hmm_pt_level_next(&mirror->pt, addr, cend,
+						 mirror->pt.llevel);
+			if (!hmm_pte_test_valid_pfn(hmm_pte) ||
+			    !hmm_pte_test_write(hmm_pte))
+				continue;
+			hmm_pte_set_dirty(hmm_pte);
+		} while (addr = next, hmm_pte++, addr != cend);
+	}
+	hmm_pt_iter_fini(&iter, &mirror->pt);
+}
+EXPORT_SYMBOL(hmm_mirror_range_dirty);
+
 /* hmm_mirror_register() - register mirror against current process for a device.
  *
  * @mirror: The mirror struct being registered.
-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/