linux-kernel - [PATCH 26/28] x86: return conditional to mmu

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: <12076718382647-git-send-email-gcosta@redhat.com>
Date:	Tue,  8 Apr 2008 13:21:08 -0300
From:	Glauber Costa <gcosta@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	akpm@...ux-foundation.org, glommer@...il.com, mingo@...e.hu,
	tglx@...utronix.de, kvm-devel@...ts.sourceforge.net,
	amit.shah@...ranet.com, avi@...ranet.com,
	Glauber Costa <gcosta@...hat.com>
Subject: [PATCH 26/28] x86: return conditional to mmu

Just return our allocation if we don't have an mmu. For i386, where this patch
is being applied, we never have. So our goal is just to have the code to look like
x86_64's.

Signed-off-by: Glauber Costa <gcosta@...hat.com>
---
 arch/x86/kernel/pci-dma_32.c |   34 ++++++++++++++++++++++++++++++++--
 1 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 5450bd1..f134de3 100644
--- a/arch/x86/kernel/pci-dma_32.c
+++ b/arch/x86/kernel/pci-dma_32.c
@@ -116,12 +116,42 @@ again:
 				gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
 				goto again;
 			}
+
+			/* Let low level make its own zone decisions */
+			gfp &= ~(GFP_DMA32|GFP_DMA);
+
+			if (dma_ops->alloc_coherent)
+				return dma_ops->alloc_coherent(dev, size,
+							   dma_handle, gfp);
+			return NULL;
+
 		}
 		memset(ret, 0, size);
-		*dma_handle = bus;
+		if (!mmu) {
+			*dma_handle = bus;
+			return ret;
+		}
+	}
+
+	if (dma_ops->alloc_coherent) {
+		free_pages((unsigned long)ret, get_order(size));
+		gfp &= ~(GFP_DMA|GFP_DMA32);
+		return dma_ops->alloc_coherent(dev, size, dma_handle, gfp);
+	}
+
+	if (dma_ops->map_simple) {
+		*dma_handle = dma_ops->map_simple(dev, virt_to_phys(ret),
+					      size,
+					      PCI_DMA_BIDIRECTIONAL);
+		if (*dma_handle != bad_dma_address)
+			return ret;
 	}
 
-	return ret;
+	if (panic_on_overflow)
+		panic("dma_alloc_coherent: IOMMU overflow by %lu bytes\n",
+		      (unsigned long)size);
+	free_pages((unsigned long)ret, get_order(size));
+	return NULL;
 }
 EXPORT_SYMBOL(dma_alloc_coherent);
 
-- 
1.5.0.6

--
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/