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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 26 Oct 2009 15:41:46 +0100
From:	Tejun Heo <>
To:	the arch/x86 maintainers <>,
	Thomas Gleixner <>,
	Ingo Molnar <>, "H. Peter Anvin" <>,
CC:	Linux Kernel Mailing List <>
Subject: [PATCH] x86: fix iommu=nodac parameter handling

nodac should forbid dac instead of enabling it.  Fix it.

Signed-off-by: Tejun Heo <>
Cc: Matteo Frigo <>
This was posted several months ago in a two patch series.  The second
one was rejected by Alan and with that the first one got lost too
although it's an apparent bug fix.  Matteo hit this bug recently and
reminded me about this patch.  So, regenerated and reposting.


 arch/x86/kernel/pci-dma.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index d20009b..8cf3996 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -216,7 +216,7 @@ static __init int iommu_setup(char *p)
 		if (!strncmp(p, "allowdac", 8))
 			forbid_dac = 0;
 		if (!strncmp(p, "nodac", 5))
-			forbid_dac = -1;
+			forbid_dac = 1;
 		if (!strncmp(p, "usedac", 6)) {
 			forbid_dac = -1;
 			return 1;
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists