Re: Regression - Xorg start failed

[Chris Wright <chrisw@sous-sol.org>]

* Linus Torvalds (torvalds@linux-foundation.org) wrote:
> On Sat, Feb 12, 2011 at 11:53 PM, Dave Airlie <airlied@gmail.com> wrote:
> > Probably should revert first, then work out what is crapping out libpciaccess.
> 
> Yeah, I'll revert. The patch is one of those "obviously a good idea,
> but in practice it's not something we can change now".

Turns out I'm just a bona fide idiot.

I was not testing the right kernel _and_ didn't get the logic right.

sorry for the screw up,
-chris
---

Subject: [PATCH] pci: use security_capable correctly during config space read

Commit 47970b1 ("pci: use security_capable() when checking capablities
during config space read") is just plain broken.  The normal capable()
interface returns true on success, but the LSM interface returns 0 on
success.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

I've tested this quickly (lspci behaviour is as expected).

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index f7771f3..ea25e5b 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -369,7 +369,7 @@ pci_read_config(struct file *filp, struct kobject *kobj,
 	u8 *data = (u8*) buf;
 
 	/* Several chips lock up trying to read undefined config space */
-	if (security_capable(filp->f_cred, CAP_SYS_ADMIN)) {
+	if (security_capable(filp->f_cred, CAP_SYS_ADMIN) == 0) {
 		size = dev->cfg_size;
 	} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
 		size = 128;