From: Chuck Anderson <chuck.anderson@oracle.com>
Date: Tue, 4 Apr 2017 21:59:51 +0000 (-0700)
Subject: Revert "restrict /dev/mem to idle io memory ranges"
X-Git-Tag: v4.1.12-102.0.20170529_2200~6
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8ba1b9a0ef5f475b26690afe8c354cdb41b8ba08;p=users%2Fjedix%2Flinux-maple.git

Revert "restrict /dev/mem to idle io memory ranges"

This reverts commit bf6ac7102b7207b2327a1b8259b89fd290b67412.
restrict /dev/mem to idle io memory ranges

There is an interaction with the bnx2i driver that prevents iSCSI logins.

Orabug: 25832750
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>
---

diff --git a/kernel/resource.c b/kernel/resource.c
index 3669d1bfc4254..249b1eb1e6e13 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1499,15 +1499,8 @@ int iomem_is_exclusive(u64 addr)
 			break;
 		if (p->end < addr)
 			continue;
-		/*
-		 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
-		 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
-		 * resource is busy.
-		 */
-		if ((p->flags & IORESOURCE_BUSY) == 0)
-			continue;
-		if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
-				|| p->flags & IORESOURCE_EXCLUSIVE) {
+		if (p->flags & IORESOURCE_BUSY &&
+		     p->flags & IORESOURCE_EXCLUSIVE) {
 			err = 1;
 			break;
 		}
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index e911f7c9b014c..af7bec643ae41 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1793,26 +1793,9 @@ config STRICT_DEVMEM
 	  enabled, even in this case there are restrictions on /dev/mem
 	  use due to the cache aliasing requirements.
 
-	  If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
-	  file only allows userspace access to PCI space and the BIOS code and
-	  data regions.  This is sufficient for dosemu and X and all common
-	  users of /dev/mem.
-
-	  If in doubt, say Y.
-
-config IO_STRICT_DEVMEM
-	bool "Filter I/O access to /dev/mem"
-	depends on STRICT_DEVMEM
-	default STRICT_DEVMEM
-	---help---
-	  If this option is disabled, you allow userspace (root) access to all
-	  io-memory regardless of whether a driver is actively using that
-	  range.  Accidental access to this is obviously disastrous, but
-	  specific access can be used by people debugging kernel drivers.
-
 	  If this option is switched on, the /dev/mem file only allows
-	  userspace access to *idle* io-memory ranges (see /proc/iomem) This
-	  may break traditional users of /dev/mem (dosemu, legacy X, etc...)
-	  if the driver using a given range cannot be disabled.
+	  userspace access to PCI space and the BIOS code and data regions.
+	  This is sufficient for dosemu and X and all common users of
+	  /dev/mem.
 
 	  If in doubt, say Y.