svn commit: r312394 - in stable/11/sys: amd64/amd64 arm/arm arm64/arm64 i386/i386 mips/mips powerpc/powerpc sparc64/sparc64

[John Baldwin]

Author: jhb
Date: Wed Jan 18 19:38:53 2017
New Revision: 312394
URL: https://svnweb.freebsd.org/changeset/base/312394

Log:
  MFC 307332,312086: Drop support for using mmap() with /dev/kmem.
  
  307332:
  Drop support for using mmap() with /dev/kmem.
  
  Using the device pager with /dev/kmem is not stable since KVA mappings
  are transient, but the device pager caches the PA associated with a
  given offset forever.  Interestingly, mips' implementation of
  memmap() already refused requests for /dev/kmem.
  
  Note that kvm_read/kvm_write do not use mmap, but use read and write on
  /dev/kmem, so this should not affect libkvm users.
  
  312086:
  Trim a few comments on platforms that did not implement mmap of /dev/kmem.
  
  After r307332, no platforms implement mmap for /dev/kmem, so the lack of
  it for these platforms is no longer unique.

Modified:
  stable/11/sys/amd64/amd64/mem.c
  stable/11/sys/arm/arm/mem.c
  stable/11/sys/arm64/arm64/mem.c
  stable/11/sys/i386/i386/mem.c
  stable/11/sys/mips/mips/mem.c
  stable/11/sys/powerpc/powerpc/mem.c
  stable/11/sys/sparc64/sparc64/mem.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/amd64/amd64/mem.c
==============================================================================
--- stable/11/sys/amd64/amd64/mem.c	Wed Jan 18 18:16:57 2017	(r312393)
+++ stable/11/sys/amd64/amd64/mem.c	Wed Jan 18 19:38:53 2017	(r312394)
@@ -172,10 +172,9 @@ memmmap(struct cdev *dev, vm_ooffset_t o
 		if (offset > cpu_getmaxphyaddr())
 			return (-1);
 		*paddr = offset;
-	} else if (dev2unit(dev) == CDEV_MINOR_KMEM)
-        	*paddr = vtophys(offset);
-	/* else panic! */
-	return (0);
+		return (0);
+	}
+	return (-1);
 }
 
 /*

Modified: stable/11/sys/arm/arm/mem.c
==============================================================================
--- stable/11/sys/arm/arm/mem.c	Wed Jan 18 18:16:57 2017	(r312393)
+++ stable/11/sys/arm/arm/mem.c	Wed Jan 18 19:38:53 2017	(r312394)
@@ -161,10 +161,9 @@ int
 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
     int prot __unused, vm_memattr_t *memattr __unused)
 {
-	if (dev2unit(dev) == CDEV_MINOR_MEM)
+	if (dev2unit(dev) == CDEV_MINOR_MEM) {
 		*paddr = offset;
-	else if (dev2unit(dev) == CDEV_MINOR_KMEM)
-        	*paddr = vtophys(offset);
-	/* else panic! */
-	return (0);
+		return (0);
+	}
+	return (-1);
 }

Modified: stable/11/sys/arm64/arm64/mem.c
==============================================================================
--- stable/11/sys/arm64/arm64/mem.c	Wed Jan 18 18:16:57 2017	(r312393)
+++ stable/11/sys/arm64/arm64/mem.c	Wed Jan 18 19:38:53 2017	(r312394)
@@ -123,10 +123,9 @@ int
 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
     int prot __unused, vm_memattr_t *memattr __unused)
 {
-	if (dev2unit(dev) == CDEV_MINOR_MEM)
+	if (dev2unit(dev) == CDEV_MINOR_MEM) {
 		*paddr = offset;
-	else if (dev2unit(dev) == CDEV_MINOR_KMEM)
-		*paddr = vtophys(offset);
-	/* else panic! */
-	return (0);
+		return (0);
+	}
+	return (-1);
 }

Modified: stable/11/sys/i386/i386/mem.c
==============================================================================
--- stable/11/sys/i386/i386/mem.c	Wed Jan 18 18:16:57 2017	(r312393)
+++ stable/11/sys/i386/i386/mem.c	Wed Jan 18 19:38:53 2017	(r312394)
@@ -168,10 +168,9 @@ memmmap(struct cdev *dev, vm_ooffset_t o
 		if (offset > cpu_getmaxphyaddr())
 			return (-1);
 		*paddr = offset;
-	} else if (dev2unit(dev) == CDEV_MINOR_KMEM)
-        	*paddr = vtophys(offset);
-	/* else panic! */
-	return (0);
+		return (0);
+	}
+	return (-1);
 }
 
 /*

Modified: stable/11/sys/mips/mips/mem.c
==============================================================================
--- stable/11/sys/mips/mips/mem.c	Wed Jan 18 18:16:57 2017	(r312393)
+++ stable/11/sys/mips/mips/mem.c	Wed Jan 18 19:38:53 2017	(r312394)
@@ -151,12 +151,6 @@ int
 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
     int prot, vm_memattr_t *memattr)
 {
-	/*
-	 * /dev/mem is the only one that makes sense through this
-	 * interface.  For /dev/kmem any physaddr we return here
-	 * could be transient and hence incorrect or invalid at
-	 * a later time.
-	 */
 	if (dev2unit(dev) != CDEV_MINOR_MEM)
 		return (-1);
 

Modified: stable/11/sys/powerpc/powerpc/mem.c
==============================================================================
--- stable/11/sys/powerpc/powerpc/mem.c	Wed Jan 18 18:16:57 2017	(r312393)
+++ stable/11/sys/powerpc/powerpc/mem.c	Wed Jan 18 19:38:53 2017	(r312394)
@@ -179,8 +179,6 @@ memmmap(struct cdev *dev, vm_ooffset_t o
 
 	if (dev2unit(dev) == CDEV_MINOR_MEM)
 		*paddr = offset;
-	else if (dev2unit(dev) == CDEV_MINOR_KMEM)
-		*paddr = vtophys(offset);
 	else
 		return (EFAULT);
 

Modified: stable/11/sys/sparc64/sparc64/mem.c
==============================================================================
--- stable/11/sys/sparc64/sparc64/mem.c	Wed Jan 18 18:16:57 2017	(r312393)
+++ stable/11/sys/sparc64/sparc64/mem.c	Wed Jan 18 19:38:53 2017	(r312394)
@@ -43,7 +43,7 @@ __FBSDID("$FreeBSD$");
 /*
  * Memory special file
  *
- * NOTE: other architectures support mmap()'ing the mem and kmem devices; this
+ * NOTE: other architectures support mmap()'ing the mem device; this
  * might cause illegal aliases to be created for the locked kernel page(s), so
  * it is not implemented.
  */