4.8.13-stable review

This is the start of the stable review cycle for the 4.8.13 release. There are 35 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.

Responses should be made by Fri Dec 9 07:07:11 UTC 2016. Anything received after that time might be too late.

The whole patch series can be found in one patch at:

	kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.8.13-rc1.gz

or in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.8.y
and the diffstat can be found below.

thanks,

greg k-h

-------------
Pseudo-Shortlog of commits:

Greg Kroah-Hartman <[email protected]>

    Linux 4.8.13-rc1

James Morse <[email protected]>
arm64: suspend: Reconfigure PSTATE after resume from idle

James Morse <[email protected]>
arm64: mm: Set PSTATE.PAN from the cpu_enable_pan() call

James Morse <[email protected]>
arm64: cpufeature: Schedule enable() calls instead of calling them via IPI

Sven Eckelmann <[email protected]>
batman-adv: Detect missing primaryif during tp_send as error

Stéphan Rafin <[email protected]>
clk: sunxi: Fix M factor computation for APB1

Johannes Weiner <[email protected]>
perf/x86: Restore TASK_SIZE check on frame pointer

Matthias Brugger <[email protected]>
drm/mediatek: fix null pointer dereference

Johan Hovold <[email protected]>
pwm: Fix device reference leak

Dan Carpenter <[email protected]>
KVM: use after free in kvm_ioctl_create_device()

Sudeep Holla <[email protected]>
arm64: dts: juno: fix cluster sleep state entry latency on all SoC versions

Alex Deucher <[email protected]>
drm/radeon: fix check for port PM availability

Peter Wu <[email protected]>
drm/amdgpu: fix check for port PM availability

Peter Wu <[email protected]>
drm/radeon: fix power state when port pm is unavailable (v2)

Peter Wu <[email protected]>
drm/amdgpu: fix power state when port pm is unavailable

Matthew Auld <[email protected]>
drm/i915: drop the struct_mutex when wedged or trying to reset

Chris Wilson <[email protected]>
drm/i915: Don't touch NULL sg on i915_gem_object_get_pages_gtt() error

Marc Zyngier <[email protected]>
KVM: arm/arm64: vgic: Don't notify EOI for non-SPIs

Brian Norris <[email protected]>
mwifiex: printk() overflow with 32-byte SSIDs

Johannes Thumshirn <[email protected]>
PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX)

Johannes Thumshirn <[email protected]>
PCI: Export pcie_find_root_port

Michal Hocko <[email protected]>
mm: workingset: fix NULL ptr in count_shadow_nodes

Ding Tianhong <[email protected]>
rcu: Fix soft lockup for rcu_nocb_kthread

Dmitry Torokhov <[email protected]>
Input: psmouse - disable automatic probing of BYD touchpads

Ping Cheng <[email protected]>

    Input: change KEY_DATA from 0x275 to 0x277

Miklos Szeredi <[email protected]>
ovl: fix d_real() for stacked fs

Kirill A. Shutemov <[email protected]>
mm: fix false-positive WARN_ON() in truncate/invalidate for hugetlb

Dmitry Vyukov <[email protected]>
kasan: update kasan_global for gcc 7

Takashi Iwai <[email protected]>
zram: fix unbalanced idr management at hot removal

Kirill A. Shutemov <[email protected]>
thp: fix corner case of munlock() of PTE-mapped THPs

Jérémy Lefaure <[email protected]>
mm, thp: propagation of conditional compilation in khugepaged.c

Vineet Gupta <[email protected]>
ARC: Don't use "+l" inline asm constraint

Yuriy Kolerov <[email protected]>
ARC: mm: PAE40: Fix crash at munmap

Johannes Thumshirn <[email protected]>
scsi: libfc: fix seconds_since_last_reset miscalculation

Hannes Reinecke <[email protected]>
scsi: hpsa: use bus '3' for legacy HBA devices

Hannes Reinecke <[email protected]>
libata-scsi: Fixup ata_gen_passthru_sense()

-------------

Diffstat:

 Makefile                                         |  4 ++--
 arch/arc/include/asm/delay.h                     |  9 ++++----
 arch/arc/include/asm/pgtable.h                   |  2 +-
 arch/arm64/boot/dts/arm/juno-r1.dts              |  2 +-
 arch/arm64/boot/dts/arm/juno-r2.dts              |  2 +-
 arch/arm64/boot/dts/arm/juno.dts                 |  2 +-
 arch/arm64/include/asm/cpufeature.h              |  2 +-
 arch/arm64/include/asm/exec.h                    |  3 +++
 arch/arm64/include/asm/processor.h               |  6 ++---
 arch/arm64/kernel/cpufeature.c                   | 10 ++++++++-
 arch/arm64/kernel/process.c                      |  3 ++-
 arch/arm64/kernel/suspend.c                      | 11 ++++++++++
 arch/arm64/kernel/traps.c                        |  3 ++-
 arch/arm64/mm/fault.c                            | 15 +++++++++++--
 arch/x86/events/core.c                           | 10 ++-------
 drivers/ata/libata-scsi.c                        |  2 +-
 drivers/block/zram/zram_drv.c                    |  3 ++-
 drivers/clk/sunxi/clk-sunxi.c                    |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c | 16 +++++++++++++-
 drivers/gpu/drm/i915/i915_gem.c                  |  5 +++--
 drivers/gpu/drm/i915/intel_display.c             |  3 ++-
 drivers/gpu/drm/mediatek/mtk_disp_ovl.c          | 14 ++++++------
 drivers/gpu/drm/radeon/radeon_atpx_handler.c     | 16 +++++++++++++-
 drivers/input/mouse/psmouse-base.c               |  4 ----
 drivers/net/wireless/marvell/mwifiex/cfg80211.c  | 13 ++++++-----
 drivers/pci/pcie/aer/aer_inject.c                | 14 ------------
 drivers/pci/probe.c                              | 28 +++++++++++++++++++++++-
 drivers/pwm/sysfs.c                              |  2 ++
 drivers/scsi/hpsa.c                              | 16 +++++++++-----
 drivers/scsi/hpsa.h                              |  2 ++
 drivers/scsi/libfc/fc_lport.c                    |  2 +-
 fs/overlayfs/super.c                             |  6 ++---
 include/linux/compiler-gcc.h                     |  4 +++-
 include/linux/pagemap.h                          | 21 +++++++++++++-----
 include/linux/pci.h                              | 14 ++++++++++++
 include/uapi/linux/input-event-codes.h           |  2 +-
 kernel/rcu/tree_plugin.h                         |  1 +
 mm/kasan/kasan.h                                 |  3 +++
 mm/khugepaged.c                                  |  2 ++
 mm/mlock.c                                       |  7 ++++--
 mm/truncate.c                                    |  8 +++----
 mm/workingset.c                                  |  2 +-
 net/batman-adv/tp_meter.c                        |  1 +
 virt/kvm/arm/vgic/vgic-v2.c                      |  6 +++--
 virt/kvm/arm/vgic/vgic-v3.c                      |  6 +++--
 virt/kvm/kvm_main.c                              |  2 +-
 46 files changed, 215 insertions(+), 96 deletions(-)

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hannes Reinecke <[email protected]>

commit e0029dcb5b6e1c23e68f578ce7a3d6c5caba0501 upstream.

There's a typo in ata_gen_passthru_sense(), where the first byte would be overwritten incorrectly later on.

---
 drivers/ata/libata-scsi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -1088,7 +1088,7 @@ static void ata_gen_passthru_sense(struc
 		desc[1] = tf->command; /* status */
 		desc[2] = tf->device;
 		desc[3] = tf->nsect;
-		desc[0] = 0;
+		desc[7] = 0;
 		if (tf->flags & ATA_TFLAG_LBA48)  {
 			desc[8] |= 0x80;
 			if (tf->hob_nsect)

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hannes Reinecke <[email protected]>

commit 7630b3a599e2c6d1c042945d32ff2debc855ad29 upstream.

Older controllers use SCSI target id '0' for the first internal disk. As the controllers are now placed on the same bus as the internal disks this leads to a clash with the SCSI target id of controller. This patch checks the SCSI revision, and moves older controller to bus '3' to be compatible with older releases and avoid this problem.

[mkp: fixed uninitialized variable]

---
 drivers/scsi/hpsa.c |   16 +++++++++++-----
 drivers/scsi/hpsa.h |    2 ++
 2 files changed, 13 insertions(+), 5 deletions(-)

@@ -2007,7 +2007,7 @@ static struct hpsa_scsi_dev_t *lookup_hp
 
 static int hpsa_slave_alloc(struct scsi_device *sdev)
 {
-	struct hpsa_scsi_dev_t *sd;
+	struct hpsa_scsi_dev_t *sd = NULL;
 	unsigned long flags;
 	struct ctlr_info *h;
 

@@ -2024,7 +2024,8 @@ static int hpsa_slave_alloc(struct scsi_
 			sd->target = sdev_id(sdev);
 			sd->lun = sdev->lun;
 		}
-	} else
+	}
+	if (!sd)
 		sd = lookup_hpsa_scsi_dev(h, sdev_channel(sdev),
 					sdev_id(sdev), sdev->lun);
 

@@ -3805,6 +3806,7 @@ static int hpsa_update_device_info(struc
 		sizeof(this_device->vendor));
 	memcpy(this_device->model, &inq_buff[16],
 		sizeof(this_device->model));
+	this_device->rev = inq_buff[2];
 	memset(this_device->device_id, 0,
 		sizeof(this_device->device_id));
 	hpsa_get_device_id(h, scsi3addr, this_device->device_id, 8,

@@ -3887,10 +3889,14 @@ static void figure_bus_target_lun(struct
 
 	if (!is_logical_dev_addr_mode(lunaddrbytes)) {
 		/* physical device, target and lun filled in later */
-		if (is_hba_lunid(lunaddrbytes))
+		if (is_hba_lunid(lunaddrbytes)) {
+			int bus = HPSA_HBA_BUS;
+
+			if (!device->rev)
+				bus = HPSA_LEGACY_HBA_BUS;
 			hpsa_set_bus_target_lun(device,
-					HPSA_HBA_BUS, 0, lunid & 0x3fff);
-		else
+					bus, 0, lunid & 0x3fff);
+		} else
 			/* defer target, lun assignment for physical devices */
 			hpsa_set_bus_target_lun(device,
 					HPSA_PHYSICAL_DEVICE_BUS, -1, -1);

@@ -69,6 +69,7 @@ struct hpsa_scsi_dev_t {
 	u64 sas_address;
 	unsigned char vendor[8];        /* bytes 8-15 of inquiry data */
 	unsigned char model[16];        /* bytes 16-31 of inquiry data */
+	unsigned char rev;		/* byte 2 of inquiry data */
 	unsigned char raid_level;	/* from inquiry page 0xC1 */
 	unsigned char volume_offline;	/* discovered via TUR or VPD */
 	u16 queue_depth;		/* max queue_depth for this device */

@@ -403,6 +404,7 @@ struct offline_device_entry {
 #define HPSA_RAID_VOLUME_BUS		1
 #define HPSA_EXTERNAL_RAID_VOLUME_BUS	2
 #define HPSA_HBA_BUS			0
+#define HPSA_LEGACY_HBA_BUS		3
 
 /*
 	Send the command to the hardware

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johannes Thumshirn <[email protected]>

commit 208da78e8ec8b6d6ce3747ab0e5c120458e08ae6 upstream.

Commit 540eb1eef0ab ("scsi: libfc: fix seconds_since_last_reset calculation") removed the use of 'struct timespec' from fc_get_host_stats(). This broke the output of 'fcoeadm -s' after kernel 4.8-rc1.

---
 drivers/scsi/libfc/fc_lport.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -308,7 +308,7 @@ struct fc_host_statistics *fc_get_host_s
 	fc_stats = &lport->host_stats;
 	memset(fc_stats, 0, sizeof(struct fc_host_statistics));
 
-	fc_stats->seconds_since_last_reset = (lport->boot_time - jiffies) / HZ;
+	fc_stats->seconds_since_last_reset = (jiffies - lport->boot_time) / HZ;
 
 	for_each_possible_cpu(cpu) {
 		struct fc_stats *stats;

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Yuriy Kolerov <[email protected]>

commit 6a8b2ca702b279bea0e8f0363056439352e2081c upstream.

commit 1c3c90930392 broke PAE40. Macro pfn_pte(pfn, prot) creates paddr from pfn, but the page shift was getting truncated to 32 bits since we lost the proper cast to 64 bits (for PAE400

Instead of reverting that commit, use a better helper which is 32/64 bits safe just like ARM implementation.

---
 arch/arc/include/asm/pgtable.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -280,7 +280,7 @@ static inline void pmd_set(pmd_t *pmdp,
 
 #define pte_page(pte)		pfn_to_page(pte_pfn(pte))
 #define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)
-#define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
+#define pfn_pte(pfn, prot)	__pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 
 /* Don't use virt_to_pfn for macros below: could cause truncations for PAE40*/
 #define pte_pfn(pte)		(pte_val(pte) >> PAGE_SHIFT)

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vineet Gupta <[email protected]>

commit 3c7c7a2fc8811bc7097479f69acf2527693d7562 upstream.

Apparenty this is coming in the way of gcc fix which inhibits the usage of LP_COUNT as a gpr.

---
 arch/arc/include/asm/delay.h |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

@@ -22,10 +22,11 @@
 static inline void __delay(unsigned long loops)
 {
 	__asm__ __volatile__(
-	"	lp  1f	\n"
-	"	nop	\n"
-	"1:		\n"
-	: "+l"(loops));
+	"	mov lp_count, %0	\n"
+	"	lp  1f			\n"
+	"	nop			\n"
+	"1:				\n"
+	: : "r"(loops));
 }
 
 extern void __bad_udelay(void);

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kirill A. Shutemov <[email protected]>

commit 655548bf6271b212cd1e4c259da9dbe616348d38 upstream.

The following program triggers BUG() in munlock_vma_pages_range():

	// autogenerated by syzkaller (http://github.com/google/syzkaller)
	#include <sys/mman.h>

	int main()
	{
	  mmap((void*)0x20105000ul, 0xc00000ul, 0x2ul, 0x2172ul, -1, 0);
	  mremap((void*)0x201fd000ul, 0x4000ul, 0xc00000ul, 0x3ul, 0x203f0000ul);
	  return 0;
	}

The test-case constructs the situation when munlock_vma_pages_range() finds PTE-mapped THP-head in the middle of page table and, by mistake, skips HPAGE_PMD_NR pages after that.

As result, on the next iteration it hits the middle of PMD-mapped THP and gets upset seeing mlocked tail page.

The solution is only skip HPAGE_PMD_NR pages if the THP was mlocked during munlock_vma_page(). It would guarantee that the page is PMD-mapped as we never mlock PTE-mapeed THPs.

---
 mm/mlock.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

@@ -190,10 +190,13 @@ unsigned int munlock_vma_page(struct pag
 	 */
 	spin_lock_irq(zone_lru_lock(zone));
 
-	nr_pages = hpage_nr_pages(page);
-	if (!TestClearPageMlocked(page))
+	if (!TestClearPageMlocked(page)) {
+		/* Potentially, PTE-mapped THP: do not skip the rest PTEs */
+		nr_pages = 1;
 		goto unlock_out;
+	}
 
+	nr_pages = hpage_nr_pages(page);
 	__mod_zone_page_state(zone, NR_MLOCK, -nr_pages);
 
 	if (__munlock_isolate_lru_page(page, true)) {

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <[email protected]>

commit 529e71e16403830ae0d737a66c55c5f360f3576b upstream.

The zram hot removal code calls idr_remove() even when zram_remove() returns an error (typically -EBUSY). This results in a leftover at the device release, eventually leading to a crash when the module is reloaded.

As described in the bug report below, the following procedure would cause an Oops with zram:

- provision three zram devices via modprobe zram num_devices=3
- configure a size for each device
+ echo "1G" > /sys/block/$zram_name/disksize
- mkfs and mount zram0 only
- attempt to hot remove all three devices
+ echo 2 > /sys/class/zram-control/hot_remove
+ echo 1 > /sys/class/zram-control/hot_remove
+ echo 0 > /sys/class/zram-control/hot_remove
- zram0 removal fails with EBUSY, as expected
- unmount zram0
- try zram0 hot remove again
+ echo 0 > /sys/class/zram-control/hot_remove
- fails with ENODEV (unexpected)
- unload zram kernel module
+ completes successfully
- zram0 device node still exists
- attempt to mount /dev/zram0
+ mount command is killed
+ following BUG is encountered

 BUG: unable to handle kernel paging request at ffffffffa0002ba0
 IP: get_disk+0x16/0x50
 Oops: 0000 [#1] SMP
 CPU: 0 PID: 252 Comm: mount Not tainted 4.9.0-rc6 #176
 Call Trace:
   exact_lock+0xc/0x20
   kobj_lookup+0xdc/0x160
   get_gendisk+0x2f/0x110
   __blkdev_get+0x10c/0x3c0
   blkdev_get+0x19d/0x2e0
   blkdev_open+0x56/0x70
   do_dentry_open.isra.19+0x1ff/0x310
   vfs_open+0x43/0x60
   path_openat+0x2c9/0xf30
   do_filp_open+0x79/0xd0
   do_sys_open+0x114/0x1e0
   SyS_open+0x19/0x20
   entry_SYSCALL_64_fastpath+0x13/0x94

This patch adds the proper error check in hot_remove_store() not to call idr_remove() unconditionally.

Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=1010970

---
 drivers/block/zram/zram_drv.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -1403,7 +1403,8 @@ static ssize_t hot_remove_store(struct c
 	zram = idr_find(&zram_index_idr, dev_id);
 	if (zram) {
 		ret = zram_remove(zram);
-		idr_remove(&zram_index_idr, dev_id);
+		if (!ret)
+			idr_remove(&zram_index_idr, dev_id);
 	} else {
 		ret = -ENODEV;
 	}

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dmitry Vyukov <[email protected]>

commit 045d599a286bc01daa3510d59272440a17b23c2e upstream.

kasan_global struct is part of compiler/runtime ABI. gcc revision 241983 has added a new field to kasan_global struct. Update kernel definition of kasan_global struct to include the new field.

Without this patch KASAN is broken with gcc 7.

---
 include/linux/compiler-gcc.h |    4 +++-
 mm/kasan/kasan.h             |    3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

@@ -256,7 +256,9 @@
 #endif
 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
 
-#if GCC_VERSION >= 50000
+#if GCC_VERSION >= 70000
+#define KASAN_ABI_VERSION 5
+#elif GCC_VERSION >= 50000
 #define KASAN_ABI_VERSION 4
 #elif GCC_VERSION >= 40902
 #define KASAN_ABI_VERSION 3

@@ -53,6 +53,9 @@ struct kasan_global {
 #if KASAN_ABI_VERSION >= 4
 	struct kasan_source_location *location;
 #endif
+#if KASAN_ABI_VERSION >= 5
+	char *odr_indicator;
+#endif
 };
 
 /**

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kirill A. Shutemov <[email protected]>

commit 5cbc198ae08d84bd416b672ad8bd1222acd0855c upstream.

Hugetlb pages have ->index in size of the huge pages (PMD_SIZE or PUD_SIZE), not in PAGE_SIZE as other types of pages. This means we cannot user page_to_pgoff() to check whether we've got the right page for the radix-tree index.

Let's introduce page_to_index() which would return radix-tree index for given page.

We will be able to get rid of this once hugetlb will be switched to multi-order entries.

---
 include/linux/pagemap.h |   21 +++++++++++++++------
 mm/truncate.c           |    8 ++++----
 2 files changed, 19 insertions(+), 10 deletions(-)

@@ -364,16 +364,13 @@ static inline struct page *read_mapping_
 }
 
 /*
- * Get the offset in PAGE_SIZE.
- * (TODO: hugepage should have ->index in PAGE_SIZE)
+ * Get index of the page with in radix-tree
+ * (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE)
  */
-static inline pgoff_t page_to_pgoff(struct page *page)
+static inline pgoff_t page_to_index(struct page *page)
 {
 	pgoff_t pgoff;
 
-	if (unlikely(PageHeadHuge(page)))
-		return page->index << compound_order(page);
-
 	if (likely(!PageTransTail(page)))
 		return page->index;
 

@@ -387,6 +384,18 @@ static inline pgoff_t page_to_pgoff(stru
 }
 
 /*
+ * Get the offset in PAGE_SIZE.
+ * (TODO: hugepage should have ->index in PAGE_SIZE)
+ */
+static inline pgoff_t page_to_pgoff(struct page *page)
+{
+	if (unlikely(PageHeadHuge(page)))
+		return page->index << compound_order(page);
+
+	return page_to_index(page);
+}
+
+/*
  * Return byte-offset into filesystem object for page.
  */
 static inline loff_t page_offset(struct page *page)

@@ -283,7 +283,7 @@ void truncate_inode_pages_range(struct a
 
 			if (!trylock_page(page))
 				continue;
-			WARN_ON(page_to_pgoff(page) != index);
+			WARN_ON(page_to_index(page) != index);
 			if (PageWriteback(page)) {
 				unlock_page(page);
 				continue;

@@ -371,7 +371,7 @@ void truncate_inode_pages_range(struct a
 			}
 
 			lock_page(page);
-			WARN_ON(page_to_pgoff(page) != index);
+			WARN_ON(page_to_index(page) != index);
 			wait_on_page_writeback(page);
 			truncate_inode_page(mapping, page);
 			unlock_page(page);

@@ -492,7 +492,7 @@ unsigned long invalidate_mapping_pages(s
 			if (!trylock_page(page))
 				continue;
 
-			WARN_ON(page_to_pgoff(page) != index);
+			WARN_ON(page_to_index(page) != index);
 
 			/* Middle of THP: skip */
 			if (PageTransTail(page)) {

@@ -612,7 +612,7 @@ int invalidate_inode_pages2_range(struct
 			}
 
 			lock_page(page);
-			WARN_ON(page_to_pgoff(page) != index);
+			WARN_ON(page_to_index(page) != index);
 			if (page->mapping != mapping) {
 				unlock_page(page);
 				continue;

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <[email protected]>

commit c4fcfc1619ea43a8a89ad2f83ff23905eee088bd upstream.

Handling of recursion in d_real() is completely broken. Recursion is only done in the 'inode != NULL' case. But when opening the file we have 'inode == NULL' hence d_real() will return an overlay dentry. This won't work since overlayfs doesn't define its own file operations, so all file ops will fail.

Fix by doing the recursion first and the check against the inode second.

Bash script to reproduce the issue written by Quentin:

- 8< - - - - - 8< - - - - - 8< - - - - - 8< - - - -
tmpdir=$(mktemp -d)
pushd ${tmpdir}

mkdir -p {upper,lower,work}
echo -n 'rocks' > lower/ksplice
mount -t overlay level_zero upper -o lowerdir=lower,upperdir=upper,workdir=work cat upper/ksplice

tmpdir2=$(mktemp -d)
pushd ${tmpdir2}

mkdir -p {upper,work}
mount -t overlay level_one upper -o lowerdir=${tmpdir}/upper,upperdir=upper,workdir=work ls -l upper/ksplice
cat upper/ksplice
- 8< - - - - - 8< - - - - - 8< - - - - - 8< - - - -

---
 fs/overlayfs/super.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -329,11 +329,11 @@ static struct dentry *ovl_d_real(struct
 	if (!real)
 		goto bug;
 
+	/* Handle recursion */
+	real = d_real(real, inode, open_flags);
+
 	if (!inode || inode == d_inode(real))
 		return real;
-
-	/* Handle recursion */
-	return d_real(real, inode, open_flags);
 bug:
 	WARN(1, "ovl_d_real(%pd4, %s:%lu): real dentry not found\n", dentry,
 	     inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0);

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ping Cheng <[email protected]>

commit 2425f1808123bf69a8f66d4ec90e0d0e302c2613 upstream.

0x275 is used by KEY_FASTREVERSE.

---
 include/uapi/linux/input-event-codes.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -640,7 +640,7 @@
  * Control a data application associated with the currently viewed channel,
  * e.g. teletext or data broadcast application (MHEG, MHP, HbbTV, etc.)
  */
-#define KEY_DATA			0x275
+#define KEY_DATA			0x277
 
 #define BTN_TRIGGER_HAPPY		0x2c0
 #define BTN_TRIGGER_HAPPY1		0x2c0

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ding Tianhong <[email protected]>

commit bedc1969150d480c462cdac320fa944b694a7162 upstream.

Carrying out the following steps results in a softlockup in the RCU callback-offload (rcuo) kthreads:

1. Connect to ixgbevf, and set the speed to 10Gb/s.
2. Use ifconfig to bring the nic up and down repeatedly.

[  317.005148] IPv6: ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready
[  368.106005] BUG: soft lockup - CPU#1 stuck for 22s! [rcuos/1:15]
[  368.106005] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  368.106005] task: ffff88057dd8a220 ti: ffff88057dd9c000 task.ti: ffff88057dd9c000
[  368.106005] RIP: 0010:[<ffffffff81579e04>]  [<ffffffff81579e04>] fib_table_lookup+0x14/0x390
[  368.106005] RSP: 0018:ffff88061fc83ce8  EFLAGS: 00000286
[  368.106005] RAX: 0000000000000001 RBX: 00000000020155c0 RCX: 0000000000000001
[  368.106005] RDX: ffff88061fc83d50 RSI: ffff88061fc83d70 RDI: ffff880036d11a00
[  368.106005] RBP: ffff88061fc83d08 R08: 0000000000000001 R09: 0000000000000000
[  368.106005] R10: ffff880036d11a00 R11: ffffffff819e0900 R12: ffff88061fc83c58
[  368.106005] R13: ffffffff816154dd R14: ffff88061fc83d08 R15: 00000000020155c0
[  368.106005] FS:  0000000000000000(0000) GS:ffff88061fc80000(0000) knlGS:0000000000000000
[  368.106005] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  368.106005] CR2: 00007f8c2aee9c40 CR3: 000000057b222000 CR4: 00000000000407e0
[  368.106005] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  368.106005] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  368.106005] Stack:
[  368.106005]  00000000010000c0 ffff88057b766000 ffff8802e380b000 ffff88057af03e00
[  368.106005]  ffff88061fc83dc0 ffffffff815349a6 ffff88061fc83d40 ffffffff814ee146
[  368.106005]  ffff8802e380af00 00000000e380af00 ffffffff819e0900 020155c0010000c0
[  368.106005] Call Trace:
[  368.106005]  <IRQ>
[  368.106005]
[  368.106005]  [<ffffffff815349a6>] ip_route_input_noref+0x516/0xbd0
[  368.106005]  [<ffffffff814ee146>] ? skb_release_data+0xd6/0x110
[  368.106005]  [<ffffffff814ee20a>] ? kfree_skb+0x3a/0xa0
[  368.106005]  [<ffffffff8153698f>] ip_rcv_finish+0x29f/0x350
[  368.106005]  [<ffffffff81537034>] ip_rcv+0x234/0x380
[  368.106005]  [<ffffffff814fd656>] __netif_receive_skb_core+0x676/0x870
[  368.106005]  [<ffffffff814fd868>] __netif_receive_skb+0x18/0x60
[  368.106005]  [<ffffffff814fe4de>] process_backlog+0xae/0x180
[  368.106005]  [<ffffffff814fdcb2>] net_rx_action+0x152/0x240
[  368.106005]  [<ffffffff81077b3f>] __do_softirq+0xef/0x280
[  368.106005]  [<ffffffff8161619c>] call_softirq+0x1c/0x30
[  368.106005]  <EOI>
[  368.106005]
[  368.106005]  [<ffffffff81015d95>] do_softirq+0x65/0xa0
[  368.106005]  [<ffffffff81077174>] local_bh_enable+0x94/0xa0
[  368.106005]  [<ffffffff81114922>] rcu_nocb_kthread+0x232/0x370
[  368.106005]  [<ffffffff81098250>] ? wake_up_bit+0x30/0x30
[  368.106005]  [<ffffffff811146f0>] ? rcu_start_gp+0x40/0x40
[  368.106005]  [<ffffffff8109728f>] kthread+0xcf/0xe0
[  368.106005]  [<ffffffff810971c0>] ? kthread_create_on_node+0x140/0x140
[  368.106005]  [<ffffffff816147d8>] ret_from_fork+0x58/0x90
[  368.106005]  [<ffffffff810971c0>] ? kthread_create_on_node+0x140/0x140

==================================cut here==============================

It turns out that the rcuos callback-offload kthread is busy processing a very large quantity of RCU callbacks, and it is not reliquishing the CPU while doing so. This commit therefore adds an cond_resched_rcu_qs() within the loop to allow other tasks to run.

---
 kernel/rcu/tree_plugin.h |    1 +
 1 file changed, 1 insertion(+)

@@ -2173,6 +2173,7 @@ static int rcu_nocb_kthread(void *arg)
 				cl++;
 			c++;
 			local_bh_enable();
+			cond_resched_rcu_qs();
 			list = next;
 		}
 		trace_rcu_batch_end(rdp->rsp->name, c, !!list, 0, 0, 1);

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johannes Thumshirn <[email protected]>

commit e784930bd645e7df78c66e7872fec282b0620075 upstream.

Export pcie_find_root_port() so we can use it outside of PCIe-AER error injection.

---
 drivers/pci/pcie/aer/aer_inject.c |   14 --------------
 include/linux/pci.h               |   14 ++++++++++++++
 2 files changed, 14 insertions(+), 14 deletions(-)

@@ -307,20 +307,6 @@ out:
 	return 0;
 }
 
-static struct pci_dev *pcie_find_root_port(struct pci_dev *dev)
-{
-	while (1) {
-		if (!pci_is_pcie(dev))
-			break;
-		if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-			return dev;
-		if (!dev->bus->self)
-			break;
-		dev = dev->bus->self;
-	}
-	return NULL;
-}
-
 static int find_aer_device_iter(struct device *device, void *data)
 {
 	struct pcie_device **result = data;

@@ -1896,6 +1896,20 @@ static inline int pci_pcie_type(const st
 	return (pcie_caps_reg(dev) & PCI_EXP_FLAGS_TYPE) >> 4;
 }
 
+static inline struct pci_dev *pcie_find_root_port(struct pci_dev *dev)
+{
+	while (1) {
+		if (!pci_is_pcie(dev))
+			break;
+		if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
+			return dev;
+		if (!dev->bus->self)
+			break;
+		dev = dev->bus->self;
+	}
+	return NULL;
+}
+
 void pci_request_acs(void);
 bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags);
 bool pci_acs_path_enabled(struct pci_dev *start,

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Brian Norris <[email protected]>

commit fcd2042e8d36cf644bd2d69c26378d17158b17df upstream.

SSIDs aren't guaranteed to be 0-terminated. Let's cap the max length when we print them out.

This can be easily noticed by connecting to a network with a 32-octet SSID:

[ 3903.502925] mwifiex_pcie 0000:01:00.0: info: trying to associate to

'0123456789abcdef0123456789abcdef <uninitialized mem>' bssid xx:xx:xx:xx:xx:xx

---
 drivers/net/wireless/marvell/mwifiex/cfg80211.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

@@ -2203,8 +2203,9 @@ done:
 			is_scanning_required = 1;
 		} else {
 			mwifiex_dbg(priv->adapter, MSG,
-				    "info: trying to associate to '%s' bssid %pM\n",
-				    (char *)req_ssid.ssid, bss->bssid);
+				    "info: trying to associate to '%.*s' bssid %pM\n",
+				    req_ssid.ssid_len, (char *)req_ssid.ssid,
+				    bss->bssid);
 			memcpy(&priv->cfg_bssid, bss->bssid, ETH_ALEN);
 			break;
 		}

@@ -2264,8 +2265,8 @@ mwifiex_cfg80211_connect(struct wiphy *w
 	}
 
 	mwifiex_dbg(adapter, INFO,
-		    "info: Trying to associate to %s and bssid %pM\n",
-		    (char *)sme->ssid, sme->bssid);
+		    "info: Trying to associate to %.*s and bssid %pM\n",
+		    (int)sme->ssid_len, (char *)sme->ssid, sme->bssid);
 
 	if (!mwifiex_stop_bg_scan(priv))
 		cfg80211_sched_scan_stopped_rtnl(priv->wdev.wiphy);

@@ -2398,8 +2399,8 @@ mwifiex_cfg80211_join_ibss(struct wiphy
 	}
 
 	mwifiex_dbg(priv->adapter, MSG,
-		    "info: trying to join to %s and bssid %pM\n",
-		    (char *)params->ssid, params->bssid);
+		    "info: trying to join to %.*s and bssid %pM\n",
+		    params->ssid_len, (char *)params->ssid, params->bssid);
 
 	mwifiex_set_ibss_params(priv, params);
 

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Marc Zyngier <[email protected]>

commit 8ca18eec2b2276b449c1dc86b98bf083c5fe4e09 upstream.

When we inject a level triggerered interrupt (and unless it is backed by the physical distributor - timer style), we request a maintenance interrupt. Part of the processing for that interrupt is to feed to the rest of KVM (and to the eventfd subsystem) the information that the interrupt has been EOIed.

But that notification only makes sense for SPIs, and not PPIs (such as the PMU interrupt). Skip over the notification if the interrupt is not an SPI.

---
 virt/kvm/arm/vgic/vgic-v2.c |    6 ++++--
 virt/kvm/arm/vgic/vgic-v3.c |    6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

@@ -50,8 +50,10 @@ void vgic_v2_process_maintenance(struct
 
 			WARN_ON(cpuif->vgic_lr[lr] & GICH_LR_STATE);
 
-			kvm_notify_acked_irq(vcpu->kvm, 0,
-					     intid - VGIC_NR_PRIVATE_IRQS);
+			/* Only SPIs require notification */
+			if (vgic_valid_spi(vcpu->kvm, intid))
+				kvm_notify_acked_irq(vcpu->kvm, 0,
+						     intid - VGIC_NR_PRIVATE_IRQS);
 		}
 	}
 

@@ -41,8 +41,10 @@ void vgic_v3_process_maintenance(struct
 
 			WARN_ON(cpuif->vgic_lr[lr] & ICH_LR_STATE);
 
-			kvm_notify_acked_irq(vcpu->kvm, 0,
-					     intid - VGIC_NR_PRIVATE_IRQS);
+			/* Only SPIs require notification */
+			if (vgic_valid_spi(vcpu->kvm, intid))
+				kvm_notify_acked_irq(vcpu->kvm, 0,
+						     intid - VGIC_NR_PRIVATE_IRQS);
 		}
 
 		/*

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chris Wilson <[email protected]>

commit 2420489bcb8910188578acc0c11c75445c2e4b92 upstream.

On the DMA mapping error path, sg may be NULL (it has already been marked as the last scatterlist entry), and we should avoid dereferencing it again.

---
 drivers/gpu/drm/i915/i915_gem.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -2540,7 +2540,7 @@ i915_gem_object_get_pages_gtt(struct drm
 			page = shmem_read_mapping_page(mapping, i);
 			if (IS_ERR(page)) {
 				ret = PTR_ERR(page);
-				goto err_pages;
+				goto err_sg;
 			}
 		}
 #ifdef CONFIG_SWIOTLB

@@ -2583,8 +2583,9 @@ i915_gem_object_get_pages_gtt(struct drm
 
 	return 0;
 
-err_pages:
+err_sg:
 	sg_mark_end(sg);
+err_pages:
 	for_each_sgt_page(page, sgt_iter, st)
 		put_page(page);
 	sg_free_table(st);

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Matthew Auld <[email protected]>

commit e411072d5740a49cdc9d0713798c30440757e451 upstream.

We grab the struct_mutex in intel_crtc_page_flip, but if we are wedged or a reset is in progress we bail early but never seem to actually release the lock.

---
 drivers/gpu/drm/i915/intel_display.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -11791,7 +11791,7 @@ static int intel_crtc_page_flip(struct d
 	intel_crtc->reset_counter = i915_reset_counter(&dev_priv->gpu_error);
 	if (__i915_reset_in_progress_or_wedged(intel_crtc->reset_counter)) {
 		ret = -EIO;
-		goto cleanup;
+		goto unlock;
 	}
 
 	atomic_inc(&intel_crtc->unpin_work_count);

@@ -11877,6 +11877,7 @@ cleanup_pending:
 	if (!IS_ERR_OR_NULL(request))
 		i915_add_request_no_flush(request);
 	atomic_dec(&intel_crtc->unpin_work_count);
+unlock:
 	mutex_unlock(&dev->struct_mutex);
 cleanup:
 	crtc->primary->fb = old_fb;

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Peter Wu <[email protected]>

commit d3ac31f3b4bf9fade93d69770cb9c34912e017be upstream.

When PCIe port PM is not enabled (system BIOS is pre-2015 or the pcie_port_pm=off parameter is set), legacy ATPX PM should still be marked as supported. Otherwise the GPU can fail to power on after runtime suspend. This affected a Dell Inspiron 5548.

Ideally the BIOS date in the PCI core is lowered to 2013 (the first year where hybrid graphics platforms using power resources was introduced), but that seems more risky at this point and would not solve the pcie_port_pm=off issue.

v2: agd: fix typo

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98505

---
 drivers/gpu/drm/radeon/radeon_atpx_handler.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

@@ -33,6 +33,7 @@ struct radeon_atpx {
 
 static struct radeon_atpx_priv {
 	bool atpx_detected;
+	bool bridge_pm_usable;
 	/* handle for device - and atpx */
 	acpi_handle dhandle;
 	struct radeon_atpx atpx;

@@ -198,7 +199,11 @@ static int radeon_atpx_validate(struct r
 	atpx->is_hybrid = false;
 	if (valid_bits & ATPX_MS_HYBRID_GFX_SUPPORTED) {
 		printk("ATPX Hybrid Graphics\n");
-		atpx->functions.power_cntl = false;
+		/*
+		 * Disable legacy PM methods only when pcie port PM is usable,
+		 * otherwise the device might fail to power off or power on.
+		 */
+		atpx->functions.power_cntl = !radeon_atpx_priv.bridge_pm_usable;
 		atpx->is_hybrid = true;
 	}
 

@@ -469,6 +474,7 @@ static int radeon_atpx_power_state(enum
  */
 static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
 {
+	struct pci_dev *parent_pdev = pci_upstream_bridge(pdev);
 	acpi_handle dhandle, atpx_handle;
 	acpi_status status;
 

@@ -482,6 +488,7 @@ static bool radeon_atpx_pci_probe_handle
 
 	radeon_atpx_priv.dhandle = dhandle;
 	radeon_atpx_priv.atpx.handle = atpx_handle;
+	radeon_atpx_priv.bridge_pm_usable = parent_pdev && parent_pdev->bridge_d3;
 	return true;
 }
 

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Peter Wu <[email protected]>

commit 7ac33e47d5769632010e537964c7e45498f8dc26 upstream.

The ATPX method does not always exist on the dGPU, it may be located at the iGPU. The parent device of the iGPU is the root port for which bridge_d3 is false. This accidentally enables the legacy PM method which conflicts with port PM and prevented the dGPU from powering on.

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

@@ -476,7 +476,6 @@ static int amdgpu_atpx_power_state(enum
  */
 static bool amdgpu_atpx_pci_probe_handle(struct pci_dev *pdev)
 {
-	struct pci_dev *parent_pdev = pci_upstream_bridge(pdev);
 	acpi_handle dhandle, atpx_handle;
 	acpi_status status;
 

@@ -491,7 +490,6 @@ static bool amdgpu_atpx_pci_probe_handle
 	}
 	amdgpu_atpx_priv.dhandle = dhandle;
 	amdgpu_atpx_priv.atpx.handle = atpx_handle;
-	amdgpu_atpx_priv.bridge_pm_usable = parent_pdev && parent_pdev->bridge_d3;
 	return true;
 }
 

@@ -553,17 +551,25 @@ static bool amdgpu_atpx_detect(void)
 	struct pci_dev *pdev = NULL;
 	bool has_atpx = false;
 	int vga_count = 0;
+	bool d3_supported = false;
+	struct pci_dev *parent_pdev;
 
 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
 		vga_count++;
 
 		has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true);
+
+		parent_pdev = pci_upstream_bridge(pdev);
+		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
 	}
 
 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
 		vga_count++;
 
 		has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true);
+
+		parent_pdev = pci_upstream_bridge(pdev);
+		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
 	}
 
 	if (has_atpx && vga_count == 2) {

@@ -571,6 +577,7 @@ static bool amdgpu_atpx_detect(void)
 		printk(KERN_INFO "vga_switcheroo: detected switching method %s handle\n",
 		       acpi_method_name);
 		amdgpu_atpx_priv.atpx_detected = true;
+		amdgpu_atpx_priv.bridge_pm_usable = d3_supported;
 		amdgpu_atpx_init();
 		return true;
 	}

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alex Deucher <[email protected]>

commit bcfdd5d5105087e6f33dfeb08a1ca6b2c0287b61 upstream.

The ATPX method does not always exist on the dGPU, it may be located at the iGPU. The parent device of the iGPU is the root port for which bridge_d3 is false. This accidentally enables the legacy PM method which conflicts with port PM and prevented the dGPU from powering on.

Ported from amdgpu commit:
drm/amdgpu: fix check for port PM availability
from Peter Wu.

---
 drivers/gpu/drm/radeon/radeon_atpx_handler.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

@@ -474,7 +474,6 @@ static int radeon_atpx_power_state(enum
  */
 static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
 {
-	struct pci_dev *parent_pdev = pci_upstream_bridge(pdev);
 	acpi_handle dhandle, atpx_handle;
 	acpi_status status;
 

@@ -488,7 +487,6 @@ static bool radeon_atpx_pci_probe_handle
 
 	radeon_atpx_priv.dhandle = dhandle;
 	radeon_atpx_priv.atpx.handle = atpx_handle;
-	radeon_atpx_priv.bridge_pm_usable = parent_pdev && parent_pdev->bridge_d3;
 	return true;
 }
 

@@ -550,11 +548,16 @@ static bool radeon_atpx_detect(void)
 	struct pci_dev *pdev = NULL;
 	bool has_atpx = false;
 	int vga_count = 0;
+	bool d3_supported = false;
+	struct pci_dev *parent_pdev;
 
 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
 		vga_count++;
 
 		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
+
+		parent_pdev = pci_upstream_bridge(pdev);
+		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
 	}
 
 	/* some newer PX laptops mark the dGPU as a non-VGA display device */

@@ -562,6 +565,9 @@ static bool radeon_atpx_detect(void)
 		vga_count++;
 
 		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
+
+		parent_pdev = pci_upstream_bridge(pdev);
+		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
 	}
 
 	if (has_atpx && vga_count == 2) {

@@ -569,6 +575,7 @@ static bool radeon_atpx_detect(void)
 		printk(KERN_INFO "vga_switcheroo: detected switching method %s handle\n",
 		       acpi_method_name);
 		radeon_atpx_priv.atpx_detected = true;
+		radeon_atpx_priv.bridge_pm_usable = d3_supported;
 		radeon_atpx_init();
 		return true;
 	}

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sudeep Holla <[email protected]>

commit 909e481e2467f202b97d42beef246e8829416a85 upstream.

The core and the cluster sleep state entry latencies can't be same as cluster sleep involves more work compared to core level e.g. shared cache maintenance.

Experiments have shown on an average about 100us more latency for the cluster sleep state compared to the core level sleep. This patch fixes the entry latency for the cluster sleep state.

---
 arch/arm64/boot/dts/arm/juno-r1.dts |    2 +-
 arch/arm64/boot/dts/arm/juno-r2.dts |    2 +-
 arch/arm64/boot/dts/arm/juno.dts    |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

@@ -76,7 +76,7 @@
 				compatible = "arm,idle-state";
 				arm,psci-suspend-param = <0x1010000>;
 				local-timer-stop;
-				entry-latency-us = <300>;
+				entry-latency-us = <400>;
 				exit-latency-us = <1200>;
 				min-residency-us = <2500>;
 			};

@@ -76,7 +76,7 @@
 				compatible = "arm,idle-state";
 				arm,psci-suspend-param = <0x1010000>;
 				local-timer-stop;
-				entry-latency-us = <300>;
+				entry-latency-us = <400>;
 				exit-latency-us = <1200>;
 				min-residency-us = <2500>;
 			};

@@ -76,7 +76,7 @@
 				compatible = "arm,idle-state";
 				arm,psci-suspend-param = <0x1010000>;
 				local-timer-stop;
-				entry-latency-us = <300>;
+				entry-latency-us = <400>;
 				exit-latency-us = <1200>;
 				min-residency-us = <2500>;
 			};

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johan Hovold <[email protected]>

commit 0e1614ac84f1719d87bed577963bb8140d0c9ce8 upstream.

Make sure to drop the reference to the parent device taken by class_find_device() after "unexporting" any children when deregistering a PWM chip.

---
 drivers/pwm/sysfs.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -425,6 +425,8 @@ void pwmchip_sysfs_unexport_children(str
 		if (test_bit(PWMF_EXPORTED, &pwm->flags))
 			pwm_unexport_child(parent, pwm);
 	}
+
+	put_device(parent);
 }
 
 static int __init pwm_sysfs_init(void)

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Matthias Brugger <[email protected]>

commit 5ad45307d990020b25a8f7486178b6e033790f70 upstream.

The probe function requests the interrupt before initializing the ddp component. Which leads to a null pointer dereference at boot. Fix this by requesting the interrput after all components got initialized properly.

Change-Id: I57193a7ab554dfb37c35a455900689333adf511c

---
 drivers/gpu/drm/mediatek/mtk_disp_ovl.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

@@ -249,13 +249,6 @@ static int mtk_disp_ovl_probe(struct pla
 	if (irq < 0)
 		return irq;
 
-	ret = devm_request_irq(dev, irq, mtk_disp_ovl_irq_handler,
-			       IRQF_TRIGGER_NONE, dev_name(dev), priv);
-	if (ret < 0) {
-		dev_err(dev, "Failed to request irq %d: %d\n", irq, ret);
-		return ret;
-	}
-
 	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DISP_OVL);
 	if (comp_id < 0) {
 		dev_err(dev, "Failed to identify by alias: %d\n", comp_id);

@@ -271,6 +264,13 @@ static int mtk_disp_ovl_probe(struct pla
 
 	platform_set_drvdata(pdev, priv);
 
+	ret = devm_request_irq(dev, irq, mtk_disp_ovl_irq_handler,
+			       IRQF_TRIGGER_NONE, dev_name(dev), priv);
+	if (ret < 0) {
+		dev_err(dev, "Failed to request irq %d: %d\n", irq, ret);
+		return ret;
+	}
+
 	ret = component_add(dev, &mtk_disp_ovl_component_ops);
 	if (ret)
 		dev_err(dev, "Failed to add component: %d\n", ret);

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johannes Weiner <[email protected]>

commit ae31fe51a3cceaa0cabdb3058f69669ecb47f12e upstream.

The following commit:

75925e1ad7f5 ("perf/x86: Optimize stack walk user accesses")

... switched from copy_from_user_nmi() to __copy_from_user_nmi() with a manual access_ok() check.

Unfortunately, copy_from_user_nmi() does an explicit check against TASK_SIZE, whereas the access_ok() uses whatever the current address limit of the task is.

We are getting NMIs when __probe_kernel_read() has switched to KERNEL_DS, and then see vmalloc faults when we access what looks like pointers into vmalloc space:

[] WARNING: CPU: 3 PID: 3685731 at arch/x86/mm/fault.c:435 vmalloc_fault+0x289/0x290
[] CPU: 3 PID: 3685731 Comm: sh Tainted: G W 4.6.0-5_fbk1_223_gdbf0f40 #1
[] Call Trace:

  []  <NMI>  [<ffffffff814717d1>] dump_stack+0x4d/0x6c
  []  [<ffffffff81076e43>] __warn+0xd3/0xf0
  []  [<ffffffff81076f2d>] warn_slowpath_null+0x1d/0x20
  []  [<ffffffff8104a899>] vmalloc_fault+0x289/0x290
  []  [<ffffffff8104b5a0>] __do_page_fault+0x330/0x490
  []  [<ffffffff8104b70c>] do_page_fault+0xc/0x10
  []  [<ffffffff81794e82>] page_fault+0x22/0x30
  []  [<ffffffff81006280>] ? perf_callchain_user+0x100/0x2a0
  []  [<ffffffff8115124f>] get_perf_callchain+0x17f/0x190
  []  [<ffffffff811512c7>] perf_callchain+0x67/0x80
  []  [<ffffffff8114e750>] perf_prepare_sample+0x2a0/0x370
  []  [<ffffffff8114e840>] perf_event_output+0x20/0x60
  []  [<ffffffff8114aee7>] ? perf_event_update_userpage+0xc7/0x130
  []  [<ffffffff8114ea01>] __perf_event_overflow+0x181/0x1d0
  []  [<ffffffff8114f484>] perf_event_overflow+0x14/0x20
  []  [<ffffffff8100a6e3>] intel_pmu_handle_irq+0x1d3/0x490
  []  [<ffffffff8147daf7>] ? copy_user_enhanced_fast_string+0x7/0x10
  []  [<ffffffff81197191>] ? vunmap_page_range+0x1a1/0x2f0
  []  [<ffffffff811972f1>] ? unmap_kernel_range_noflush+0x11/0x20
  []  [<ffffffff814f2056>] ? ghes_copy_tofrom_phys+0x116/0x1f0
  []  [<ffffffff81040d1d>] ? x2apic_send_IPI_self+0x1d/0x20
  []  [<ffffffff8100411d>] perf_event_nmi_handler+0x2d/0x50
  []  [<ffffffff8101ea31>] nmi_handle+0x61/0x110
  []  [<ffffffff8101ef94>] default_do_nmi+0x44/0x110
  []  [<ffffffff8101f13b>] do_nmi+0xdb/0x150
  []  [<ffffffff81795187>] end_repeat_nmi+0x1a/0x1e
  []  [<ffffffff8147daf7>] ? copy_user_enhanced_fast_string+0x7/0x10
  []  [<ffffffff8147daf7>] ? copy_user_enhanced_fast_string+0x7/0x10
  []  [<ffffffff8147daf7>] ? copy_user_enhanced_fast_string+0x7/0x10
  []  <<EOE>>  <IRQ>  [<ffffffff8115d05e>] ? __probe_kernel_read+0x3e/0xa0

Fix this by moving the valid_user_frame() check to before the uaccess that loads the return address and the pointer to the next frame.

---
 arch/x86/events/core.c |   10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

@@ -2344,7 +2344,7 @@ perf_callchain_user32(struct pt_regs *re
 		frame.next_frame     = 0;
 		frame.return_address = 0;
 
-		if (!access_ok(VERIFY_READ, fp, 8))
+		if (!valid_user_frame(fp, sizeof(frame)))
 			break;
 
 		bytes = __copy_from_user_nmi(&frame.next_frame, fp, 4);

@@ -2354,9 +2354,6 @@ perf_callchain_user32(struct pt_regs *re
 		if (bytes != 0)
 			break;
 
-		if (!valid_user_frame(fp, sizeof(frame)))
-			break;
-
 		perf_callchain_store(entry, cs_base + frame.return_address);
 		fp = compat_ptr(ss_base + frame.next_frame);
 	}

@@ -2405,7 +2402,7 @@ perf_callchain_user(struct perf_callchai
 		frame.next_frame	     = NULL;
 		frame.return_address = 0;
 
-		if (!access_ok(VERIFY_READ, fp, sizeof(*fp) * 2))
+		if (!valid_user_frame(fp, sizeof(frame)))
 			break;
 
 		bytes = __copy_from_user_nmi(&frame.next_frame, fp, sizeof(*fp));

@@ -2415,9 +2412,6 @@ perf_callchain_user(struct perf_callchai
 		if (bytes != 0)
 			break;
 
-		if (!valid_user_frame(fp, sizeof(frame)))
-			break;
-
 		perf_callchain_store(entry, frame.return_address);
 		fp = (void __user *)frame.next_frame;
 	}

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sven Eckelmann <[email protected]>

commit e13258f38e927b61cdb5f4ad25309450d3b127d1 upstream.

The throughput meter detects different situations as problems for the current test. It stops the test after these and reports it to userspace. This also has to be done when the primary interface disappeared during the test.

---
 net/batman-adv/tp_meter.c |    1 +
 1 file changed, 1 insertion(+)

@@ -837,6 +837,7 @@ static int batadv_tp_send(void *arg)
 	primary_if = batadv_primary_if_get_selected(bat_priv);
 	if (unlikely(!primary_if)) {
 		err = BATADV_TP_REASON_DST_UNREACHABLE;
+		tp_vars->reason = err;
 		goto out;
 	}
 

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: James Morse <[email protected]>

commit 2a6dcb2b5f3e21592ca8dfa198dcce7bec09b020 upstream.

The enable() call for a cpufeature/errata is called using on_each_cpu(). This issues a cross-call IPI to get the work done. Implicitly, this stashes the running PSTATE in SPSR when the CPU receives the IPI, and restores it when we return. This means an enable() call can never modify PSTATE.

To allow PAN to do this, change the on_each_cpu() call to use stop_machine(). This schedules the work on each CPU which allows us to modify PSTATE.

This involves changing the protype of all the enable() functions.

enable_cpu_capabilities() is called during boot and enables the feature on all online CPUs. This path now uses stop_machine(). CPU features for hotplug'd CPUs are enabled by verify_local_cpu_features() which only acts on the local CPU, and can already modify the running PSTATE as it is called from secondary_start_kernel().

---
 arch/arm64/include/asm/cpufeature.h |    2 +-
 arch/arm64/include/asm/processor.h  |    6 +++---
 arch/arm64/kernel/cpufeature.c      |   10 +++++++++-
 arch/arm64/kernel/traps.c           |    3 ++-
 arch/arm64/mm/fault.c               |    6 ++++--
 5 files changed, 19 insertions(+), 8 deletions(-)

@@ -90,7 +90,7 @@ struct arm64_cpu_capabilities {
 	u16 capability;
 	int def_scope;			/* default scope */
 	bool (*matches)(const struct arm64_cpu_capabilities *caps, int scope);
-	void (*enable)(void *);		/* Called on all active CPUs */
+	int (*enable)(void *);		/* Called on all active CPUs */
 	union {
 		struct {	/* To be used for erratum handling only */
 			u32 midr_model;

@@ -190,8 +190,8 @@ static inline void spin_lock_prefetch(co
 
 #endif
 
-void cpu_enable_pan(void *__unused);
-void cpu_enable_uao(void *__unused);
-void cpu_enable_cache_maint_trap(void *__unused);
+int cpu_enable_pan(void *__unused);
+int cpu_enable_uao(void *__unused);
+int cpu_enable_cache_maint_trap(void *__unused);
 
 #endif /* __ASM_PROCESSOR_H */

@@ -19,7 +19,9 @@
 #define pr_fmt(fmt) "CPU features: " fmt
 
 #include <linux/bsearch.h>
+#include <linux/cpumask.h>
 #include <linux/sort.h>
+#include <linux/stop_machine.h>
 #include <linux/types.h>
 #include <asm/cpu.h>
 #include <asm/cpufeature.h>

@@ -936,7 +938,13 @@ void __init enable_cpu_capabilities(cons
 {
 	for (; caps->matches; caps++)
 		if (caps->enable && cpus_have_cap(caps->capability))
-			on_each_cpu(caps->enable, NULL, true);
+			/*
+			 * Use stop_machine() as it schedules the work allowing
+			 * us to modify PSTATE, instead of on_each_cpu() which
+			 * uses an IPI, giving us a PSTATE that disappears when
+			 * we return.
+			 */
+			stop_machine(caps->enable, NULL, cpu_online_mask);
 }
 
 /*

@@ -428,9 +428,10 @@ asmlinkage void __exception do_undefinst
 	force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0);
 }
 
-void cpu_enable_cache_maint_trap(void *__unused)
+int cpu_enable_cache_maint_trap(void *__unused)
 {
 	config_sctlr_el1(SCTLR_EL1_UCI, 0);
+	return 0;
 }
 
 #define __user_cache_maint(insn, address, res)			\

@@ -671,9 +671,10 @@ asmlinkage int __exception do_debug_exce
 NOKPROBE_SYMBOL(do_debug_exception);
 
 #ifdef CONFIG_ARM64_PAN
-void cpu_enable_pan(void *__unused)
+int cpu_enable_pan(void *__unused)
 {
 	config_sctlr_el1(SCTLR_EL1_SPAN, 0);
+	return 0;
 }
 #endif /* CONFIG_ARM64_PAN */
 

@@ -684,8 +685,9 @@ void cpu_enable_pan(void *__unused)
  * We need to enable the feature at runtime (instead of adding it to
  * PSR_MODE_EL1h) as the feature may not be implemented by the cpu.
  */
-void cpu_enable_uao(void *__unused)
+int cpu_enable_uao(void *__unused)
 {
 	asm(SET_PSTATE_UAO(1));
+	return 0;
 }
 #endif /* CONFIG_ARM64_UAO */

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: James Morse <[email protected]>

commit 7209c868600bd8926e37c10b9aae83124ccc1dd8 upstream.

Commit 338d4f49d6f7 ("arm64: kernel: Add support for Privileged Access Never") enabled PAN by enabling the 'SPAN' feature-bit in SCTLR_EL1. This means the PSTATE.PAN bit won't be set until the next return to the kernel from userspace. On a preemptible kernel we may schedule work that accesses userspace on a CPU before it has done this.

Now that cpufeature enable() calls are scheduled via stop_machine(), we can set PSTATE.PAN from the cpu_enable_pan() call.

Add WARN_ON_ONCE(in_interrupt()) to check the PSTATE value we updated is not immediately discarded.

---
 arch/arm64/mm/fault.c |    9 +++++++++
 1 file changed, 9 insertions(+)

@@ -29,7 +29,9 @@
 #include <linux/sched.h>
 #include <linux/highmem.h>
 #include <linux/perf_event.h>
+#include <linux/preempt.h>
 
+#include <asm/bug.h>
 #include <asm/cpufeature.h>
 #include <asm/exception.h>
 #include <asm/debug-monitors.h>

@@ -673,7 +675,14 @@ NOKPROBE_SYMBOL(do_debug_exception);
 #ifdef CONFIG_ARM64_PAN
 int cpu_enable_pan(void *__unused)
 {
+	/*
+	 * We modify PSTATE. This won't work from irq context as the PSTATE
+	 * is discarded once we return from the exception.
+	 */
+	WARN_ON_ONCE(in_interrupt());
+
 	config_sctlr_el1(SCTLR_EL1_SPAN, 0);
+	asm(SET_PSTATE_PAN(1));
 	return 0;
 }
 #endif /* CONFIG_ARM64_PAN */

4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: James Morse <[email protected]>

commit d08544127d9fb4505635e3cb6871fd50a42947bd upstream.

The suspend/resume path in kernel/sleep.S, as used by cpu-idle, does not save/restore PSTATE. As a result of this cpufeatures that were detected and have bits in PSTATE get lost when we resume from idle.

UAO gets set appropriately on the next context switch. PAN will be re-enabled next time we return from user-space, but on a preemptible kernel we may run work accessing user space before this point.

Add code to re-enable theses two features in __cpu_suspend_exit(). We re-use uao_thread_switch() passing current.

---
 arch/arm64/include/asm/exec.h |    3 +++
 arch/arm64/kernel/process.c   |    3 ++-
 arch/arm64/kernel/suspend.c   |   11 +++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

@@ -18,6 +18,9 @@
 #ifndef __ASM_EXEC_H
 #define __ASM_EXEC_H
 
+#include <linux/sched.h>
+
 extern unsigned long arch_align_stack(unsigned long sp);
+void uao_thread_switch(struct task_struct *next);
 
 #endif	/* __ASM_EXEC_H */

@@ -49,6 +49,7 @@
 #include <asm/alternative.h>
 #include <asm/compat.h>
 #include <asm/cacheflush.h>
+#include <asm/exec.h>
 #include <asm/fpsimd.h>
 #include <asm/mmu_context.h>
 #include <asm/processor.h>

@@ -303,7 +304,7 @@ static void tls_thread_switch(struct tas
 }
 
 /* Restore the UAO state depending on next's addr_limit */
-static void uao_thread_switch(struct task_struct *next)
+void uao_thread_switch(struct task_struct *next)
 {
 	if (IS_ENABLED(CONFIG_ARM64_UAO)) {
 		if (task_thread_info(next)->addr_limit == KERNEL_DS)

@@ -1,8 +1,11 @@
 #include <linux/ftrace.h>
 #include <linux/percpu.h>
 #include <linux/slab.h>
+#include <asm/alternative.h>
 #include <asm/cacheflush.h>
+#include <asm/cpufeature.h>
 #include <asm/debug-monitors.h>
+#include <asm/exec.h>
 #include <asm/pgtable.h>
 #include <asm/memory.h>
 #include <asm/mmu_context.h>

@@ -48,6 +51,14 @@ void notrace __cpu_suspend_exit(void)
 	set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
 
 	/*
+	 * PSTATE was not saved over suspend/resume, re-enable any detected
+	 * features that might not have been set correctly.
+	 */
+	asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN,
+			CONFIG_ARM64_PAN));
+	uao_thread_switch(current);
+
+	/*
 	 * Restore HW breakpoint registers to sane values
 	 * before debug exceptions are possibly reenabled
 	 * through local_dbg_restore.

Build results:

	total: 149 pass: 149 fail: 0
Qemu test results:
	total: 122 pass: 122 fail: 0

Details are available at http://kerneltests.org/builders.

Guenter

Thanks for testing all of these and letting me know.

greg k-h

Compiled and booted on my test system. No dmesg regressions.

thanks,
-- Shuah

Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America(Silicon Valley)
[email protected]

Thanks for testing both of these and letting me know.

greg k-h

Great, thanks for the interpretation.

greg k-h