Patch "powerpc/mm/hash64: Fix might_have_hea() check" has been added to the 4.8-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    powerpc/mm/hash64: Fix might_have_hea() check

to the 4.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     powerpc-mm-hash64-fix-might_have_hea-check.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 08bf75ba852ef8304a84b6a030466b4b4850382e Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Tue, 11 Oct 2016 21:15:04 +1100
Subject: powerpc/mm/hash64: Fix might_have_hea() check

From: Michael Ellerman <mpe@ellerman.id.au>

commit 08bf75ba852ef8304a84b6a030466b4b4850382e upstream.

In commit 2b4e3ad8f579 ("powerpc/mm/hash64: Don't test for machine type
to detect HEA special case") we changed the logic in might_have_hea()
to check FW_FEATURE_SPLPAR rather than machine_is(pseries).

However the check was incorrectly negated, leading to crashes on
machines with HEA adapters, such as:

  mm: Hashing failure ! EA=0xd000080080004040 access=0x800000000000000e current=NetworkManager
      trap=0x300 vsid=0x13d349c ssize=1 base psize=2 psize 2 pte=0xc0003cc033e701ae
  Unable to handle kernel paging request for data at address 0xd000080080004040
  Call Trace:
    .ehea_create_cq+0x148/0x340 [ehea] (unreliable)
    .ehea_up+0x258/0x1200 [ehea]
    .ehea_open+0x44/0x1a0 [ehea]
    ...

Fix it by removing the negation.

Fixes: 2b4e3ad8f579 ("powerpc/mm/hash64: Don't test for machine type to detect HEA special case")
Reported-by: Denis Kirjanov <kda@linux-powerpc.org>
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/mm/hash_utils_64.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -526,7 +526,7 @@ static bool might_have_hea(void)
 	 */
 #ifdef CONFIG_IBMEBUS
 	return !cpu_has_feature(CPU_FTR_ARCH_207S) &&
-		!firmware_has_feature(FW_FEATURE_SPLPAR);
+		firmware_has_feature(FW_FEATURE_SPLPAR);
 #else
 	return false;
 #endif


Patches currently in stable-queue which might be from mpe@ellerman.id.au are

queue-4.8/powerpc-powernv-pass-cpu-endian-pe-number-to-opal_pci_eeh_freeze_clear.patch
queue-4.8/powerpc-powernv-use-cpu-endian-hub-diag-data-type-in-pnv_eeh_get_and_dump_hub_diag.patch
queue-4.8/powerpc-vdso64-use-double-word-compare-on-pointers.patch
queue-4.8/powerpc-mm-hash64-fix-might_have_hea-check.patch
queue-4.8/powerpc-pseries-fix-stack-corruption-in-htpe-code.patch
queue-4.8/powerpc-eeh-null-check-uses-of-eeh_pe_bus_get.patch
queue-4.8/powerpc-mm-update-force_max_zoneorder-range-to-allow-hugetlb-w-4k.patch
queue-4.8/powerpc-powernv-use-cpu-endian-pest-in-pnv_pci_dump_p7ioc_diag_data.patch
queue-4.8/powerpc-64-fix-incorrect-return-value-from-__copy_tofrom_user.patch
queue-4.8/powerpc-xmon-don-t-use-ld-on-32-bit.patch