4.19-stable patches

added patches:
	pseries-eeh-fix-the-kdump-kernel-crash-during-eeh_pseries_init.patch

diff --git a/queue-4.19/pseries-eeh-fix-the-kdump-kernel-crash-during-eeh_pseries_init.patch b/queue-4.19/pseries-eeh-fix-the-kdump-kernel-crash-during-eeh_pseries_init.patch
new file mode 100644 (file)
index 0000000..bc7da51
--- /dev/null
+++ b/queue-4.19/pseries-eeh-fix-the-kdump-kernel-crash-during-eeh_pseries_init.patch
@@ -0,0 +1,73 @@
+From eb8257a12192f43ffd41bd90932c39dade958042 Mon Sep 17 00:00:00 2001
+From: Mahesh Salgaonkar <mahesh@linux.ibm.com>
+Date: Mon, 20 Sep 2021 22:03:26 +0530
+Subject: pseries/eeh: Fix the kdump kernel crash during eeh_pseries_init
+
+From: Mahesh Salgaonkar <mahesh@linux.ibm.com>
+
+commit eb8257a12192f43ffd41bd90932c39dade958042 upstream.
+
+On pseries LPAR when an empty slot is assigned to partition OR in single
+LPAR mode, kdump kernel crashes during issuing PHB reset.
+
+In the kdump scenario, we traverse all PHBs and issue reset using the
+pe_config_addr of the first child device present under each PHB. However
+the code assumes that none of the PHB slots can be empty and uses
+list_first_entry() to get the first child device under the PHB. Since
+list_first_entry() expects the list to be non-empty, it returns an
+invalid pci_dn entry and ends up accessing NULL phb pointer under
+pci_dn->phb causing kdump kernel crash.
+
+This patch fixes the below kdump kernel crash by skipping empty slots:
+
+  audit: initializing netlink subsys (disabled)
+  thermal_sys: Registered thermal governor 'fair_share'
+  thermal_sys: Registered thermal governor 'step_wise'
+  cpuidle: using governor menu
+  pstore: Registered nvram as persistent store backend
+  Issue PHB reset ...
+  audit: type=2000 audit(1631267818.000:1): state=initialized audit_enabled=0 res=1
+  BUG: Kernel NULL pointer dereference on read at 0x00000268
+  Faulting instruction address: 0xc000000008101fb0
+  Oops: Kernel access of bad area, sig: 7 [#1]
+  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
+  Modules linked in:
+  CPU: 7 PID: 1 Comm: swapper/7 Not tainted 5.14.0 #1
+  NIP:  c000000008101fb0 LR: c000000009284ccc CTR: c000000008029d70
+  REGS: c00000001161b840 TRAP: 0300   Not tainted  (5.14.0)
+  MSR:  8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 28000224  XER: 20040002
+  CFAR: c000000008101f0c DAR: 0000000000000268 DSISR: 00080000 IRQMASK: 0
+  ...
+  NIP pseries_eeh_get_pe_config_addr+0x100/0x1b0
+  LR  __machine_initcall_pseries_eeh_pseries_init+0x2cc/0x350
+  Call Trace:
+    0xc00000001161bb80 (unreliable)
+    __machine_initcall_pseries_eeh_pseries_init+0x2cc/0x350
+    do_one_initcall+0x60/0x2d0
+    kernel_init_freeable+0x350/0x3f8
+    kernel_init+0x3c/0x17c
+    ret_from_kernel_thread+0x5c/0x64
+
+Fixes: 5a090f7c363fd ("powerpc/pseries: PCIE PHB reset")
+Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
+[mpe: Tweak wording and trim oops]
+Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
+Link: https://lore.kernel.org/r/163215558252.413351.8600189949820258982.stgit@jupiter
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/powerpc/platforms/pseries/eeh_pseries.c |    4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
++++ b/arch/powerpc/platforms/pseries/eeh_pseries.c
+@@ -957,6 +957,10 @@ static int __init eeh_pseries_init(void)
+       if (is_kdump_kernel() || reset_devices) {
+               pr_info("Issue PHB reset ...\n");
+               list_for_each_entry(phb, &hose_list, list_node) {
++                      // Skip if the slot is empty
++                      if (list_empty(&PCI_DN(phb->dn)->child_list))
++                              continue;
++
+                       pdn = list_first_entry(&PCI_DN(phb->dn)->child_list, struct pci_dn, list);
+                       addr = (pdn->busno << 16) | (pdn->devfn << 8);
+                       config_addr = pseries_eeh_get_config_addr(phb, addr);

diff --git a/queue-4.19/series b/queue-4.19/series
index 3050a3526ce135a0bc711aa90b277fe465e761ae..57696299c5b9c6d05ac87435475ca912acd7aefc 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -516,3 +516,4 @@ arm64-cmpxchg_double-hazard-against-entire-exchange-.patch
 efi-fix-null-deref-in-init-error-path.patch
 revert-usb-ulpi-defer-ulpi_register-on-ulpi_read_id-timeout.patch
 tty-serial-tegra-handle-rx-transfer-in-pio-mode-if-dma-wasn-t-started.patch
+pseries-eeh-fix-the-kdump-kernel-crash-during-eeh_pseries_init.patch