mpc85xx: backport "fix oops when CONFIG_FSL_PMC=n"

[openwrt/openwrt.git] / target / linux / mpc85xx / patches-5.10 / 002-powerpc-85xx-fix-oops-when-CONFIG_FSL_PMC-n.patch

diff --git a/target/linux/mpc85xx/patches-5.10/002-powerpc-85xx-fix-oops-when-CONFIG_FSL_PMC-n.patch b/target/linux/mpc85xx/patches-5.10/002-powerpc-85xx-fix-oops-when-CONFIG_FSL_PMC-n.patch
new file mode 100644 (file)
index 0000000..e9c2ec7
--- /dev/null
+++ b/target/linux/mpc85xx/patches-5.10/002-powerpc-85xx-fix-oops-when-CONFIG_FSL_PMC-n.patch
@@ -0,0 +1,55 @@
+From e7757563e621522f5cd862b3aff473aedf8b66c0 Mon Sep 17 00:00:00 2001
+From: Xiaoming Ni <nixiaoming@huawei.com>
+Date: Fri, 26 Nov 2021 12:11:53 +0800
+Subject: [PATCH] powerpc/85xx: fix oops when CONFIG_FSL_PMC=n
+
+When CONFIG_FSL_PMC is set to n, no value is assigned to cpu_up_prepare
+ in the mpc85xx_pm_ops structure. As a result, oops is triggered in
+ smp_85xx_start_cpu().
+
+       [    0.627233] smp: Bringing up secondary CPUs ...
+       [    0.681659] kernel tried to execute user page (0) - exploit attempt? (uid: 0)
+       [    0.766618] BUG: Unable to handle kernel instruction fetch (NULL pointer?)
+       [    0.848899] Faulting instruction address: 0x00000000
+       [    0.908273] Oops: Kernel access of bad area, sig: 11 [#1]
+       ...
+       [    1.758220] NIP [00000000] 0x0
+       [    1.794688] LR [c0021d2c] smp_85xx_kick_cpu+0xe8/0x568
+       [    1.856126] Call Trace:
+       [    1.885295] [c1051da8] [c0021cb8] smp_85xx_kick_cpu+0x74/0x568 (unreliable)
+       [    1.968633] [c1051de8] [c0011460] __cpu_up+0xc0/0x228
+       [    2.029038] [c1051e18] [c0031bbc] bringup_cpu+0x30/0x224
+       [    2.092572] [c1051e48] [c0031f3c] cpu_up.constprop.0+0x180/0x33c
+       [    2.164443] [c1051e88] [c00322e8] bringup_nonboot_cpus+0x88/0xc8
+       [    2.236326] [c1051eb8] [c07e67bc] smp_init+0x30/0x78
+       [    2.295698] [c1051ed8] [c07d9e28] kernel_init_freeable+0x118/0x2a8
+       [    2.369641] [c1051f18] [c00032d8] kernel_init+0x14/0x124
+       [    2.433176] [c1051f38] [c0010278] ret_from_kernel_thread+0x14/0x1c
+
+Fixes: c45361abb9185b ("powerpc/85xx: fix timebase sync issue when
+ CONFIG_HOTPLUG_CPU=n")
+Link: https://lore.kernel.org/lkml/CANA18Uyba4kMJQrbCSZVTFep2Exe5izE45whNJgwwUvNSEcNLg@mail.gmail.com/
+Reported-by: Martin Kennedy <hurricos@gmail.com>
+Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
+Tested-by: Martin Kennedy <hurricos@gmail.com>
+Cc: stable@vger.kernel.org
+--- a/arch/powerpc/platforms/85xx/smp.c
++++ b/arch/powerpc/platforms/85xx/smp.c
+@@ -220,7 +220,7 @@ static int smp_85xx_start_cpu(int cpu)
+       local_irq_save(flags);
+       hard_irq_disable();
+ 
+-      if (qoriq_pm_ops)
++      if (qoriq_pm_ops && qoriq_pm_ops->cpu_up_prepare)
+               qoriq_pm_ops->cpu_up_prepare(cpu);
+ 
+       /* if cpu is not spinning, reset it */
+@@ -292,7 +292,7 @@ static int smp_85xx_kick_cpu(int nr)
+               booting_thread_hwid = cpu_thread_in_core(nr);
+               primary = cpu_first_thread_sibling(nr);
+ 
+-              if (qoriq_pm_ops)
++              if (qoriq_pm_ops && qoriq_pm_ops->cpu_up_prepare)
+                       qoriq_pm_ops->cpu_up_prepare(nr);
+ 
+               /*