[PATCH AUTOSEL 5.4 02/21] powerpc/6xx: add missing of_node_put

[PATCH AUTOSEL 5.4 02/21] powerpc/6xx: add missing of_node_put

[Sasha Levin]

From: Julia Lawall <Julia.Lawall@lip6.fr>

[ Upstream commit f6e82647ff71d427d4148964b71f239fba9d7937 ]

for_each_compatible_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression e;
local idexpression n;
@@

@@
local idexpression n;
expression e;
@@

 for_each_compatible_node(n,...) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  break;
)
   ...
 }
... when != n
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-2-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/embedded6xx/hlwd-pic.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
index a1b7f79a8a152..de10c13de15c6 100644
--- a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
+++ b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
@@ -215,6 +215,7 @@ void hlwd_pic_probe(void)
 			irq_set_chained_handler(cascade_virq,
 						hlwd_pic_irq_cascade);
 			hlwd_irq_host = host;
+			of_node_put(np);
 			break;
 		}
 	}
-- 
2.34.1

[PATCH AUTOSEL 5.4 03/21] powerpc/powernv: add missing of_node_put

[Sasha Levin]

From: Julia Lawall <Julia.Lawall@lip6.fr>

[ Upstream commit 7d405a939ca960162eb30c1475759cb2fdf38f8c ]

for_each_compatible_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
local idexpression n;
expression e;
@@

 for_each_compatible_node(n,...) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  break;
)
   ...
 }
... when != n
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-4-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/powernv/opal-lpc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/powernv/opal-lpc.c b/arch/powerpc/platforms/powernv/opal-lpc.c
index 608569082ba0b..123a0e799b7bd 100644
--- a/arch/powerpc/platforms/powernv/opal-lpc.c
+++ b/arch/powerpc/platforms/powernv/opal-lpc.c
@@ -396,6 +396,7 @@ void __init opal_lpc_init(void)
 		if (!of_get_property(np, "primary", NULL))
 			continue;
 		opal_lpc_chip_id = of_get_ibm_chip_id(np);
+		of_node_put(np);
 		break;
 	}
 	if (opal_lpc_chip_id < 0)
-- 
2.34.1

[PATCH AUTOSEL 5.4 04/21] powerpc/cell: add missing of_node_put

[Sasha Levin]

From: Julia Lawall <Julia.Lawall@lip6.fr>

[ Upstream commit a841fd009e51c8c0a8f07c942e9ab6bb48da8858 ]

for_each_node_by_name performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression e,e1;
local idexpression n;
@@

 for_each_node_by_name(n, e1) {
   ... when != of_node_put(n)
       when != e = n
(
   return n;
|
+  of_node_put(n);
?  return ...;
)
   ...
 }
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-7-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/cell/iommu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index ca9ffc1c8685d..a6a60e2b8f453 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -976,6 +976,7 @@ static int __init cell_iommu_fixed_mapping_init(void)
 			if (hbase < dbase || (hend > (dbase + dsize))) {
 				pr_debug("iommu: hash window doesn't fit in"
 					 "real DMA window\n");
+				of_node_put(np);
 				return -1;
 			}
 		}
-- 
2.34.1

[PATCH AUTOSEL 5.4 05/21] powerpc/btext: add missing of_node_put

[Sasha Levin]

From: Julia Lawall <Julia.Lawall@lip6.fr>

[ Upstream commit a1d2b210ffa52d60acabbf7b6af3ef7e1e69cda0 ]

for_each_node_by_type performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
local idexpression n;
expression e;
@@

 for_each_node_by_type(n,...) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  break;
)
   ...
 }
... when != n
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-6-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/btext.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/btext.c b/arch/powerpc/kernel/btext.c
index 6dfceaa820e42..b0e0b3cd91eec 100644
--- a/arch/powerpc/kernel/btext.c
+++ b/arch/powerpc/kernel/btext.c
@@ -250,8 +250,10 @@ int __init btext_find_display(int allow_nonstdout)
 			rc = btext_initialize(np);
 			printk("result: %d\n", rc);
 		}
-		if (rc == 0)
+		if (rc == 0) {
+			of_node_put(np);
 			break;
+		}
 	}
 	return rc;
 }
-- 
2.34.1

[PATCH AUTOSEL 5.4 06/21] powerpc/watchdog: Fix missed watchdog reset due to memory ordering race

[Sasha Levin]

From: Nicholas Piggin <npiggin@gmail.com>

[ Upstream commit 5dad4ba68a2483fc80d70b9dc90bbe16e1f27263 ]

It is possible for all CPUs to miss the pending cpumask becoming clear,
and then nobody resetting it, which will cause the lockup detector to
stop working. It will eventually expire, but watchdog_smp_panic will
avoid doing anything if the pending mask is clear and it will never be
reset.

Order the cpumask clear vs the subsequent test to close this race.

Add an extra check for an empty pending mask when the watchdog fires and
finds its bit still clear, to try to catch any other possible races or
bugs here and keep the watchdog working. The extra test in
arch_touch_nmi_watchdog is required to prevent the new warning from
firing off.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Debugged-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211110025056.2084347-2-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/watchdog.c | 41 +++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index af3c15a1d41eb..75b2a6c4db5a5 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c
@@ -132,6 +132,10 @@ static void set_cpumask_stuck(const struct cpumask *cpumask, u64 tb)
 {
 	cpumask_or(&wd_smp_cpus_stuck, &wd_smp_cpus_stuck, cpumask);
 	cpumask_andnot(&wd_smp_cpus_pending, &wd_smp_cpus_pending, cpumask);
+	/*
+	 * See wd_smp_clear_cpu_pending()
+	 */
+	smp_mb();
 	if (cpumask_empty(&wd_smp_cpus_pending)) {
 		wd_smp_last_reset_tb = tb;
 		cpumask_andnot(&wd_smp_cpus_pending,
@@ -217,13 +221,44 @@ static void wd_smp_clear_cpu_pending(int cpu, u64 tb)
 
 			cpumask_clear_cpu(cpu, &wd_smp_cpus_stuck);
 			wd_smp_unlock(&flags);
+		} else {
+			/*
+			 * The last CPU to clear pending should have reset the
+			 * watchdog so we generally should not find it empty
+			 * here if our CPU was clear. However it could happen
+			 * due to a rare race with another CPU taking the
+			 * last CPU out of the mask concurrently.
+			 *
+			 * We can't add a warning for it. But just in case
+			 * there is a problem with the watchdog that is causing
+			 * the mask to not be reset, try to kick it along here.
+			 */
+			if (unlikely(cpumask_empty(&wd_smp_cpus_pending)))
+				goto none_pending;
 		}
 		return;
 	}
+
 	cpumask_clear_cpu(cpu, &wd_smp_cpus_pending);
+
+	/*
+	 * Order the store to clear pending with the load(s) to check all
+	 * words in the pending mask to check they are all empty. This orders
+	 * with the same barrier on another CPU. This prevents two CPUs
+	 * clearing the last 2 pending bits, but neither seeing the other's
+	 * store when checking if the mask is empty, and missing an empty
+	 * mask, which ends with a false positive.
+	 */
+	smp_mb();
 	if (cpumask_empty(&wd_smp_cpus_pending)) {
 		unsigned long flags;
 
+none_pending:
+		/*
+		 * Double check under lock because more than one CPU could see
+		 * a clear mask with the lockless check after clearing their
+		 * pending bits.
+		 */
 		wd_smp_lock(&flags);
 		if (cpumask_empty(&wd_smp_cpus_pending)) {
 			wd_smp_last_reset_tb = tb;
@@ -314,8 +349,12 @@ void arch_touch_nmi_watchdog(void)
 {
 	unsigned long ticks = tb_ticks_per_usec * wd_timer_period_ms * 1000;
 	int cpu = smp_processor_id();
-	u64 tb = get_tb();
+	u64 tb;
 
+	if (!cpumask_test_cpu(cpu, &watchdog_cpumask))
+		return;
+
+	tb = get_tb();
 	if (tb - per_cpu(wd_timer_tb, cpu) >= ticks) {
 		per_cpu(wd_timer_tb, cpu) = tb;
 		wd_smp_clear_cpu_pending(cpu, tb);
-- 
2.34.1

[PATCH AUTOSEL 5.4 08/21] powerpc/smp: Move setup_profiling_timer() under CONFIG_PROFILING

[Sasha Levin]

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

[ Upstream commit a4ac0d249a5db80e79d573db9e4ad29354b643a8 ]

setup_profiling_timer() is only needed when CONFIG_PROFILING is enabled.

Fixes the following W=1 warning when CONFIG_PROFILING=n:
  linux/arch/powerpc/kernel/smp.c:1638:5: error: no previous prototype for ‘setup_profiling_timer’

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211124093254.1054750-5-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/smp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index c06cac543f188..82dff003a7fd6 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1296,10 +1296,12 @@ void start_secondary(void *unused)
 	BUG();
 }
 
+#ifdef CONFIG_PROFILING
 int setup_profiling_timer(unsigned int multiplier)
 {
 	return 0;
 }
+#endif
 
 #ifdef CONFIG_SCHED_SMT
 /* cpumask of CPUs with asymetric SMT dependancy */
-- 
2.34.1

[PATCH AUTOSEL 5.4 11/21] powerpc/powermac: Add missing lockdep_register_key()

[Sasha Levin]

From: Christophe Leroy <christophe.leroy@csgroup.eu>

[ Upstream commit df1f679d19edb9eeb67cc2f96b29375f21991945 ]

KeyWest i2c @0xf8001003 irq 42 /uni-n@f8000000/i2c@f8001000
BUG: key c2d00cbc has not been registered!
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:4801 lockdep_init_map_type+0x4c0/0xb4c
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.5-gentoo-PowerMacG4 #9
NIP:  c01a9428 LR: c01a9428 CTR: 00000000
REGS: e1033cf0 TRAP: 0700   Not tainted  (5.15.5-gentoo-PowerMacG4)
MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 24002002  XER: 00000000

GPR00: c01a9428 e1033db0 c2d1cf20 00000016 00000004 00000001 c01c0630 e1033a73
GPR08: 00000000 00000000 00000000 e1033db0 24002004 00000000 f8729377 00000003
GPR16: c1829a9c 00000000 18305357 c1416fc0 c1416f80 c006ac60 c2d00ca8 c1416f00
GPR24: 00000000 c21586f0 c2160000 00000000 c2d00cbc c2170000 c216e1a0 c2160000
NIP [c01a9428] lockdep_init_map_type+0x4c0/0xb4c
LR [c01a9428] lockdep_init_map_type+0x4c0/0xb4c
Call Trace:
[e1033db0] [c01a9428] lockdep_init_map_type+0x4c0/0xb4c (unreliable)
[e1033df0] [c1c177b8] kw_i2c_add+0x334/0x424
[e1033e20] [c1c18294] pmac_i2c_init+0x9ec/0xa9c
[e1033e80] [c1c1a790] smp_core99_probe+0xbc/0x35c
[e1033eb0] [c1c03cb0] kernel_init_freeable+0x190/0x5a4
[e1033f10] [c000946c] kernel_init+0x28/0x154
[e1033f30] [c0035148] ret_from_kernel_thread+0x14/0x1c

Add missing lockdep_register_key()

Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/69e4f55565bb45ebb0843977801b245af0c666fe.1638264741.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/powermac/low_i2c.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
index bf4be4b53b44d..c93ba97b3cb67 100644
--- a/arch/powerpc/platforms/powermac/low_i2c.c
+++ b/arch/powerpc/platforms/powermac/low_i2c.c
@@ -582,6 +582,7 @@ static void __init kw_i2c_add(struct pmac_i2c_host_kw *host,
 	bus->close = kw_i2c_close;
 	bus->xfer = kw_i2c_xfer;
 	mutex_init(&bus->mutex);
+	lockdep_register_key(&bus->lock_key);
 	lockdep_set_class(&bus->mutex, &bus->lock_key);
 	if (controller == busnode)
 		bus->flags = pmac_i2c_multibus;
-- 
2.34.1

[PATCH AUTOSEL 5.4 12/21] KVM: PPC: Book3S: Suppress failed alloc warning in H_COPY_TOFROM_GUEST

[Sasha Levin]

From: Alexey Kardashevskiy <aik@ozlabs.ru>

[ Upstream commit 792020907b11c6f9246c21977cab3bad985ae4b6 ]

H_COPY_TOFROM_GUEST is an hcall for an upper level VM to access its nested
VMs memory. The userspace can trigger WARN_ON_ONCE(!(gfp & __GFP_NOWARN))
in __alloc_pages() by constructing a tiny VM which only does
H_COPY_TOFROM_GUEST with a too big GPR9 (number of bytes to copy).

This silences the warning by adding __GFP_NOWARN.

Spotted by syzkaller.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210901084550.1658699-1-aik@ozlabs.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kvm/book3s_hv_nested.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 9906d203d9d39..613d24b707abe 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -510,7 +510,7 @@ long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu)
 	if (eaddr & (0xFFFUL << 52))
 		return H_PARAMETER;
 
-	buf = kzalloc(n, GFP_KERNEL);
+	buf = kzalloc(n, GFP_KERNEL | __GFP_NOWARN);
 	if (!buf)
 		return H_NO_MEM;
 
-- 
2.34.1

[PATCH AUTOSEL 5.4 16/21] powerpc: handle kdump appropriately with crash_kexec_post_notifiers option

[Sasha Levin]

From: Hari Bathini <hbathini@linux.ibm.com>

[ Upstream commit 219572d2fc4135b5ce65c735d881787d48b10e71 ]

Kdump can be triggered after panic_notifers since commit f06e5153f4ae2
("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump
after panic_notifers") introduced crash_kexec_post_notifiers option.
But using this option would mean smp_send_stop(), that marks all other
CPUs as offline, gets called before kdump is triggered. As a result,
kdump routines fail to save other CPUs' registers. To fix this, kdump
friendly crash_smp_send_stop() function was introduced with kernel
commit 0ee59413c967 ("x86/panic: replace smp_send_stop() with kdump
friendly version in panic path"). Override this kdump friendly weak
function to handle crash_kexec_post_notifiers option appropriately
on powerpc.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
[Fixed signature of crash_stop_this_cpu() - reported by lkp@intel.com]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211207103719.91117-1-hbathini@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/smp.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 82dff003a7fd6..4de63ec2e1551 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -582,6 +582,36 @@ void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 }
 #endif
 
+#ifdef CONFIG_NMI_IPI
+static void crash_stop_this_cpu(struct pt_regs *regs)
+#else
+static void crash_stop_this_cpu(void *dummy)
+#endif
+{
+	/*
+	 * Just busy wait here and avoid marking CPU as offline to ensure
+	 * register data is captured appropriately.
+	 */
+	while (1)
+		cpu_relax();
+}
+
+void crash_smp_send_stop(void)
+{
+	static bool stopped = false;
+
+	if (stopped)
+		return;
+
+	stopped = true;
+
+#ifdef CONFIG_NMI_IPI
+	smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, crash_stop_this_cpu, 1000000);
+#else
+	smp_call_function(crash_stop_this_cpu, NULL, 0);
+#endif /* CONFIG_NMI_IPI */
+}
+
 #ifdef CONFIG_NMI_IPI
 static void nmi_stop_this_cpu(struct pt_regs *regs)
 {
-- 
2.34.1