The patch below does not apply to the v6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
Thanks,
Sasha
------------------ original commit in Linus's tree ------------------
From b5413156bad91dc2995a5c4eab1b05e56914638a Mon Sep 17 00:00:00 2001
From: Benjamin Segall <bsegall(a)google.com>
Date: Fri, 25 Oct 2024 18:35:35 -0700
Subject: [PATCH] posix-cpu-timers: Clear TICK_DEP_BIT_POSIX_TIMER on clone
When cloning a new thread, its posix_cputimers are not inherited, and
are cleared by posix_cputimers_init(). However, this does not clear the
tick dependency it creates in tsk->tick_dep_mask, and the handler does
not reach the code to clear the dependency if there were no timers to
begin with.
Thus if a thread has a cputimer running before clone/fork, all
descendants will prevent nohz_full unless they create a cputimer of
their own.
Fix this by entirely clearing the tick_dep_mask in copy_process().
(There is currently no inherited state that needs a tick dependency)
Process-wide timers do not have this problem because fork does not copy
signal_struct as a baseline, it creates one from scratch.
Fixes: b78783000d5c ("posix-cpu-timers: Migrate to use new tick dependency mask model")
Signed-off-by: Ben Segall <bsegall(a)google.com>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic(a)kernel.org>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/all/xm26o737bq8o.fsf@google.com
---
include/linux/tick.h | 8 ++++++++
kernel/fork.c | 2 ++
2 files changed, 10 insertions(+)
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 72744638c5b0f..99c9c5a7252aa 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -251,12 +251,19 @@ static inline void tick_dep_set_task(struct task_struct *tsk,
if (tick_nohz_full_enabled())
tick_nohz_dep_set_task(tsk, bit);
}
+
static inline void tick_dep_clear_task(struct task_struct *tsk,
enum tick_dep_bits bit)
{
if (tick_nohz_full_enabled())
tick_nohz_dep_clear_task(tsk, bit);
}
+
+static inline void tick_dep_init_task(struct task_struct *tsk)
+{
+ atomic_set(&tsk->tick_dep_mask, 0);
+}
+
static inline void tick_dep_set_signal(struct task_struct *tsk,
enum tick_dep_bits bit)
{
@@ -290,6 +297,7 @@ static inline void tick_dep_set_task(struct task_struct *tsk,
enum tick_dep_bits bit) { }
static inline void tick_dep_clear_task(struct task_struct *tsk,
enum tick_dep_bits bit) { }
+static inline void tick_dep_init_task(struct task_struct *tsk) { }
static inline void tick_dep_set_signal(struct task_struct *tsk,
enum tick_dep_bits bit) { }
static inline void tick_dep_clear_signal(struct signal_struct *signal,
diff --git a/kernel/fork.c b/kernel/fork.c
index 89ceb4a68af25..6fa9fe62e01e3 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -105,6 +105,7 @@
#include <linux/rseq.h>
#include <uapi/linux/pidfd.h>
#include <linux/pidfs.h>
+#include <linux/tick.h>
#include <asm/pgalloc.h>
#include <linux/uaccess.h>
@@ -2292,6 +2293,7 @@ __latent_entropy struct task_struct *copy_process(
acct_clear_integrals(p);
posix_cputimers_init(&p->posix_cputimers);
+ tick_dep_init_task(p);
p->io_context = NULL;
audit_set_context(p, NULL);
--
2.43.0
From: Javier Carrasco <javier.carrasco.cruz(a)gmail.com>
This loop requires explicit calls to of_node_put() upon early exits
(break, goto, return) to decrement the child refcounter and avoid memory
leaks if the child is not required out of the loop.
A more robust solution is using the scoped variant of the macro, which
automatically calls of_node_put() when the child goes out of scope.
Cc: stable(a)vger.kernel.org
Fixes: 979987371739 ("spmi: pmic-arb: Add multi bus support")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz(a)gmail.com>
Link: https://lore.kernel.org/r/20241001-spmi-pmic-arb-scoped-v1-1-5872bab34ed6@g…
Reviewed-by: Neil Armstrong <neil.armstrong(a)linaro.org>
Signed-off-by: Stephen Boyd <sboyd(a)kernel.org>
---
drivers/spmi/spmi-pmic-arb.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 9ba9495fcc4b..ea843159b745 100644
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -1763,14 +1763,13 @@ static int spmi_pmic_arb_register_buses(struct spmi_pmic_arb *pmic_arb,
{
struct device *dev = &pdev->dev;
struct device_node *node = dev->of_node;
- struct device_node *child;
int ret;
/* legacy mode doesn't provide child node for the bus */
if (of_device_is_compatible(node, "qcom,spmi-pmic-arb"))
return spmi_pmic_arb_bus_init(pdev, node, pmic_arb);
- for_each_available_child_of_node(node, child) {
+ for_each_available_child_of_node_scoped(node, child) {
if (of_node_name_eq(child, "spmi")) {
ret = spmi_pmic_arb_bus_init(pdev, child, pmic_arb);
if (ret)
--
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git