Commit 1a783057 authored Jun 14, 2019 by Roman Kiryanov

ANDROID: kernel: cgroup: cpuset: Add missing allocation of cpus_requested in alloc_trial_cpuset



alloc_trial_cpuset missed allocation of the alloc_trial_cpuset
field which caused it to be shared from the base cs provided.

Once update_cpumask parsed buf into cpus_requested and updated
cpus_allowed, the result were never written to cs because
cs and trialcs shared the same pointer to cpus_requested and
cpus_requested always matched to itself and no updates were
written. This caused cpus_requested to be non-empty and
cpus_allowed empty.

This issue occurs only with CONFIG_CPUMASK_OFFSTACK enabled
(e.g. via CONFIG_MAXSMP).

Bug: 134051784
Bug: 120444281
Fixes: 4803def4e0b2 ("ANDROID: cpuset: Make cpusets restore on hotplug")
Test: enable CONFIG_CPUSETS, boot and check logcat that
Test: libprocessgroup does not fail with something similar to
Test: AddTidToCgroup failed to write '2354'; fd=93: No space left on device
Signed-off-by: Roman Kiryanov <rkir@google.com>
Change-Id: I866836b5c0acfde8349c250a510ee89d8d37cb8e

parent f613e893

kernel/cgroup/cpuset.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -433,14 +433,19 @@ static struct cpuset alloc_trial_cpuset(struct cpuset cs)

		if (!alloc_cpumask_var(&trial->cpus_allowed, GFP_KERNEL))
		goto free_cs;
		if (!alloc_cpumask_var(&trial->cpus_requested, GFP_KERNEL))
		goto free_allowed;
		if (!alloc_cpumask_var(&trial->effective_cpus, GFP_KERNEL))
		goto free_cpus;

		cpumask_copy(trial->cpus_allowed, cs->cpus_allowed);
		cpumask_copy(trial->cpus_requested, cs->cpus_requested);
		cpumask_copy(trial->effective_cpus, cs->effective_cpus);
		return trial;

		free_cpus:
		free_cpumask_var(trial->cpus_requested);
		free_allowed:
		free_cpumask_var(trial->cpus_allowed);
		free_cs:
		kfree(trial);
		@@ -454,6 +459,7 @@ static struct cpuset alloc_trial_cpuset(struct cpuset cs)
		static void free_trial_cpuset(struct cpuset *trial)
		{
		free_cpumask_var(trial->effective_cpus);
		free_cpumask_var(trial->cpus_requested);
		free_cpumask_var(trial->cpus_allowed);
		kfree(trial);
		}