linux-kernel - [PATCH v3] NUMA: Early use of cpu_to_node() returns 0 instead of the correct node id

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date: Fri, 26 Jan 2024 14:44:51 +0800
From: Huang Shijie <shijie@...amperecomputing.com>
To: gregkh@...uxfoundation.org
Cc: patches@...erecomputing.com,
	rafael@...nel.org,
	paul.walmsley@...ive.com,
	palmer@...belt.com,
	aou@...s.berkeley.edu,
	yury.norov@...il.com,
	kuba@...nel.org,
	vschneid@...hat.com,
	mingo@...nel.org,
	akpm@...ux-foundation.org,
	vbabka@...e.cz,
	rppt@...nel.org,
	tglx@...utronix.de,
	jpoimboe@...nel.org,
	ndesaulniers@...gle.com,
	mikelley@...rosoft.com,
	mhiramat@...nel.org,
	arnd@...db.de,
	linux-kernel@...r.kernel.org,
	linux-riscv@...ts.infradead.org,
	linux-arm-kernel@...ts.infradead.org,
	catalin.marinas@....com,
	will@...nel.org,
	mark.rutland@....com,
	mpe@...erman.id.au,
	linuxppc-dev@...ts.ozlabs.org,
	chenhuacai@...nel.org,
	jiaxun.yang@...goat.com,
	linux-mips@...r.kernel.org,
	cl@...amperecomputing.com,
	Huang Shijie <shijie@...amperecomputing.com>
Subject: [PATCH v3] NUMA: Early use of cpu_to_node() returns 0 instead of the correct node id

During the kernel booting, the generic cpu_to_node() is called too early in
arm64, powerpc and riscv when CONFIG_NUMA is enabled.

There are at least four places in the common code where
the generic cpu_to_node() is called before it is initialized:
	   1.) early_trace_init()         in kernel/trace/trace.c
	   2.) sched_init()               in kernel/sched/core.c
	   3.) init_sched_fair_class()    in kernel/sched/fair.c
	   4.) workqueue_init_early()     in kernel/workqueue.c

In order to fix the bug, the patch introduces early_numa_node_init()
which is called after smp_prepare_boot_cpu() in start_kernel.
early_numa_node_init will initialize the "numa_node" as soon as
the early_cpu_to_node() is ready, before the cpu_to_node() is called
at the first time.

Signed-off-by: Huang Shijie <shijie@...amperecomputing.com>
---
v2 --> v3:
	Do not change the cpu_to_node to function pointer.
	Introduce early_numa_node_init() which initialize
	the numa_node at an early stage.

	v2: https://lore.kernel.org/all/20240123045843.75969-1-shijie@os.amperecomputing.com/
	
v1 --> v2:
	In order to fix the x86 compiling error, move the cpu_to_node()
       	from driver/base/arch_numa.c to driver/base/node.c.

	v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2024-January/896160.html

	An old different title patch:
	http://lists.infradead.org/pipermail/linux-arm-kernel/2024-January/895963.html

---
 init/main.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/init/main.c b/init/main.c
index e24b0780fdff..39efe5ed58a0 100644
--- a/init/main.c
+++ b/init/main.c
@@ -870,6 +870,19 @@ static void __init print_unknown_bootoptions(void)
 	memblock_free(unknown_options, len);
 }
 
+static void __init early_numa_node_init(void)
+{
+#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
+#ifndef cpu_to_node
+	int cpu;
+
+	/* The early_cpu_to_node() should be ready here. */
+	for_each_possible_cpu(cpu)
+		set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
+#endif
+#endif
+}
+
 asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
 void start_kernel(void)
 {
@@ -900,6 +913,7 @@ void start_kernel(void)
 	setup_nr_cpu_ids();
 	setup_per_cpu_areas();
 	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
+	early_numa_node_init();
 	boot_cpu_hotplug_init();
 
 	pr_notice("Kernel command line: %s\n", saved_command_line);
-- 
2.40.1