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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>,
	Huacai Chen <chenhuacai@loongson.cn>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 6.2 10/13] LoongArch: Only call get_timer_irq() once in constant_clockevent_init()
Date: Tue, 14 Mar 2023 08:43:02 -0400	[thread overview]
Message-ID: <20230314124305.470657-10-sashal@kernel.org> (raw)
In-Reply-To: <20230314124305.470657-1-sashal@kernel.org>

From: Tiezhu Yang <yangtiezhu@loongson.cn>

[ Upstream commit bb7a78e343468873bf00b2b181fcfd3c02d8cb56 ]

Under CONFIG_DEBUG_ATOMIC_SLEEP=y and CONFIG_DEBUG_PREEMPT=y, we can see
the following messages on LoongArch, this is because using might_sleep()
in preemption disable context.

[    0.001127] smp: Bringing up secondary CPUs ...
[    0.001222] Booting CPU#1...
[    0.001244] 64-bit Loongson Processor probed (LA464 Core)
[    0.001247] CPU1 revision is: 0014c012 (Loongson-64bit)
[    0.001250] FPU1 revision is: 00000000
[    0.001252] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283
[    0.001255] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
[    0.001257] preempt_count: 1, expected: 0
[    0.001258] RCU nest depth: 0, expected: 0
[    0.001259] Preemption disabled at:
[    0.001261] [<9000000000223800>] arch_dup_task_struct+0x20/0x110
[    0.001272] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.2.0-rc7+ #43
[    0.001275] Hardware name: Loongson Loongson-3A5000-7A1000-1w-A2101/Loongson-LS3A5000-7A1000-1w-A2101, BIOS vUDK2018-LoongArch-V4.0.05132-beta10 12/13/202
[    0.001277] Stack : 0072617764726148 0000000000000000 9000000000222f1c 90000001001e0000
[    0.001286]         90000001001e3be0 90000001001e3be8 0000000000000000 0000000000000000
[    0.001292]         90000001001e3be8 0000000000000040 90000001001e3cb8 90000001001e3a50
[    0.001297]         9000000001642000 90000001001e3be8 be694d10ce4139dd 9000000100174500
[    0.001303]         0000000000000001 0000000000000001 00000000ffffe0a2 0000000000000020
[    0.001309]         000000000000002f 9000000001354116 00000000056b0000 ffffffffffffffff
[    0.001314]         0000000000000000 0000000000000000 90000000014f6e90 9000000001642000
[    0.001320]         900000000022b69c 0000000000000001 0000000000000000 9000000001736a90
[    0.001325]         9000000100038000 0000000000000000 9000000000222f34 0000000000000000
[    0.001331]         00000000000000b0 0000000000000004 0000000000000000 0000000000070000
[    0.001337]         ...
[    0.001339] Call Trace:
[    0.001342] [<9000000000222f34>] show_stack+0x5c/0x180
[    0.001346] [<90000000010bdd80>] dump_stack_lvl+0x60/0x88
[    0.001352] [<9000000000266418>] __might_resched+0x180/0x1cc
[    0.001356] [<90000000010c742c>] mutex_lock+0x20/0x64
[    0.001359] [<90000000002a8ccc>] irq_find_matching_fwspec+0x48/0x124
[    0.001364] [<90000000002259c4>] constant_clockevent_init+0x68/0x204
[    0.001368] [<900000000022acf4>] start_secondary+0x40/0xa8
[    0.001371] [<90000000010c0124>] smpboot_entry+0x60/0x64

Here are the complete call chains:

smpboot_entry()
  start_secondary()
    constant_clockevent_init()
      get_timer_irq()
        irq_find_matching_fwnode()
          irq_find_matching_fwspec()
            mutex_lock()
              might_sleep()
                __might_sleep()
                  __might_resched()

In order to avoid the above issue, we should break the call chains,
using timer_irq_installed variable as check condition to only call
get_timer_irq() once in constant_clockevent_init() is a simple and
proper way.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/loongarch/kernel/time.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c
index a6576dea590c0..4351f69d99501 100644
--- a/arch/loongarch/kernel/time.c
+++ b/arch/loongarch/kernel/time.c
@@ -140,16 +140,17 @@ static int get_timer_irq(void)
 
 int constant_clockevent_init(void)
 {
-	int irq;
 	unsigned int cpu = smp_processor_id();
 	unsigned long min_delta = 0x600;
 	unsigned long max_delta = (1UL << 48) - 1;
 	struct clock_event_device *cd;
-	static int timer_irq_installed = 0;
+	static int irq = 0, timer_irq_installed = 0;
 
-	irq = get_timer_irq();
-	if (irq < 0)
-		pr_err("Failed to map irq %d (timer)\n", irq);
+	if (!timer_irq_installed) {
+		irq = get_timer_irq();
+		if (irq < 0)
+			pr_err("Failed to map irq %d (timer)\n", irq);
+	}
 
 	cd = &per_cpu(constant_clockevent_device, cpu);
 
-- 
2.39.2


  parent reply	other threads:[~2023-03-14 12:46 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-14 12:42 [PATCH AUTOSEL 6.2 01/13] mmc: atmel-mci: fix race between stop command and start of next command Sasha Levin
2023-03-14 12:42 ` [PATCH AUTOSEL 6.2 02/13] soc: mediatek: mtk-svs: keep svs alive if CONFIG_DEBUG_FS not supported Sasha Levin
2023-03-14 12:42 ` [PATCH AUTOSEL 6.2 03/13] jffs2: correct logic when creating a hole in jffs2_write_begin Sasha Levin
2023-03-14 12:42 ` [PATCH AUTOSEL 6.2 04/13] rust: arch/um: Disable FP/SIMD instruction to match x86 Sasha Levin
2023-03-14 12:42 ` [PATCH AUTOSEL 6.2 05/13] ext4: fail ext4_iget if special inode unallocated Sasha Levin
2023-03-14 12:42 ` [PATCH AUTOSEL 6.2 06/13] ext4: update s_journal_inum if it changes after journal replay Sasha Levin
2023-03-14 12:42 ` [PATCH AUTOSEL 6.2 07/13] ext4: fix task hung in ext4_xattr_delete_inode Sasha Levin
2023-03-14 12:43 ` [PATCH AUTOSEL 6.2 08/13] drm/amdkfd: Fix an illegal memory access Sasha Levin
2023-03-14 12:43 ` [PATCH AUTOSEL 6.2 09/13] net/9p: fix bug in client create for .L Sasha Levin
2023-03-14 12:43 ` Sasha Levin [this message]
2023-03-14 12:43 ` [PATCH AUTOSEL 6.2 11/13] sh: intc: Avoid spurious sizeof-pointer-div warning Sasha Levin
2023-03-14 12:43 ` [PATCH AUTOSEL 6.2 12/13] drm/amdgpu: fix ttm_bo calltrace warning in psp_hw_fini Sasha Levin
2023-03-14 12:43 ` [PATCH AUTOSEL 6.2 13/13] drm/amd/display: fix shift-out-of-bounds in CalculateVMAndRowBytes Sasha Levin

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