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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Johannes Berg <johannes.berg@intel.com>,
	Richard Weinberger <richard@nod.at>,
	Sasha Levin <sashal@kernel.org>,
	linux-um@lists.infradead.org
Subject: [PATCH AUTOSEL 4.9 05/30] um: change sigio_spinlock to a mutex
Date: Mon, 26 Oct 2020 20:10:19 -0400	[thread overview]
Message-ID: <20201027001044.1027349-5-sashal@kernel.org> (raw)
In-Reply-To: <20201027001044.1027349-1-sashal@kernel.org>

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit f2d05059e15af3f70502074f4e3a504530af504a ]

Lockdep complains at boot:

=============================
[ BUG: Invalid wait context ]
5.7.0-05093-g46d91ecd597b #98 Not tainted
-----------------------------
swapper/1 is trying to lock:
0000000060931b98 (&desc[i].request_mutex){+.+.}-{3:3}, at: __setup_irq+0x11d/0x623
other info that might help us debug this:
context-{4:4}
1 lock held by swapper/1:
 #0: 000000006074fed8 (sigio_spinlock){+.+.}-{2:2}, at: sigio_lock+0x1a/0x1c
stack backtrace:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0-05093-g46d91ecd597b #98
Stack:
 7fa4fab0 6028dfd1 0000002a 6008bea5
 7fa50700 7fa50040 7fa4fac0 6028e016
 7fa4fb50 6007f6da 60959c18 00000000
Call Trace:
 [<60023a0e>] show_stack+0x13b/0x155
 [<6028e016>] dump_stack+0x2a/0x2c
 [<6007f6da>] __lock_acquire+0x515/0x15f2
 [<6007eb50>] lock_acquire+0x245/0x273
 [<6050d9f1>] __mutex_lock+0xbd/0x325
 [<6050dc76>] mutex_lock_nested+0x1d/0x1f
 [<6008e27e>] __setup_irq+0x11d/0x623
 [<6008e8ed>] request_threaded_irq+0x169/0x1a6
 [<60021eb0>] um_request_irq+0x1ee/0x24b
 [<600234ee>] write_sigio_irq+0x3b/0x76
 [<600383ca>] sigio_broken+0x146/0x2e4
 [<60020bd8>] do_one_initcall+0xde/0x281

Because we hold sigio_spinlock and then get into requesting
an interrupt with a mutex.

Change the spinlock to a mutex to avoid that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/um/kernel/sigio.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/um/kernel/sigio.c b/arch/um/kernel/sigio.c
index b5e0cbb343828..476ded92affac 100644
--- a/arch/um/kernel/sigio.c
+++ b/arch/um/kernel/sigio.c
@@ -36,14 +36,14 @@ int write_sigio_irq(int fd)
 }
 
 /* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
-static DEFINE_SPINLOCK(sigio_spinlock);
+static DEFINE_MUTEX(sigio_mutex);
 
 void sigio_lock(void)
 {
-	spin_lock(&sigio_spinlock);
+	mutex_lock(&sigio_mutex);
 }
 
 void sigio_unlock(void)
 {
-	spin_unlock(&sigio_spinlock);
+	mutex_unlock(&sigio_mutex);
 }
-- 
2.25.1


  parent reply	other threads:[~2020-10-27  0:17 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-27  0:10 [PATCH AUTOSEL 4.9 01/30] powerpc/powernv/smp: Fix spurious DBG() warning Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 02/30] sparc64: remove mm_cpumask clearing to fix kthread_use_mm race Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 03/30] f2fs: add trace exit in exception path Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 04/30] f2fs: fix to check segment boundary during SIT page readahead Sasha Levin
2020-10-27  0:10 ` Sasha Levin [this message]
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 06/30] ARM: 8997/2: hw_breakpoint: Handle inexact watchpoint addresses Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 07/30] xfs: fix realtime bitmap/summary file truncation when growing rt volume Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 08/30] video: fbdev: pvr2fb: initialize variables Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 09/30] ath10k: fix VHT NSS calculation when STBC is enabled Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 10/30] media: tw5864: check status of tw5864_frameinterval_get Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 11/30] mmc: via-sdmmc: Fix data race bug Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 12/30] printk: reduce LOG_BUF_SHIFT range for H8300 Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 13/30] kgdb: Make "kgdbcon" work properly with "kgdb_earlycon" Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 14/30] cpufreq: sti-cpufreq: add stih418 support Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 15/30] USB: adutux: fix debugging Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 16/30] arm64/mm: return cpu_all_mask when node is NUMA_NO_NODE Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 17/30] dm: change max_io_len() to use blk_max_size_offset() Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 18/30] drivers/net/wan/hdlc_fr: Correctly handle special skb->protocol values Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 19/30] bus/fsl_mc: Do not rely on caller to provide non NULL mc_io Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 20/30] power: supply: test_power: add missing newlines when printing parameters by sysfs Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 21/30] md/bitmap: md_bitmap_get_counter returns wrong blocks Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 22/30] clk: ti: clockdomain: fix static checker warning Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 23/30] net: 9p: initialize sun_server.sun_path to have addr's value only when addr is valid Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 24/30] drivers: watchdog: rdc321x_wdt: Fix race condition bugs Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 25/30] ext4: Detect already used quota file early Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 26/30] gfs2: add validation checks for size of superblock Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 27/30] memory: emif: Remove bogus debugfs error handling Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 28/30] ARM: dts: s5pv210: remove DMA controller bus node name to fix dtschema warnings Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 29/30] ARM: dts: s5pv210: move PMU node out of clock controller Sasha Levin
2020-10-27  0:10 ` [PATCH AUTOSEL 4.9 30/30] ARM: dts: s5pv210: remove dedicated 'audio-subsystem' node Sasha Levin

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