gpu: host1x: Fix a use of uninitialized mutex

RJS1512 · mehmetb0 · commit 620cb37bdd17 · 2025-03-31T17:01:59.000+03:00
BugLink: https://bugs.launchpad.net/bugs/2104873 [ Upstream commit 02458fb ] commit c8347f9 ("gpu: host1x: Fix boot regression for Tegra") caused a use of uninitialized mutex leading to below warning when CONFIG_DEBUG_MUTEXES and CONFIG_DEBUG_LOCK_ALLOC are enabled. [ 41.662843] ------------[ cut here ]------------ [ 41.663012] DEBUG_LOCKS_WARN_ON(lock->magic != lock) [ 41.663035] WARNING: CPU: 4 PID: 794 at kernel/locking/mutex.c:587 __mutex_lock+0x670/0x878 [ 41.663458] Modules linked in: rtw88_8822c(+) bluetooth(+) rtw88_pci rtw88_core mac80211 aquantia libarc4 crc_itu_t cfg80211 tegra194_cpufreq dwmac_tegra(+) arm_dsu_pmu stmmac_platform stmmac pcs_xpcs rfkill at24 host1x(+) tegra_bpmp_thermal ramoops reed_solomon fuse loop nfnetlink xfs mmc_block rpmb_core ucsi_ccg ina3221 crct10dif_ce xhci_tegra ghash_ce lm90 sha2_ce sha256_arm64 sha1_ce sdhci_tegra pwm_fan sdhci_pltfm sdhci gpio_keys rtc_tegra cqhci mmc_core phy_tegra_xusb i2c_tegra tegra186_gpc_dma i2c_tegra_bpmp spi_tegra114 dm_mirror dm_region_hash dm_log dm_mod [ 41.665078] CPU: 4 UID: 0 PID: 794 Comm: (udev-worker) Not tainted 6.11.0-29.31_1538613708.el10.aarch64+debug #1 [ 41.665838] Hardware name: NVIDIA NVIDIA Jetson AGX Orin Developer Kit/Jetson, BIOS 36.3.0-gcid-35594366 02/26/2024 [ 41.672555] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 41.679636] pc : __mutex_lock+0x670/0x878 [ 41.683834] lr : __mutex_lock+0x670/0x878 [ 41.688035] sp : ffff800084b77090 [ 41.691446] x29: ffff800084b77160 x28: ffffdd4bebf7b000 x27: ffffdd4be96b1000 [ 41.698799] x26: 1fffe0002308361c x25: 1ffff0001096ee18 x24: 0000000000000000 [ 41.706149] x23: 0000000000000000 x22: 0000000000000002 x21: ffffdd4be6e3c7a0 [ 41.713500] x20: ffff800084b770f0 x19: ffff00011841b1e8 x18: 0000000000000000 [ 41.720675] x17: 0000000000000000 x16: 0000000000000000 x15: 0720072007200720 [ 41.728023] x14: 0000000000000000 x13: 0000000000000001 x12: ffff6001a96eaab3 [ 41.735375] x11: 1fffe001a96eaab2 x10: ffff6001a96eaab2 x9 : ffffdd4be4838bbc [ 41.742723] x8 : 00009ffe5691554e x7 : ffff000d4b755593 x6 : 0000000000000001 [ 41.749985] x5 : ffff000d4b755590 x4 : 1fffe0001d88f001 x3 : dfff800000000000 [ 41.756988] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000ec478000 [ 41.764251] Call trace: [ 41.766695] __mutex_lock+0x670/0x878 [ 41.770373] mutex_lock_nested+0x2c/0x40 [ 41.774134] host1x_intr_start+0x54/0xf8 [host1x] [ 41.778863] host1x_runtime_resume+0x150/0x228 [host1x] [ 41.783935] pm_generic_runtime_resume+0x84/0xc8 [ 41.788485] __rpm_callback+0xa0/0x478 [ 41.792422] rpm_callback+0x15c/0x1a8 [ 41.795922] rpm_resume+0x698/0xc08 [ 41.799597] __pm_runtime_resume+0xa8/0x140 [ 41.803621] host1x_probe+0x810/0xbc0 [host1x] [ 41.807909] platform_probe+0xcc/0x1a8 [ 41.811845] really_probe+0x188/0x800 [ 41.815347] __driver_probe_device+0x164/0x360 [ 41.819810] driver_probe_device+0x64/0x1a8 [ 41.823834] __driver_attach+0x180/0x490 [ 41.827773] bus_for_each_dev+0x104/0x1a0 [ 41.831797] driver_attach+0x44/0x68 [ 41.835296] bus_add_driver+0x23c/0x4e8 [ 41.839235] driver_register+0x15c/0x3a8 [ 41.843170] __platform_register_drivers+0xa4/0x208 [ 41.848159] tegra_host1x_init+0x4c/0xff8 [host1x] [ 41.853147] do_one_initcall+0xd4/0x380 [ 41.856997] do_init_module+0x1dc/0x698 [ 41.860758] load_module+0xc70/0x1300 [ 41.864435] __do_sys_init_module+0x1a8/0x1d0 [ 41.868721] __arm64_sys_init_module+0x74/0xb0 [ 41.873183] invoke_syscall.constprop.0+0xdc/0x1e8 [ 41.877997] do_el0_svc+0x154/0x1d0 [ 41.881671] el0_svc+0x54/0x140 [ 41.884820] el0t_64_sync_handler+0x120/0x130 [ 41.889285] el0t_64_sync+0x1a4/0x1a8 [ 41.892960] irq event stamp: 69737 [ 41.896370] hardirqs last enabled at (69737): [<ffffdd4be6d7768c>] _raw_spin_unlock_irqrestore+0x44/0xe8 [ 41.905739] hardirqs last disabled at (69736): [<ffffdd4be59dcd40>] clk_enable_lock+0x98/0x198 [ 41.914314] softirqs last enabled at (68082): [<ffffdd4be466b1d0>] handle_softirqs+0x4c8/0x890 [ 41.922977] softirqs last disabled at (67945): [<ffffdd4be44f02a4>] __do_softirq+0x1c/0x28 [ 41.931289] ---[ end trace 0000000000000000 ]--- Inside the probe function when pm_runtime_enable() is called, the PM core invokes a resume callback if the device Host1x is in a suspended state. As it can be seen in the logs above, this leads to host1x_intr_start() function call which is trying to acquire a mutex lock. But, the function host_intr_init() only gets called after the pm_runtime_enable() where mutex is initialised leading to the use of mutex prior to its initialisation. Fix this by moving the mutex initialisation prior to the runtime PM enablement function pm_runtime_enable() in probe. Fixes: c8347f9 ("gpu: host1x: Fix boot regression for Tegra") Signed-off-by: Rupinderjit Singh <rusingh@redhat.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Link: https://patchwork.ozlabs.org/project/linux-tegra/patch/20250206155803.201942-1-rusingh@redhat.com/ Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Noah Wager <noah.wager@canonical.com>
diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
@@ -630,6 +630,8 @@ static int host1x_probe(struct platform_device *pdev)
 		goto deinit_syncpt;
 	}
 
+	mutex_init(&host->intr_mutex);
+
 	pm_runtime_enable(&pdev->dev);
 
 	err = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);
diff --git a/drivers/gpu/host1x/intr.c b/drivers/gpu/host1x/intr.c
@@ -102,8 +102,6 @@ int host1x_intr_init(struct host1x *host)
 {
 	unsigned int id;
 
-	mutex_init(&host->intr_mutex);
-
 	for (id = 0; id < host1x_syncpt_nb_pts(host); ++id) {
 		struct host1x_syncpt *syncpt = &host->syncpt[id];
 

Original file line number	Diff line number	Diff line change
`@@ -630,6 +630,8 @@ static int host1x_probe(struct platform_device *pdev)`
`630`	`630`	`goto deinit_syncpt;`
`631`	`631`	`}`
`632`	`632`
	`633`	`+ mutex_init(&host->intr_mutex);`
	`634`	`+`
`633`	`635`	`pm_runtime_enable(&pdev->dev);`
`634`	`636`
`635`	`637`	`err = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);`
Original file line number	Diff line number	Diff line change
`@@ -102,8 +102,6 @@ int host1x_intr_init(struct host1x *host)`
`102`	`102`	`{`
`103`	`103`	`unsigned int id;`
`104`	`104`
`105`		`- mutex_init(&host->intr_mutex);`
`106`		`-`
`107`	`105`	`for (id = 0; id < host1x_syncpt_nb_pts(host); ++id) {`
`108`	`106`	`struct host1x_syncpt *syncpt = &host->syncpt[id];`
`109`	`107`