| Message ID | 20250124073354.3814674-1-avri.altman@wdc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] scsi: ufs: core: Ensure clk_gating.lock is used only after initialization | expand |
Hi Avri, On Fri, Jan 24, 2025 at 8:36 AM Avri Altman <avri.altman@wdc.com> wrote: > This commit addresses a lockdep warning triggered by the use of the > clk_gating.lock before it is properly initialized. The warning is as > follows: > > [ 4.388838] INFO: trying to register non-static key. > [ 4.395673] The code is fine but needs lockdep annotation, or maybe > [ 4.402118] you didn't initialize this object before use? > [ 4.407673] turning off the locking correctness validator. > [ 4.413334] CPU: 5 UID: 0 PID: 58 Comm: kworker/u32:1 Not tainted 6.12-rc1 #185 > [ 4.413343] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) > [ 4.413362] Call trace: > [ 4.413364] show_stack+0x18/0x24 (C) > [ 4.413374] dump_stack_lvl+0x90/0xd0 > [ 4.413384] dump_stack+0x18/0x24 > [ 4.413392] register_lock_class+0x498/0x4a8 > [ 4.413400] __lock_acquire+0xb4/0x1b90 > [ 4.413406] lock_acquire+0x114/0x310 > [ 4.413413] _raw_spin_lock_irqsave+0x60/0x88 > [ 4.413423] ufshcd_setup_clocks+0x2c0/0x490 > [ 4.413433] ufshcd_init+0x198/0x10ec > [ 4.413437] ufshcd_pltfrm_init+0x600/0x7c0 > [ 4.413444] ufs_qcom_probe+0x20/0x58 > [ 4.413449] platform_probe+0x68/0xd8 > [ 4.413459] really_probe+0xbc/0x268 > [ 4.413466] __driver_probe_device+0x78/0x12c > [ 4.413473] driver_probe_device+0x40/0x11c > [ 4.413481] __device_attach_driver+0xb8/0xf8 > [ 4.413489] bus_for_each_drv+0x84/0xe4 > [ 4.413495] __device_attach+0xfc/0x18c > [ 4.413502] device_initial_probe+0x14/0x20 > [ 4.413510] bus_probe_device+0xb0/0xb4 > [ 4.413517] deferred_probe_work_func+0x8c/0xc8 > [ 4.413524] process_scheduled_works+0x250/0x658 > [ 4.413534] worker_thread+0x15c/0x2c8 > [ 4.413542] kthread+0x134/0x200 > [ 4.413550] ret_from_fork+0x10/0x20 > > To fix this issue, ensure that the spinlock is only used after it > has been properly initialized before using it in `ufshcd_setup_clocks`. > > Fixes: 209f4e43b806 ("scsi: ufs: core: Introduce a new clock_gating lock") > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Signed-off-by: Avri Altman <avri.altman@wdc.com> > > --- > Changes since v1: > - move the spin_lock_init(&hba->clk_gating.lock) call from > ufshcd_init_clk_gating() just before the ufshcd_hba_init() call in > ufshcd_init() (Bart) Thanks for the update! On Renesas R-Car S4 Starter Kit: BUG: spinlock bad magic on CPU#6, swapper/0/1 lock: 0xffffff84443014e8, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 CPU: 6 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.13.0-rcar3-initrd-08318-g75abbef32a94 #896 Hardware name: R-Car S4 Starter Kit board (DT) Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0x60/0x80 dump_stack+0x18/0x24 spin_bug+0x7c/0xa0 do_raw_spin_lock+0x34/0xb4 _raw_spin_lock_irqsave+0x1c/0x30 class_spinlock_irqsave_constructor+0x18/0x30 ufshcd_setup_clocks+0x98/0x23c ufshcd_init+0x288/0xd38 ufshcd_pltfrm_init+0x618/0x738 ufs_renesas_probe+0x18/0x24 platform_probe+0x68/0xb8 really_probe+0x138/0x268 __driver_probe_device+0xf4/0x10c driver_probe_device+0x3c/0xf8 __driver_attach+0xf0/0x100 bus_for_each_dev+0x84/0xdc driver_attach+0x24/0x30 bus_add_driver+0xe8/0x1dc driver_register+0xbc/0xf8 __platform_driver_register+0x24/0x30 ufs_renesas_platform_init+0x1c/0x28 do_one_initcall+0x84/0x1f4 kernel_init_freeable+0x238/0x23c kernel_init+0x20/0x120 ret_from_fork+0x10/0x20 Gr{oetje,eeting}s, Geert
> > > > To fix this issue, ensure that the spinlock is only used after it has > > been properly initialized before using it in `ufshcd_setup_clocks`. > > > > Fixes: 209f4e43b806 ("scsi: ufs: core: Introduce a new clock_gating > > lock") > > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > > Signed-off-by: Avri Altman <avri.altman@wdc.com> > > > > --- > > Changes since v1: > > - move the spin_lock_init(&hba->clk_gating.lock) call from > > ufshcd_init_clk_gating() just before the ufshcd_hba_init() call in > > ufshcd_init() (Bart) > > Thanks for the update! > > On Renesas R-Car S4 Starter Kit: Thanks. This is not happening on my RB5. I need some time to get a Renesas R-Car platform. Meanwhile, let me revert the offending patch. Will do that on Sunday after some more testing. Thanks, Avri > > BUG: spinlock bad magic on CPU#6, swapper/0/1 > lock: 0xffffff84443014e8, .magic: 00000000, .owner: <none>/-1, > .owner_cpu: 0 > CPU: 6 UID: 0 PID: 1 Comm: swapper/0 Not tainted > 6.13.0-rcar3-initrd-08318-g75abbef32a94 #896 > Hardware name: R-Car S4 Starter Kit board (DT) > Call trace: > show_stack+0x18/0x24 (C) > dump_stack_lvl+0x60/0x80 > dump_stack+0x18/0x24 > spin_bug+0x7c/0xa0 > do_raw_spin_lock+0x34/0xb4 > _raw_spin_lock_irqsave+0x1c/0x30 > class_spinlock_irqsave_constructor+0x18/0x30 > ufshcd_setup_clocks+0x98/0x23c > ufshcd_init+0x288/0xd38 > ufshcd_pltfrm_init+0x618/0x738 > ufs_renesas_probe+0x18/0x24 > platform_probe+0x68/0xb8 > really_probe+0x138/0x268 > __driver_probe_device+0xf4/0x10c > driver_probe_device+0x3c/0xf8 > __driver_attach+0xf0/0x100 > bus_for_each_dev+0x84/0xdc > driver_attach+0x24/0x30 > bus_add_driver+0xe8/0x1dc > driver_register+0xbc/0xf8 > __platform_driver_register+0x24/0x30 > ufs_renesas_platform_init+0x1c/0x28 > do_one_initcall+0x84/0x1f4 > kernel_init_freeable+0x238/0x23c > kernel_init+0x20/0x120 > ret_from_fork+0x10/0x20 > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux- > m68k.org > > In personal conversations with technical people, I call myself a hacker. But when > I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
Hi Avri, On Fri, Jan 24, 2025 at 8:36 AM Avri Altman <avri.altman@wdc.com> wrote: > This commit addresses a lockdep warning triggered by the use of the > clk_gating.lock before it is properly initialized. The warning is as > follows: > > [ 4.388838] INFO: trying to register non-static key. > [ 4.395673] The code is fine but needs lockdep annotation, or maybe > [ 4.402118] you didn't initialize this object before use? > [ 4.407673] turning off the locking correctness validator. > [ 4.413334] CPU: 5 UID: 0 PID: 58 Comm: kworker/u32:1 Not tainted 6.12-rc1 #185 > [ 4.413343] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) > [ 4.413362] Call trace: > [ 4.413364] show_stack+0x18/0x24 (C) > [ 4.413374] dump_stack_lvl+0x90/0xd0 > [ 4.413384] dump_stack+0x18/0x24 > [ 4.413392] register_lock_class+0x498/0x4a8 > [ 4.413400] __lock_acquire+0xb4/0x1b90 > [ 4.413406] lock_acquire+0x114/0x310 > [ 4.413413] _raw_spin_lock_irqsave+0x60/0x88 > [ 4.413423] ufshcd_setup_clocks+0x2c0/0x490 > [ 4.413433] ufshcd_init+0x198/0x10ec > [ 4.413437] ufshcd_pltfrm_init+0x600/0x7c0 > [ 4.413444] ufs_qcom_probe+0x20/0x58 > [ 4.413449] platform_probe+0x68/0xd8 > [ 4.413459] really_probe+0xbc/0x268 > [ 4.413466] __driver_probe_device+0x78/0x12c > [ 4.413473] driver_probe_device+0x40/0x11c > [ 4.413481] __device_attach_driver+0xb8/0xf8 > [ 4.413489] bus_for_each_drv+0x84/0xe4 > [ 4.413495] __device_attach+0xfc/0x18c > [ 4.413502] device_initial_probe+0x14/0x20 > [ 4.413510] bus_probe_device+0xb0/0xb4 > [ 4.413517] deferred_probe_work_func+0x8c/0xc8 > [ 4.413524] process_scheduled_works+0x250/0x658 > [ 4.413534] worker_thread+0x15c/0x2c8 > [ 4.413542] kthread+0x134/0x200 > [ 4.413550] ret_from_fork+0x10/0x20 > > To fix this issue, ensure that the spinlock is only used after it > has been properly initialized before using it in `ufshcd_setup_clocks`. > > Fixes: 209f4e43b806 ("scsi: ufs: core: Introduce a new clock_gating lock") > Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Signed-off-by: Avri Altman <avri.altman@wdc.com> > --- a/drivers/ufs/core/ufshcd.c > +++ b/drivers/ufs/core/ufshcd.c > @@ -10412,6 +10410,13 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) > hba->irq = irq; > hba->vps = &ufs_hba_vps; > > + /* > + * Initialize clk_gating.lock early since it is being used in > + * ufshcd_setup_clocks() > + */ > + if (ufshcd_is_clkgating_allowed(hba)) This checks if the UFSHCD_CAP_CLK_GATING flag is set, which is only done in a subset of the host drivers: drivers/ufs/host/ufs-exynos.c: hba->caps |= UFSHCD_CAP_CLK_GATING | UFSHCD_CAP_HIBERN8_WITH_CLK_GATING; drivers/ufs/host/ufs-mediatek.c: hba->caps |= UFSHCD_CAP_CLK_GATING; drivers/ufs/host/ufs-qcom.c: hba->caps |= UFSHCD_CAP_CLK_GATING | UFSHCD_CAP_HIBERN8_WITH_CLK_GATING; drivers/ufs/host/ufs-sprd.c: hba->caps |= UFSHCD_CAP_CLK_GATING | > + spin_lock_init(&hba->clk_gating.lock); Hence the spinlock is not uninitialized on all other host drivers. > + > err = ufshcd_hba_init(hba); > if (err) > goto out_error; Gr{oetje,eeting}s, Geert
> > + /* > > + * Initialize clk_gating.lock early since it is being used in > > + * ufshcd_setup_clocks() > > + */ > > + if (ufshcd_is_clkgating_allowed(hba)) > > This checks if the UFSHCD_CAP_CLK_GATING flag is set, which is only done in a > subset of the host drivers: > > drivers/ufs/host/ufs-exynos.c: hba->caps |= UFSHCD_CAP_CLK_GATING | > UFSHCD_CAP_HIBERN8_WITH_CLK_GATING; > drivers/ufs/host/ufs-mediatek.c: hba->caps |= UFSHCD_CAP_CLK_GATING; > drivers/ufs/host/ufs-qcom.c: hba->caps |= UFSHCD_CAP_CLK_GATING | > UFSHCD_CAP_HIBERN8_WITH_CLK_GATING; > drivers/ufs/host/ufs-sprd.c: hba->caps |= UFSHCD_CAP_CLK_GATING | > > > + spin_lock_init(&hba->clk_gating.lock); > > Hence the spinlock is not uninitialized on all other host drivers. Oh - Thanks for pointing this out. I totally missed it. At is appears when clock_gating was invented - 1ab27c9cf8b6 ("ufs: Add support for clock gating") The below was added without checking if ufshcd_is_clkgating_allowed, or better yet - clk_gating.is_initialized: @@ -4151,12 +4420,19 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on, clki->name, on ? "en" : "dis"); } } + } else if (!ret && on) { + spin_lock_irqsave(hba->host->host_lock, flags); + hba->clk_gating.state = CLKS_ON; + spin_unlock_irqrestore(hba->host->host_lock, flags); } Looks like this is the missing piece. Will fix this in a 2nd patch. Thanks, Avri > > > + > > err = ufshcd_hba_init(hba); > > if (err) > > goto out_error; > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux- > m68k.org > > In personal conversations with technical people, I call myself a hacker. But when > I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
On 1/23/25 11:33 PM, Avri Altman wrote: > + /* > + * Initialize clk_gating.lock early since it is being used in > + * ufshcd_setup_clocks() > + */ > + if (ufshcd_is_clkgating_allowed(hba)) > + spin_lock_init(&hba->clk_gating.lock); Initializing a spinlock is a very fast operation so please do this unconditionally. Thanks, Bart.
> On 1/23/25 11:33 PM, Avri Altman wrote: > > + /* > > + * Initialize clk_gating.lock early since it is being used in > > + * ufshcd_setup_clocks() > > + */ > > + if (ufshcd_is_clkgating_allowed(hba)) > > + spin_lock_init(&hba->clk_gating.lock); > > Initializing a spinlock is a very fast operation so please do this unconditionally. Done. Thanks, Avri > > Thanks, > > Bart.
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index f6c38cf10382..9b17f6e2f807 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -2120,8 +2120,6 @@ static void ufshcd_init_clk_gating(struct ufs_hba *hba) INIT_DELAYED_WORK(&hba->clk_gating.gate_work, ufshcd_gate_work); INIT_WORK(&hba->clk_gating.ungate_work, ufshcd_ungate_work); - spin_lock_init(&hba->clk_gating.lock); - hba->clk_gating.clk_gating_workq = alloc_ordered_workqueue( "ufs_clk_gating_%d", WQ_MEM_RECLAIM | WQ_HIGHPRI, hba->host->host_no); @@ -10412,6 +10410,13 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) hba->irq = irq; hba->vps = &ufs_hba_vps; + /* + * Initialize clk_gating.lock early since it is being used in + * ufshcd_setup_clocks() + */ + if (ufshcd_is_clkgating_allowed(hba)) + spin_lock_init(&hba->clk_gating.lock); + err = ufshcd_hba_init(hba); if (err) goto out_error;
This commit addresses a lockdep warning triggered by the use of the clk_gating.lock before it is properly initialized. The warning is as follows: [ 4.388838] INFO: trying to register non-static key. [ 4.395673] The code is fine but needs lockdep annotation, or maybe [ 4.402118] you didn't initialize this object before use? [ 4.407673] turning off the locking correctness validator. [ 4.413334] CPU: 5 UID: 0 PID: 58 Comm: kworker/u32:1 Not tainted 6.12-rc1 #185 [ 4.413343] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) [ 4.413362] Call trace: [ 4.413364] show_stack+0x18/0x24 (C) [ 4.413374] dump_stack_lvl+0x90/0xd0 [ 4.413384] dump_stack+0x18/0x24 [ 4.413392] register_lock_class+0x498/0x4a8 [ 4.413400] __lock_acquire+0xb4/0x1b90 [ 4.413406] lock_acquire+0x114/0x310 [ 4.413413] _raw_spin_lock_irqsave+0x60/0x88 [ 4.413423] ufshcd_setup_clocks+0x2c0/0x490 [ 4.413433] ufshcd_init+0x198/0x10ec [ 4.413437] ufshcd_pltfrm_init+0x600/0x7c0 [ 4.413444] ufs_qcom_probe+0x20/0x58 [ 4.413449] platform_probe+0x68/0xd8 [ 4.413459] really_probe+0xbc/0x268 [ 4.413466] __driver_probe_device+0x78/0x12c [ 4.413473] driver_probe_device+0x40/0x11c [ 4.413481] __device_attach_driver+0xb8/0xf8 [ 4.413489] bus_for_each_drv+0x84/0xe4 [ 4.413495] __device_attach+0xfc/0x18c [ 4.413502] device_initial_probe+0x14/0x20 [ 4.413510] bus_probe_device+0xb0/0xb4 [ 4.413517] deferred_probe_work_func+0x8c/0xc8 [ 4.413524] process_scheduled_works+0x250/0x658 [ 4.413534] worker_thread+0x15c/0x2c8 [ 4.413542] kthread+0x134/0x200 [ 4.413550] ret_from_fork+0x10/0x20 To fix this issue, ensure that the spinlock is only used after it has been properly initialized before using it in `ufshcd_setup_clocks`. Fixes: 209f4e43b806 ("scsi: ufs: core: Introduce a new clock_gating lock") Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Signed-off-by: Avri Altman <avri.altman@wdc.com> --- Changes since v1: - move the spin_lock_init(&hba->clk_gating.lock) call from ufshcd_init_clk_gating() just before the ufshcd_hba_init() call in ufshcd_init() (Bart) --- drivers/ufs/core/ufshcd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)