On Fri, Nov 22, 2024 at 06:51:27PM +0100, Arnaud Pouliquen wrote:
> In the rproc_alloc() function, on error, put_device(&rproc->dev) is
> called, leading to the call of the rproc_type_release() function.
> An error can occurs before ida_alloc is called.
>
> In such case in rproc_type_release(), the condition (rproc->index >= 0) is
> true as rproc->index has been initialized to 0.
> ida_free() is called reporting a warning:
> [ 4.181906] WARNING: CPU: 1 PID: 24 at lib/idr.c:525 ida_free+0x100/0x164
> [ 4.186378] stm32-display-dsi 5a000000.dsi: Fixed dependency cycle(s) with /soc/dsi@5a000000/panel@0
> [ 4.188854] ida_free called for id=0 which is not allocated.
> [ 4.198256] mipi-dsi 5a000000.dsi.0: Fixed dependency cycle(s) with /soc/dsi@5a000000
> [ 4.203556] Modules linked in: panel_orisetech_otm8009a dw_mipi_dsi_stm(+) gpu_sched dw_mipi_dsi stm32_rproc stm32_crc32 stm32_ipcc(+) optee(+)
> [ 4.224307] CPU: 1 UID: 0 PID: 24 Comm: kworker/u10:0 Not tainted 6.12.0 #442
> [ 4.231481] Hardware name: STM32 (Device Tree Support)
> [ 4.236627] Workqueue: events_unbound deferred_probe_work_func
> [ 4.242504] Call trace:
> [ 4.242522] unwind_backtrace from show_stack+0x10/0x14
> [ 4.250218] show_stack from dump_stack_lvl+0x50/0x64
> [ 4.255274] dump_stack_lvl from __warn+0x80/0x12c
> [ 4.260134] __warn from warn_slowpath_fmt+0x114/0x188
> [ 4.265199] warn_slowpath_fmt from ida_free+0x100/0x164
> [ 4.270565] ida_free from rproc_type_release+0x38/0x60
> [ 4.275832] rproc_type_release from device_release+0x30/0xa0
> [ 4.281601] device_release from kobject_put+0xc4/0x294
> [ 4.286762] kobject_put from rproc_alloc.part.0+0x208/0x28c
> [ 4.292430] rproc_alloc.part.0 from devm_rproc_alloc+0x80/0xc4
> [ 4.298393] devm_rproc_alloc from stm32_rproc_probe+0xd0/0x844 [stm32_rproc]
> [ 4.305575] stm32_rproc_probe [stm32_rproc] from platform_probe+0x5c/0xbc
>
>
> Calling ida_alloc earlier in rproc_alloc ensures that the rproc->index is
> properly set.
>
> Fixes: 08333b911f01 ("remoteproc: Directly use ida_alloc()/free()")
>
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
> ---
> Note for backporting to previous kernel versions: The SHA 08333b911f01
> seems to correspond to the last commit that updated IDA allocation.
> The issue existed before, but the fix could not be applied without some
> rework.
> ---
> drivers/remoteproc/remoteproc_core.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index f276956f2c5c..ef6febe35633 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -2486,6 +2486,13 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
> rproc->dev.driver_data = rproc;
> idr_init(&rproc->notifyids);
>
> + /* Assign a unique device index and name */
> + rproc->index = ida_alloc(&rproc_dev_index, GFP_KERNEL);
> + if (rproc->index < 0) {
> + dev_err(dev, "ida_alloc failed: %d\n", rproc->index);
> + goto put_device;
> + }
> +
> rproc->name = kstrdup_const(name, GFP_KERNEL);
> if (!rproc->name)
> goto put_device;
> @@ -2496,13 +2503,6 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
> if (rproc_alloc_ops(rproc, ops))
> goto put_device;
>
> - /* Assign a unique device index and name */
> - rproc->index = ida_alloc(&rproc_dev_index, GFP_KERNEL);
> - if (rproc->index < 0) {
> - dev_err(dev, "ida_alloc failed: %d\n", rproc->index);
> - goto put_device;
> - }
> -
I have applied this patch.
Thanks,
Mathieu
> dev_set_name(&rproc->dev, "remoteproc%d", rproc->index);
>
> atomic_set(&rproc->power, 0);
>
> base-commit: adc218676eef25575469234709c2d87185ca223a
> --
> 2.25.1
>
