[PATCH 0/2] of: overlay: Miscellaneous improvements

[PATCH 0/2] of: overlay: Miscellaneous improvements

[Geert Uytterhoeven]

	Hi,

While performing the long-overdue rebase of my topic/overlays branch[1]
on top of the overlay rework in v5.19-rc1, I identified a few areas for
improvement in the upstream code.

Thanks for your comments!

[1] https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/log/?h=topic/overlays

Geert Uytterhoeven (2):
  of: overlay: Move devicetree_corrupt() check up
  of: overlay: Simplify of_overlay_fdt_apply() tail

 drivers/of/overlay.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

-- 
2.25.1

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

[PATCH 1/2] of: overlay: Move devicetree_corrupt() check up

[Geert Uytterhoeven]

There is no point in doing several preparatory steps in
of_overlay_fdt_apply(), only to see of_overlay_apply() return early
because of a corrupt device tree.

Move the check for a corrupt device tree from of_overlay_apply() to
of_overlay_fdt_apply(), to check for this as early as possible.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/of/overlay.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 4044ddcb02c60a58..84a8d402009cb3b2 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -903,12 +903,6 @@ static int of_overlay_apply(struct overlay_changeset *ovcs)
 {
 	int ret = 0, ret_revert, ret_tmp;
 
-	if (devicetree_corrupt()) {
-		pr_err("devicetree state suspect, refuse to apply overlay\n");
-		ret = -EBUSY;
-		goto out;
-	}
-
 	ret = of_resolve_phandles(ovcs->overlay_root);
 	if (ret)
 		goto out;
@@ -983,6 +977,11 @@ int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,
 
 	*ret_ovcs_id = 0;
 
+	if (devicetree_corrupt()) {
+		pr_err("devicetree state suspect, refuse to apply overlay\n");
+		return -EBUSY;
+	}
+
 	if (overlay_fdt_size < sizeof(struct fdt_header) ||
 	    fdt_check_header(overlay_fdt)) {
 		pr_err("Invalid overlay_fdt header\n");
-- 
2.25.1

[PATCH 2/2] of: overlay: Simplify of_overlay_fdt_apply() tail

[Geert Uytterhoeven]

It does not hurt to fill in the changeset id while the mutex is still
held.  After doing so, the function tails for the success and failure
cases become identical, so they can be unified.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/of/overlay.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 84a8d402009cb3b2..bd8ff4df723da217 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -1043,20 +1043,15 @@ int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,
 	 * goto err_free_ovcs.  Instead, the caller of of_overlay_fdt_apply()
 	 * can call of_overlay_remove();
 	 */
-
-	mutex_unlock(&of_mutex);
-	of_overlay_mutex_unlock();
-
 	*ret_ovcs_id = ovcs->id;
-
-	return ret;
+	goto out_unlock;
 
 err_free_ovcs:
 	free_overlay_changeset(ovcs);
 
+out_unlock:
 	mutex_unlock(&of_mutex);
 	of_overlay_mutex_unlock();
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(of_overlay_fdt_apply);
-- 
2.25.1

Re: [PATCH 0/2] of: overlay: Miscellaneous improvements

[Frank Rowand]

On 7/15/22 09:03, Geert Uytterhoeven wrote:
> 	Hi,
> 
> While performing the long-overdue rebase of my topic/overlays branch[1]
> on top of the overlay rework in v5.19-rc1, I identified a few areas for
> improvement in the upstream code.
> 
> Thanks for your comments!
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/log/?h=topic/overlays
> 
> Geert Uytterhoeven (2):
>   of: overlay: Move devicetree_corrupt() check up
>   of: overlay: Simplify of_overlay_fdt_apply() tail
> 
>  drivers/of/overlay.c | 20 +++++++-------------
>  1 file changed, 7 insertions(+), 13 deletions(-)
> 

The patches look good, based on a visual inspection.  I'll build the kernel
and test the patches tomorrow morning.

-Frank

Re: [PATCH 0/2] of: overlay: Miscellaneous improvements

[Frank Rowand]

On 7/15/22 09:03, Geert Uytterhoeven wrote:
> 	Hi,
> 
> While performing the long-overdue rebase of my topic/overlays branch[1]
> on top of the overlay rework in v5.19-rc1, I identified a few areas for
> improvement in the upstream code.
> 
> Thanks for your comments!
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/log/?h=topic/overlays
> 
> Geert Uytterhoeven (2):
>   of: overlay: Move devicetree_corrupt() check up
>   of: overlay: Simplify of_overlay_fdt_apply() tail
> 
>  drivers/of/overlay.c | 20 +++++++-------------
>  1 file changed, 7 insertions(+), 13 deletions(-)
> 

For the entire series:

Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Tested-by: Frank Rowand <frank.rowand@sony.com>

Re: [PATCH 1/2] of: overlay: Move devicetree_corrupt() check up

[Rob Herring]

On Fri, 15 Jul 2022 16:03:14 +0200, Geert Uytterhoeven wrote:
> There is no point in doing several preparatory steps in
> of_overlay_fdt_apply(), only to see of_overlay_apply() return early
> because of a corrupt device tree.
> 
> Move the check for a corrupt device tree from of_overlay_apply() to
> of_overlay_fdt_apply(), to check for this as early as possible.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
>  drivers/of/overlay.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 

Applied, thanks!

Re: [PATCH 2/2] of: overlay: Simplify of_overlay_fdt_apply() tail

[Rob Herring]

On Fri, 15 Jul 2022 16:03:15 +0200, Geert Uytterhoeven wrote:
> It does not hurt to fill in the changeset id while the mutex is still
> held.  After doing so, the function tails for the success and failure
> cases become identical, so they can be unified.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
>  drivers/of/overlay.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 

Applied, thanks!