[lvc-project] [PATCH RFC] renesas: add zero check for prate variable

[Тигран Согомонян]

Четверг, Март 27, 2025 18:10 MSK, Tigran Sogomonian <tsogomonian at astralinux.ru> писал(а):

 
To avoid division by zero, a check was added to the prate
variable, since no guarantees were found that it could not
be equal to zero.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Tigran Sogomonian <tsogomonian at astralinux.ru>
---
drivers/clk/renesas/rcar-gen3-cpg.c | 2 ++
drivers/clk/renesas/rcar-gen4-cpg.c | 2 ++
2 files changed, 4 insertions(+)

diff --git a/drivers/clk/renesas/rcar-gen3-cpg.c b/drivers/clk/renesas/rcar-gen3-cpg.c
index 027100e84ee4..66da3b4398cd 100644
--- a/drivers/clk/renesas/rcar-gen3-cpg.c
+++ b/drivers/clk/renesas/rcar-gen3-cpg.c
@@ -205,6 +205,8 @@ static int cpg_z_clk_determine_rate(struct clk_hw *hw,
prate * zclk->fixed_div);

prate = req->best_parent_rate / zclk->fixed_div;
+ if (prate == 0)
+ return -EINVAL;
min_mult = max(div64_ul(req->min_rate * 32ULL, prate), 1ULL);
max_mult = min(div64_ul(req->max_rate * 32ULL, prate), 32ULL);
if (max_mult < min_mult)
diff --git a/drivers/clk/renesas/rcar-gen4-cpg.c b/drivers/clk/renesas/rcar-gen4-cpg.c
index 31aa790fd003..4c9a7d699290 100644
--- a/drivers/clk/renesas/rcar-gen4-cpg.c
+++ b/drivers/clk/renesas/rcar-gen4-cpg.c
@@ -308,6 +308,8 @@ static int cpg_z_clk_determine_rate(struct clk_hw *hw,
prate * zclk->fixed_div);

prate = req->best_parent_rate / zclk->fixed_div;
+ if (prate == 0)
+ return -EINVAL;
min_mult = max(div64_ul(req->min_rate * 32ULL, prate), 1ULL);
max_mult = min(div64_ul(req->max_rate * 32ULL, prate), 32ULL);
if (max_mult < min_mult)
-- 
2.47.1

 
Just a friendly reminder)


 
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