| Message ID | 20241106014654.206860-1-luoyifan@cmss.chinamobile.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ASoC: stm: Prevent potential division by zero in stm32_sai_mclk_round_rate() | expand |
Hi Luo, On 11/6/24 02:46, Luo Yifan wrote: > This patch checks if div is less than or equal to zero (div <= 0). If > div is zero or negative, the function returns -EINVAL, ensuring the > division operation (*prate / div) is safe to perform. > > Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com> > --- > sound/soc/stm/stm32_sai_sub.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c > index 7bc4a96b7..2570daa3e 100644 > --- a/sound/soc/stm/stm32_sai_sub.c > +++ b/sound/soc/stm/stm32_sai_sub.c > @@ -378,8 +378,8 @@ static long stm32_sai_mclk_round_rate(struct clk_hw *hw, unsigned long rate, > int div; > > div = stm32_sai_get_clk_div(sai, *prate, rate); > - if (div < 0) > - return div; > + if (div <= 0) > + return -EINVAL; > > mclk->freq = *prate / div; > Thanks for your patch. It looks fine, but I think that it has to be extended. In CR1 register, MCKDIV = 0 gives the same result as MCKDIV = 1. But while MCKDIV = 0 is valid, for sure div = 0 is not valid. I agree that that div = 0 has to be managed as an error This could be rather handled in stm32_sai_get_clk_div() function itself, by returning an error, if div is null. This is relevant as we may also get an error on test "if (input_rate % div)". I suggest to add a specific test and error message to handle this case in stm32_sai_get_clk_div(). Something like: if (!div)) { dev_err(&sai->pdev->dev, "Invalid null divider\n"); return -EINVAL; } BRs Olivier
Sure, I can submit a new patch with specific tests and error messages added to stm32_sai_get_clk_div().
On Wed, 06 Nov 2024 09:46:54 +0800, Luo Yifan wrote: > This patch checks if div is less than or equal to zero (div <= 0). If > div is zero or negative, the function returns -EINVAL, ensuring the > division operation (*prate / div) is safe to perform. > > Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next Thanks! [1/1] ASoC: stm: Prevent potential division by zero in stm32_sai_mclk_round_rate() commit: 63c1c87993e0e5bb11bced3d8224446a2bc62338 [1/1] ASoC: stm: Prevent potential division by zero in stm32_sai_get_clk_div() commit: 23569c8b314925bdb70dd1a7b63cfe6100868315 All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c index 7bc4a96b7..2570daa3e 100644 --- a/sound/soc/stm/stm32_sai_sub.c +++ b/sound/soc/stm/stm32_sai_sub.c @@ -378,8 +378,8 @@ static long stm32_sai_mclk_round_rate(struct clk_hw *hw, unsigned long rate, int div; div = stm32_sai_get_clk_div(sai, *prate, rate); - if (div < 0) - return div; + if (div <= 0) + return -EINVAL; mclk->freq = *prate / div;
This patch checks if div is less than or equal to zero (div <= 0). If div is zero or negative, the function returns -EINVAL, ensuring the division operation (*prate / div) is safe to perform. Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com> --- sound/soc/stm/stm32_sai_sub.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)