On ven., déc. 15, 2023 at 13:34, Mattijs Korpershoek mkorpershoek@baylibre.com wrote:
Hi Julien,
Thank you for the patch.
On mar., nov. 21, 2023 at 15:42, Julien Masson jmasson@baylibre.com wrote:
When we call clk_get_rate(), we expect to get clock rate value as ulong. In that case we should not use log_ret() macro since it use internally an int.
This is quite subtle, it only happens when log_reg is enabled via CONFIG_LOG_ERROR_RETURN.
Otherwise we may return an invalid/truncated clock rate value.
Signed-off-by: Julien Masson jmasson@baylibre.com
I'm wondering if there are any other places where this happens, but this change looks good to me.
Reviewed-by: Mattijs Korpershoek mkorpershoek@baylibre.com
Thinking a bit more about this, shouldn't we add some check for downcasting in log.h in order to make sure this does not happen in the future?
Something like this should work:
diff --git a/include/log.h b/include/log.h index 6e84f080ef3d..20088399617c 100644 --- a/include/log.h +++ b/include/log.h @@ -332,12 +332,14 @@ void __assert_fail(const char *assertion, const char *file, unsigned int line, * use 4 bytes in rodata */ #define log_ret(_ret) ({ \ + _Static_assert(sizeof(_ret) <= sizeof(int), "Cannot log without downcasting"); \ int __ret = (_ret); \ if (__ret < 0) \ log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \ __ret; \ })
Downcasting just when logs are enabled can be the cause for quite some subtle bugs so breaking the build in these cases might be a good warning.
Any thoughts?
drivers/clk/clk-uclass.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c index 3b5e3f9c86..41dcd14be5 100644 --- a/drivers/clk/clk-uclass.c +++ b/drivers/clk/clk-uclass.c @@ -488,11 +488,7 @@ ulong clk_get_rate(struct clk *clk) if (!ops->get_rate) return -ENOSYS;
- ret = ops->get_rate(clk);
- if (ret)
return log_ret(ret);- return 0;
- return ops->get_rate(clk);
}
struct clk *clk_get_parent(struct clk *clk)
2.41.0