| Message ID | 1516956529-32264-1-git-send-email-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 26-01-18, 16:48, Jia-Ju Bai wrote: > After checking all possible call chains to > dev_pm_opp_init_cpufreq_table() here, > my tool finds that this function is never called in atomic context, > namely never in an interrupt handler or holding a spinlock. > And dev_pm_opp_init_cpufreq_table() calls dev_pm_opp_get_opp_count(), > which calls mutex_lock that can sleep. > It indicates that atmtcp_v_send() can call functions which may sleep. > Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL. > > This is found by a static analysis tool named DCNS written by myself. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> > --- > drivers/opp/cpu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/opp/cpu.c b/drivers/opp/cpu.c > index 2d87bc1..0c09107 100644 > --- a/drivers/opp/cpu.c > +++ b/drivers/opp/cpu.c > @@ -55,7 +55,7 @@ int dev_pm_opp_init_cpufreq_table(struct device *dev, > if (max_opps <= 0) > return max_opps ? max_opps : -ENODATA; > > - freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC); > + freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_KERNEL); > if (!freq_table) > return -ENOMEM; Applied thanks.
diff --git a/drivers/opp/cpu.c b/drivers/opp/cpu.c index 2d87bc1..0c09107 100644 --- a/drivers/opp/cpu.c +++ b/drivers/opp/cpu.c @@ -55,7 +55,7 @@ int dev_pm_opp_init_cpufreq_table(struct device *dev, if (max_opps <= 0) return max_opps ? max_opps : -ENODATA; - freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC); + freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_KERNEL); if (!freq_table) return -ENOMEM;
After checking all possible call chains to dev_pm_opp_init_cpufreq_table() here, my tool finds that this function is never called in atomic context, namely never in an interrupt handler or holding a spinlock. And dev_pm_opp_init_cpufreq_table() calls dev_pm_opp_get_opp_count(), which calls mutex_lock that can sleep. It indicates that atmtcp_v_send() can call functions which may sleep. Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL. This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/opp/cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)