| Message ID | 0cdf3cb10293ead1acd271fdb8a70369c298c082.1637186628.git.christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | i3c/master: Fix a potentially infinite loop in 'hci_dat_v1_get_index()' | expand |
On Wed, 17 Nov 2021, Christophe JAILLET wrote: > The code in 'hci_dat_v1_get_index()' really looks like a hand coded version > of 'for_each_set_bit()', except that a +1 is missing when searching for the > next set bit. > > This really looks odd and it seems that it will loop until 'dat_w0_read()' > returns the expected result. > > So use 'for_each_set_bit()' instead. It is less verbose and should be more > correct. > > Fixes: 9ad9a52cce28 ("i3c/master: introduce the mipi-i3c-hci driver") > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Nicolas Pitre <npitre@baylibre.com> > --- > Speculative fix. Untested. > --- > drivers/i3c/master/mipi-i3c-hci/dat_v1.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c > index 783e551a2c85..97bb49ff5b53 100644 > --- a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c > +++ b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c > @@ -160,9 +160,7 @@ static int hci_dat_v1_get_index(struct i3c_hci *hci, u8 dev_addr) > unsigned int dat_idx; > u32 dat_w0; > > - for (dat_idx = find_first_bit(hci->DAT_data, hci->DAT_entries); > - dat_idx < hci->DAT_entries; > - dat_idx = find_next_bit(hci->DAT_data, hci->DAT_entries, dat_idx)) { > + for_each_set_bit(dat_idx, hci->DAT_data, hci->DAT_entries) { > dat_w0 = dat_w0_read(dat_idx); > if (FIELD_GET(DAT_0_DYNAMIC_ADDRESS, dat_w0) == dev_addr) > return dat_idx; > -- > 2.30.2 > > > -- > linux-i3c mailing list > linux-i3c@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-i3c >
On Wed, 17 Nov 2021 23:05:23 +0100, Christophe JAILLET wrote: > The code in 'hci_dat_v1_get_index()' really looks like a hand coded version > of 'for_each_set_bit()', except that a +1 is missing when searching for the > next set bit. > > This really looks odd and it seems that it will loop until 'dat_w0_read()' > returns the expected result. > > [...] Applied, thanks! [1/1] i3c/master: Fix a potentially infinite loop in 'hci_dat_v1_get_index()' commit: 3f43926f271287fb1744c9ac9ae1122497f2b0c2 Best regards,
diff --git a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c index 783e551a2c85..97bb49ff5b53 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c +++ b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c @@ -160,9 +160,7 @@ static int hci_dat_v1_get_index(struct i3c_hci *hci, u8 dev_addr) unsigned int dat_idx; u32 dat_w0; - for (dat_idx = find_first_bit(hci->DAT_data, hci->DAT_entries); - dat_idx < hci->DAT_entries; - dat_idx = find_next_bit(hci->DAT_data, hci->DAT_entries, dat_idx)) { + for_each_set_bit(dat_idx, hci->DAT_data, hci->DAT_entries) { dat_w0 = dat_w0_read(dat_idx); if (FIELD_GET(DAT_0_DYNAMIC_ADDRESS, dat_w0) == dev_addr) return dat_idx;
The code in 'hci_dat_v1_get_index()' really looks like a hand coded version of 'for_each_set_bit()', except that a +1 is missing when searching for the next set bit. This really looks odd and it seems that it will loop until 'dat_w0_read()' returns the expected result. So use 'for_each_set_bit()' instead. It is less verbose and should be more correct. Fixes: 9ad9a52cce28 ("i3c/master: introduce the mipi-i3c-hci driver") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- Speculative fix. Untested. --- drivers/i3c/master/mipi-i3c-hci/dat_v1.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)