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| author | Billy Tsai <billy_tsai@aspeedtech.com> | 2023-10-23 16:02:37 +0800 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2023-11-04 00:39:52 +0100 |
| commit | b53e9758a31c683fc8615df930262192ed5f034b (patch) | |
| tree | 386625d06c7566a64f20a2a4c740a9598a62ac75 /drivers/i3c | |
| parent | 8911eae9c8a947e5c1cc4fcce40473f1f5e475cd (diff) | |
| download | lwn-b53e9758a31c683fc8615df930262192ed5f034b.tar.gz lwn-b53e9758a31c683fc8615df930262192ed5f034b.zip | |
i3c: master: mipi-i3c-hci: Fix a kernel panic for accessing DAT_data.
The `i3c_master_bus_init` function may attach the I2C devices before the
I3C bus initialization. In this flow, the DAT `alloc_entry`` will be used
before the DAT `init`. Additionally, if the `i3c_master_bus_init` fails,
the DAT `cleanup` will execute before the device is detached, which will
execue DAT `free_entry` function. The above scenario can cause the driver
to use DAT_data when it is NULL.
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Link: https://lore.kernel.org/r/20231023080237.560936-1-billy_tsai@aspeedtech.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/i3c')
| -rw-r--r-- | drivers/i3c/master/mipi-i3c-hci/dat_v1.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c index 97bb49ff5b53..47b9b4d4ed3f 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c +++ b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c @@ -64,15 +64,17 @@ static int hci_dat_v1_init(struct i3c_hci *hci) return -EOPNOTSUPP; } - /* use a bitmap for faster free slot search */ - hci->DAT_data = bitmap_zalloc(hci->DAT_entries, GFP_KERNEL); - if (!hci->DAT_data) - return -ENOMEM; - - /* clear them */ - for (dat_idx = 0; dat_idx < hci->DAT_entries; dat_idx++) { - dat_w0_write(dat_idx, 0); - dat_w1_write(dat_idx, 0); + if (!hci->DAT_data) { + /* use a bitmap for faster free slot search */ + hci->DAT_data = bitmap_zalloc(hci->DAT_entries, GFP_KERNEL); + if (!hci->DAT_data) + return -ENOMEM; + + /* clear them */ + for (dat_idx = 0; dat_idx < hci->DAT_entries; dat_idx++) { + dat_w0_write(dat_idx, 0); + dat_w1_write(dat_idx, 0); + } } return 0; @@ -87,7 +89,13 @@ static void hci_dat_v1_cleanup(struct i3c_hci *hci) static int hci_dat_v1_alloc_entry(struct i3c_hci *hci) { unsigned int dat_idx; + int ret; + if (!hci->DAT_data) { + ret = hci_dat_v1_init(hci); + if (ret) + return ret; + } dat_idx = find_first_zero_bit(hci->DAT_data, hci->DAT_entries); if (dat_idx >= hci->DAT_entries) return -ENOENT; @@ -103,7 +111,8 @@ static void hci_dat_v1_free_entry(struct i3c_hci *hci, unsigned int dat_idx) { dat_w0_write(dat_idx, 0); dat_w1_write(dat_idx, 0); - __clear_bit(dat_idx, hci->DAT_data); + if (hci->DAT_data) + __clear_bit(dat_idx, hci->DAT_data); } static void hci_dat_v1_set_dynamic_addr(struct i3c_hci *hci, |