diff options
| author |   Frank Rowand <frank.rowand@sony.com> | 2021-04-08 15:45:08 -0500 |
|---|---|---|
| committer |   Rob Herring <robh@kernel.org> | 2021-04-08 16:38:47 -0500 |
| commit | 48d499bd89191b359a6dbe44d32107e3021571c2 (patch) | |
| tree | 2fa58efa7eeb0a6367f6efbcd4b5f4438a1fdfc0 /drivers/of/unittest.c | |
| parent | of: properly check for error returned by fdt_get_name() (diff) | |
| download | linux-dev-48d499bd89191b359a6dbe44d32107e3021571c2.tar.xz linux-dev-48d499bd89191b359a6dbe44d32107e3021571c2.zip | |
of: unittest: overlay: ensure proper alignment of copied FDT
The Devicetree standard specifies an 8 byte alignment of the FDT.
Code in libfdt expects this alignment for an FDT image in memory.
kmemdup() returns 4 byte alignment on openrisc. Replace kmemdup()
with kmalloc(), align pointer, memcpy() to get proper alignment.
The 4 byte alignment exposed a related bug which triggered a crash
on openrisc with:
commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
as reported in:
https://lore.kernel.org/lkml/20210327224116.69309-1-linux@roeck-us.net/
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Link: https://lore.kernel.org/r/20210408204508.2276230-1-frowand.list@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/of/unittest.c')
| -rw-r--r-- | drivers/of/unittest.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index f9b5b698249f..819a20acaa93 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -22,6 +22,7 @@ #include <linux/slab.h> #include <linux/device.h> #include <linux/platform_device.h> +#include <linux/kernel.h> #include <linux/i2c.h> #include <linux/i2c-mux.h> @@ -1408,6 +1409,7 @@ static void attach_node_and_children(struct device_node *np) static int __init unittest_data_add(void) { void *unittest_data; + void *unittest_data_align; struct device_node *unittest_data_node = NULL, *np; /* * __dtb_testcases_begin[] and __dtb_testcases_end[] are magically @@ -1425,11 +1427,14 @@ static int __init unittest_data_add(void) } /* creating copy */ - unittest_data = kmemdup(__dtb_testcases_begin, size, GFP_KERNEL); + unittest_data = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL); if (!unittest_data) return -ENOMEM; - ret = of_fdt_unflatten_tree(unittest_data, NULL, &unittest_data_node); + unittest_data_align = PTR_ALIGN(unittest_data, FDT_ALIGN_SIZE); + memcpy(unittest_data_align, __dtb_testcases_begin, size); + + ret = of_fdt_unflatten_tree(unittest_data_align, NULL, &unittest_data_node); if (!ret) { pr_warn("%s: unflatten testcases tree failed\n", __func__); kfree(unittest_data); |