linux.git/drivers/of/fdt.c, branch v5.4.192

of: Fix truncation of memory sizes on 32-bit platforms

2021-07-14T14:53:45+00:00

[ Upstream commit 2892d8a00d23d511a0591ac4b2ff3f050ae1f004 ]

Variable "size" has type "phys_addr_t", which can be either 32-bit or
64-bit on 32-bit systems, while "unsigned long" is always 32-bit on
32-bit systems.  Hence the cast in

    (unsigned long)size / SZ_1M

may truncate a 64-bit size to 32-bit, as casts have a higher operator
precedence than divisions.

Fix this by inverting the order of the cast and division, which should
be safe for memory blocks smaller than 4 PiB.  Note that the division is
actually a shift, as SZ_1M is a power-of-two constant, hence there is no
need to use div_u64().

While at it, use "%lu" to format "unsigned long".

Fixes: e8d9d1f5485b52ec ("drivers: of: add initialization code for static reserved memory")
Fixes: 3f0c8206644836e4 ("drivers: of: add initialization code for dynamic reserved memory")
Signed-off-by: Geert Uytterhoeven 
Acked-by: Marek Szyprowski 
Link: https://lore.kernel.org/r/4a1117e72d13d26126f57be034c20dac02f1e915.1623835273.git.geert+renesas@glider.be
Signed-off-by: Rob Herring 
Signed-off-by: Sasha Levin

Revert "fdt: Properly handle "no-map" field in the memory region"

2021-05-14T07:44:33+00:00

This reverts commit fb326c6ce0dcbb6273202c6e012759754ec8538d.
It is not really a fix, and the backport misses dependencies, which
breaks existing platforms.

Reported-by: Alexandre TORGUE 
Signed-off-by: Quentin Perret 
Signed-off-by: Greg Kroah-Hartman

Revert "of/fdt: Make sure no-map does not remove already reserved regions"

2021-05-14T07:44:33+00:00

This reverts commit 3cbd3038c9155038020560729cde50588311105d.
It is not really a fix, and the backport misses dependencies, which
breaks existing platforms.

Reported-by: Alexandre TORGUE 
Signed-off-by: Quentin Perret 
Signed-off-by: Greg Kroah-Hartman

of/fdt: Make sure no-map does not remove already reserved regions

2021-03-04T09:26:28+00:00

[ Upstream commit 8a5a75e5e9e55de1cef5d83ca3589cb4899193ef ]

If the device tree is incorrectly configured, and attempts to
define a "no-map" reserved memory that overlaps with the kernel
data/code, the kernel would crash quickly after boot, with no
obvious clue about the nature of the issue.

For example, this would happen if we have the kernel mapped at
these addresses (from /proc/iomem):
40000000-41ffffff : System RAM
  40080000-40dfffff : Kernel code
  40e00000-411fffff : reserved
  41200000-413e0fff : Kernel data

And we declare a no-map shared-dma-pool region at a fixed address
within that range:
mem_reserved: mem_region {
	compatible = "shared-dma-pool";
	reg = <0 0x40000000 0 0x01A00000>;
	no-map;
};

To fix this, when removing memory regions at early boot (which is
what "no-map" regions do), we need to make sure that the memory
is not already reserved. If we do, __reserved_mem_reserve_reg
will throw an error:
[    0.000000] OF: fdt: Reserved memory: failed to reserve memory
   for node 'mem_region': base 0x0000000040000000, size 26 MiB
and the code that will try to use the region should also fail,
later on.

We do not do anything for non-"no-map" regions, as memblock
explicitly allows reserved regions to overlap, and the commit
that this fixes removed the check for that precise reason.

[ qperret: fixed conflicts caused by the usage of memblock_mark_nomap ]

Fixes: 094cb98179f19b7 ("of/fdt: memblock_reserve /memreserve/ regions in the case of partial overlap")
Signed-off-by: Nicolas Boichat 
Reviewed-by: Stephen Boyd 
Signed-off-by: Quentin Perret 
Link: https://lore.kernel.org/r/20210115114544.1830068-3-qperret@google.com
Signed-off-by: Rob Herring 
Signed-off-by: Sasha Levin

fdt: Properly handle "no-map" field in the memory region

2021-03-04T09:26:28+00:00

[ Upstream commit 86588296acbfb1591e92ba60221e95677ecadb43 ]

Mark the memory region with NOMAP flag instead of completely removing it
from the memory blocks. That makes the FDT handling consistent with the EFI
memory map handling.

Cc: Rob Herring 
Cc: Frank Rowand 
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: KarimAllah Ahmed 
Signed-off-by: Quentin Perret 
Link: https://lore.kernel.org/r/20210115114544.1830068-2-qperret@google.com
Signed-off-by: Rob Herring 
Signed-off-by: Sasha Levin

fdt: Update CRC check for rng-seed

2019-08-27T11:27:07+00:00

Commit 428826f5358c ("fdt: add support for rng-seed") moves of_fdt_crc32
from early_init_dt_verify() to early_init_dt_scan() since
early_init_dt_scan_chosen() may modify fdt to erase rng-seed.

However, arm and some other arch won't call early_init_dt_scan(), they
call early_init_dt_verify() then early_init_dt_scan_nodes().

Restore of_fdt_crc32 to early_init_dt_verify() then update it in
early_init_dt_scan_chosen() if fdt if updated.

Fixes: 428826f5358c ("fdt: add support for rng-seed")
Reported-by: Geert Uytterhoeven 
Signed-off-by: Hsin-Yi Wang 
Tested-by: Geert Uytterhoeven 
Signed-off-by: Will Deacon

fdt: add support for rng-seed

2019-08-23T15:39:26+00:00

Introducing a chosen node, rng-seed, which is an entropy that can be
passed to kernel called very early to increase initial device
randomness. Bootloader should provide this entropy and the value is
read from /chosen/rng-seed in DT.

Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(),
since early_init_dt_scan_chosen() would modify fdt to erase rng-seed.

Add a new interface add_bootloader_randomness() for rng-seed use case.
Depends on whether the seed is trustworthy, rng seed would be passed to
add_hwgenerator_randomness(). Otherwise it would be passed to
add_device_randomness(). Decision is controlled by kernel config
RANDOM_TRUST_BOOTLOADER.

Signed-off-by: Hsin-Yi Wang 
Reviewed-by: Stephen Boyd 
Reviewed-by: Rob Herring 
Reviewed-by: Theodore Ts'o  # drivers/char/random.c
Signed-off-by: Will Deacon

of/fdt: pass early_init_dt_reserve_memory_arch() with bool type nomap

2019-07-08T21:28:15+00:00

The third argument 'nomap' of early_init_dt_reserve_memory_arch() is
bool. It is preferred to pass it with a bool type parameter.

Signed-off-by: Masahiro Yamada 
Reviewed-by: Frank Rowand 
Signed-off-by: Rob Herring

of/fdt: Fix ‘of_fdt_match’ defined but not used compiler warning

2019-06-18T14:10:43+00:00

When CONFIG_OF_EARLY_FLATTREE is disabled, there is a compiler
warning,

drivers/of/fdt.c:129:19: warning: ‘of_fdt_match’ defined but not used [-Wunused-function]
 static int __init of_fdt_match(const void *blob, unsigned long node,

Since the only caller of of_fdt_match() is of_flat_dt_match(),
let's move the body of of_fdt_match() into of_flat_dt_match()
and eliminate of_fdt_match().

Meanwhile, move of_fdt_is_compatible() under CONFIG_OF_EARLY_FLATTREE,
as all callers are over there.

Fixes: 9b4d2b635bd0 ("of/fdt: Remove dead code and mark functions with __init")
Cc: Frank Rowand 
Signed-off-by: Kefeng Wang 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rob Herring

of/fdt: Mark initial_boot_params as __ro_after_init

2019-05-24T21:39:27+00:00

The FDT pointer, i.e. initial_boot_params, shouldn't be changed after
init. It's only set by boot code and then the only user of the FDT is
the raw sysfs reading API. Mark this pointer with __ro_after_init so
that the pointer can't be changed after init.

Cc: Hsin-Yi Wang 
Signed-off-by: Stephen Boyd 
Signed-off-by: Rob Herring