nios2: reserve boot memory for device tree

Make sure to reserve the boot memory for the flattened device tree.
Otherwise it might get overwritten, e.g. when initial_boot_params is
copied, leading to a corrupted FDT and a boot hang/crash:

  bootconsole [early0] enabled
  Early console on uart16650 initialized at 0xf8001600
  OF: fdt: Error -11 processing FDT
  Kernel panic - not syncing: setup_cpuinfo: No CPU found in devicetree!

  ---[ end Kernel panic - not syncing: setup_cpuinfo: No CPU found in devicetree!

Guenter Roeck says:

> I think I found the problem. In unflatten_and_copy_device_tree(), with added
> debug information:
>
> OF: fdt: initial_boot_params=c861e400, dt=c861f000 size=28874 (0x70ca)
>
> ... and then initial_boot_params is copied to dt, which results in corrupted
> fdt since the memory overlaps. Looks like the initial_boot_params memory
> is not reserved and (re-)allocated by early_init_dt_alloc_memory_arch().

Cc: stable@vger.kernel.org
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reference: http://lkml.kernel.org/r/20170226210338.GA19476@roeck-us.net
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Ley Foon Tan <ley.foon.tan@intel.com>
This commit is contained in:
Tobias Klauser 2017-04-02 20:08:04 -07:00 committed by Ley Foon Tan
parent a71c9a1c77
commit 921d701e6f
2 changed files with 10 additions and 0 deletions

View File

@ -48,6 +48,13 @@ void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
return alloc_bootmem_align(size, align);
}
int __init early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
bool nomap)
{
reserve_bootmem(base, size, BOOTMEM_DEFAULT);
return 0;
}
void __init early_init_devtree(void *params)
{
__be32 *dtb = (u32 *)__dtb_start;

View File

@ -201,6 +201,9 @@ void __init setup_arch(char **cmdline_p)
}
#endif /* CONFIG_BLK_DEV_INITRD */
early_init_fdt_reserve_self();
early_init_fdt_scan_reserved_mem();
unflatten_and_copy_device_tree();
setup_cpuinfo();