On Fri, 2017-03-31 at 11:40 +0200, Tobias Klauser wrote: > 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@xxxxxxxxxxxxxxx > Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> > Reference: http://lkml.kernel.org/r/20170226210338.GA19476@roeck-us.n > et > Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> > Signed-off-by: Tobias Klauser <tklauser@xxxxxxxxxx> Acked-by: Ley Foon Tan <ley.foon.tan@xxxxxxxxx> Thanks for the fix. Will add this for 4.11. Regards Ley Foon > --- > arch/nios2/kernel/prom.c | 7 +++++++ > arch/nios2/kernel/setup.c | 3 +++ > 2 files changed, 10 insertions(+) > > diff --git a/arch/nios2/kernel/prom.c b/arch/nios2/kernel/prom.c > index 367c5426157b..3901b80d4420 100644 > --- a/arch/nios2/kernel/prom.c > +++ b/arch/nios2/kernel/prom.c > @@ -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; > diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c > index 6e57ffa5db27..6044d9be28b4 100644 > --- a/arch/nios2/kernel/setup.c > +++ b/arch/nios2/kernel/setup.c > @@ -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(); > -- > 2.12.2.399.g034667a45805 > > > > ________________________________ > > Confidentiality Notice. > This message may contain information that is confidential or > otherwise protected from disclosure. If you are not the intended > recipient, you are hereby notified that any use, disclosure, > dissemination, distribution, or copying of this message, or any > attachments, is strictly prohibited. If you have received this > message in error, please advise the sender by reply e-mail, and > delete the message and any attachments. Thank you.