| From 921d701e6f31e1ffaca3560416af1aa04edb4c4f Mon Sep 17 00:00:00 2001 |
| From: Tobias Klauser <tklauser@distanz.ch> |
| Date: Sun, 2 Apr 2017 20:08:04 -0700 |
| Subject: nios2: reserve boot memory for device tree |
| |
| From: Tobias Klauser <tklauser@distanz.ch> |
| |
| commit 921d701e6f31e1ffaca3560416af1aa04edb4c4f upstream. |
| |
| 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(). |
| |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/nios2/kernel/prom.c | 7 +++++++ |
| arch/nios2/kernel/setup.c | 3 +++ |
| 2 files changed, 10 insertions(+) |
| |
| --- a/arch/nios2/kernel/prom.c |
| +++ b/arch/nios2/kernel/prom.c |
| @@ -48,6 +48,13 @@ void * __init early_init_dt_alloc_memory |
| 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; |
| --- a/arch/nios2/kernel/setup.c |
| +++ b/arch/nios2/kernel/setup.c |
| @@ -195,6 +195,9 @@ 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(); |