On Tue, Sep 5, 2017 at 1:06 PM, Marcin Nowakowski
<marcin.nowakowski@xxxxxxxxxx> wrote:
> Change 73fbc1eba7ff added a fix to ensure that the memory range between
> PHYS_OFFSET and low memory address specified by mem= cmdline argument is
> not later processed by free_all_bootmem.
> This change was incorrect for systems where the commandline specifies
> more than 1 mem argument, as it will cause all memory between
> PHYS_OFFSET and each of the memory offsets to be marked as reserved,
> which results in parts of the RAM marked as reserved (Creator CI20's
> u-boot has a default commandline argument 'mem=256M@0x0
> mem=768M@0x30000000').
>
> Change the behaviour to ensure that only the range between PHYS_OFFSET
> and the lowest start address of the memories is marked as protected.
>
> This change also ensures that the range is marked protected even if it's
> only defined through the devicetree and not only via commandline
> arguments.
>
> Reported-by: Mathieu Malaterre <mathieu.malaterre@xxxxxxxxx>
> Signed-off-by: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
> Fixes: 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing")
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> arch/mips/kernel/setup.c | 19 ++++++++++++++++---
> 1 file changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index fe39397..a1c39ec 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -374,6 +374,7 @@ static void __init bootmem_init(void)
> unsigned long reserved_end;
> unsigned long mapstart = ~0UL;
> unsigned long bootmap_size;
> + phys_addr_t ramstart = ~0UL;
> bool bootmap_valid = false;
> int i;
>
> @@ -394,6 +395,21 @@ static void __init bootmem_init(void)
> max_low_pfn = 0;
>
> /*
> + * Reserve any memory between the start of RAM and PHYS_OFFSET
> + */
> + for (i = 0; i < boot_mem_map.nr_map; i++) {
> + if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
> + continue;
> +
> + ramstart = min(ramstart, boot_mem_map.map[i].addr);
> + }
> +
> + if (ramstart > PHYS_OFFSET)
> + add_memory_region(PHYS_OFFSET, ramstart - PHYS_OFFSET,
> + BOOT_MEM_RESERVED);
> +
> +
> + /*
> * Find the highest page frame number we have available.
> */
> for (i = 0; i < boot_mem_map.nr_map; i++) {
> @@ -663,9 +679,6 @@ static int __init early_parse_mem(char *p)
>
> add_memory_region(start, size, BOOT_MEM_RAM);
>
> - if (start && start > PHYS_OFFSET)
> - add_memory_region(PHYS_OFFSET, start - PHYS_OFFSET,
> - BOOT_MEM_RESERVED);
> return 0;
> }
> early_param("mem", early_parse_mem);
> --
> 2.7.4
>
>
Teested-by: Mathieu Malaterre <malat@xxxxxxxxxx>
Would be nice to have it upstream at some point...
Thanks
