James,
On Tue, Feb 13, 2018 at 2:38 PM, James Hogan <jhogan@xxxxxxxxxx> wrote:
> On Tue, Feb 13, 2018 at 01:14:29PM +0100, Mathieu Malaterre wrote:
>> On Thu, Feb 1, 2018 at 1:12 PM, Mathieu Malaterre <malat@xxxxxxxxxx> wrote:
>> > On Thu, Feb 1, 2018 at 12:37 PM, Marcin Nowakowski
>> > <marcin.nowakowski@xxxxxxxx> wrote:
>> >> Commit 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing") 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@xxxxxxxx>
>> >> Fixes: 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing")
>> >> Cc: <stable@xxxxxxxxxxxxxxx> # v4.11+
>> >> ---
>> >> v3: Update stable version, code cleanup as suggested by James Hogan
>> >> v2: Use updated email adress, add tag for stable.
>> >> ---
>> >> arch/mips/kernel/setup.c | 16 ++++++++++++----
>> >> 1 file changed, 12 insertions(+), 4 deletions(-)
>> >>
>> >> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
>> >> index 702c678de116..e4a1581ce822 100644
>> >> --- a/arch/mips/kernel/setup.c
>> >> +++ b/arch/mips/kernel/setup.c
>> >> @@ -375,6 +375,7 @@ static void __init bootmem_init(void)
>> >> unsigned long reserved_end;
>> >> unsigned long mapstart = ~0UL;
>> >> unsigned long bootmap_size;
>> >> + phys_addr_t ramstart = (phys_addr_t)ULLONG_MAX;
>> >> bool bootmap_valid = false;
>> >> int i;
>> >>
>> >> @@ -395,7 +396,8 @@ static void __init bootmem_init(void)
>> >> max_low_pfn = 0;
>> >>
>> >> /*
>> >> - * Find the highest page frame number we have available.
>> >> + * Find the highest page frame number we have available
>> >> + * and the lowest used RAM address
>> >> */
>> >> for (i = 0; i < boot_mem_map.nr_map; i++) {
>> >> unsigned long start, end;
>> >> @@ -407,6 +409,8 @@ static void __init bootmem_init(void)
>> >> end = PFN_DOWN(boot_mem_map.map[i].addr
>> >> + boot_mem_map.map[i].size);
>> >>
>> >> + ramstart = min(ramstart, boot_mem_map.map[i].addr);
>> >> +
>> >> #ifndef CONFIG_HIGHMEM
>> >> /*
>> >> * Skip highmem here so we get an accurate max_low_pfn if low
>> >> @@ -436,6 +440,13 @@ static void __init bootmem_init(void)
>> >> mapstart = max(reserved_end, start);
>> >> }
>> >>
>> >> + /*
>> >> + * Reserve any memory between the start of RAM and PHYS_OFFSET
>> >> + */
>> >> + if (ramstart > PHYS_OFFSET)
>> >> + add_memory_region(PHYS_OFFSET, ramstart - PHYS_OFFSET,
>> >> + BOOT_MEM_RESERVED);
>> >> +
>> >> if (min_low_pfn >= max_low_pfn)
>> >> panic("Incorrect memory mapping !!!");
>> >> if (min_low_pfn > ARCH_PFN_OFFSET) {
>> >> @@ -664,9 +675,6 @@ 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);
>> >> --
>> >> 2.14.1
>> >>
>> >
>> > Looks good to me:
>> >
>> > $ cat /proc/cpuinfo
>> > system type : JZ4780
>> > machine : Creator CI20
>> > processor : 0
>> > cpu model : Ingenic JZRISC V4.15 FPU V0.0
>> > BogoMIPS : 956.00
>> > wait instruction : yes
>> > microsecond timers : no
>> > tlb_entries : 32
>> > extra interrupt vector : yes
>> > hardware watchpoint : yes, count: 1, address/irw mask: [0x0fff]
>> > isa : mips1 mips2 mips32r1 mips32r2
>> > ASEs implemented :
>> > shadow register sets : 1
>> > kscratch registers : 0
>> > package : 0
>> > core : 0
>> > VCED exceptions : not available
>> > VCEI exceptions : not available
>> > $ uname -a
>> > Linux ci20 4.15.0+ #323 PREEMPT Thu Feb 1 13:08:11 CET 2018 mips GNU/Linux
>> >
>> > Tested-by: Mathieu Malaterre <malat@xxxxxxxxxx>
>> >
>> > Thanks
>>
>> Could you please review the patch v3 ?
>
> Yes, looks good to me, and Ralf had applied to his test branch so I
> presume he's happy with it too. I'll apply for 4.16.
Hum, just to be sure I understand the process. Which branch are you
talking about:
https://git.kernel.org/pub/scm/linux/kernel/git/ralf/linux.git
> Commit 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing") which
> this fixes was evidently requested to be backported to stable (unsure
> who by) and added to the 4.9 queue, but then this arose and it was
> removed until this fix is merged (see
> https://patchwork.linux-mips.org/patch/17268/).
>
> Anybody know how far back before 4.11 both of these patches should be
> applied to stable? If not I'll just leave it at 4.11 and if its
> important before then for kexec or whatever they can be requested again.