Re: [Linux-stable-mirror] [PATCH] MIPS: fix incorrect mem=X@Y handling

On Tue, Sep 5, 2017 at 1:06 PM, Marcin Nowakowski marcin.nowakowski@imgtec.com 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@gmail.com Signed-off-by: Marcin Nowakowski marcin.nowakowski@imgtec.com Fixes: 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing") Cc: stable@vger.kernel.org

---

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@debian.org

Would be nice to have it upstream at some point...

Thanks