From 6072cf567a2be7f13fb3522156409ca0e7a27ff9 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Fri, 26 Oct 2018 15:04:48 -0700 Subject: of: ignore sub-page memory regions Memory region size is rounded down to page boundary and with sub-page region it becomes 0 and there is no point to add an empty region. Moreover, when the base is less than PAGE_SIZE we get a bogus size as (base + size - 1) evaluates to -1. 8cccffc52694 ("of: check for size < 0 after rounding in early_init_dt_add_memory_arch") introduced a test for wrap around for the case when base is not page aligned, the same test can be used to ignore sub-page region sizes. Link: http://lkml.kernel.org/r/1533326330-31677-3-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Reviewed-by: Rob Herring Cc: Guan Xuetao Cc: Ley Foon Tan Cc: Richard Kuo Cc: Richard Weinberger Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/of/fdt.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'drivers/of') diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 800ad252cf9c..76c83c1ffeda 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -1127,12 +1127,13 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) { const u64 phys_offset = MIN_MEMBLOCK_ADDR; + if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { + pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", + base, base + size); + return; + } + if (!PAGE_ALIGNED(base)) { - if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { - pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", - base, base + size); - return; - } size -= PAGE_SIZE - (base & ~PAGE_MASK); base = PAGE_ALIGN(base); } -- cgit v1.2.3