linux-kernel - Re: [PATCH v2 1/2] Revert "memblock: exclude NOMAP regions from kmemleak"

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Date:   Fri, 22 Oct 2021 14:22:38 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Mike Rapoport <rppt@...nel.org>, linux-mm@...ck.org
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Mike Rapoport <rppt@...ux.ibm.com>,
        Qian Cai <quic_qiancai@...cinc.com>,
        Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/2] Revert "memblock: exclude NOMAP regions from
 kmemleak"

On 21.10.21 09:09, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@...ux.ibm.com>
> 
> Commit 6e44bd6d34d6 ("memblock: exclude NOMAP regions from kmemleak")
> breaks boot on EFI systems with kmemleak and VM_DEBUG enabled:
> 
> efi: Processing EFI memory map:
> efi:   0x000090000000-0x000091ffffff [Conventional|   |  |  |  |  |  |  |  |  |   |WB|WT|WC|UC]
> efi:   0x000092000000-0x0000928fffff [Runtime Data|RUN|  |  |  |  |  |  |  |  |   |WB|WT|WC|UC]
> ------------[ cut here ]------------
> kernel BUG at mm/kmemleak.c:1140!
> Internal error: Oops - BUG: 0 [#1] SMP
> Modules linked in:
> CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.0-rc6-next-20211019+ #104
> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : kmemleak_free_part_phys+0x64/0x8c
> lr : kmemleak_free_part_phys+0x38/0x8c
> sp : ffff800011eafbc0
> x29: ffff800011eafbc0 x28: 1fffff7fffb41c0d x27: fffffbfffda0e068
> x26: 0000000092000000 x25: 1ffff000023d5f94 x24: ffff800011ed84d0
> x23: ffff800011ed84c0 x22: ffff800011ed83d8 x21: 0000000000900000
> x20: ffff800011782000 x19: 0000000092000000 x18: ffff800011ee0730
> x17: 0000000000000000 x16: 0000000000000000 x15: 1ffff0000233252c
> x14: ffff800019a905a0 x13: 0000000000000001 x12: ffff7000023d5ed7
> x11: 1ffff000023d5ed6 x10: ffff7000023d5ed6 x9 : dfff800000000000
> x8 : ffff800011eaf6b7 x7 : 0000000000000001 x6 : ffff800011eaf6b0
> x5 : 00008ffffdc2a12a x4 : ffff7000023d5ed7 x3 : 1ffff000023dbf99
> x2 : 1ffff000022f0463 x1 : 0000000000000000 x0 : ffffffffffffffff
> Call trace:
>  kmemleak_free_part_phys+0x64/0x8c
>  memblock_mark_nomap+0x5c/0x78
>  reserve_regions+0x294/0x33c
>  efi_init+0x2d0/0x490
>  setup_arch+0x80/0x138
>  start_kernel+0xa0/0x3ec
>  __primary_switched+0xc0/0xc8
> Code: 34000041 97d526e7 f9418e80 36000040 (d4210000)
> random: get_random_bytes called from print_oops_end_marker+0x34/0x80 with crng_init=0
> ---[ end trace 0000000000000000 ]---
> 
> The crash happens because kmemleak_free_part_phys() tries to use __va()
> before memstart_addr is initialized and this triggers a VM_BUG_ON() in
> arch/arm64/include/asm/memory.h:
> 
> Revert 6e44bd6d34d6 ("memblock: exclude NOMAP regions from kmemleak"), the
> issue it is fixing will be fixed differently.
> 
> Reported-by: Qian Cai <quic_qiancai@...cinc.com>
> Signed-off-by: Mike Rapoport <rppt@...ux.ibm.com>
> ---
>  mm/memblock.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 5c3503c98b2f..184dcd2e5d99 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -936,12 +936,7 @@ int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
>   */
>  int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size)
>  {
> -	int ret = memblock_setclr_flag(base, size, 1, MEMBLOCK_NOMAP);
> -
> -	if (!ret)
> -		kmemleak_free_part_phys(base, size);
> -
> -	return ret;
> +	return memblock_setclr_flag(base, size, 1, MEMBLOCK_NOMAP);
>  }
>  
>  /**
> 

Reviewed-by: David Hildenbrand <david@...hat.com>

-- 
Thanks,

David / dhildenb