Re: kmemleak: Cannot insert 0xff7f1000 into the object search tree (overlaps existing)

[Vignesh R]

On Friday 12 August 2016 03:34 PM, Catalin Marinas wrote:
> On Fri, Aug 12, 2016 at 09:45:05AM +0530, Vignesh R wrote:
>> On Thursday 11 August 2016 10:38 PM, Catalin Marinas wrote:
[...]
> From b8b9141fffc1fd3c73583c1fd50a724c4a6452e1 Mon Sep 17 00:00:00 2001
> From: Catalin Marinas <catalin.marinas@xxxxxxx>
> Date: Fri, 12 Aug 2016 10:43:06 +0100
> Subject: [PATCH] mm: kmemleak: Avoid using __va() on addresses that don't have
>  a lowmem mapping
> 
> Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a
> physical address to a virtual one using __va(). However, such physical
> addresses may sometimes be located in highmem and using __va() is
> incorrect, leading to inconsistent object tracking in kmemleak.
> 
> The following functions have been added to the kmemleak API and they
> take a physical address as the object pointer. They only perform the
> corresponding action if the address has a lowmem mapping:
> 
> kmemleak_alloc_phys
> kmemleak_free_part_phys
> kmemleak_not_leak_phys
> kmemleak_ignore_phys
> 
> The affected calling placess have been updated to use the new kmemleak
> API.
> 
> Reported-by: Vignesh R <vigneshr@xxxxxx>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>

Thanks, this solves the issue!
I tested on AM335x GP EVM and DRA72 EVM on linux-next with below patch
applied. FWIW,
Tested-by: Vignesh R <vigneshr@xxxxxx>

I can see this issue on stable v4.4.17 kernel as well. So, can this
patch be marked for stable backport?


Regards
Vignesh

> ---
>  Documentation/kmemleak.txt |  9 +++++++++
>  include/linux/kmemleak.h   | 26 ++++++++++++++++++++++++++
>  mm/bootmem.c               |  6 +++---
>  mm/cma.c                   |  2 +-
>  mm/memblock.c              |  8 ++++----
>  mm/nobootmem.c             |  2 +-
>  6 files changed, 44 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/kmemleak.txt b/Documentation/kmemleak.txt
> index 18e24abb3ecf..35e1a8891e3a 100644
> --- a/Documentation/kmemleak.txt
> +++ b/Documentation/kmemleak.txt
> @@ -155,6 +155,15 @@ kmemleak_erase		 - erase an old value in a pointer variable
>  kmemleak_alloc_recursive - as kmemleak_alloc but checks the recursiveness
>  kmemleak_free_recursive	 - as kmemleak_free but checks the recursiveness
>  
> +The following functions take a physical address as the object pointer
> +and only perform the corresponding action if the address has a lowmem
> +mapping:
> +
> +kmemleak_alloc_phys
> +kmemleak_free_part_phys
> +kmemleak_not_leak_phys
> +kmemleak_ignore_phys
> +
>  Dealing with false positives/negatives
>  --------------------------------------
>  
> diff --git a/include/linux/kmemleak.h b/include/linux/kmemleak.h
> index 4894c6888bc6..380f72bc3657 100644
> --- a/include/linux/kmemleak.h
> +++ b/include/linux/kmemleak.h
> @@ -21,6 +21,7 @@
>  #ifndef __KMEMLEAK_H
>  #define __KMEMLEAK_H
>  
> +#include <linux/mm.h>
>  #include <linux/slab.h>
>  
>  #ifdef CONFIG_DEBUG_KMEMLEAK
> @@ -109,4 +110,29 @@ static inline void kmemleak_no_scan(const void *ptr)
>  
>  #endif	/* CONFIG_DEBUG_KMEMLEAK */
>  
> +static inline void kmemleak_alloc_phys(phys_addr_t phys, size_t size,
> +				       int min_count, gfp_t gfp)
> +{
> +	if (!IS_ENABLED(CONFIG_HIGHMEM) || phys < __pa(high_memory))
> +		kmemleak_alloc(__va(phys), size, min_count, gfp);
> +}
> +
> +static inline void kmemleak_free_part_phys(phys_addr_t phys, size_t size)
> +{
> +	if (!IS_ENABLED(CONFIG_HIGHMEM) || phys < __pa(high_memory))
> +		kmemleak_free_part(__va(phys), size);
> +}
> +
> +static inline void kmemleak_not_leak_phys(phys_addr_t phys)
> +{
> +	if (!IS_ENABLED(CONFIG_HIGHMEM) || phys < __pa(high_memory))
> +		kmemleak_not_leak(__va(phys));
> +}
> +
> +static inline void kmemleak_ignore_phys(phys_addr_t phys)
> +{
> +	if (!IS_ENABLED(CONFIG_HIGHMEM) || phys < __pa(high_memory))
> +		kmemleak_ignore(__va(phys));
> +}
> +
>  #endif	/* __KMEMLEAK_H */
> diff --git a/mm/bootmem.c b/mm/bootmem.c
> index 0aa7dda52402..80f1d70bad2d 100644
> --- a/mm/bootmem.c
> +++ b/mm/bootmem.c
> @@ -158,7 +158,7 @@ void __init free_bootmem_late(unsigned long physaddr, unsigned long size)
>  {
>  	unsigned long cursor, end;
>  
> -	kmemleak_free_part(__va(physaddr), size);
> +	kmemleak_free_part_phys(physaddr, size);
>  
>  	cursor = PFN_UP(physaddr);
>  	end = PFN_DOWN(physaddr + size);
> @@ -402,7 +402,7 @@ void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
>  {
>  	unsigned long start, end;
>  
> -	kmemleak_free_part(__va(physaddr), size);
> +	kmemleak_free_part_phys(physaddr, size);
>  
>  	start = PFN_UP(physaddr);
>  	end = PFN_DOWN(physaddr + size);
> @@ -423,7 +423,7 @@ void __init free_bootmem(unsigned long physaddr, unsigned long size)
>  {
>  	unsigned long start, end;
>  
> -	kmemleak_free_part(__va(physaddr), size);
> +	kmemleak_free_part_phys(physaddr, size);
>  
>  	start = PFN_UP(physaddr);
>  	end = PFN_DOWN(physaddr + size);
> diff --git a/mm/cma.c b/mm/cma.c
> index bd0e1412475e..384c2cb51b56 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -336,7 +336,7 @@ int __init cma_declare_contiguous(phys_addr_t base,
>  		 * kmemleak scans/reads tracked objects for pointers to other
>  		 * objects but this address isn't mapped and accessible
>  		 */
> -		kmemleak_ignore(phys_to_virt(addr));
> +		kmemleak_ignore_phys(addr);
>  		base = addr;
>  	}
>  
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 483197ef613f..30ecea7b45d1 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -723,7 +723,7 @@ int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
>  		     (unsigned long long)base + size - 1,
>  		     (void *)_RET_IP_);
>  
> -	kmemleak_free_part(__va(base), size);
> +	kmemleak_free_part_phys(base, size);
>  	return memblock_remove_range(&memblock.reserved, base, size);
>  }
>  
> @@ -1152,7 +1152,7 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
>  		 * The min_count is set to 0 so that memblock allocations are
>  		 * never reported as leaks.
>  		 */
> -		kmemleak_alloc(__va(found), size, 0, 0);
> +		kmemleak_alloc_phys(found, size, 0, 0);
>  		return found;
>  	}
>  	return 0;
> @@ -1399,7 +1399,7 @@ void __init __memblock_free_early(phys_addr_t base, phys_addr_t size)
>  	memblock_dbg("%s: [%#016llx-%#016llx] %pF\n",
>  		     __func__, (u64)base, (u64)base + size - 1,
>  		     (void *)_RET_IP_);
> -	kmemleak_free_part(__va(base), size);
> +	kmemleak_free_part_phys(base, size);
>  	memblock_remove_range(&memblock.reserved, base, size);
>  }
>  
> @@ -1419,7 +1419,7 @@ void __init __memblock_free_late(phys_addr_t base, phys_addr_t size)
>  	memblock_dbg("%s: [%#016llx-%#016llx] %pF\n",
>  		     __func__, (u64)base, (u64)base + size - 1,
>  		     (void *)_RET_IP_);
> -	kmemleak_free_part(__va(base), size);
> +	kmemleak_free_part_phys(base, size);
>  	cursor = PFN_UP(base);
>  	end = PFN_DOWN(base + size);
>  
> diff --git a/mm/nobootmem.c b/mm/nobootmem.c
> index bd05a70f44b9..a056d31dff7e 100644
> --- a/mm/nobootmem.c
> +++ b/mm/nobootmem.c
> @@ -81,7 +81,7 @@ void __init free_bootmem_late(unsigned long addr, unsigned long size)
>  {
>  	unsigned long cursor, end;
>  
> -	kmemleak_free_part(__va(addr), size);
> +	kmemleak_free_part_phys(addr, size);
>  
>  	cursor = PFN_UP(addr);
>  	end = PFN_DOWN(addr + size);
>