On Wednesday 17 August 2016 02:58 PM, Catalin Marinas wrote:
> 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 places have been updated to use the new kmemleak
> API.
>
> Reported-by: Vignesh R <vigneshr@xxxxxx>
> Cc: Vignesh R <vigneshr@xxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> ---
>
> v1 -> v2:
> Moved the kmemleak_*_phys() functions out of line to avoid including
> linux/mm.h in linux/kmemleak.h and cause build errors on several platforms
>
> Vignesh, I removed your tested/acked tags since this patch has been modified
> slightly. Could you please give it another try? Thank you.
Tested on AM335x EVM and DRA72 EVM on top of linux-next:
Tested-by: Vignesh R <vigneshr@xxxxxx>
Thanks
Vignesh
>
> Documentation/kmemleak.txt | 9 +++++++++
> include/linux/kmemleak.h | 18 ++++++++++++++++++
> mm/bootmem.c | 6 +++---
> mm/cma.c | 2 +-
> mm/kmemleak.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
> mm/memblock.c | 8 ++++----
> mm/nobootmem.c | 2 +-
> 7 files changed, 81 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..1c2a32829620 100644
> --- a/include/linux/kmemleak.h
> +++ b/include/linux/kmemleak.h
> @@ -38,6 +38,11 @@ extern void kmemleak_not_leak(const void *ptr) __ref;
> extern void kmemleak_ignore(const void *ptr) __ref;
> extern void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) __ref;
> extern void kmemleak_no_scan(const void *ptr) __ref;
> +extern void kmemleak_alloc_phys(phys_addr_t phys, size_t size, int min_count,
> + gfp_t gfp) __ref;
> +extern void kmemleak_free_part_phys(phys_addr_t phys, size_t size) __ref;
> +extern void kmemleak_not_leak_phys(phys_addr_t phys) __ref;
> +extern void kmemleak_ignore_phys(phys_addr_t phys) __ref;
>
> static inline void kmemleak_alloc_recursive(const void *ptr, size_t size,
> int min_count, unsigned long flags,
> @@ -106,6 +111,19 @@ static inline void kmemleak_erase(void **ptr)
> static inline void kmemleak_no_scan(const void *ptr)
> {
> }
> +static inline void kmemleak_alloc_phys(phys_addr_t phys, size_t size,
> + int min_count, gfp_t gfp)
> +{
> +}
> +static inline void kmemleak_free_part_phys(phys_addr_t phys, size_t size)
> +{
> +}
> +static inline void kmemleak_not_leak_phys(phys_addr_t phys)
> +{
> +}
> +static inline void kmemleak_ignore_phys(phys_addr_t phys)
> +{
> +}
>
> #endif /* CONFIG_DEBUG_KMEMLEAK */
>
> 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/kmemleak.c b/mm/kmemleak.c
> index 086292f7c59d..4a717788998b 100644
> --- a/mm/kmemleak.c
> +++ b/mm/kmemleak.c
> @@ -1121,6 +1121,51 @@ void __ref kmemleak_no_scan(const void *ptr)
> }
> EXPORT_SYMBOL(kmemleak_no_scan);
>
> +/**
> + * kmemleak_alloc_phys - similar to kmemleak_alloc but taking a physical
> + * address argument
> + */
> +void __ref 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);
> +}
> +EXPORT_SYMBOL(kmemleak_alloc_phys);
> +
> +/**
> + * kmemleak_free_part_phys - similar to kmemleak_free_part but taking a
> + * physical address argument
> + */
> +void __ref 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);
> +}
> +EXPORT_SYMBOL(kmemleak_free_part_phys);
> +
> +/**
> + * kmemleak_not_leak_phys - similar to kmemleak_not_leak but taking a physical
> + * address argument
> + */
> +void __ref kmemleak_not_leak_phys(phys_addr_t phys)
> +{
> + if (!IS_ENABLED(CONFIG_HIGHMEM) || phys < __pa(high_memory))
> + kmemleak_not_leak(__va(phys));
> +}
> +EXPORT_SYMBOL(kmemleak_not_leak_phys);
> +
> +/**
> + * kmemleak_ignore_phys - similar to kmemleak_ignore but taking a physical
> + * address argument
> + */
> +void __ref kmemleak_ignore_phys(phys_addr_t phys)
> +{
> + if (!IS_ENABLED(CONFIG_HIGHMEM) || phys < __pa(high_memory))
> + kmemleak_ignore(__va(phys));
> +}
> +EXPORT_SYMBOL(kmemleak_ignore_phys);
> +
> /*
> * Update an object's checksum and return true if it was modified.
> */
> 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);
>
--
Regards
Vignesh
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