[2/3] mm/vmalloc: do not call kmemleak_free() on not yet accounted memory
diff mbox series

Message ID 20190103145954.16942-3-rpenyaev@suse.de
State In Next
Commit dc6d46f5eb27ab007b33ea6f73603e897caa1af4
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Series
  • mm/vmalloc: fix size check and few cleanups
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Commit Message

Roman Penyaev Jan. 3, 2019, 2:59 p.m. UTC
__vmalloc_area_node() calls vfree() on error path, which in turn calls
kmemleak_free(), but area is not yet accounted by kmemleak_vmalloc().

Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Joe Perches <joe@perches.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
---
 mm/vmalloc.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

Comments

Andrey Ryabinin Jan. 11, 2019, 7:26 p.m. UTC | #1
On 1/3/19 5:59 PM, Roman Penyaev wrote:
> __vmalloc_area_node() calls vfree() on error path, which in turn calls
> kmemleak_free(), but area is not yet accounted by kmemleak_vmalloc().
> 
> Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
> Cc: Joe Perches <joe@perches.com>
> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  mm/vmalloc.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 2cd24186ba84..dc6a62bca503 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1565,6 +1565,14 @@ void vfree_atomic(const void *addr)
>  	__vfree_deferred(addr);
>  }
>  
> +static void __vfree(const void *addr)
> +{
> +	if (unlikely(in_interrupt()))
> +		__vfree_deferred(addr);
> +	else
> +		__vunmap(addr, 1);
> +}
> +
>  /**
>   *	vfree  -  release memory allocated by vmalloc()
>   *	@addr:		memory base address
> @@ -1591,10 +1599,8 @@ void vfree(const void *addr)
>  
>  	if (!addr)
>  		return;
> -	if (unlikely(in_interrupt()))
> -		__vfree_deferred(addr);
> -	else
> -		__vunmap(addr, 1);
> +
> +	__vfree(addr);
>  }
>  EXPORT_SYMBOL(vfree);
>  
> @@ -1709,7 +1715,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
>  	warn_alloc(gfp_mask, NULL,
>  			  "vmalloc: allocation failure, allocated %ld of %ld bytes",
>  			  (area->nr_pages*PAGE_SIZE), area->size);
> -	vfree(area->addr);
> +	__vfree(area->addr);

This can't be an interrupt context for a several reasons. One of them is BUG_ON(in_interrupt()) in __get_vm_area_node()
which is called right before __vmalloc_are_node().

So you can just do __vunmap(area->addr, 1); instead of __vfree().


>  	return NULL;
>  }
>  
>
Roman Penyaev Jan. 12, 2019, 5:19 p.m. UTC | #2
On 2019-01-11 20:26, Andrey Ryabinin wrote:
> On 1/3/19 5:59 PM, Roman Penyaev wrote:
>> __vmalloc_area_node() calls vfree() on error path, which in turn calls
>> kmemleak_free(), but area is not yet accounted by kmemleak_vmalloc().
>> 
>> Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: Michal Hocko <mhocko@suse.com>
>> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
>> Cc: Joe Perches <joe@perches.com>
>> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
>> Cc: linux-mm@kvack.org
>> Cc: linux-kernel@vger.kernel.org
>> ---
>>  mm/vmalloc.c | 16 +++++++++++-----
>>  1 file changed, 11 insertions(+), 5 deletions(-)
>> 
>> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
>> index 2cd24186ba84..dc6a62bca503 100644
>> --- a/mm/vmalloc.c
>> +++ b/mm/vmalloc.c
>> @@ -1565,6 +1565,14 @@ void vfree_atomic(const void *addr)
>>  	__vfree_deferred(addr);
>>  }
>> 
>> +static void __vfree(const void *addr)
>> +{
>> +	if (unlikely(in_interrupt()))
>> +		__vfree_deferred(addr);
>> +	else
>> +		__vunmap(addr, 1);
>> +}
>> +
>>  /**
>>   *	vfree  -  release memory allocated by vmalloc()
>>   *	@addr:		memory base address
>> @@ -1591,10 +1599,8 @@ void vfree(const void *addr)
>> 
>>  	if (!addr)
>>  		return;
>> -	if (unlikely(in_interrupt()))
>> -		__vfree_deferred(addr);
>> -	else
>> -		__vunmap(addr, 1);
>> +
>> +	__vfree(addr);
>>  }
>>  EXPORT_SYMBOL(vfree);
>> 
>> @@ -1709,7 +1715,7 @@ static void *__vmalloc_area_node(struct 
>> vm_struct *area, gfp_t gfp_mask,
>>  	warn_alloc(gfp_mask, NULL,
>>  			  "vmalloc: allocation failure, allocated %ld of %ld bytes",
>>  			  (area->nr_pages*PAGE_SIZE), area->size);
>> -	vfree(area->addr);
>> +	__vfree(area->addr);
> 
> This can't be an interrupt context for a several reasons. One of them
> is BUG_ON(in_interrupt()) in __get_vm_area_node()
> which is called right before __vmalloc_are_node().
> 
> So you can just do __vunmap(area->addr, 1); instead of __vfree().

Thanks, I missed that BUG_ON and could not prove, that we can call only
from a task context, thus decided not to make it strict.  Of course
simple __vunmap() is much better.  The other reason is that we call a
spin_lock without disabling the interrupts.  Now I see.

Andrew, may I resend just an updated version of this patch?

--
Roman

Patch
diff mbox series

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2cd24186ba84..dc6a62bca503 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1565,6 +1565,14 @@  void vfree_atomic(const void *addr)
 	__vfree_deferred(addr);
 }
 
+static void __vfree(const void *addr)
+{
+	if (unlikely(in_interrupt()))
+		__vfree_deferred(addr);
+	else
+		__vunmap(addr, 1);
+}
+
 /**
  *	vfree  -  release memory allocated by vmalloc()
  *	@addr:		memory base address
@@ -1591,10 +1599,8 @@  void vfree(const void *addr)
 
 	if (!addr)
 		return;
-	if (unlikely(in_interrupt()))
-		__vfree_deferred(addr);
-	else
-		__vunmap(addr, 1);
+
+	__vfree(addr);
 }
 EXPORT_SYMBOL(vfree);
 
@@ -1709,7 +1715,7 @@  static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 	warn_alloc(gfp_mask, NULL,
 			  "vmalloc: allocation failure, allocated %ld of %ld bytes",
 			  (area->nr_pages*PAGE_SIZE), area->size);
-	vfree(area->addr);
+	__vfree(area->addr);
 	return NULL;
 }