[PATCH 1/1] alloc_tag: avoid execmem

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* [PATCH 1/1] alloc_tag: avoid execmem_vmap() when !MMU
@ 2024-10-28 20:29 Suren Baghdasaryan
  2024-10-29 17:09 ` Mike Rapoport
  0 siblings, 1 reply; 5+ messages in thread
From: Suren Baghdasaryan @ 2024-10-28 20:29 UTC (permalink / raw)
  To: akpm
  Cc: arnd, arnd, rppt, pasha.tatashin, mcgrof, song, mhiramat,
	linux-mm, linux-kernel, surenb, kernel test robot

With CONFIG_MMU=n __get_vm_area_node() is not available and memory for the
allocation tags cannot be populated as needed. For this case, populate the
required memory at initialization time.

Fixes: 57bc3834fb6f ("alloc_tag: populate memory for module tags as needed")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410250808.dQGyYjlk-lkp@intel.com/
Closes: https://lore.kernel.org/oe-lkp/202410251525.9f85854d-oliver.sang@intel.com
Closes: https://lore.kernel.org/oe-kbuild-all/202410261016.IO7C6Cml-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202410270919.LebQlmxD-lkp@intel.com/
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
 include/linux/execmem.h |  2 ++
 lib/alloc_tag.c         | 23 ++++++++++++++++++++++-
 mm/execmem.c            | 32 ++++++++++++++++----------------
 3 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/include/linux/execmem.h b/include/linux/execmem.h
index 5a5e2917f870..64130ae19690 100644
--- a/include/linux/execmem.h
+++ b/include/linux/execmem.h
@@ -139,6 +139,7 @@ void *execmem_alloc(enum execmem_type type, size_t size);
  */
 void execmem_free(void *ptr);
 
+#ifdef CONFIG_MMU
 /**
  * execmem_vmap - create virtual mapping for EXECMEM_MODULE_DATA memory
  * @size: size of the virtual mapping in bytes
@@ -148,6 +149,7 @@ void execmem_free(void *ptr);
  * Return: the area descriptor on success or %NULL on failure.
  */
 struct vm_struct *execmem_vmap(size_t size);
+#endif
 
 /**
  * execmem_update_copy - copy an update to executable memory
diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index c1ddac2d29f0..1c74942e6dfd 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -268,7 +268,6 @@ void __init alloc_tag_sec_init(void)
 #ifdef CONFIG_MODULES
 
 static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
-static struct vm_struct *vm_module_tags;
 /* A dummy object used to indicate an unloaded module */
 static struct module unloaded_mod;
 /* A dummy object used to indicate a module prepended area */
@@ -391,6 +390,9 @@ static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
 	return false;
 }
 
+#ifdef CONFIG_MMU
+static struct vm_struct *vm_module_tags;
+
 static int vm_module_tags_populate(void)
 {
 	unsigned long phys_size = vm_module_tags->nr_pages << PAGE_SHIFT;
@@ -417,6 +419,13 @@ static int vm_module_tags_populate(void)
 
 	return 0;
 }
+#else
+static int vm_module_tags_populate(void)
+{
+	/* Memory was already allocated */
+	return 0;
+}
+#endif
 
 static void *reserve_module_tags(struct module *mod, unsigned long size,
 				 unsigned int prepend, unsigned long align)
@@ -561,6 +570,7 @@ static void replace_module(struct module *mod, struct module *new_mod)
 
 static int __init alloc_mod_tags_mem(void)
 {
+#ifdef CONFIG_MMU
 	/* Map space to copy allocation tags */
 	vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
 	if (!vm_module_tags) {
@@ -578,6 +588,13 @@ static int __init alloc_mod_tags_mem(void)
 	}
 
 	module_tags.start_addr = (unsigned long)vm_module_tags->addr;
+#else
+	/* Allocate space to copy allocation tags */
+	module_tags.start_addr = (unsigned long)execmem_alloc(EXECMEM_MODULE_DATA,
+							      MODULE_ALLOC_TAG_VMAP_SIZE);
+	if (!module_tags.start_addr)
+		return -ENOMEM;
+#endif
 	module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
 	/* Ensure the base is alloc_tag aligned when required for indexing */
 	module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
@@ -587,6 +604,7 @@ static int __init alloc_mod_tags_mem(void)
 
 static void __init free_mod_tags_mem(void)
 {
+#ifdef CONFIG_MMU
 	int i;
 
 	module_tags.start_addr = 0;
@@ -594,6 +612,9 @@ static void __init free_mod_tags_mem(void)
 		__free_page(vm_module_tags->pages[i]);
 	kfree(vm_module_tags->pages);
 	free_vm_area(vm_module_tags);
+#else
+	execmem_free((void *)module_tags.start_addr);
+#endif
 }
 
 #else /* CONFIG_MODULES */
diff --git a/mm/execmem.c b/mm/execmem.c
index 5c0f9f2d6f83..317b6a8d35be 100644
--- a/mm/execmem.c
+++ b/mm/execmem.c
@@ -64,6 +64,22 @@ static void *execmem_vmalloc(struct execmem_range *range, size_t size,
 
 	return p;
 }
+
+struct vm_struct *execmem_vmap(size_t size)
+{
+	struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
+	struct vm_struct *area;
+
+	area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
+				  range->start, range->end, NUMA_NO_NODE,
+				  GFP_KERNEL, __builtin_return_address(0));
+	if (!area && range->fallback_start)
+		area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
+					  range->fallback_start, range->fallback_end,
+					  NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
+
+	return area;
+}
 #else
 static void *execmem_vmalloc(struct execmem_range *range, size_t size,
 			     pgprot_t pgprot, unsigned long vm_flags)
@@ -368,22 +384,6 @@ void execmem_free(void *ptr)
 		vfree(ptr);
 }
 
-struct vm_struct *execmem_vmap(size_t size)
-{
-	struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
-	struct vm_struct *area;
-
-	area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
-				  range->start, range->end, NUMA_NO_NODE,
-				  GFP_KERNEL, __builtin_return_address(0));
-	if (!area && range->fallback_start)
-		area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
-					  range->fallback_start, range->fallback_end,
-					  NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
-
-	return area;
-}
-
 void *execmem_update_copy(void *dst, const void *src, size_t size)
 {
 	return text_poke_copy(dst, src, size);

base-commit: 92409df3e00a17d6fd5bb27732fa186749725ed5
-- 
2.47.0.163.g1226f6d8fa-goog



^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/1] alloc_tag: avoid execmem_vmap() when !MMU
  2024-10-28 20:29 [PATCH 1/1] alloc_tag: avoid execmem_vmap() when !MMU Suren Baghdasaryan
@ 2024-10-29 17:09 ` Mike Rapoport
  2024-10-29 20:03   ` Suren Baghdasaryan
  0 siblings, 1 reply; 5+ messages in thread
From: Mike Rapoport @ 2024-10-29 17:09 UTC (permalink / raw)
  To: Suren Baghdasaryan
  Cc: akpm, arnd, arnd, pasha.tatashin, mcgrof, song, mhiramat,
	linux-mm, linux-kernel, kernel test robot

Hi Suren,

On Mon, Oct 28, 2024 at 01:29:35PM -0700, Suren Baghdasaryan wrote:
> With CONFIG_MMU=n __get_vm_area_node() is not available and memory for the
> allocation tags cannot be populated as needed. For this case, populate the
> required memory at initialization time.

Do we care that much to have alloc_tags on !MMU configs?

Your patch is great, but it would have been a lot easier to make
MEM_ALLOC_PROFILING depend on MMU.
 
> Fixes: 57bc3834fb6f ("alloc_tag: populate memory for module tags as needed")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202410250808.dQGyYjlk-lkp@intel.com/
> Closes: https://lore.kernel.org/oe-lkp/202410251525.9f85854d-oliver.sang@intel.com
> Closes: https://lore.kernel.org/oe-kbuild-all/202410261016.IO7C6Cml-lkp@intel.com/
> Closes: https://lore.kernel.org/oe-kbuild-all/202410270919.LebQlmxD-lkp@intel.com/
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> ---
>  include/linux/execmem.h |  2 ++
>  lib/alloc_tag.c         | 23 ++++++++++++++++++++++-
>  mm/execmem.c            | 32 ++++++++++++++++----------------
>  3 files changed, 40 insertions(+), 17 deletions(-)
> 
> diff --git a/include/linux/execmem.h b/include/linux/execmem.h
> index 5a5e2917f870..64130ae19690 100644
> --- a/include/linux/execmem.h
> +++ b/include/linux/execmem.h
> @@ -139,6 +139,7 @@ void *execmem_alloc(enum execmem_type type, size_t size);
>   */
>  void execmem_free(void *ptr);
>  
> +#ifdef CONFIG_MMU
>  /**
>   * execmem_vmap - create virtual mapping for EXECMEM_MODULE_DATA memory
>   * @size: size of the virtual mapping in bytes
> @@ -148,6 +149,7 @@ void execmem_free(void *ptr);
>   * Return: the area descriptor on success or %NULL on failure.
>   */
>  struct vm_struct *execmem_vmap(size_t size);
> +#endif
>  
>  /**
>   * execmem_update_copy - copy an update to executable memory
> diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> index c1ddac2d29f0..1c74942e6dfd 100644
> --- a/lib/alloc_tag.c
> +++ b/lib/alloc_tag.c
> @@ -268,7 +268,6 @@ void __init alloc_tag_sec_init(void)
>  #ifdef CONFIG_MODULES
>  
>  static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
> -static struct vm_struct *vm_module_tags;
>  /* A dummy object used to indicate an unloaded module */
>  static struct module unloaded_mod;
>  /* A dummy object used to indicate a module prepended area */
> @@ -391,6 +390,9 @@ static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
>  	return false;
>  }
>  
> +#ifdef CONFIG_MMU
> +static struct vm_struct *vm_module_tags;
> +
>  static int vm_module_tags_populate(void)
>  {
>  	unsigned long phys_size = vm_module_tags->nr_pages << PAGE_SHIFT;
> @@ -417,6 +419,13 @@ static int vm_module_tags_populate(void)
>  
>  	return 0;
>  }
> +#else
> +static int vm_module_tags_populate(void)
> +{
> +	/* Memory was already allocated */
> +	return 0;
> +}
> +#endif
>  
>  static void *reserve_module_tags(struct module *mod, unsigned long size,
>  				 unsigned int prepend, unsigned long align)
> @@ -561,6 +570,7 @@ static void replace_module(struct module *mod, struct module *new_mod)
>  
>  static int __init alloc_mod_tags_mem(void)
>  {
> +#ifdef CONFIG_MMU
>  	/* Map space to copy allocation tags */
>  	vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
>  	if (!vm_module_tags) {
> @@ -578,6 +588,13 @@ static int __init alloc_mod_tags_mem(void)
>  	}
>  
>  	module_tags.start_addr = (unsigned long)vm_module_tags->addr;
> +#else
> +	/* Allocate space to copy allocation tags */
> +	module_tags.start_addr = (unsigned long)execmem_alloc(EXECMEM_MODULE_DATA,
> +							      MODULE_ALLOC_TAG_VMAP_SIZE);
> +	if (!module_tags.start_addr)
> +		return -ENOMEM;
> +#endif
>  	module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
>  	/* Ensure the base is alloc_tag aligned when required for indexing */
>  	module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
> @@ -587,6 +604,7 @@ static int __init alloc_mod_tags_mem(void)
>  
>  static void __init free_mod_tags_mem(void)
>  {
> +#ifdef CONFIG_MMU
>  	int i;
>  
>  	module_tags.start_addr = 0;
> @@ -594,6 +612,9 @@ static void __init free_mod_tags_mem(void)
>  		__free_page(vm_module_tags->pages[i]);
>  	kfree(vm_module_tags->pages);
>  	free_vm_area(vm_module_tags);
> +#else
> +	execmem_free((void *)module_tags.start_addr);
> +#endif
>  }
>  
>  #else /* CONFIG_MODULES */
> diff --git a/mm/execmem.c b/mm/execmem.c
> index 5c0f9f2d6f83..317b6a8d35be 100644
> --- a/mm/execmem.c
> +++ b/mm/execmem.c
> @@ -64,6 +64,22 @@ static void *execmem_vmalloc(struct execmem_range *range, size_t size,
>  
>  	return p;
>  }
> +
> +struct vm_struct *execmem_vmap(size_t size)
> +{
> +	struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
> +	struct vm_struct *area;
> +
> +	area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> +				  range->start, range->end, NUMA_NO_NODE,
> +				  GFP_KERNEL, __builtin_return_address(0));
> +	if (!area && range->fallback_start)
> +		area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> +					  range->fallback_start, range->fallback_end,
> +					  NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
> +
> +	return area;
> +}
>  #else
>  static void *execmem_vmalloc(struct execmem_range *range, size_t size,
>  			     pgprot_t pgprot, unsigned long vm_flags)
> @@ -368,22 +384,6 @@ void execmem_free(void *ptr)
>  		vfree(ptr);
>  }
>  
> -struct vm_struct *execmem_vmap(size_t size)
> -{
> -	struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
> -	struct vm_struct *area;
> -
> -	area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> -				  range->start, range->end, NUMA_NO_NODE,
> -				  GFP_KERNEL, __builtin_return_address(0));
> -	if (!area && range->fallback_start)
> -		area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> -					  range->fallback_start, range->fallback_end,
> -					  NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
> -
> -	return area;
> -}
> -
>  void *execmem_update_copy(void *dst, const void *src, size_t size)
>  {
>  	return text_poke_copy(dst, src, size);
> 
> base-commit: 92409df3e00a17d6fd5bb27732fa186749725ed5
> -- 
> 2.47.0.163.g1226f6d8fa-goog
> 

-- 
Sincerely yours,
Mike.


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/1] alloc_tag: avoid execmem_vmap() when !MMU
  2024-10-29 17:09 ` Mike Rapoport
@ 2024-10-29 20:03   ` Suren Baghdasaryan
  2024-10-30 12:43     ` Mike Rapoport
  0 siblings, 1 reply; 5+ messages in thread
From: Suren Baghdasaryan @ 2024-10-29 20:03 UTC (permalink / raw)
  To: Mike Rapoport
  Cc: akpm, arnd, arnd, pasha.tatashin, mcgrof, song, mhiramat,
	linux-mm, linux-kernel, kernel test robot

On Tue, Oct 29, 2024 at 10:13 AM Mike Rapoport <rppt@kernel.org> wrote:
>
> Hi Suren,
>
> On Mon, Oct 28, 2024 at 01:29:35PM -0700, Suren Baghdasaryan wrote:
> > With CONFIG_MMU=n __get_vm_area_node() is not available and memory for the
> > allocation tags cannot be populated as needed. For this case, populate the
> > required memory at initialization time.
>
> Do we care that much to have alloc_tags on !MMU configs?
>
> Your patch is great, but it would have been a lot easier to make
> MEM_ALLOC_PROFILING depend on MMU.

I didn't want to prevent !MMU users from using allocation profiling
but I'm not aware of any current !MMU users. Therefore I have no
objections to making MEM_ALLOC_PROFILING dependent on MMU if we indeed
don't care about !MMU && MEM_ALLOC_PROFILING configuration.
I'll be posting v5 tomorrow with all these fixes, so please let me
know which way you prefer. Thanks!

>
> > Fixes: 57bc3834fb6f ("alloc_tag: populate memory for module tags as needed")
> > Reported-by: kernel test robot <lkp@intel.com>
> > Closes: https://lore.kernel.org/oe-kbuild-all/202410250808.dQGyYjlk-lkp@intel.com/
> > Closes: https://lore.kernel.org/oe-lkp/202410251525.9f85854d-oliver.sang@intel.com
> > Closes: https://lore.kernel.org/oe-kbuild-all/202410261016.IO7C6Cml-lkp@intel.com/
> > Closes: https://lore.kernel.org/oe-kbuild-all/202410270919.LebQlmxD-lkp@intel.com/
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
> > Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> > ---
> >  include/linux/execmem.h |  2 ++
> >  lib/alloc_tag.c         | 23 ++++++++++++++++++++++-
> >  mm/execmem.c            | 32 ++++++++++++++++----------------
> >  3 files changed, 40 insertions(+), 17 deletions(-)
> >
> > diff --git a/include/linux/execmem.h b/include/linux/execmem.h
> > index 5a5e2917f870..64130ae19690 100644
> > --- a/include/linux/execmem.h
> > +++ b/include/linux/execmem.h
> > @@ -139,6 +139,7 @@ void *execmem_alloc(enum execmem_type type, size_t size);
> >   */
> >  void execmem_free(void *ptr);
> >
> > +#ifdef CONFIG_MMU
> >  /**
> >   * execmem_vmap - create virtual mapping for EXECMEM_MODULE_DATA memory
> >   * @size: size of the virtual mapping in bytes
> > @@ -148,6 +149,7 @@ void execmem_free(void *ptr);
> >   * Return: the area descriptor on success or %NULL on failure.
> >   */
> >  struct vm_struct *execmem_vmap(size_t size);
> > +#endif
> >
> >  /**
> >   * execmem_update_copy - copy an update to executable memory
> > diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> > index c1ddac2d29f0..1c74942e6dfd 100644
> > --- a/lib/alloc_tag.c
> > +++ b/lib/alloc_tag.c
> > @@ -268,7 +268,6 @@ void __init alloc_tag_sec_init(void)
> >  #ifdef CONFIG_MODULES
> >
> >  static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
> > -static struct vm_struct *vm_module_tags;
> >  /* A dummy object used to indicate an unloaded module */
> >  static struct module unloaded_mod;
> >  /* A dummy object used to indicate a module prepended area */
> > @@ -391,6 +390,9 @@ static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
> >       return false;
> >  }
> >
> > +#ifdef CONFIG_MMU
> > +static struct vm_struct *vm_module_tags;
> > +
> >  static int vm_module_tags_populate(void)
> >  {
> >       unsigned long phys_size = vm_module_tags->nr_pages << PAGE_SHIFT;
> > @@ -417,6 +419,13 @@ static int vm_module_tags_populate(void)
> >
> >       return 0;
> >  }
> > +#else
> > +static int vm_module_tags_populate(void)
> > +{
> > +     /* Memory was already allocated */
> > +     return 0;
> > +}
> > +#endif
> >
> >  static void *reserve_module_tags(struct module *mod, unsigned long size,
> >                                unsigned int prepend, unsigned long align)
> > @@ -561,6 +570,7 @@ static void replace_module(struct module *mod, struct module *new_mod)
> >
> >  static int __init alloc_mod_tags_mem(void)
> >  {
> > +#ifdef CONFIG_MMU
> >       /* Map space to copy allocation tags */
> >       vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
> >       if (!vm_module_tags) {
> > @@ -578,6 +588,13 @@ static int __init alloc_mod_tags_mem(void)
> >       }
> >
> >       module_tags.start_addr = (unsigned long)vm_module_tags->addr;
> > +#else
> > +     /* Allocate space to copy allocation tags */
> > +     module_tags.start_addr = (unsigned long)execmem_alloc(EXECMEM_MODULE_DATA,
> > +                                                           MODULE_ALLOC_TAG_VMAP_SIZE);
> > +     if (!module_tags.start_addr)
> > +             return -ENOMEM;
> > +#endif
> >       module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
> >       /* Ensure the base is alloc_tag aligned when required for indexing */
> >       module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
> > @@ -587,6 +604,7 @@ static int __init alloc_mod_tags_mem(void)
> >
> >  static void __init free_mod_tags_mem(void)
> >  {
> > +#ifdef CONFIG_MMU
> >       int i;
> >
> >       module_tags.start_addr = 0;
> > @@ -594,6 +612,9 @@ static void __init free_mod_tags_mem(void)
> >               __free_page(vm_module_tags->pages[i]);
> >       kfree(vm_module_tags->pages);
> >       free_vm_area(vm_module_tags);
> > +#else
> > +     execmem_free((void *)module_tags.start_addr);
> > +#endif
> >  }
> >
> >  #else /* CONFIG_MODULES */
> > diff --git a/mm/execmem.c b/mm/execmem.c
> > index 5c0f9f2d6f83..317b6a8d35be 100644
> > --- a/mm/execmem.c
> > +++ b/mm/execmem.c
> > @@ -64,6 +64,22 @@ static void *execmem_vmalloc(struct execmem_range *range, size_t size,
> >
> >       return p;
> >  }
> > +
> > +struct vm_struct *execmem_vmap(size_t size)
> > +{
> > +     struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
> > +     struct vm_struct *area;
> > +
> > +     area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > +                               range->start, range->end, NUMA_NO_NODE,
> > +                               GFP_KERNEL, __builtin_return_address(0));
> > +     if (!area && range->fallback_start)
> > +             area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > +                                       range->fallback_start, range->fallback_end,
> > +                                       NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
> > +
> > +     return area;
> > +}
> >  #else
> >  static void *execmem_vmalloc(struct execmem_range *range, size_t size,
> >                            pgprot_t pgprot, unsigned long vm_flags)
> > @@ -368,22 +384,6 @@ void execmem_free(void *ptr)
> >               vfree(ptr);
> >  }
> >
> > -struct vm_struct *execmem_vmap(size_t size)
> > -{
> > -     struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
> > -     struct vm_struct *area;
> > -
> > -     area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > -                               range->start, range->end, NUMA_NO_NODE,
> > -                               GFP_KERNEL, __builtin_return_address(0));
> > -     if (!area && range->fallback_start)
> > -             area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > -                                       range->fallback_start, range->fallback_end,
> > -                                       NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
> > -
> > -     return area;
> > -}
> > -
> >  void *execmem_update_copy(void *dst, const void *src, size_t size)
> >  {
> >       return text_poke_copy(dst, src, size);
> >
> > base-commit: 92409df3e00a17d6fd5bb27732fa186749725ed5
> > --
> > 2.47.0.163.g1226f6d8fa-goog
> >
>
> --
> Sincerely yours,
> Mike.


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/1] alloc_tag: avoid execmem_vmap() when !MMU
  2024-10-29 20:03   ` Suren Baghdasaryan
@ 2024-10-30 12:43     ` Mike Rapoport
  2024-10-30 23:42       ` Suren Baghdasaryan
  0 siblings, 1 reply; 5+ messages in thread
From: Mike Rapoport @ 2024-10-30 12:43 UTC (permalink / raw)
  To: Suren Baghdasaryan
  Cc: akpm, arnd, arnd, pasha.tatashin, mcgrof, song, mhiramat,
	linux-mm, linux-kernel, kernel test robot

On Tue, Oct 29, 2024 at 01:03:51PM -0700, Suren Baghdasaryan wrote:
> On Tue, Oct 29, 2024 at 10:13 AM Mike Rapoport <rppt@kernel.org> wrote:
> >
> > Hi Suren,
> >
> > On Mon, Oct 28, 2024 at 01:29:35PM -0700, Suren Baghdasaryan wrote:
> > > With CONFIG_MMU=n __get_vm_area_node() is not available and memory for the
> > > allocation tags cannot be populated as needed. For this case, populate the
> > > required memory at initialization time.
> >
> > Do we care that much to have alloc_tags on !MMU configs?
> >
> > Your patch is great, but it would have been a lot easier to make
> > MEM_ALLOC_PROFILING depend on MMU.
> 
> I didn't want to prevent !MMU users from using allocation profiling
> but I'm not aware of any current !MMU users. Therefore I have no
> objections to making MEM_ALLOC_PROFILING dependent on MMU if we indeed
> don't care about !MMU && MEM_ALLOC_PROFILING configuration.
> I'll be posting v5 tomorrow with all these fixes, so please let me
> know which way you prefer. Thanks!
 
I think if nommu users would want that feature, we can add the ifdefery
later

> > > Fixes: 57bc3834fb6f ("alloc_tag: populate memory for module tags as needed")
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202410250808.dQGyYjlk-lkp@intel.com/
> > > Closes: https://lore.kernel.org/oe-lkp/202410251525.9f85854d-oliver.sang@intel.com
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202410261016.IO7C6Cml-lkp@intel.com/
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202410270919.LebQlmxD-lkp@intel.com/
> > > Cc: Arnd Bergmann <arnd@arndb.de>
> > > Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
> > > Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> > > ---
> > >  include/linux/execmem.h |  2 ++
> > >  lib/alloc_tag.c         | 23 ++++++++++++++++++++++-
> > >  mm/execmem.c            | 32 ++++++++++++++++----------------
> > >  3 files changed, 40 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/include/linux/execmem.h b/include/linux/execmem.h
> > > index 5a5e2917f870..64130ae19690 100644
> > > --- a/include/linux/execmem.h
> > > +++ b/include/linux/execmem.h
> > > @@ -139,6 +139,7 @@ void *execmem_alloc(enum execmem_type type, size_t size);
> > >   */
> > >  void execmem_free(void *ptr);
> > >
> > > +#ifdef CONFIG_MMU
> > >  /**
> > >   * execmem_vmap - create virtual mapping for EXECMEM_MODULE_DATA memory
> > >   * @size: size of the virtual mapping in bytes
> > > @@ -148,6 +149,7 @@ void execmem_free(void *ptr);
> > >   * Return: the area descriptor on success or %NULL on failure.
> > >   */
> > >  struct vm_struct *execmem_vmap(size_t size);
> > > +#endif
> > >
> > >  /**
> > >   * execmem_update_copy - copy an update to executable memory
> > > diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> > > index c1ddac2d29f0..1c74942e6dfd 100644
> > > --- a/lib/alloc_tag.c
> > > +++ b/lib/alloc_tag.c
> > > @@ -268,7 +268,6 @@ void __init alloc_tag_sec_init(void)
> > >  #ifdef CONFIG_MODULES
> > >
> > >  static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
> > > -static struct vm_struct *vm_module_tags;
> > >  /* A dummy object used to indicate an unloaded module */
> > >  static struct module unloaded_mod;
> > >  /* A dummy object used to indicate a module prepended area */
> > > @@ -391,6 +390,9 @@ static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
> > >       return false;
> > >  }
> > >
> > > +#ifdef CONFIG_MMU
> > > +static struct vm_struct *vm_module_tags;
> > > +
> > >  static int vm_module_tags_populate(void)
> > >  {
> > >       unsigned long phys_size = vm_module_tags->nr_pages << PAGE_SHIFT;
> > > @@ -417,6 +419,13 @@ static int vm_module_tags_populate(void)
> > >
> > >       return 0;
> > >  }
> > > +#else
> > > +static int vm_module_tags_populate(void)
> > > +{
> > > +     /* Memory was already allocated */
> > > +     return 0;
> > > +}
> > > +#endif
> > >
> > >  static void *reserve_module_tags(struct module *mod, unsigned long size,
> > >                                unsigned int prepend, unsigned long align)
> > > @@ -561,6 +570,7 @@ static void replace_module(struct module *mod, struct module *new_mod)
> > >
> > >  static int __init alloc_mod_tags_mem(void)
> > >  {
> > > +#ifdef CONFIG_MMU
> > >       /* Map space to copy allocation tags */
> > >       vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
> > >       if (!vm_module_tags) {
> > > @@ -578,6 +588,13 @@ static int __init alloc_mod_tags_mem(void)
> > >       }
> > >
> > >       module_tags.start_addr = (unsigned long)vm_module_tags->addr;
> > > +#else
> > > +     /* Allocate space to copy allocation tags */
> > > +     module_tags.start_addr = (unsigned long)execmem_alloc(EXECMEM_MODULE_DATA,
> > > +                                                           MODULE_ALLOC_TAG_VMAP_SIZE);
> > > +     if (!module_tags.start_addr)
> > > +             return -ENOMEM;
> > > +#endif
> > >       module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
> > >       /* Ensure the base is alloc_tag aligned when required for indexing */
> > >       module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
> > > @@ -587,6 +604,7 @@ static int __init alloc_mod_tags_mem(void)
> > >
> > >  static void __init free_mod_tags_mem(void)
> > >  {
> > > +#ifdef CONFIG_MMU
> > >       int i;
> > >
> > >       module_tags.start_addr = 0;
> > > @@ -594,6 +612,9 @@ static void __init free_mod_tags_mem(void)
> > >               __free_page(vm_module_tags->pages[i]);
> > >       kfree(vm_module_tags->pages);
> > >       free_vm_area(vm_module_tags);
> > > +#else
> > > +     execmem_free((void *)module_tags.start_addr);
> > > +#endif
> > >  }
> > >
> > >  #else /* CONFIG_MODULES */
> > > diff --git a/mm/execmem.c b/mm/execmem.c
> > > index 5c0f9f2d6f83..317b6a8d35be 100644
> > > --- a/mm/execmem.c
> > > +++ b/mm/execmem.c
> > > @@ -64,6 +64,22 @@ static void *execmem_vmalloc(struct execmem_range *range, size_t size,
> > >
> > >       return p;
> > >  }
> > > +
> > > +struct vm_struct *execmem_vmap(size_t size)
> > > +{
> > > +     struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
> > > +     struct vm_struct *area;
> > > +
> > > +     area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > > +                               range->start, range->end, NUMA_NO_NODE,
> > > +                               GFP_KERNEL, __builtin_return_address(0));
> > > +     if (!area && range->fallback_start)
> > > +             area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > > +                                       range->fallback_start, range->fallback_end,
> > > +                                       NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
> > > +
> > > +     return area;
> > > +}
> > >  #else
> > >  static void *execmem_vmalloc(struct execmem_range *range, size_t size,
> > >                            pgprot_t pgprot, unsigned long vm_flags)
> > > @@ -368,22 +384,6 @@ void execmem_free(void *ptr)
> > >               vfree(ptr);
> > >  }
> > >
> > > -struct vm_struct *execmem_vmap(size_t size)
> > > -{
> > > -     struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
> > > -     struct vm_struct *area;
> > > -
> > > -     area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > > -                               range->start, range->end, NUMA_NO_NODE,
> > > -                               GFP_KERNEL, __builtin_return_address(0));
> > > -     if (!area && range->fallback_start)
> > > -             area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > > -                                       range->fallback_start, range->fallback_end,
> > > -                                       NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
> > > -
> > > -     return area;
> > > -}
> > > -
> > >  void *execmem_update_copy(void *dst, const void *src, size_t size)
> > >  {
> > >       return text_poke_copy(dst, src, size);
> > >
> > > base-commit: 92409df3e00a17d6fd5bb27732fa186749725ed5
> > > --
> > > 2.47.0.163.g1226f6d8fa-goog
> > >
> >
> > --
> > Sincerely yours,
> > Mike.

-- 
Sincerely yours,
Mike.


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/1] alloc_tag: avoid execmem_vmap() when !MMU
  2024-10-30 12:43     ` Mike Rapoport
@ 2024-10-30 23:42       ` Suren Baghdasaryan
  0 siblings, 0 replies; 5+ messages in thread
From: Suren Baghdasaryan @ 2024-10-30 23:42 UTC (permalink / raw)
  To: Mike Rapoport
  Cc: akpm, arnd, arnd, pasha.tatashin, mcgrof, song, mhiramat,
	linux-mm, linux-kernel, kernel test robot

On Wed, Oct 30, 2024 at 5:46 AM Mike Rapoport <rppt@kernel.org> wrote:
>
> On Tue, Oct 29, 2024 at 01:03:51PM -0700, Suren Baghdasaryan wrote:
> > On Tue, Oct 29, 2024 at 10:13 AM Mike Rapoport <rppt@kernel.org> wrote:
> > >
> > > Hi Suren,
> > >
> > > On Mon, Oct 28, 2024 at 01:29:35PM -0700, Suren Baghdasaryan wrote:
> > > > With CONFIG_MMU=n __get_vm_area_node() is not available and memory for the
> > > > allocation tags cannot be populated as needed. For this case, populate the
> > > > required memory at initialization time.
> > >
> > > Do we care that much to have alloc_tags on !MMU configs?
> > >
> > > Your patch is great, but it would have been a lot easier to make
> > > MEM_ALLOC_PROFILING depend on MMU.
> >
> > I didn't want to prevent !MMU users from using allocation profiling
> > but I'm not aware of any current !MMU users. Therefore I have no
> > objections to making MEM_ALLOC_PROFILING dependent on MMU if we indeed
> > don't care about !MMU && MEM_ALLOC_PROFILING configuration.
> > I'll be posting v5 tomorrow with all these fixes, so please let me
> > know which way you prefer. Thanks!
>
> I think if nommu users would want that feature, we can add the ifdefery
> later

Sounds good. I'll add the dependency and simplify this fix in my next posting.
Thanks!

>
> > > > Fixes: 57bc3834fb6f ("alloc_tag: populate memory for module tags as needed")
> > > > Reported-by: kernel test robot <lkp@intel.com>
> > > > Closes: https://lore.kernel.org/oe-kbuild-all/202410250808.dQGyYjlk-lkp@intel.com/
> > > > Closes: https://lore.kernel.org/oe-lkp/202410251525.9f85854d-oliver.sang@intel.com
> > > > Closes: https://lore.kernel.org/oe-kbuild-all/202410261016.IO7C6Cml-lkp@intel.com/
> > > > Closes: https://lore.kernel.org/oe-kbuild-all/202410270919.LebQlmxD-lkp@intel.com/
> > > > Cc: Arnd Bergmann <arnd@arndb.de>
> > > > Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
> > > > Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> > > > ---
> > > >  include/linux/execmem.h |  2 ++
> > > >  lib/alloc_tag.c         | 23 ++++++++++++++++++++++-
> > > >  mm/execmem.c            | 32 ++++++++++++++++----------------
> > > >  3 files changed, 40 insertions(+), 17 deletions(-)
> > > >
> > > > diff --git a/include/linux/execmem.h b/include/linux/execmem.h
> > > > index 5a5e2917f870..64130ae19690 100644
> > > > --- a/include/linux/execmem.h
> > > > +++ b/include/linux/execmem.h
> > > > @@ -139,6 +139,7 @@ void *execmem_alloc(enum execmem_type type, size_t size);
> > > >   */
> > > >  void execmem_free(void *ptr);
> > > >
> > > > +#ifdef CONFIG_MMU
> > > >  /**
> > > >   * execmem_vmap - create virtual mapping for EXECMEM_MODULE_DATA memory
> > > >   * @size: size of the virtual mapping in bytes
> > > > @@ -148,6 +149,7 @@ void execmem_free(void *ptr);
> > > >   * Return: the area descriptor on success or %NULL on failure.
> > > >   */
> > > >  struct vm_struct *execmem_vmap(size_t size);
> > > > +#endif
> > > >
> > > >  /**
> > > >   * execmem_update_copy - copy an update to executable memory
> > > > diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> > > > index c1ddac2d29f0..1c74942e6dfd 100644
> > > > --- a/lib/alloc_tag.c
> > > > +++ b/lib/alloc_tag.c
> > > > @@ -268,7 +268,6 @@ void __init alloc_tag_sec_init(void)
> > > >  #ifdef CONFIG_MODULES
> > > >
> > > >  static struct maple_tree mod_area_mt = MTREE_INIT(mod_area_mt, MT_FLAGS_ALLOC_RANGE);
> > > > -static struct vm_struct *vm_module_tags;
> > > >  /* A dummy object used to indicate an unloaded module */
> > > >  static struct module unloaded_mod;
> > > >  /* A dummy object used to indicate a module prepended area */
> > > > @@ -391,6 +390,9 @@ static bool find_aligned_area(struct ma_state *mas, unsigned long section_size,
> > > >       return false;
> > > >  }
> > > >
> > > > +#ifdef CONFIG_MMU
> > > > +static struct vm_struct *vm_module_tags;
> > > > +
> > > >  static int vm_module_tags_populate(void)
> > > >  {
> > > >       unsigned long phys_size = vm_module_tags->nr_pages << PAGE_SHIFT;
> > > > @@ -417,6 +419,13 @@ static int vm_module_tags_populate(void)
> > > >
> > > >       return 0;
> > > >  }
> > > > +#else
> > > > +static int vm_module_tags_populate(void)
> > > > +{
> > > > +     /* Memory was already allocated */
> > > > +     return 0;
> > > > +}
> > > > +#endif
> > > >
> > > >  static void *reserve_module_tags(struct module *mod, unsigned long size,
> > > >                                unsigned int prepend, unsigned long align)
> > > > @@ -561,6 +570,7 @@ static void replace_module(struct module *mod, struct module *new_mod)
> > > >
> > > >  static int __init alloc_mod_tags_mem(void)
> > > >  {
> > > > +#ifdef CONFIG_MMU
> > > >       /* Map space to copy allocation tags */
> > > >       vm_module_tags = execmem_vmap(MODULE_ALLOC_TAG_VMAP_SIZE);
> > > >       if (!vm_module_tags) {
> > > > @@ -578,6 +588,13 @@ static int __init alloc_mod_tags_mem(void)
> > > >       }
> > > >
> > > >       module_tags.start_addr = (unsigned long)vm_module_tags->addr;
> > > > +#else
> > > > +     /* Allocate space to copy allocation tags */
> > > > +     module_tags.start_addr = (unsigned long)execmem_alloc(EXECMEM_MODULE_DATA,
> > > > +                                                           MODULE_ALLOC_TAG_VMAP_SIZE);
> > > > +     if (!module_tags.start_addr)
> > > > +             return -ENOMEM;
> > > > +#endif
> > > >       module_tags.end_addr = module_tags.start_addr + MODULE_ALLOC_TAG_VMAP_SIZE;
> > > >       /* Ensure the base is alloc_tag aligned when required for indexing */
> > > >       module_tags.start_addr = alloc_tag_align(module_tags.start_addr);
> > > > @@ -587,6 +604,7 @@ static int __init alloc_mod_tags_mem(void)
> > > >
> > > >  static void __init free_mod_tags_mem(void)
> > > >  {
> > > > +#ifdef CONFIG_MMU
> > > >       int i;
> > > >
> > > >       module_tags.start_addr = 0;
> > > > @@ -594,6 +612,9 @@ static void __init free_mod_tags_mem(void)
> > > >               __free_page(vm_module_tags->pages[i]);
> > > >       kfree(vm_module_tags->pages);
> > > >       free_vm_area(vm_module_tags);
> > > > +#else
> > > > +     execmem_free((void *)module_tags.start_addr);
> > > > +#endif
> > > >  }
> > > >
> > > >  #else /* CONFIG_MODULES */
> > > > diff --git a/mm/execmem.c b/mm/execmem.c
> > > > index 5c0f9f2d6f83..317b6a8d35be 100644
> > > > --- a/mm/execmem.c
> > > > +++ b/mm/execmem.c
> > > > @@ -64,6 +64,22 @@ static void *execmem_vmalloc(struct execmem_range *range, size_t size,
> > > >
> > > >       return p;
> > > >  }
> > > > +
> > > > +struct vm_struct *execmem_vmap(size_t size)
> > > > +{
> > > > +     struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
> > > > +     struct vm_struct *area;
> > > > +
> > > > +     area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > > > +                               range->start, range->end, NUMA_NO_NODE,
> > > > +                               GFP_KERNEL, __builtin_return_address(0));
> > > > +     if (!area && range->fallback_start)
> > > > +             area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > > > +                                       range->fallback_start, range->fallback_end,
> > > > +                                       NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
> > > > +
> > > > +     return area;
> > > > +}
> > > >  #else
> > > >  static void *execmem_vmalloc(struct execmem_range *range, size_t size,
> > > >                            pgprot_t pgprot, unsigned long vm_flags)
> > > > @@ -368,22 +384,6 @@ void execmem_free(void *ptr)
> > > >               vfree(ptr);
> > > >  }
> > > >
> > > > -struct vm_struct *execmem_vmap(size_t size)
> > > > -{
> > > > -     struct execmem_range *range = &execmem_info->ranges[EXECMEM_MODULE_DATA];
> > > > -     struct vm_struct *area;
> > > > -
> > > > -     area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > > > -                               range->start, range->end, NUMA_NO_NODE,
> > > > -                               GFP_KERNEL, __builtin_return_address(0));
> > > > -     if (!area && range->fallback_start)
> > > > -             area = __get_vm_area_node(size, range->alignment, PAGE_SHIFT, VM_ALLOC,
> > > > -                                       range->fallback_start, range->fallback_end,
> > > > -                                       NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0));
> > > > -
> > > > -     return area;
> > > > -}
> > > > -
> > > >  void *execmem_update_copy(void *dst, const void *src, size_t size)
> > > >  {
> > > >       return text_poke_copy(dst, src, size);
> > > >
> > > > base-commit: 92409df3e00a17d6fd5bb27732fa186749725ed5
> > > > --
> > > > 2.47.0.163.g1226f6d8fa-goog
> > > >
> > >
> > > --
> > > Sincerely yours,
> > > Mike.
>
> --
> Sincerely yours,
> Mike.


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2024-10-30 23:42 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-10-28 20:29 [PATCH 1/1] alloc_tag: avoid execmem_vmap() when !MMU Suren Baghdasaryan
2024-10-29 17:09 ` Mike Rapoport
2024-10-29 20:03   ` Suren Baghdasaryan
2024-10-30 12:43     ` Mike Rapoport
2024-10-30 23:42       ` Suren Baghdasaryan

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