remove various unused set_memory_* related functions and exports

remove various unused set_memory_* related functions and exports

[Christoph Hellwig]

Hi all,

while looking into implementing a DMA memory allocator for PCIe unsnooped
transactions I've started looking at the set_memory_* and related APIs,
and it turns out that many of them are unused.  Fix for that below.

[PATCH 1/6] arm64: unexport set_memory_x and set_memory_nx

[Christoph Hellwig]

No module currently messed with clearing or setting the execute
permission of kernel memory, and none really should.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm64/mm/pageattr.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 03c53f16ee77..9ce7bd9d4d9c 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -128,7 +128,6 @@ int set_memory_nx(unsigned long addr, int numpages)
 					__pgprot(PTE_PXN),
 					__pgprot(0));
 }
-EXPORT_SYMBOL_GPL(set_memory_nx);
 
 int set_memory_x(unsigned long addr, int numpages)
 {
@@ -136,7 +135,6 @@ int set_memory_x(unsigned long addr, int numpages)
 					__pgprot(0),
 					__pgprot(PTE_PXN));
 }
-EXPORT_SYMBOL_GPL(set_memory_x);
 
 int set_memory_valid(unsigned long addr, int numpages, int enable)
 {
-- 
2.20.1

Re: [PATCH 1/6] arm64: unexport set_memory_x and set_memory_nx

[Will Deacon]

On Tue, Aug 13, 2019 at 11:01:41AM +0200, Christoph Hellwig wrote:
> No module currently messed with clearing or setting the execute
> permission of kernel memory, and none really should.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/arm64/mm/pageattr.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
> index 03c53f16ee77..9ce7bd9d4d9c 100644
> --- a/arch/arm64/mm/pageattr.c
> +++ b/arch/arm64/mm/pageattr.c
> @@ -128,7 +128,6 @@ int set_memory_nx(unsigned long addr, int numpages)
>  					__pgprot(PTE_PXN),
>  					__pgprot(0));
>  }
> -EXPORT_SYMBOL_GPL(set_memory_nx);
>  
>  int set_memory_x(unsigned long addr, int numpages)
>  {
> @@ -136,7 +135,6 @@ int set_memory_x(unsigned long addr, int numpages)
>  					__pgprot(0),
>  					__pgprot(PTE_PXN));
>  }
> -EXPORT_SYMBOL_GPL(set_memory_x);

arm64 allmodconfig and defconfig are happy with this, so I'll pick it up
for 5.4 if that's ok with you?

Will

Re: [PATCH 1/6] arm64: unexport set_memory_x and set_memory_nx

[Christoph Hellwig]

On Wed, Aug 14, 2019 at 05:50:29PM +0100, Will Deacon wrote:
> arm64 allmodconfig and defconfig are happy with this, so I'll pick it up
> for 5.4 if that's ok with you?

Sounds great.

[PATCH 2/6] x86: unexport set_memory_x and set_memory_nx

[Christoph Hellwig]

No module currently messed with clearing or setting the execute
permission of kernel memory, and none really should.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/x86/mm/pageattr.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 6a9a77a403c9..a02ca8986299 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1967,7 +1967,6 @@ int set_memory_x(unsigned long addr, int numpages)
 
 	return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0);
 }
-EXPORT_SYMBOL(set_memory_x);
 
 int set_memory_nx(unsigned long addr, int numpages)
 {
@@ -1976,7 +1975,6 @@ int set_memory_nx(unsigned long addr, int numpages)
 
 	return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0);
 }
-EXPORT_SYMBOL(set_memory_nx);
 
 int set_memory_ro(unsigned long addr, int numpages)
 {
-- 
2.20.1

[PATCH 3/6] x86: remove the unused set_memory_array_* functions

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/x86/include/asm/set_memory.h |  5 ---
 arch/x86/mm/pageattr.c            | 75 -------------------------------
 2 files changed, 80 deletions(-)

diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index ae7b909dc242..899ec9ae7cff 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -48,11 +48,6 @@ int set_memory_encrypted(unsigned long addr, int numpages);
 int set_memory_decrypted(unsigned long addr, int numpages);
 int set_memory_np_noalias(unsigned long addr, int numpages);
 
-int set_memory_array_uc(unsigned long *addr, int addrinarray);
-int set_memory_array_wc(unsigned long *addr, int addrinarray);
-int set_memory_array_wt(unsigned long *addr, int addrinarray);
-int set_memory_array_wb(unsigned long *addr, int addrinarray);
-
 int set_pages_array_uc(struct page **pages, int addrinarray);
 int set_pages_array_wc(struct page **pages, int addrinarray);
 int set_pages_array_wt(struct page **pages, int addrinarray);
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index a02ca8986299..3be5d22c005a 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1809,63 +1809,6 @@ int set_memory_uc(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL(set_memory_uc);
 
-static int _set_memory_array(unsigned long *addr, int numpages,
-		enum page_cache_mode new_type)
-{
-	enum page_cache_mode set_type;
-	int i, j;
-	int ret;
-
-	for (i = 0; i < numpages; i++) {
-		ret = reserve_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE,
-					new_type, NULL);
-		if (ret)
-			goto out_free;
-	}
-
-	/* If WC, set to UC- first and then WC */
-	set_type = (new_type == _PAGE_CACHE_MODE_WC) ?
-				_PAGE_CACHE_MODE_UC_MINUS : new_type;
-
-	ret = change_page_attr_set(addr, numpages,
-				   cachemode2pgprot(set_type), 1);
-
-	if (!ret && new_type == _PAGE_CACHE_MODE_WC)
-		ret = change_page_attr_set_clr(addr, numpages,
-					       cachemode2pgprot(
-						_PAGE_CACHE_MODE_WC),
-					       __pgprot(_PAGE_CACHE_MASK),
-					       0, CPA_ARRAY, NULL);
-	if (ret)
-		goto out_free;
-
-	return 0;
-
-out_free:
-	for (j = 0; j < i; j++)
-		free_memtype(__pa(addr[j]), __pa(addr[j]) + PAGE_SIZE);
-
-	return ret;
-}
-
-int set_memory_array_uc(unsigned long *addr, int numpages)
-{
-	return _set_memory_array(addr, numpages, _PAGE_CACHE_MODE_UC_MINUS);
-}
-EXPORT_SYMBOL(set_memory_array_uc);
-
-int set_memory_array_wc(unsigned long *addr, int numpages)
-{
-	return _set_memory_array(addr, numpages, _PAGE_CACHE_MODE_WC);
-}
-EXPORT_SYMBOL(set_memory_array_wc);
-
-int set_memory_array_wt(unsigned long *addr, int numpages)
-{
-	return _set_memory_array(addr, numpages, _PAGE_CACHE_MODE_WT);
-}
-EXPORT_SYMBOL_GPL(set_memory_array_wt);
-
 int _set_memory_wc(unsigned long addr, int numpages)
 {
 	int ret;
@@ -1942,24 +1885,6 @@ int set_memory_wb(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL(set_memory_wb);
 
-int set_memory_array_wb(unsigned long *addr, int numpages)
-{
-	int i;
-	int ret;
-
-	/* WB cache mode is hard wired to all cache attribute bits being 0 */
-	ret = change_page_attr_clear(addr, numpages,
-				      __pgprot(_PAGE_CACHE_MASK), 1);
-	if (ret)
-		return ret;
-
-	for (i = 0; i < numpages; i++)
-		free_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE);
-
-	return 0;
-}
-EXPORT_SYMBOL(set_memory_array_wb);
-
 int set_memory_x(unsigned long addr, int numpages)
 {
 	if (!(__supported_pte_mask & _PAGE_NX))
-- 
2.20.1

[PATCH 4/6] x86: remove set_memory_x and set_memory_nx

[Christoph Hellwig]

These wrappers don't provide a real benefit over just using
set_memory_x and set_memory_nx.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/x86/include/asm/set_memory.h  |  2 --
 arch/x86/kernel/machine_kexec_32.c |  4 ++--
 arch/x86/mm/init_32.c              |  2 +-
 arch/x86/mm/pageattr.c             | 16 ----------------
 4 files changed, 3 insertions(+), 21 deletions(-)

diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 899ec9ae7cff..fd549c3ebb17 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -75,8 +75,6 @@ int set_pages_array_wb(struct page **pages, int addrinarray);
 
 int set_pages_uc(struct page *page, int numpages);
 int set_pages_wb(struct page *page, int numpages);
-int set_pages_x(struct page *page, int numpages);
-int set_pages_nx(struct page *page, int numpages);
 int set_pages_ro(struct page *page, int numpages);
 int set_pages_rw(struct page *page, int numpages);
 
diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c
index 77854b192fef..7b45e8daad22 100644
--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -148,7 +148,7 @@ int machine_kexec_prepare(struct kimage *image)
 {
 	int error;
 
-	set_pages_x(image->control_code_page, 1);
+	set_memory_x((unsigned long)page_address(image->control_code_page), 1);
 	error = machine_kexec_alloc_page_tables(image);
 	if (error)
 		return error;
@@ -162,7 +162,7 @@ int machine_kexec_prepare(struct kimage *image)
  */
 void machine_kexec_cleanup(struct kimage *image)
 {
-	set_pages_nx(image->control_code_page, 1);
+	set_memory_nx((unsigned long)page_address(image->control_code_page), 1);
 	machine_kexec_free_page_tables(image);
 }
 
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 4068abb9427f..930edeb41ec3 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -916,7 +916,7 @@ static void mark_nxdata_nx(void)
 
 	if (__supported_pte_mask & _PAGE_NX)
 		printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
-	set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT);
+	set_memory_nx(start, size >> PAGE_SHIFT);
 }
 
 void mark_rodata_ro(void)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 3be5d22c005a..0e39b344556d 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -2103,22 +2103,6 @@ int set_pages_array_wb(struct page **pages, int numpages)
 }
 EXPORT_SYMBOL(set_pages_array_wb);
 
-int set_pages_x(struct page *page, int numpages)
-{
-	unsigned long addr = (unsigned long)page_address(page);
-
-	return set_memory_x(addr, numpages);
-}
-EXPORT_SYMBOL(set_pages_x);
-
-int set_pages_nx(struct page *page, int numpages)
-{
-	unsigned long addr = (unsigned long)page_address(page);
-
-	return set_memory_nx(addr, numpages);
-}
-EXPORT_SYMBOL(set_pages_nx);
-
 int set_pages_ro(struct page *page, int numpages)
 {
 	unsigned long addr = (unsigned long)page_address(page);
-- 
2.20.1

Re: [PATCH 4/6] x86: remove set_memory_x and set_memory_nx

[Peter Zijlstra]

On Tue, Aug 13, 2019 at 11:01:44AM +0200, Christoph Hellwig wrote:
> These wrappers don't provide a real benefit over just using
> set_memory_x and set_memory_nx.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/x86/include/asm/set_memory.h  |  2 --
>  arch/x86/kernel/machine_kexec_32.c |  4 ++--
>  arch/x86/mm/init_32.c              |  2 +-
>  arch/x86/mm/pageattr.c             | 16 ----------------
>  4 files changed, 3 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
> index 899ec9ae7cff..fd549c3ebb17 100644
> --- a/arch/x86/include/asm/set_memory.h
> +++ b/arch/x86/include/asm/set_memory.h
> @@ -75,8 +75,6 @@ int set_pages_array_wb(struct page **pages, int addrinarray);
>  
>  int set_pages_uc(struct page *page, int numpages);
>  int set_pages_wb(struct page *page, int numpages);
> -int set_pages_x(struct page *page, int numpages);
> -int set_pages_nx(struct page *page, int numpages);
>  int set_pages_ro(struct page *page, int numpages);
>  int set_pages_rw(struct page *page, int numpages);

$Subject and patch content don't match up.

Other than that,

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

for all x86 patches.

[PATCH 5/6] x86: remove the unused set_memory_wt function

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/x86/include/asm/set_memory.h |  1 -
 arch/x86/mm/pageattr.c            | 17 -----------------
 2 files changed, 18 deletions(-)

diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index fd549c3ebb17..2ee8e469dcf5 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -40,7 +40,6 @@ int _set_memory_wt(unsigned long addr, int numpages);
 int _set_memory_wb(unsigned long addr, int numpages);
 int set_memory_uc(unsigned long addr, int numpages);
 int set_memory_wc(unsigned long addr, int numpages);
-int set_memory_wt(unsigned long addr, int numpages);
 int set_memory_wb(unsigned long addr, int numpages);
 int set_memory_np(unsigned long addr, int numpages);
 int set_memory_4k(unsigned long addr, int numpages);
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 0e39b344556d..9acd568c4faa 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1848,23 +1848,6 @@ int _set_memory_wt(unsigned long addr, int numpages)
 				    cachemode2pgprot(_PAGE_CACHE_MODE_WT), 0);
 }
 
-int set_memory_wt(unsigned long addr, int numpages)
-{
-	int ret;
-
-	ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
-			      _PAGE_CACHE_MODE_WT, NULL);
-	if (ret)
-		return ret;
-
-	ret = _set_memory_wt(addr, numpages);
-	if (ret)
-		free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(set_memory_wt);
-
 int _set_memory_wb(unsigned long addr, int numpages)
 {
 	/* WB cache mode is hard wired to all cache attribute bits being 0 */
-- 
2.20.1

[PATCH 6/6] x86: remove the unused set_pages_array_wt function

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/x86/include/asm/set_memory.h | 1 -
 arch/x86/mm/pageattr.c            | 6 ------
 2 files changed, 7 deletions(-)

diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 2ee8e469dcf5..cff5e07c1e19 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -49,7 +49,6 @@ int set_memory_np_noalias(unsigned long addr, int numpages);
 
 int set_pages_array_uc(struct page **pages, int addrinarray);
 int set_pages_array_wc(struct page **pages, int addrinarray);
-int set_pages_array_wt(struct page **pages, int addrinarray);
 int set_pages_array_wb(struct page **pages, int addrinarray);
 
 /*
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 9acd568c4faa..255c90d6aaa7 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -2047,12 +2047,6 @@ int set_pages_array_wc(struct page **pages, int numpages)
 }
 EXPORT_SYMBOL(set_pages_array_wc);
 
-int set_pages_array_wt(struct page **pages, int numpages)
-{
-	return _set_pages_array(pages, numpages, _PAGE_CACHE_MODE_WT);
-}
-EXPORT_SYMBOL_GPL(set_pages_array_wt);
-
 int set_pages_wb(struct page *page, int numpages)
 {
 	unsigned long addr = (unsigned long)page_address(page);
-- 
2.20.1