diff mbox series

[v6,2/6] x86/mce: relocate set{clear}_mce_nospec() functions

Message ID 20220319062833.3136528-3-jane.chu@oracle.com (mailing list archive)
State New, archived
Headers show
Series DAX poison recovery | expand

Commit Message

Jane Chu March 19, 2022, 6:28 a.m. UTC 
Relocate the twin mce functions to arch/x86/mm/pat/set_memory.c
file where they belong.

Signed-off-by: Jane Chu <jane.chu@oracle.com>
---
 arch/x86/include/asm/set_memory.h | 52 -------------------------------
 arch/x86/mm/pat/set_memory.c      | 48 ++++++++++++++++++++++++++++
 include/linux/set_memory.h        |  9 +++---
 3 files changed, 53 insertions(+), 56 deletions(-)

Comments

kernel test robot March 19, 2022, 8:13 a.m. UTC | #1 
Hi Jane,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on nvdimm/libnvdimm-for-next]
[also build test WARNING on device-mapper-dm/for-next linus/master v5.17-rc8 next-20220318]
[cannot apply to tip/x86/mm]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jane-Chu/DAX-poison-recovery/20220319-143144
base:   https://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm.git libnvdimm-for-next
config: x86_64-randconfig-a015 (https://download.01.org/0day-ci/archive/20220319/202203191637.PK2oJUeq-lkp@intel.com/config)
compiler: gcc-9 (Ubuntu 9.4.0-1ubuntu1~20.04) 9.4.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/71b9b09529b207ce15667c1f5fba4b727b6754e6
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jane-Chu/DAX-poison-recovery/20220319-143144
        git checkout 71b9b09529b207ce15667c1f5fba4b727b6754e6
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/mm/pat/ fs/fuse/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> arch/x86/mm/pat/set_memory.c:1935:5: warning: no previous prototype for 'set_mce_nospec' [-Wmissing-prototypes]
    1935 | int set_mce_nospec(unsigned long pfn, bool unmap)
         |     ^~~~~~~~~~~~~~
>> arch/x86/mm/pat/set_memory.c:1968:5: warning: no previous prototype for 'clear_mce_nospec' [-Wmissing-prototypes]
    1968 | int clear_mce_nospec(unsigned long pfn)
         |     ^~~~~~~~~~~~~~~~


vim +/set_mce_nospec +1935 arch/x86/mm/pat/set_memory.c

  1927	
  1928	#ifdef CONFIG_X86_64
  1929	/*
  1930	 * Prevent speculative access to the page by either unmapping
  1931	 * it (if we do not require access to any part of the page) or
  1932	 * marking it uncacheable (if we want to try to retrieve data
  1933	 * from non-poisoned lines in the page).
  1934	 */
> 1935	int set_mce_nospec(unsigned long pfn, bool unmap)
  1936	{
  1937		unsigned long decoy_addr;
  1938		int rc;
  1939	
  1940		/* SGX pages are not in the 1:1 map */
  1941		if (arch_is_platform_page(pfn << PAGE_SHIFT))
  1942			return 0;
  1943		/*
  1944		 * We would like to just call:
  1945		 *      set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);
  1946		 * but doing that would radically increase the odds of a
  1947		 * speculative access to the poison page because we'd have
  1948		 * the virtual address of the kernel 1:1 mapping sitting
  1949		 * around in registers.
  1950		 * Instead we get tricky.  We create a non-canonical address
  1951		 * that looks just like the one we want, but has bit 63 flipped.
  1952		 * This relies on set_memory_XX() properly sanitizing any __pa()
  1953		 * results with __PHYSICAL_MASK or PTE_PFN_MASK.
  1954		 */
  1955		decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
  1956	
  1957		if (unmap)
  1958			rc = set_memory_np(decoy_addr, 1);
  1959		else
  1960			rc = set_memory_uc(decoy_addr, 1);
  1961		if (rc)
  1962			pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
  1963		return rc;
  1964	}
  1965	EXPORT_SYMBOL(set_mce_nospec);
  1966	
  1967	/* Restore full speculative operation to the pfn. */
> 1968	int clear_mce_nospec(unsigned long pfn)
  1969	{
  1970		return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
  1971	}
  1972	EXPORT_SYMBOL(clear_mce_nospec);
  1973	

---
0-DAY CI Kernel Test Service
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
kernel test robot March 19, 2022, 8:24 a.m. UTC | #2 
Hi Jane,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on nvdimm/libnvdimm-for-next]
[also build test WARNING on device-mapper-dm/for-next linus/master v5.17-rc8 next-20220318]
[cannot apply to tip/x86/mm]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jane-Chu/DAX-poison-recovery/20220319-143144
base:   https://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm.git libnvdimm-for-next
config: x86_64-randconfig-a012 (https://download.01.org/0day-ci/archive/20220319/202203191603.mQUQZZV5-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a6e70e4056dff962ec634c5bd4f2f4105a0bef71)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/71b9b09529b207ce15667c1f5fba4b727b6754e6
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jane-Chu/DAX-poison-recovery/20220319-143144
        git checkout 71b9b09529b207ce15667c1f5fba4b727b6754e6
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/mm/pat/ fs/fuse/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> arch/x86/mm/pat/set_memory.c:1935:5: warning: no previous prototype for function 'set_mce_nospec' [-Wmissing-prototypes]
   int set_mce_nospec(unsigned long pfn, bool unmap)
       ^
   arch/x86/mm/pat/set_memory.c:1935:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int set_mce_nospec(unsigned long pfn, bool unmap)
   ^
   static 
>> arch/x86/mm/pat/set_memory.c:1968:5: warning: no previous prototype for function 'clear_mce_nospec' [-Wmissing-prototypes]
   int clear_mce_nospec(unsigned long pfn)
       ^
   arch/x86/mm/pat/set_memory.c:1968:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int clear_mce_nospec(unsigned long pfn)
   ^
   static 
   2 warnings generated.


vim +/set_mce_nospec +1935 arch/x86/mm/pat/set_memory.c

  1927	
  1928	#ifdef CONFIG_X86_64
  1929	/*
  1930	 * Prevent speculative access to the page by either unmapping
  1931	 * it (if we do not require access to any part of the page) or
  1932	 * marking it uncacheable (if we want to try to retrieve data
  1933	 * from non-poisoned lines in the page).
  1934	 */
> 1935	int set_mce_nospec(unsigned long pfn, bool unmap)
  1936	{
  1937		unsigned long decoy_addr;
  1938		int rc;
  1939	
  1940		/* SGX pages are not in the 1:1 map */
  1941		if (arch_is_platform_page(pfn << PAGE_SHIFT))
  1942			return 0;
  1943		/*
  1944		 * We would like to just call:
  1945		 *      set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);
  1946		 * but doing that would radically increase the odds of a
  1947		 * speculative access to the poison page because we'd have
  1948		 * the virtual address of the kernel 1:1 mapping sitting
  1949		 * around in registers.
  1950		 * Instead we get tricky.  We create a non-canonical address
  1951		 * that looks just like the one we want, but has bit 63 flipped.
  1952		 * This relies on set_memory_XX() properly sanitizing any __pa()
  1953		 * results with __PHYSICAL_MASK or PTE_PFN_MASK.
  1954		 */
  1955		decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
  1956	
  1957		if (unmap)
  1958			rc = set_memory_np(decoy_addr, 1);
  1959		else
  1960			rc = set_memory_uc(decoy_addr, 1);
  1961		if (rc)
  1962			pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
  1963		return rc;
  1964	}
  1965	EXPORT_SYMBOL(set_mce_nospec);
  1966	
  1967	/* Restore full speculative operation to the pfn. */
> 1968	int clear_mce_nospec(unsigned long pfn)
  1969	{
  1970		return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
  1971	}
  1972	EXPORT_SYMBOL(clear_mce_nospec);
  1973	

---
0-DAY CI Kernel Test Service
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Christoph Hellwig March 22, 2022, 8:42 a.m. UTC | #3 
> +EXPORT_SYMBOL(set_mce_nospec);

No need for this export at all.

> +
> +/* Restore full speculative operation to the pfn. */
> +int clear_mce_nospec(unsigned long pfn)
> +{
> +	return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
> +}
> +EXPORT_SYMBOL(clear_mce_nospec);

And this should be EXPORT_SYMBOL_GPL.
Jane Chu March 22, 2022, 10:19 p.m. UTC | #4 
On 3/22/2022 1:42 AM, Christoph Hellwig wrote:
>> +EXPORT_SYMBOL(set_mce_nospec);
> 
> No need for this export at all.

Indeed, my bad, will remove it.

> 
>> +
>> +/* Restore full speculative operation to the pfn. */
>> +int clear_mce_nospec(unsigned long pfn)
>> +{
>> +	return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
>> +}
>> +EXPORT_SYMBOL(clear_mce_nospec);
> 
> And this should be EXPORT_SYMBOL_GPL.

Yes.

Thanks!
-jane
Borislav Petkov March 22, 2022, 10:41 p.m. UTC | #5 
On Sat, Mar 19, 2022 at 12:28:29AM -0600, Jane Chu wrote:
> Relocate the twin mce functions to arch/x86/mm/pat/set_memory.c
> file where they belong.
> 
> Signed-off-by: Jane Chu <jane.chu@oracle.com>
> ---
>  arch/x86/include/asm/set_memory.h | 52 -------------------------------
>  arch/x86/mm/pat/set_memory.c      | 48 ++++++++++++++++++++++++++++
>  include/linux/set_memory.h        |  9 +++---
>  3 files changed, 53 insertions(+), 56 deletions(-)

For the future, please use get_maintainers.pl so that you know who to Cc
on patches. In this particular case, patches touching arch/x86/ should
Cc x86@kernel.org

Thx.
Jane Chu March 22, 2022, 11:48 p.m. UTC | #6 
On 3/22/2022 3:41 PM, Borislav Petkov wrote:
> On Sat, Mar 19, 2022 at 12:28:29AM -0600, Jane Chu wrote:
>> Relocate the twin mce functions to arch/x86/mm/pat/set_memory.c
>> file where they belong.
>>
>> Signed-off-by: Jane Chu <jane.chu@oracle.com>
>> ---
>>   arch/x86/include/asm/set_memory.h | 52 -------------------------------
>>   arch/x86/mm/pat/set_memory.c      | 48 ++++++++++++++++++++++++++++
>>   include/linux/set_memory.h        |  9 +++---
>>   3 files changed, 53 insertions(+), 56 deletions(-)
> 
> For the future, please use get_maintainers.pl so that you know who to Cc
> on patches. In this particular case, patches touching arch/x86/ should
> Cc x86@kernel.org

Sure, thank you!

-jane

> 
> Thx.
>
diff mbox series

Patch

diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index ff0f2d90338a..648be0bd20df 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -88,56 +88,4 @@  void notify_range_enc_status_changed(unsigned long vaddr, int npages, bool enc);
 
 extern int kernel_set_to_readonly;
 
-#ifdef CONFIG_X86_64
-/*
- * Prevent speculative access to the page by either unmapping
- * it (if we do not require access to any part of the page) or
- * marking it uncacheable (if we want to try to retrieve data
- * from non-poisoned lines in the page).
- */
-static inline int set_mce_nospec(unsigned long pfn, bool unmap)
-{
-	unsigned long decoy_addr;
-	int rc;
-
-	/* SGX pages are not in the 1:1 map */
-	if (arch_is_platform_page(pfn << PAGE_SHIFT))
-		return 0;
-	/*
-	 * We would like to just call:
-	 *      set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);
-	 * but doing that would radically increase the odds of a
-	 * speculative access to the poison page because we'd have
-	 * the virtual address of the kernel 1:1 mapping sitting
-	 * around in registers.
-	 * Instead we get tricky.  We create a non-canonical address
-	 * that looks just like the one we want, but has bit 63 flipped.
-	 * This relies on set_memory_XX() properly sanitizing any __pa()
-	 * results with __PHYSICAL_MASK or PTE_PFN_MASK.
-	 */
-	decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
-
-	if (unmap)
-		rc = set_memory_np(decoy_addr, 1);
-	else
-		rc = set_memory_uc(decoy_addr, 1);
-	if (rc)
-		pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
-	return rc;
-}
-#define set_mce_nospec set_mce_nospec
-
-/* Restore full speculative operation to the pfn. */
-static inline int clear_mce_nospec(unsigned long pfn)
-{
-	return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
-}
-#define clear_mce_nospec clear_mce_nospec
-#else
-/*
- * Few people would run a 32-bit kernel on a machine that supports
- * recoverable errors because they have too much memory to boot 32-bit.
- */
-#endif
-
 #endif /* _ASM_X86_SET_MEMORY_H */
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 042cfac6272b..9abc6077d768 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -1925,6 +1925,54 @@  int set_memory_wb(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL(set_memory_wb);
 
+#ifdef CONFIG_X86_64
+/*
+ * Prevent speculative access to the page by either unmapping
+ * it (if we do not require access to any part of the page) or
+ * marking it uncacheable (if we want to try to retrieve data
+ * from non-poisoned lines in the page).
+ */
+int set_mce_nospec(unsigned long pfn, bool unmap)
+{
+	unsigned long decoy_addr;
+	int rc;
+
+	/* SGX pages are not in the 1:1 map */
+	if (arch_is_platform_page(pfn << PAGE_SHIFT))
+		return 0;
+	/*
+	 * We would like to just call:
+	 *      set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1);
+	 * but doing that would radically increase the odds of a
+	 * speculative access to the poison page because we'd have
+	 * the virtual address of the kernel 1:1 mapping sitting
+	 * around in registers.
+	 * Instead we get tricky.  We create a non-canonical address
+	 * that looks just like the one we want, but has bit 63 flipped.
+	 * This relies on set_memory_XX() properly sanitizing any __pa()
+	 * results with __PHYSICAL_MASK or PTE_PFN_MASK.
+	 */
+	decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
+
+	if (unmap)
+		rc = set_memory_np(decoy_addr, 1);
+	else
+		rc = set_memory_uc(decoy_addr, 1);
+	if (rc)
+		pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
+	return rc;
+}
+EXPORT_SYMBOL(set_mce_nospec);
+
+/* Restore full speculative operation to the pfn. */
+int clear_mce_nospec(unsigned long pfn)
+{
+	return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
+}
+EXPORT_SYMBOL(clear_mce_nospec);
+
+#endif
+
 int set_memory_x(unsigned long addr, int numpages)
 {
 	if (!(__supported_pte_mask & _PAGE_NX))
diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
index f36be5166c19..d6263d7afb55 100644
--- a/include/linux/set_memory.h
+++ b/include/linux/set_memory.h
@@ -42,20 +42,21 @@  static inline bool can_set_direct_map(void)
 #endif
 #endif /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */
 
-#ifndef set_mce_nospec
+#ifdef CONFIG_X86_64
+int set_mce_nospec(unsigned long pfn, bool unmap);
+int clear_mce_nospec(unsigned long pfn);
+#else
 static inline int set_mce_nospec(unsigned long pfn, bool unmap)
 {
 	return 0;
 }
-#endif
-
-#ifndef clear_mce_nospec
 static inline int clear_mce_nospec(unsigned long pfn)
 {
 	return 0;
 }
 #endif
 
+
 #ifndef CONFIG_ARCH_HAS_MEM_ENCRYPT
 static inline int set_memory_encrypted(unsigned long addr, int numpages)
 {