diff mbox series

[v12,21/22] selftests/vm: sub-page allocator

Message ID 1519264541-7621-22-git-send-email-linuxram@us.ibm.com (mailing list archive)
State Not Applicable
Headers show
Series selftests, powerpc, x86 : Memory Protection Keys | expand

Commit Message

Ram Pai Feb. 22, 2018, 1:55 a.m. UTC 
introduce a new allocator that allocates 4k hardware-pages to back
64k linux-page. This allocator is only applicable on powerpc.

cc: Dave Hansen <dave.hansen@intel.com>
cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 tools/testing/selftests/vm/protection_keys.c |   30 ++++++++++++++++++++++++++
 1 files changed, 30 insertions(+), 0 deletions(-)

Comments

Dave Hansen March 16, 2018, 10:33 p.m. UTC | #1 
On 02/21/2018 05:55 PM, Ram Pai wrote:
...
> @@ -888,6 +917,7 @@ void setup_hugetlbfs(void)
>  void *(*pkey_malloc[])(long size, int prot, u16 pkey) = {
>  
>  	malloc_pkey_with_mprotect,
> +	malloc_pkey_with_mprotect_subpage,
>  	malloc_pkey_anon_huge,
>  	malloc_pkey_hugetlb
>  /* can not do direct with the pkey_mprotect() API:


I think I'd rather have an #ifdef on the array entries than have the
malloc entry do nothing on x86.  Maybe have a ppc-specific section at
the end?
diff mbox series

Patch

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index 42c068a..1b06e59 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -766,6 +766,35 @@  void free_pkey_malloc(void *ptr)
 	return ptr;
 }
 
+void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
+{
+#ifdef __powerpc64__
+	void *ptr;
+	int ret;
+
+	dprintf1("doing %s(size=%ld, prot=0x%x, pkey=%d)\n", __func__,
+			size, prot, pkey);
+	pkey_assert(pkey < NR_PKEYS);
+	ptr = mmap(NULL, size, prot, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+	pkey_assert(ptr != (void *)-1);
+
+	ret = syscall(__NR_subpage_prot, ptr, size, NULL);
+	if (ret) {
+		perror("subpage_perm");
+		return PTR_ERR_ENOTSUP;
+	}
+
+	ret = mprotect_pkey((void *)ptr, PAGE_SIZE, prot, pkey);
+	pkey_assert(!ret);
+	record_pkey_malloc(ptr, size);
+
+	dprintf1("%s() for pkey %d @ %p\n", __func__, pkey, ptr);
+	return ptr;
+#else /*  __powerpc64__ */
+	return PTR_ERR_ENOTSUP;
+#endif /*  __powerpc64__ */
+}
+
 void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
 {
 	int ret;
@@ -888,6 +917,7 @@  void setup_hugetlbfs(void)
 void *(*pkey_malloc[])(long size, int prot, u16 pkey) = {
 
 	malloc_pkey_with_mprotect,
+	malloc_pkey_with_mprotect_subpage,
 	malloc_pkey_anon_huge,
 	malloc_pkey_hugetlb
 /* can not do direct with the pkey_mprotect() API: