[PATCH v18 20/24] selftests/vm/pkeys: Introduce a sub-page allocator

Sandipan Das
2020-01-30T06:38:16Z

This introduces a new allocator that allocates 4K hardware
pages to back 64K linux pages. This allocator is available
only on powerpc.

cc: Dave Hansen <dave.hansen@intel.com>
cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
tools/testing/selftests/vm/pkey-helpers.h | 6 +++++
tools/testing/selftests/vm/pkey-powerpc.h | 25 ++++++++++++++++++++
tools/testing/selftests/vm/pkey-x86.h | 5 ++++
tools/testing/selftests/vm/protection_keys.c | 1 +
4 files changed, 37 insertions(+)

diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h
index 59ccdff18214..622a85848f61 100644
--- a/tools/testing/selftests/vm/pkey-helpers.h
+++ b/tools/testing/selftests/vm/pkey-helpers.h
@@ -28,6 +28,9 @@
extern int dprint_in_signal;
extern char dprint_in_signal_buffer[DPRINT_IN_SIGNAL_BUF_SIZE];

+extern int test_nr;
+extern int iteration_nr;
+
#ifdef __GNUC__
__attribute__((format(printf, 1, 2)))
#endif
@@ -78,6 +81,9 @@ __attribute__((noinline)) int read_ptr(int *ptr);
void expected_pkey_fault(int pkey);
int sys_pkey_alloc(unsigned long flags, unsigned long init_val);
int sys_pkey_free(unsigned long pkey);
+int mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot,
+ unsigned long pkey);
+void record_pkey_malloc(void *ptr, long size, int prot);

#if defined(__i386__) || defined(__x86_64__) /* arch */
#include "pkey-x86.h"
diff --git a/tools/testing/selftests/vm/pkey-powerpc.h b/tools/testing/selftests/vm/pkey-powerpc.h
index 7d7c3ffafdd9..d31665c48f5e 100644
--- a/tools/testing/selftests/vm/pkey-powerpc.h
+++ b/tools/testing/selftests/vm/pkey-powerpc.h
@@ -106,4 +106,29 @@ void expect_fault_on_read_execonly_key(void *p1, int pkey)
/* 4-byte instructions * 16384 = 64K page */
#define __page_o_noops() asm(".rept 16384 ; nop; .endr")

+void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
+{
+ 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, prot);
+
+ dprintf1("%s() for pkey %d @ %p\n", __func__, pkey, ptr);
+ return ptr;
+}
+
#endif /* _PKEYS_POWERPC_H */
diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h
index 6421b846aa16..3be20f5d5275 100644
--- a/tools/testing/selftests/vm/pkey-x86.h
+++ b/tools/testing/selftests/vm/pkey-x86.h
@@ -173,4 +173,9 @@ void expect_fault_on_read_execonly_key(void *p1, int pkey)
expected_pkey_fault(pkey);
}

+void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
+{
+ return PTR_ERR_ENOTSUP;
+}
+
#endif /* _PKEYS_X86_H */
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index 8bb4de103874..d4952b57cc90 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -845,6 +845,7 @@ void *malloc_pkey_mmap_dax(long size, int prot, u16 pkey)
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:
--
2.17.1