selftests/vm/pkeys: introduce a sub-page allocator

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

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Link: http://lkml.kernel.org/r/c4a82fa962ec71015b994fab1aaf83bdfd091553.1585646528.git.sandipan@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ram Pai 2020-06-04 16:52:39 -07:00 committed by Linus Torvalds
parent 4e06e718af
commit 6e2c2d0fb7
4 changed files with 37 additions and 0 deletions

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@ -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"

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@ -107,4 +107,29 @@ 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 */

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@ -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 */

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@ -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: