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selftests: mm: hugepage-vmemmap fails on 64K page size systems

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The kernel sefltest mm/hugepage-vmemmap fails on architectures which has
different page size other than 4K.  In hugepage-vmemmap page size used is
4k so the pfn calculation will go wrong on systems which has different
page size .The length of MAP_HUGETLB memory must be hugepage aligned but
in hugepage-vmemmap map length is 2M so this will not get aligned if the
system has differnet hugepage size.

Added  psize() to get the page size and default_huge_page_size() to
get the default hugepage size at run time, hugepage-vmemmap test pass
on powerpc with 64K page size and x86 with 4K page size.

Result on powerpc without patch (page size 64K)
*# ./hugepage-vmemmap
Returned address is 0x7effff000000 whose pfn is 0
Head page flags (100000000) is invalid
check_page_flags: Invalid argument
*#

Result on powerpc with patch (page size 64K)
*# ./hugepage-vmemmap
Returned address is 0x7effff000000 whose pfn is 600
*#

Result on x86 with patch (page size 4K)
*# ./hugepage-vmemmap
Returned address is 0x7fc7c2c00000 whose pfn is 1dac00
*#

Link: https://lkml.kernel.org/r/3b3a3ae37ba21218481c482a872bbf7526031600.1704865754.git.donettom@linux.vnet.ibm.com
Fixes: b147c89cd4 ("selftests: vm: add a hugetlb test case")
Signed-off-by: Donet Tom <donettom@linux.vnet.ibm.com>
Reported-by: Geetika Moolchandani <geetika@linux.ibm.com>
Tested-by: Geetika Moolchandani <geetika@linux.ibm.com>
Acked-by: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Donet Tom 2024-01-10 14:03:35 +05:30 committed by Andrew Morton
parent 1168413414
commit 00bcfcd47a
1 changed files with 18 additions and 11 deletions
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29
tools/testing/selftests/mm/hugepage-vmemmap.c
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@ -10,10 +10,7 @@
#include <unistd.h>
#include <sys/mman.h>
#include <fcntl.h>
#define MAP_LENGTH (2UL * 1024 * 1024)
#define PAGE_SIZE 4096
#include "vm_util.h"
#define PAGE_COMPOUND_HEAD (1UL << 15)
#define PAGE_COMPOUND_TAIL (1UL << 16)
@ -39,6 +36,9 @@
#define MAP_FLAGS (MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB)
#endif
static size_t pagesize;
static size_t maplength;
static void write_bytes(char *addr, size_t length)
{
unsigned long i;
@ -56,7 +56,7 @@ static unsigned long virt_to_pfn(void *addr)
if (fd < 0)
return -1UL;
lseek(fd, (unsigned long)addr / PAGE_SIZE * sizeof(pagemap), SEEK_SET);
lseek(fd, (unsigned long)addr / pagesize * sizeof(pagemap), SEEK_SET);
read(fd, &pagemap, sizeof(pagemap));
close(fd);
@ -86,7 +86,7 @@ static int check_page_flags(unsigned long pfn)
* this also verifies kernel has correctly set the fake page_head to tail
* while hugetlb_free_vmemmap is enabled.
*/
for (i = 1; i < MAP_LENGTH / PAGE_SIZE; i++) {
for (i = 1; i < maplength / pagesize; i++) {
read(fd, &pageflags, sizeof(pageflags));
if ((pageflags & TAIL_PAGE_FLAGS) != TAIL_PAGE_FLAGS ||
(pageflags & HEAD_PAGE_FLAGS) == HEAD_PAGE_FLAGS) {
@ -106,18 +106,25 @@ int main(int argc, char **argv)
void *addr;
unsigned long pfn;
addr = mmap(MAP_ADDR, MAP_LENGTH, PROT_READ | PROT_WRITE, MAP_FLAGS, -1, 0);
pagesize = psize();
maplength = default_huge_page_size();
if (!maplength) {
printf("Unable to determine huge page size\n");
exit(1);
}
addr = mmap(MAP_ADDR, maplength, PROT_READ | PROT_WRITE, MAP_FLAGS, -1, 0);
if (addr == MAP_FAILED) {
perror("mmap");
exit(1);
}
/* Trigger allocation of HugeTLB page. */
write_bytes(addr, MAP_LENGTH);
write_bytes(addr, maplength);
pfn = virt_to_pfn(addr);
if (pfn == -1UL) {
munmap(addr, MAP_LENGTH);
munmap(addr, maplength);
perror("virt_to_pfn");
exit(1);
}
@ -125,13 +132,13 @@ int main(int argc, char **argv)
printf("Returned address is %p whose pfn is %lx\n", addr, pfn);
if (check_page_flags(pfn) < 0) {
munmap(addr, MAP_LENGTH);
munmap(addr, maplength);
perror("check_page_flags");
exit(1);
}
/* munmap() length of MAP_HUGETLB memory must be hugepage aligned */
if (munmap(addr, MAP_LENGTH)) {
if (munmap(addr, maplength)) {
perror("munmap");
exit(1);
}