On the latest RHEL the test fails due to executable mapped at 256MB address

# ./map_fixed_noreplace mmap() @ 0x10000000-0x10050000 p=0xffffffffffffffff result=File exists 10000000-10010000 r-xp 00000000 fd:04 34905657 /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace 10010000-10020000 r--p 00000000 fd:04 34905657 /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace 10020000-10030000 rw-p 00010000 fd:04 34905657 /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace 10029b90000-10029bc0000 rw-p 00000000 00:00 0 [heap] 7fffbb510000-7fffbb750000 r-xp 00000000 fd:04 24534 /usr/lib64/libc.so.6 7fffbb750000-7fffbb760000 r--p 00230000 fd:04 24534 /usr/lib64/libc.so.6 7fffbb760000-7fffbb770000 rw-p 00240000 fd:04 24534 /usr/lib64/libc.so.6 7fffbb780000-7fffbb7a0000 r--p 00000000 00:00 0 [vvar] 7fffbb7a0000-7fffbb7b0000 r-xp 00000000 00:00 0 [vdso] 7fffbb7b0000-7fffbb800000 r-xp 00000000 fd:04 24514 /usr/lib64/ld64.so.2 7fffbb800000-7fffbb810000 r--p 00040000 fd:04 24514 /usr/lib64/ld64.so.2 7fffbb810000-7fffbb820000 rw-p 00050000 fd:04 24514 /usr/lib64/ld64.so.2 7fffd93f0000-7fffd9420000 rw-p 00000000 00:00 0 [stack] Error: couldn't map the space we need for the test

Fix this by finding a free address using mmap instead of hardcoding BASE_ADDRESS.

Cc: Michael Ellerman mpe@ellerman.id.au Cc: Jann Horn jannh@google.com Cc: Shuah Khan shuah@kernel.org Cc: linux-kselftest@vger.kernel.org Signed-off-by: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com --- .../selftests/vm/map_fixed_noreplace.c | 49 ++++++++++++++----- 1 file changed, 37 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/vm/map_fixed_noreplace.c b/tools/testing/selftests/vm/map_fixed_noreplace.c index d91bde511268..eed44322d1a6 100644 --- a/tools/testing/selftests/vm/map_fixed_noreplace.c +++ b/tools/testing/selftests/vm/map_fixed_noreplace.c @@ -17,9 +17,6 @@ #define MAP_FIXED_NOREPLACE 0x100000 #endif

-#define BASE_ADDRESS (256ul * 1024 * 1024) - - static void dump_maps(void) { char cmd[32]; @@ -28,18 +25,46 @@ static void dump_maps(void) system(cmd); }

+static unsigned long find_base_addr(unsigned long size) +{ + void *addr; + unsigned long flags; + + flags = MAP_PRIVATE | MAP_ANONYMOUS; + addr = mmap(NULL, size, PROT_NONE, flags, -1, 0); + if (addr == MAP_FAILED) { + printf("Error: couldn't map the space we need for the test\n"); + return 0; + } + + if (munmap(addr, size) != 0) { + printf("Error: couldn't map the space we need for the test\n"); + return 0; + } + return (unsigned long)addr; +} + int main(void) { + unsigned long base_addr; unsigned long flags, addr, size, page_size; char *p;

page_size = sysconf(_SC_PAGE_SIZE);

+ //let's find a base addr that is free before we start the tests + size = 5 * page_size; + base_addr = find_base_addr(size); + if (!base_addr) { + printf("Error: couldn't map the space we need for the test\n"); + return 1; + } + flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE;

// Check we can map all the areas we need below errno = 0; - addr = BASE_ADDRESS; + addr = base_addr; size = 5 * page_size; p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0);

@@ -60,7 +85,7 @@ int main(void) printf("unmap() successful\n");

errno = 0; - addr = BASE_ADDRESS + page_size; + addr = base_addr + page_size; size = 3 * page_size; p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); @@ -80,7 +105,7 @@ int main(void) * +4 | free | new */ errno = 0; - addr = BASE_ADDRESS; + addr = base_addr; size = 5 * page_size; p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); @@ -101,7 +126,7 @@ int main(void) * +4 | free | */ errno = 0; - addr = BASE_ADDRESS + (2 * page_size); + addr = base_addr + (2 * page_size); size = page_size; p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); @@ -121,7 +146,7 @@ int main(void) * +4 | free | new */ errno = 0; - addr = BASE_ADDRESS + (3 * page_size); + addr = base_addr + (3 * page_size); size = 2 * page_size; p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); @@ -141,7 +166,7 @@ int main(void) * +4 | free | */ errno = 0; - addr = BASE_ADDRESS; + addr = base_addr; size = 2 * page_size; p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); @@ -161,7 +186,7 @@ int main(void) * +4 | free | */ errno = 0; - addr = BASE_ADDRESS; + addr = base_addr; size = page_size; p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); @@ -181,7 +206,7 @@ int main(void) * +4 | free | new */ errno = 0; - addr = BASE_ADDRESS + (4 * page_size); + addr = base_addr + (4 * page_size); size = page_size; p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); printf("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p); @@ -192,7 +217,7 @@ int main(void) return 1; }

- addr = BASE_ADDRESS; + addr = base_addr; size = 5 * page_size; if (munmap((void *)addr, size) != 0) { dump_maps();