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Subject[PATCH] proc: fix map_files test on F29
F29 bans mapping first 64KB even for root making test fail.
Iterate from address 0 until mmap() works.

Gentoo (root):

openat(AT_FDCWD, "/dev/zero", O_RDONLY) = 3
mmap(NULL, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0

Gentoo (non-root):

openat(AT_FDCWD, "/dev/zero", O_RDONLY) = 3
mmap(NULL, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EPERM (Operation not permitted)
mmap(0x1000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0x1000

F29 (root):

openat(AT_FDCWD, "/dev/zero", O_RDONLY) = 3
mmap(NULL, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x1000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x2000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x3000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x4000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x5000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x6000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x7000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x8000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x9000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0xa000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0xb000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0xc000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0xd000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0xe000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0xf000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = -1 EACCES (Permission denied)
mmap(0x10000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0x10000

Now all proc tests succeed on F29 if run as root, at last!

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

tools/testing/selftests/proc/proc-self-map-files-002.c | 20 ++++++++---------
1 file changed, 10 insertions(+), 10 deletions(-)

--- a/tools/testing/selftests/proc/proc-self-map-files-002.c
+++ b/tools/testing/selftests/proc/proc-self-map-files-002.c
@@ -46,12 +46,9 @@ static void fail(const char *fmt, unsigned long a, unsigned long b)

int main(void)
{
- const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
-#ifdef __arm__
- unsigned long va = 2 * PAGE_SIZE;
-#else
- unsigned long va = 0;
-#endif
+ const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+ const unsigned long va_max = 1UL << 32;
+ unsigned long va;
void *p;
int fd;
unsigned long a, b;
@@ -60,10 +57,13 @@ int main(void)
if (fd == -1)
return 1;

- p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
- if (p == MAP_FAILED) {
- if (errno == EPERM)
- return 4;
+ for (va = 0; va < va_max; va += PAGE_SIZE) {
+ p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
+ if (p == (void *)va)
+ break;
+ }
+ if (va == va_max) {
+ fprintf(stderr, "error: mmap doesn't like you\n");
return 1;
}

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