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author | Alexey Dobriyan <adobriyan@gmail.com> | 2019-04-18 17:50:23 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-04-19 09:46:04 -0700 |
commit | 8cd40d1d41ffc305d9aed77937896e1712b2490c (patch) | |
tree | 6c6f790ec7a6dca4d51629eeda6ccdc092acac83 | |
parent | e8277b3b52240ec1caad8e6df278863e4bf42eac (diff) | |
download | lwn-8cd40d1d41ffc305d9aed77937896e1712b2490c.tar.gz lwn-8cd40d1d41ffc305d9aed77937896e1712b2490c.zip |
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!
Link: http://lkml.kernel.org/r/20190414123612.GB12971@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | tools/testing/selftests/proc/proc-self-map-files-002.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/tools/testing/selftests/proc/proc-self-map-files-002.c b/tools/testing/selftests/proc/proc-self-map-files-002.c index 762cb01f2ca7..47b7473dedef 100644 --- 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; } |