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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-19 02:34:01 +08:00
linux-next/tools/testing
Axel Rasmussen 573a259336 userfaultfd: selftests: fix SIGSEGV if huge mmap fails
The error handling in hugetlb_allocate_area() was incorrect for the
hugetlb_shared test case.

Previously the behavior was:

- mmap a hugetlb area
  - If this fails, set the pointer to NULL, and carry on
- mmap an alias of the same hugetlb fd
  - If this fails, munmap the original area

If the original mmap failed, it's likely the second one did too.  If
both failed, we'd blindly try to munmap a NULL pointer, causing a
SIGSEGV.  Instead, "goto fail" so we return before trying to mmap the
alias.

This issue can be hit "in real life" by forgetting to set
/proc/sys/vm/nr_hugepages (leaving it at 0), and then trying to run the
hugetlb_shared test.

Another small improvement is, when the original mmap fails, don't just
print "it failed": perror(), so we can see *why*.  :)

Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Alan Gilbert <dgilbert@redhat.com>
Link: https://lkml.kernel.org/r/20201204203443.2714693-1-axelrasmussen@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-06 10:19:07 -08:00
..
fault-injection docs: fault-injection: convert docs to ReST and rename to *.rst 2019-06-14 14:21:07 -06:00
ktest Updates for ktest 5.9 2020-08-10 19:16:26 -07:00
kunit kunit: tool: fix extra trailing \n in raw + parsed test output 2020-11-10 13:44:35 -07:00
nvdimm device-dax: add dis-contiguous resource support 2020-10-13 18:38:28 -07:00
radix-tree ida: Free allocated bitmap in error path 2020-10-07 09:11:33 -04:00
scatterlist tools/testing/scatterlist: Fix test to compile and run 2020-11-17 20:02:20 -04:00
selftests userfaultfd: selftests: fix SIGSEGV if huge mmap fails 2020-12-06 10:19:07 -08:00
vsock SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00