Messages in this thread | | | Date | Fri, 4 Aug 2023 20:00:26 +0200 | Subject | Re: [PATCH v3 7/7] selftest/mm: ksm_functional_tests: Add PROT_NONE test | From | David Hildenbrand <> |
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On 03.08.23 21:06, Peter Xu wrote: > On Thu, Aug 03, 2023 at 04:32:08PM +0200, David Hildenbrand wrote: >> Let's test whether merging and unmerging in PROT_NONE areas works as >> expected. >> >> Pass a page protection to mmap_and_merge_range(), which will trigger >> an mprotect() after writing to the pages, but before enabling merging. >> >> Make sure that unsharing works as expected, by performing a ptrace write >> (using /proc/self/mem) and by setting MADV_UNMERGEABLE. >> >> Note that this implicitly tests that ptrace writes in an inaccessible >> (PROT_NONE) mapping work as expected. >> >> Signed-off-by: David Hildenbrand <david@redhat.com> > > [...] > >> +static void test_prot_none(void) >> +{ >> + const unsigned int size = 2 * MiB; >> + char *map; >> + int i; >> + >> + ksft_print_msg("[RUN] %s\n", __func__); >> + >> + map = mmap_and_merge_range(0x11, size, PROT_NONE, false); >> + if (map == MAP_FAILED) >> + goto unmap; >> + >> + /* Store a unique value in each page on one half using ptrace */ >> + for (i = 0; i < size / 2; i += pagesize) { >> + lseek(mem_fd, (uintptr_t) map + i, SEEK_SET); >> + if (write(mem_fd, &i, sizeof(size)) != sizeof(size)) { > > sizeof(i)? May not matter a huge lot, though..
Oh, indeed, thanks!
> >> + ksft_test_result_fail("ptrace write failed\n"); >> + goto unmap; >> + } >> + } > > Acked-by: Peter Xu <peterx@redhat.com> >
Thanks!
-- Cheers,
David / dhildenb
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