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Diffstat (limited to 'tools/testing/selftests/mm/merge.c')
| -rw-r--r-- | tools/testing/selftests/mm/merge.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/merge.c b/tools/testing/selftests/mm/merge.c new file mode 100644 index 000000000000..c76646cdf6e6 --- /dev/null +++ b/tools/testing/selftests/mm/merge.c @@ -0,0 +1,455 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#define _GNU_SOURCE +#include "../kselftest_harness.h" +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/mman.h> +#include <sys/wait.h> +#include "vm_util.h" + +FIXTURE(merge) +{ + unsigned int page_size; + char *carveout; + struct procmap_fd procmap; +}; + +FIXTURE_SETUP(merge) +{ + self->page_size = psize(); + /* Carve out PROT_NONE region to map over. */ + self->carveout = mmap(NULL, 12 * self->page_size, PROT_NONE, + MAP_ANON | MAP_PRIVATE, -1, 0); + ASSERT_NE(self->carveout, MAP_FAILED); + /* Setup PROCMAP_QUERY interface. */ + ASSERT_EQ(open_self_procmap(&self->procmap), 0); +} + +FIXTURE_TEARDOWN(merge) +{ + ASSERT_EQ(munmap(self->carveout, 12 * self->page_size), 0); + ASSERT_EQ(close_procmap(&self->procmap), 0); +} + +TEST_F(merge, mprotect_unfaulted_left) +{ + unsigned int page_size = self->page_size; + char *carveout = self->carveout; + struct procmap_fd *procmap = &self->procmap; + char *ptr; + + /* + * Map 10 pages of R/W memory within. MAP_NORESERVE so we don't hit + * merge failure due to lack of VM_ACCOUNT flag by mistake. + * + * |-----------------------| + * | unfaulted | + * |-----------------------| + */ + ptr = mmap(&carveout[page_size], 10 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE, -1, 0); + ASSERT_NE(ptr, MAP_FAILED); + /* + * Now make the first 5 pages read-only, splitting the VMA: + * + * RO RW + * |-----------|-----------| + * | unfaulted | unfaulted | + * |-----------|-----------| + */ + ASSERT_EQ(mprotect(ptr, 5 * page_size, PROT_READ), 0); + /* + * Fault in the first of the last 5 pages so it gets an anon_vma and + * thus the whole VMA becomes 'faulted': + * + * RO RW + * |-----------|-----------| + * | unfaulted | faulted | + * |-----------|-----------| + */ + ptr[5 * page_size] = 'x'; + /* + * Now mprotect() the RW region read-only, we should merge (though for + * ~15 years we did not! :): + * + * RO + * |-----------------------| + * | faulted | + * |-----------------------| + */ + ASSERT_EQ(mprotect(&ptr[5 * page_size], 5 * page_size, PROT_READ), 0); + + /* Assert that the merge succeeded using PROCMAP_QUERY. */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 10 * page_size); +} + +TEST_F(merge, mprotect_unfaulted_right) +{ + unsigned int page_size = self->page_size; + char *carveout = self->carveout; + struct procmap_fd *procmap = &self->procmap; + char *ptr; + + /* + * |-----------------------| + * | unfaulted | + * |-----------------------| + */ + ptr = mmap(&carveout[page_size], 10 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE, -1, 0); + ASSERT_NE(ptr, MAP_FAILED); + /* + * Now make the last 5 pages read-only, splitting the VMA: + * + * RW RO + * |-----------|-----------| + * | unfaulted | unfaulted | + * |-----------|-----------| + */ + ASSERT_EQ(mprotect(&ptr[5 * page_size], 5 * page_size, PROT_READ), 0); + /* + * Fault in the first of the first 5 pages so it gets an anon_vma and + * thus the whole VMA becomes 'faulted': + * + * RW RO + * |-----------|-----------| + * | faulted | unfaulted | + * |-----------|-----------| + */ + ptr[0] = 'x'; + /* + * Now mprotect() the RW region read-only, we should merge: + * + * RO + * |-----------------------| + * | faulted | + * |-----------------------| + */ + ASSERT_EQ(mprotect(ptr, 5 * page_size, PROT_READ), 0); + + /* Assert that the merge succeeded using PROCMAP_QUERY. */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 10 * page_size); +} + +TEST_F(merge, mprotect_unfaulted_both) +{ + unsigned int page_size = self->page_size; + char *carveout = self->carveout; + struct procmap_fd *procmap = &self->procmap; + char *ptr; + + /* + * |-----------------------| + * | unfaulted | + * |-----------------------| + */ + ptr = mmap(&carveout[2 * page_size], 9 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE, -1, 0); + ASSERT_NE(ptr, MAP_FAILED); + /* + * Now make the first and last 3 pages read-only, splitting the VMA: + * + * RO RW RO + * |-----------|-----------|-----------| + * | unfaulted | unfaulted | unfaulted | + * |-----------|-----------|-----------| + */ + ASSERT_EQ(mprotect(ptr, 3 * page_size, PROT_READ), 0); + ASSERT_EQ(mprotect(&ptr[6 * page_size], 3 * page_size, PROT_READ), 0); + /* + * Fault in the first of the middle 3 pages so it gets an anon_vma and + * thus the whole VMA becomes 'faulted': + * + * RO RW RO + * |-----------|-----------|-----------| + * | unfaulted | faulted | unfaulted | + * |-----------|-----------|-----------| + */ + ptr[3 * page_size] = 'x'; + /* + * Now mprotect() the RW region read-only, we should merge: + * + * RO + * |-----------------------| + * | faulted | + * |-----------------------| + */ + ASSERT_EQ(mprotect(&ptr[3 * page_size], 3 * page_size, PROT_READ), 0); + + /* Assert that the merge succeeded using PROCMAP_QUERY. */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 9 * page_size); +} + +TEST_F(merge, mprotect_faulted_left_unfaulted_right) +{ + unsigned int page_size = self->page_size; + char *carveout = self->carveout; + struct procmap_fd *procmap = &self->procmap; + char *ptr; + + /* + * |-----------------------| + * | unfaulted | + * |-----------------------| + */ + ptr = mmap(&carveout[2 * page_size], 9 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE, -1, 0); + ASSERT_NE(ptr, MAP_FAILED); + /* + * Now make the last 3 pages read-only, splitting the VMA: + * + * RW RO + * |-----------------------|-----------| + * | unfaulted | unfaulted | + * |-----------------------|-----------| + */ + ASSERT_EQ(mprotect(&ptr[6 * page_size], 3 * page_size, PROT_READ), 0); + /* + * Fault in the first of the first 6 pages so it gets an anon_vma and + * thus the whole VMA becomes 'faulted': + * + * RW RO + * |-----------------------|-----------| + * | unfaulted | unfaulted | + * |-----------------------|-----------| + */ + ptr[0] = 'x'; + /* + * Now make the first 3 pages read-only, splitting the VMA: + * + * RO RW RO + * |-----------|-----------|-----------| + * | faulted | faulted | unfaulted | + * |-----------|-----------|-----------| + */ + ASSERT_EQ(mprotect(ptr, 3 * page_size, PROT_READ), 0); + /* + * Now mprotect() the RW region read-only, we should merge: + * + * RO + * |-----------------------| + * | faulted | + * |-----------------------| + */ + ASSERT_EQ(mprotect(&ptr[3 * page_size], 3 * page_size, PROT_READ), 0); + + /* Assert that the merge succeeded using PROCMAP_QUERY. */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 9 * page_size); +} + +TEST_F(merge, mprotect_unfaulted_left_faulted_right) +{ + unsigned int page_size = self->page_size; + char *carveout = self->carveout; + struct procmap_fd *procmap = &self->procmap; + char *ptr; + + /* + * |-----------------------| + * | unfaulted | + * |-----------------------| + */ + ptr = mmap(&carveout[2 * page_size], 9 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE, -1, 0); + ASSERT_NE(ptr, MAP_FAILED); + /* + * Now make the first 3 pages read-only, splitting the VMA: + * + * RO RW + * |-----------|-----------------------| + * | unfaulted | unfaulted | + * |-----------|-----------------------| + */ + ASSERT_EQ(mprotect(ptr, 3 * page_size, PROT_READ), 0); + /* + * Fault in the first of the last 6 pages so it gets an anon_vma and + * thus the whole VMA becomes 'faulted': + * + * RO RW + * |-----------|-----------------------| + * | unfaulted | faulted | + * |-----------|-----------------------| + */ + ptr[3 * page_size] = 'x'; + /* + * Now make the last 3 pages read-only, splitting the VMA: + * + * RO RW RO + * |-----------|-----------|-----------| + * | unfaulted | faulted | faulted | + * |-----------|-----------|-----------| + */ + ASSERT_EQ(mprotect(&ptr[6 * page_size], 3 * page_size, PROT_READ), 0); + /* + * Now mprotect() the RW region read-only, we should merge: + * + * RO + * |-----------------------| + * | faulted | + * |-----------------------| + */ + ASSERT_EQ(mprotect(&ptr[3 * page_size], 3 * page_size, PROT_READ), 0); + + /* Assert that the merge succeeded using PROCMAP_QUERY. */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 9 * page_size); +} + +TEST_F(merge, forked_target_vma) +{ + unsigned int page_size = self->page_size; + char *carveout = self->carveout; + struct procmap_fd *procmap = &self->procmap; + pid_t pid; + char *ptr, *ptr2; + int i; + + /* + * |-----------| + * | unfaulted | + * |-----------| + */ + ptr = mmap(&carveout[page_size], 5 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0); + ASSERT_NE(ptr, MAP_FAILED); + + /* + * Fault in process. + * + * |-----------| + * | faulted | + * |-----------| + */ + ptr[0] = 'x'; + + pid = fork(); + ASSERT_NE(pid, -1); + + if (pid != 0) { + wait(NULL); + return; + } + + /* Child process below: */ + + /* Reopen for child. */ + ASSERT_EQ(close_procmap(&self->procmap), 0); + ASSERT_EQ(open_self_procmap(&self->procmap), 0); + + /* unCOWing everything does not cause the AVC to go away. */ + for (i = 0; i < 5 * page_size; i += page_size) + ptr[i] = 'x'; + + /* + * Map in adjacent VMA in child. + * + * forked + * |-----------|-----------| + * | faulted | unfaulted | + * |-----------|-----------| + * ptr ptr2 + */ + ptr2 = mmap(&ptr[5 * page_size], 5 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0); + ASSERT_NE(ptr2, MAP_FAILED); + + /* Make sure not merged. */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 5 * page_size); +} + +TEST_F(merge, forked_source_vma) +{ + unsigned int page_size = self->page_size; + char *carveout = self->carveout; + struct procmap_fd *procmap = &self->procmap; + pid_t pid; + char *ptr, *ptr2; + int i; + + /* + * |-----------|------------| + * | unfaulted | <unmapped> | + * |-----------|------------| + */ + ptr = mmap(&carveout[page_size], 5 * page_size, PROT_READ | PROT_WRITE, + MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE, -1, 0); + ASSERT_NE(ptr, MAP_FAILED); + + /* + * Fault in process. + * + * |-----------|------------| + * | faulted | <unmapped> | + * |-----------|------------| + */ + ptr[0] = 'x'; + + pid = fork(); + ASSERT_NE(pid, -1); + + if (pid != 0) { + wait(NULL); + return; + } + + /* Child process below: */ + + /* Reopen for child. */ + ASSERT_EQ(close_procmap(&self->procmap), 0); + ASSERT_EQ(open_self_procmap(&self->procmap), 0); + + /* unCOWing everything does not cause the AVC to go away. */ + for (i = 0; i < 5 * page_size; i += page_size) + ptr[i] = 'x'; + + /* + * Map in adjacent VMA in child, ptr2 after ptr, but incompatible. + * + * forked RW RWX + * |-----------|-----------| + * | faulted | unfaulted | + * |-----------|-----------| + * ptr ptr2 + */ + ptr2 = mmap(&carveout[6 * page_size], 5 * page_size, PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_NORESERVE, -1, 0); + ASSERT_NE(ptr2, MAP_FAILED); + + /* Make sure not merged. */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr2)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr2); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr2 + 5 * page_size); + + /* + * Now mprotect forked region to RWX so it becomes the source for the + * merge to unfaulted region: + * + * forked RWX RWX + * |-----------|-----------| + * | faulted | unfaulted | + * |-----------|-----------| + * ptr ptr2 + * + * This should NOT result in a merge, as ptr was forked. + */ + ASSERT_EQ(mprotect(ptr, 5 * page_size, PROT_READ | PROT_WRITE | PROT_EXEC), 0); + /* Again, make sure not merged. */ + ASSERT_TRUE(find_vma_procmap(procmap, ptr2)); + ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr2); + ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr2 + 5 * page_size); +} + +TEST_HARNESS_MAIN |