selftest mm/mseal read-only elf memory segment

Sealing read-only of elf mapping so it can't be changed by mprotect.

[jeffxu@chromium.org: style change]
Link: https://lkml.kernel.org/r/20240416220944.2481203-2-jeffxu@chromium.org
[amer.shanawany@gmail.com: fix linker error for inline function]
Link: https://lkml.kernel.org/r/20240420202346.546444-1-amer.shanawany@gmail.com
[jeffxu@chromium.org: fix compile warning]
Link: https://lkml.kernel.org/r/20240420003515.345982-2-jeffxu@chromium.org
[jeffxu@chromium.org: fix arm build]
Link: https://lkml.kernel.org/r/20240502225331.3806279-2-jeffxu@chromium.org
Link: https://lkml.kernel.org/r/20240415163527.626541-6-jeffxu@chromium.org
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Signed-off-by: Amer Al Shanawany <amer.shanawany@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Amer Al Shanawany <amer.shanawany@gmail.com>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/.gitignore b/tools/testing/selftests/mm/.gitignore
index 98eaa4590f116d4f4275bda6e10b5e72948460be..0b9ab987601cca9bc9cc2cd66d4d729bf05d7c90 100644 (file)
--- a/tools/testing/selftests/mm/.gitignore
+++ b/tools/testing/selftests/mm/.gitignore
@@ -48,3 +48,4 @@ va_high_addr_switch
 hugetlb_fault_after_madv
 hugetlb_madv_vs_map
 mseal_test
+seal_elf

diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 3482b5aef984bd2ba1ae8933c603a48c44ff6fe7..3b49bc3d0a3b29df7e1c7e2b62047f7ac9ff6129 100644 (file)
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -60,6 +60,7 @@ TEST_GEN_FILES += mrelease_test
 TEST_GEN_FILES += mremap_dontunmap
 TEST_GEN_FILES += mremap_test
 TEST_GEN_FILES += mseal_test
+TEST_GEN_FILES += seal_elf
 TEST_GEN_FILES += on-fault-limit
 TEST_GEN_FILES += pagemap_ioctl
 TEST_GEN_FILES += thuge-gen

diff --git a/tools/testing/selftests/mm/mseal_test.c b/tools/testing/selftests/mm/mseal_test.c
index 06c780d1d8e577e99f0be4b7b8ea144040b2b69c..41998cf1dcf579468ba6f1b11257820ecf515880 100644 (file)
--- a/tools/testing/selftests/mm/mseal_test.c
+++ b/tools/testing/selftests/mm/mseal_test.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #define _GNU_SOURCE
+#include <linux/mman.h>
 #include <sys/mman.h>
 #include <stdint.h>
 #include <unistd.h>
@@ -12,9 +13,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <assert.h>
 #include <fcntl.h>
-#include <assert.h>
 #include <sys/ioctl.h>
 #include <sys/vfs.h>
 #include <sys/stat.h>
@@ -31,7 +30,7 @@
 # define PKEY_DISABLE_WRITE     0x2
 #endif
 
-#ifndef PKEY_BITS_PER_KEY
+#ifndef PKEY_BITS_PER_PKEY
 #define PKEY_BITS_PER_PKEY      2
 #endif
 
@@ -81,7 +80,7 @@ static unsigned long get_vma_size(void *addr, int *prot)
                return 0;
 
        while (fgets(line, sizeof(line), maps)) {
-               if (sscanf(line, "%lx-%lx %4s", &addr_start, &addr_end, &protstr) == 3) {
+               if (sscanf(line, "%lx-%lx %4s", &addr_start, &addr_end, protstr) == 3) {
                        if (addr_start == (uintptr_t) addr) {
                                size = addr_end - addr_start;
                                if (protstr[0] == 'r')
@@ -189,7 +188,6 @@ static void __write_pkey_reg(u64 pkey_reg)
 
        asm volatile(".byte 0x0f,0x01,0xef\n\t"
                        : : "a" (eax), "c" (ecx), "d" (edx));
-       assert(pkey_reg == __read_pkey_reg());
 #endif
 }
 
@@ -211,10 +209,8 @@ static u64 set_pkey_bits(u64 reg, int pkey, u64 flags)
 
 static void set_pkey(int pkey, unsigned long pkey_value)
 {
-       unsigned long mask = (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE);
        u64 new_pkey_reg;
 
-       assert(!(pkey_value & ~mask));
        new_pkey_reg = set_pkey_bits(__read_pkey_reg(), pkey, pkey_value);
        __write_pkey_reg(new_pkey_reg);
 }
@@ -224,7 +220,6 @@ static void setup_single_address(int size, void **ptrOut)
        void *ptr;
 
        ptr = sys_mmap(NULL, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-       assert(ptr != (void *)-1);
        *ptrOut = ptr;
 }
 
@@ -234,24 +229,21 @@ static void setup_single_address_rw(int size, void **ptrOut)
        unsigned long mapflags = MAP_ANONYMOUS | MAP_PRIVATE;
 
        ptr = sys_mmap(NULL, size, PROT_READ | PROT_WRITE, mapflags, -1, 0);
-       assert(ptr != (void *)-1);
        *ptrOut = ptr;
 }
 
-static void clean_single_address(void *ptr, int size)
+static int clean_single_address(void *ptr, int size)
 {
        int ret;
-
        ret = munmap(ptr, size);
-       assert(!ret);
+       return ret;
 }
 
-static void seal_single_address(void *ptr, int size)
+static int seal_single_address(void *ptr, int size)
 {
        int ret;
-
        ret = sys_mseal(ptr, size);
-       assert(!ret);
+       return ret;
 }
 
 bool seal_support(void)
@@ -290,6 +282,7 @@ static void test_seal_addseal(void)
        unsigned long size = 4 * page_size;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        ret = sys_mseal(ptr, size);
        FAIL_TEST_IF_FALSE(!ret);
@@ -305,6 +298,7 @@ static void test_seal_unmapped_start(void)
        unsigned long size = 4 * page_size;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* munmap 2 pages from ptr. */
        ret = sys_munmap(ptr, 2 * page_size);
@@ -332,6 +326,7 @@ static void test_seal_unmapped_middle(void)
        unsigned long size = 4 * page_size;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* munmap 2 pages from ptr + page. */
        ret = sys_munmap(ptr + page_size, 2 * page_size);
@@ -363,6 +358,7 @@ static void test_seal_unmapped_end(void)
        unsigned long size = 4 * page_size;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* unmap last 2 pages. */
        ret = sys_munmap(ptr + 2 * page_size, 2 * page_size);
@@ -391,6 +387,7 @@ static void test_seal_multiple_vmas(void)
        unsigned long size = 4 * page_size;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split the vma into 3. */
        ret = sys_mprotect(ptr + page_size, 2 * page_size,
@@ -421,6 +418,7 @@ static void test_seal_split_start(void)
        unsigned long size = 4 * page_size;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split at middle */
        ret = sys_mprotect(ptr, 2 * page_size, PROT_READ | PROT_WRITE);
@@ -445,6 +443,7 @@ static void test_seal_split_end(void)
        unsigned long size = 4 * page_size;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split at middle */
        ret = sys_mprotect(ptr, 2 * page_size, PROT_READ | PROT_WRITE);
@@ -469,7 +468,9 @@ static void test_seal_invalid_input(void)
        int ret;
 
        setup_single_address(8 * page_size, &ptr);
-       clean_single_address(ptr + 4 * page_size, 4 * page_size);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
+       ret = clean_single_address(ptr + 4 * page_size, 4 * page_size);
+       FAIL_TEST_IF_FALSE(!ret);
 
        /* invalid flag */
        ret = syscall(__NR_mseal, ptr, size, 0x20);
@@ -502,6 +503,7 @@ static void test_seal_zero_length(void)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        ret = sys_mprotect(ptr, 0, PROT_READ | PROT_WRITE);
        FAIL_TEST_IF_FALSE(!ret);
@@ -551,6 +553,7 @@ static void test_seal_twice(void)
        unsigned long size = 4 * page_size;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        ret = sys_mseal(ptr, size);
        FAIL_TEST_IF_FALSE(!ret);
@@ -570,9 +573,12 @@ static void test_seal_mprotect(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
-       if (seal)
-               seal_single_address(ptr, size);
+       if (seal) {
+               ret = seal_single_address(ptr, size);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
        if (seal)
@@ -591,9 +597,12 @@ static void test_seal_start_mprotect(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
-       if (seal)
-               seal_single_address(ptr, page_size);
+       if (seal) {
+               ret = seal_single_address(ptr, page_size);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        /* the first page is sealed. */
        ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
@@ -618,9 +627,12 @@ static void test_seal_end_mprotect(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
-       if (seal)
-               seal_single_address(ptr + page_size, 3 * page_size);
+       if (seal) {
+               ret = seal_single_address(ptr + page_size, 3 * page_size);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        /* first page is not sealed */
        ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
@@ -645,9 +657,12 @@ static void test_seal_mprotect_unalign_len(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
-       if (seal)
-               seal_single_address(ptr, page_size * 2 - 1);
+       if (seal) {
+               ret = seal_single_address(ptr, page_size * 2 - 1);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        /* 2 pages are sealed. */
        ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
@@ -671,8 +686,11 @@ static void test_seal_mprotect_unalign_len_variant_2(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
-       if (seal)
-               seal_single_address(ptr, page_size * 2 + 1);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
+       if (seal) {
+               ret =  seal_single_address(ptr, page_size * 2 + 1);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        /* 3 pages are sealed. */
        ret = sys_mprotect(ptr, page_size * 3, PROT_READ | PROT_WRITE);
@@ -696,13 +714,16 @@ static void test_seal_mprotect_two_vma(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split */
        ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
        FAIL_TEST_IF_FALSE(!ret);
 
-       if (seal)
-               seal_single_address(ptr, page_size * 4);
+       if (seal) {
+               ret = seal_single_address(ptr, page_size * 4);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
        if (seal)
@@ -728,14 +749,17 @@ static void test_seal_mprotect_two_vma_with_split(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split as two vma. */
        ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
        FAIL_TEST_IF_FALSE(!ret);
 
        /* mseal can apply across 2 vma, also split them. */
-       if (seal)
-               seal_single_address(ptr + page_size, page_size * 2);
+       if (seal) {
+               ret = seal_single_address(ptr + page_size, page_size * 2);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        /* the first page is not sealed. */
        ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
@@ -772,10 +796,13 @@ static void test_seal_mprotect_partial_mprotect(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* seal one page. */
-       if (seal)
-               seal_single_address(ptr, page_size);
+       if (seal) {
+               ret = seal_single_address(ptr, page_size);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        /* mprotect first 2 page will fail, since the first page are sealed. */
        ret = sys_mprotect(ptr, 2 * page_size, PROT_READ | PROT_WRITE);
@@ -795,6 +822,7 @@ static void test_seal_mprotect_two_vma_with_gap(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split. */
        ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
@@ -837,6 +865,7 @@ static void test_seal_mprotect_split(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split. */
        ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
@@ -873,6 +902,7 @@ static void test_seal_mprotect_merge(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split one page. */
        ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
@@ -906,6 +936,7 @@ static void test_seal_munmap(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -936,6 +967,7 @@ static void test_seal_munmap_two_vma(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect to split */
        ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
@@ -976,6 +1008,7 @@ static void test_seal_munmap_vma_with_gap(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        ret = sys_munmap(ptr + page_size, page_size * 2);
        FAIL_TEST_IF_FALSE(!ret);
@@ -1007,6 +1040,7 @@ static void test_munmap_start_freed(bool seal)
        int prot;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* unmap the first page. */
        ret = sys_munmap(ptr, page_size);
@@ -1045,6 +1079,8 @@ static void test_munmap_end_freed(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
+
        /* unmap last page. */
        ret = sys_munmap(ptr + page_size * 3, page_size);
        FAIL_TEST_IF_FALSE(!ret);
@@ -1074,6 +1110,8 @@ static void test_munmap_middle_freed(bool seal)
        int prot;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
+
        /* unmap 2 pages in the middle. */
        ret = sys_munmap(ptr + page_size, page_size * 2);
        FAIL_TEST_IF_FALSE(!ret);
@@ -1116,6 +1154,7 @@ static void test_seal_mremap_shrink(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -1144,6 +1183,7 @@ static void test_seal_mremap_expand(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
        /* ummap last 2 pages. */
        ret = sys_munmap(ptr + 2 * page_size, 2 * page_size);
        FAIL_TEST_IF_FALSE(!ret);
@@ -1175,8 +1215,11 @@ static void test_seal_mremap_move(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
        setup_single_address(size, &newPtr);
-       clean_single_address(newPtr, size);
+       FAIL_TEST_IF_FALSE(newPtr != (void *)-1);
+       ret = clean_single_address(newPtr, size);
+       FAIL_TEST_IF_FALSE(!ret);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -1205,6 +1248,7 @@ static void test_seal_mmap_overwrite_prot(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -1232,6 +1276,7 @@ static void test_seal_mmap_expand(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
        /* ummap last 4 pages. */
        ret = sys_munmap(ptr + 8 * page_size, 4 * page_size);
        FAIL_TEST_IF_FALSE(!ret);
@@ -1262,6 +1307,7 @@ static void test_seal_mmap_shrink(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -1290,7 +1336,9 @@ static void test_seal_mremap_shrink_fixed(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
        setup_single_address(size, &newAddr);
+       FAIL_TEST_IF_FALSE(newAddr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -1319,7 +1367,9 @@ static void test_seal_mremap_expand_fixed(bool seal)
        void *ret2;
 
        setup_single_address(page_size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
        setup_single_address(size, &newAddr);
+       FAIL_TEST_IF_FALSE(newAddr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(newAddr, size);
@@ -1348,7 +1398,9 @@ static void test_seal_mremap_move_fixed(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
        setup_single_address(size, &newAddr);
+       FAIL_TEST_IF_FALSE(newAddr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(newAddr, size);
@@ -1375,6 +1427,7 @@ static void test_seal_mremap_move_fixed_zero(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -1406,6 +1459,7 @@ static void test_seal_mremap_move_dontunmap(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -1434,6 +1488,7 @@ static void test_seal_mremap_move_dontunmap_anyaddr(bool seal)
        void *ret2;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        if (seal) {
                ret = sys_mseal(ptr, size);
@@ -1469,6 +1524,7 @@ static void test_seal_merge_and_split(void)
 
        /* (24 RO) */
        setup_single_address(24 * page_size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
        /* use mprotect(NONE) to set out boundary */
        /* (1 NONE) (22 RO) (1 NONE) */
@@ -1700,9 +1756,12 @@ static void test_seal_discard_ro_anon(bool seal)
        int ret;
 
        setup_single_address(size, &ptr);
+       FAIL_TEST_IF_FALSE(ptr != (void *)-1);
 
-       if (seal)
-               seal_single_address(ptr, size);
+       if (seal) {
+               ret = seal_single_address(ptr, size);
+               FAIL_TEST_IF_FALSE(!ret);
+       }
 
        ret = sys_madvise(ptr, size, MADV_DONTNEED);
        if (seal)
@@ -1832,5 +1891,4 @@ int main(int argc, char **argv)
        test_seal_discard_ro_anon_on_pkey(true);
 
        ksft_finished();
-       return 0;
 }

diff --git a/tools/testing/selftests/mm/seal_elf.c b/tools/testing/selftests/mm/seal_elf.c
new file mode 100644 (file)
index 0000000..f2babec
--- /dev/null
+++ b/tools/testing/selftests/mm/seal_elf.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sys/mman.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <stdbool.h>
+#include "../kselftest.h"
+#include <syscall.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/vfs.h>
+#include <sys/stat.h>
+
+/*
+ * need those definition for manually build using gcc.
+ * gcc -I ../../../../usr/include   -DDEBUG -O3  -DDEBUG -O3 seal_elf.c -o seal_elf
+ */
+#define FAIL_TEST_IF_FALSE(c) do {\
+               if (!(c)) {\
+                       ksft_test_result_fail("%s, line:%d\n", __func__, __LINE__);\
+                       goto test_end;\
+               } \
+       } \
+       while (0)
+
+#define SKIP_TEST_IF_FALSE(c) do {\
+               if (!(c)) {\
+                       ksft_test_result_skip("%s, line:%d\n", __func__, __LINE__);\
+                       goto test_end;\
+               } \
+       } \
+       while (0)
+
+
+#define TEST_END_CHECK() {\
+               ksft_test_result_pass("%s\n", __func__);\
+               return;\
+test_end:\
+               return;\
+}
+
+#ifndef u64
+#define u64 unsigned long long
+#endif
+
+/*
+ * define sys_xyx to call syscall directly.
+ */
+static int sys_mseal(void *start, size_t len)
+{
+       int sret;
+
+       errno = 0;
+       sret = syscall(__NR_mseal, start, len, 0);
+       return sret;
+}
+
+static void *sys_mmap(void *addr, unsigned long len, unsigned long prot,
+       unsigned long flags, unsigned long fd, unsigned long offset)
+{
+       void *sret;
+
+       errno = 0;
+       sret = (void *) syscall(__NR_mmap, addr, len, prot,
+               flags, fd, offset);
+       return sret;
+}
+
+static inline int sys_mprotect(void *ptr, size_t size, unsigned long prot)
+{
+       int sret;
+
+       errno = 0;
+       sret = syscall(__NR_mprotect, ptr, size, prot);
+       return sret;
+}
+
+static bool seal_support(void)
+{
+       int ret;
+       void *ptr;
+       unsigned long page_size = getpagesize();
+
+       ptr = sys_mmap(NULL, page_size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+       if (ptr == (void *) -1)
+               return false;
+
+       ret = sys_mseal(ptr, page_size);
+       if (ret < 0)
+               return false;
+
+       return true;
+}
+
+const char somestr[4096] = {"READONLY"};
+
+static void test_seal_elf(void)
+{
+       int ret;
+       FILE *maps;
+       char line[512];
+       uintptr_t  addr_start, addr_end;
+       char prot[5];
+       char filename[256];
+       unsigned long page_size = getpagesize();
+       unsigned long long ptr = (unsigned long long) somestr;
+       char *somestr2 = (char *)somestr;
+
+       /*
+        * Modify the protection of readonly somestr
+        */
+       if (((unsigned long long)ptr % page_size) != 0)
+               ptr = (unsigned long long)ptr & ~(page_size - 1);
+
+       ksft_print_msg("somestr = %s\n", somestr);
+       ksft_print_msg("change protection to rw\n");
+       ret = sys_mprotect((void *)ptr, page_size, PROT_READ|PROT_WRITE);
+       FAIL_TEST_IF_FALSE(!ret);
+       *somestr2 = 'A';
+       ksft_print_msg("somestr is modified to: %s\n", somestr);
+       ret = sys_mprotect((void *)ptr, page_size, PROT_READ);
+       FAIL_TEST_IF_FALSE(!ret);
+
+       maps = fopen("/proc/self/maps", "r");
+       FAIL_TEST_IF_FALSE(maps);
+
+       /*
+        * apply sealing to elf binary
+        */
+       while (fgets(line, sizeof(line), maps)) {
+               if (sscanf(line, "%lx-%lx %4s %*x %*x:%*x %*u %255[^\n]",
+                       &addr_start, &addr_end, prot, filename) == 4) {
+                       if (strlen(filename)) {
+                               /*
+                                * seal the mapping if read only.
+                                */
+                               if (strstr(prot, "r-")) {
+                                       ret = sys_mseal((void *)addr_start, addr_end - addr_start);
+                                       FAIL_TEST_IF_FALSE(!ret);
+                                       ksft_print_msg("sealed: %lx-%lx %s %s\n",
+                                               addr_start, addr_end, prot, filename);
+                                       if ((uintptr_t) somestr >= addr_start &&
+                                               (uintptr_t) somestr <= addr_end)
+                                               ksft_print_msg("mapping for somestr found\n");
+                               }
+                       }
+               }
+       }
+       fclose(maps);
+
+       ret = sys_mprotect((void *)ptr, page_size, PROT_READ | PROT_WRITE);
+       FAIL_TEST_IF_FALSE(ret < 0);
+       ksft_print_msg("somestr is sealed, mprotect is rejected\n");
+
+       TEST_END_CHECK();
+}
+
+int main(int argc, char **argv)
+{
+       bool test_seal = seal_support();
+
+       ksft_print_header();
+       ksft_print_msg("pid=%d\n", getpid());
+
+       if (!test_seal)
+               ksft_exit_skip("sealing not supported, check CONFIG_64BIT\n");
+
+       ksft_set_plan(1);
+
+       test_seal_elf();
+
+       ksft_finished();
+}