The quilt patch titled
Subject: selftest mm/mseal read-only elf memory segment
has been removed from the -mm tree. Its filename was
selftest-mm-mseal-read-only-elf-memory-segment.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Jeff Xu <jeffxu@xxxxxxxxxxxx>
Subject: selftest mm/mseal read-only elf memory segment
Date: Mon, 15 Apr 2024 16:35:24 +0000
Sealing read-only of elf mapping so it can't be changed by mprotect.
[jeffxu@xxxxxxxxxxxx: style change]
Link: https://lkml.kernel.org/r/20240416220944.2481203-2-jeffxu@xxxxxxxxxxxx
[amer.shanawany@xxxxxxxxx: fix linker error for inline function]
Link: https://lkml.kernel.org/r/20240420202346.546444-1-amer.shanawany@xxxxxxxxx
[jeffxu@xxxxxxxxxxxx: fix compile warning]
Link: https://lkml.kernel.org/r/20240420003515.345982-2-jeffxu@xxxxxxxxxxxx
[jeffxu@xxxxxxxxxxxx: fix arm build]
Link: https://lkml.kernel.org/r/20240502225331.3806279-2-jeffxu@xxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20240415163527.626541-6-jeffxu@xxxxxxxxxxxx
Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>
Signed-off-by: Amer Al Shanawany <amer.shanawany@xxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Guenter Roeck <groeck@xxxxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Jeff Xu <jeffxu@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Jorge Lucangeli Obes <jorgelo@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Cc: Pedro Falcato <pedro.falcato@xxxxxxxxx>
Cc: Stephen Röttger <sroettger@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Amer Al Shanawany <amer.shanawany@xxxxxxxxx>
Cc: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/mm/.gitignore | 1
tools/testing/selftests/mm/Makefile | 1
tools/testing/selftests/mm/mseal_test.c | 130 +++++++++++----
tools/testing/selftests/mm/seal_elf.c | 179 ++++++++++++++++++++++
4 files changed, 275 insertions(+), 36 deletions(-)
--- a/tools/testing/selftests/mm/.gitignore~selftest-mm-mseal-read-only-elf-memory-segment
+++ a/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
--- a/tools/testing/selftests/mm/Makefile~selftest-mm-mseal-read-only-elf-memory-segment
+++ a/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
--- a/tools/testing/selftests/mm/mseal_test.c~selftest-mm-mseal-read-only-elf-memory-segment
+++ a/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 *
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_re
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 pk
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 siz
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
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(voi
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(vo
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(boo
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
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_l
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_l
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(b
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_w
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_m
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_w
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(boo
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(boo
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(boo
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_ga
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
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 s
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(boo
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
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
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 s
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_pro
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 s
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 s
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_fixe
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_fixe
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(
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_
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_dontun
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_dontun
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(vo
/* (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(bo
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;
}
--- /dev/null
+++ a/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();
+}
_
Patches currently in -mm which might be from jeffxu@xxxxxxxxxxxx are
