Commit a52b4f11 authored by Jeff Xu's avatar Jeff Xu Committed by Andrew Morton
Browse files

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: default avatarJeff Xu <jeffxu@chromium.org>
Signed-off-by: default avatarAmer Al Shanawany <amer.shanawany@gmail.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarLiam 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c010d099

tools/testing/selftests/mm/.gitignore

+1 −0
Original line number Diff line number Diff line
@@ -48,3 +48,4 @@ va_high_addr_switch 
hugetlb_fault_after_madv

hugetlb_madv_vs_map

mseal_test

seal_elf

tools/testing/selftests/mm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

tools/testing/selftests/mm/mseal_test.c

+94 −36
Original line number Diff line number Diff line 
// 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;

}

tools/testing/selftests/mm/seal_elf.c

0 → 100644
+179 −0
Original line number Diff line number Diff line 
// 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();

}