Re: [RFC PATCH v3 10/11] selftest mm/mseal memory sealing

From: Muhammad Usama Anjum
Date: Sun Dec 31 2023 - 01:40:08 EST

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I wasn't CC-ed on the patch even though I'd reviewed the earlier revision.

On 12/13/23 4:17 AM, jeffxu@xxxxxxxxxxxx wrote:
> From: Jeff Xu <jeffxu@xxxxxxxxxxxx>
>
> selftest for memory sealing change in mmap() and mseal().
>
> Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>
> ---
> tools/testing/selftests/mm/.gitignore | 1 +
> tools/testing/selftests/mm/Makefile | 1 +
> tools/testing/selftests/mm/config | 1 +
> tools/testing/selftests/mm/mseal_test.c | 2141 +++++++++++++++++++++++
> 4 files changed, 2144 insertions(+)
> create mode 100644 tools/testing/selftests/mm/mseal_test.c
>
> diff --git a/tools/testing/selftests/mm/.gitignore b/tools/testing/selftests/mm/.gitignore
> index cdc9ce4426b9..f0f22a649985 100644
> --- a/tools/testing/selftests/mm/.gitignore
> +++ b/tools/testing/selftests/mm/.gitignore
> @@ -43,3 +43,4 @@ mdwe_test
> gup_longterm
> mkdirty
> va_high_addr_switch
> +mseal_test
> diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
> index 6a9fc5693145..0c086cecc093 100644
> --- a/tools/testing/selftests/mm/Makefile
> +++ b/tools/testing/selftests/mm/Makefile
> @@ -59,6 +59,7 @@ TEST_GEN_FILES += mlock2-tests
> TEST_GEN_FILES += mrelease_test
> TEST_GEN_FILES += mremap_dontunmap
> TEST_GEN_FILES += mremap_test
> +TEST_GEN_FILES += mseal_test
> TEST_GEN_FILES += on-fault-limit
> TEST_GEN_FILES += thuge-gen
> TEST_GEN_FILES += transhuge-stress
> diff --git a/tools/testing/selftests/mm/config b/tools/testing/selftests/mm/config
> index be087c4bc396..cf2b8780e9b1 100644
> --- a/tools/testing/selftests/mm/config
> +++ b/tools/testing/selftests/mm/config
> @@ -6,3 +6,4 @@ CONFIG_TEST_HMM=m
> CONFIG_GUP_TEST=y
> CONFIG_TRANSPARENT_HUGEPAGE=y
> CONFIG_MEM_SOFT_DIRTY=y
> +CONFIG_MSEAL=y
> diff --git a/tools/testing/selftests/mm/mseal_test.c b/tools/testing/selftests/mm/mseal_test.c
> new file mode 100644
> index 000000000000..0692485d8b3c
> --- /dev/null
> +++ b/tools/testing/selftests/mm/mseal_test.c
> @@ -0,0 +1,2141 @@
> +// 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 <assert.h>
> +#include <fcntl.h>
> +#include <assert.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 mseal_test.c -o mseal_test
> + */
> +#ifndef MM_SEAL_SEAL
> +#define MM_SEAL_SEAL 0x1
> +#endif
> +
> +#ifndef MM_SEAL_BASE
> +#define MM_SEAL_BASE 0x2
> +#endif
> +
> +#ifndef MM_SEAL_PROT_PKEY
> +#define MM_SEAL_PROT_PKEY 0x4
> +#endif
> +
> +#ifndef MM_SEAL_DISCARD_RO_ANON
> +#define MM_SEAL_DISCARD_RO_ANON 0x8
> +#endif
> +
> +#ifndef MAP_SEALABLE
> +#define MAP_SEALABLE 0x8000000
> +#endif
> +
> +#ifndef PROT_SEAL_SEAL
> +#define PROT_SEAL_SEAL 0x04000000
> +#endif
> +
> +#ifndef PROT_SEAL_BASE
> +#define PROT_SEAL_BASE 0x08000000
> +#endif
> +
> +#ifndef PROT_SEAL_PROT_PKEY
> +#define PROT_SEAL_PROT_PKEY 0x10000000
> +#endif
> +
> +#ifndef PROT_SEAL_DISCARD_RO_ANON
> +#define PROT_SEAL_DISCARD_RO_ANON 0x20000000
> +#endif
> +
> +#ifndef PKEY_DISABLE_ACCESS
> +# define PKEY_DISABLE_ACCESS 0x1
> +#endif
> +
> +#ifndef PKEY_DISABLE_WRITE
> +# define PKEY_DISABLE_WRITE 0x2
> +#endif
> +
> +#ifndef PKEY_BITS_PER_KEY
> +#define PKEY_BITS_PER_PKEY 2
> +#endif
> +
> +#ifndef PKEY_MASK
> +#define PKEY_MASK (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE)
> +#endif
> +
> +#ifndef DEBUG
> +#define LOG_TEST_ENTER() {}
> +#else
> +#define LOG_TEST_ENTER() {ksft_print_msg("%s\n", __func__); }
> +#endif
> +
> +#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 types)
> +{
> + int sret;
> +
> + errno = 0;
> + sret = syscall(__NR_mseal, start, len, types, 0);
> + return sret;
> +}
> +
> +int sys_mprotect(void *ptr, size_t size, unsigned long prot)
> +{
> + int sret;
> +
> + errno = 0;
> + sret = syscall(SYS_mprotect, ptr, size, prot);
> + return sret;
> +}
> +
> +int sys_mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot,
> + unsigned long pkey)
> +{
> + int sret;
> +
> + errno = 0;
> + sret = syscall(__NR_pkey_mprotect, ptr, size, orig_prot, pkey);
> + return sret;
> +}
> +
> +int sys_munmap(void *ptr, size_t size)
> +{
> + int sret;
> +
> + errno = 0;
> + sret = syscall(SYS_munmap, ptr, size);
> + return sret;
> +}
> +
> +static int sys_madvise(void *start, size_t len, int types)
> +{
> + int sret;
> +
> + errno = 0;
> + sret = syscall(__NR_madvise, start, len, types);
> + return sret;
> +}
> +
> +int sys_pkey_alloc(unsigned long flags, unsigned long init_val)
> +{
> + int ret = syscall(SYS_pkey_alloc, flags, init_val);
Add empty line here.

> + return ret;
> +}
> +
> +static inline unsigned int __read_pkey_reg(void)
> +{
> + unsigned int eax, edx;
> + unsigned int ecx = 0;
> + unsigned int pkey_reg;
> +
> + asm volatile(".byte 0x0f,0x01,0xee\n\t"
> + : "=a" (eax), "=d" (edx)
> + : "c" (ecx));
> + pkey_reg = eax;
> + return pkey_reg;
> +}
> +
> +static inline void __write_pkey_reg(u64 pkey_reg)
> +{
> + unsigned int eax = pkey_reg;
> + unsigned int ecx = 0;
> + unsigned int edx = 0;
> +
> + asm volatile(".byte 0x0f,0x01,0xef\n\t"
> + : : "a" (eax), "c" (ecx), "d" (edx));
> + assert(pkey_reg == __read_pkey_reg());
> +}
> +
> +static inline unsigned long pkey_bit_position(int pkey)
> +{
> + return pkey * PKEY_BITS_PER_PKEY;
> +}
> +
> +static inline u64 set_pkey_bits(u64 reg, int pkey, u64 flags)
> +{
> + unsigned long shift = pkey_bit_position(pkey);
> + /* mask out bits from pkey in old value */
> + reg &= ~((u64)PKEY_MASK << shift);
> + /* OR in new bits for pkey */
> + reg |= (flags & PKEY_MASK) << shift;
> + return reg;
> +}
> +
> +static inline 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);
> +}
> +
> +void setup_single_address(int size, void **ptrOut)
> +{
> + void *ptr;
> +
> + ptr = mmap(NULL, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE | MAP_SEALABLE, -1, 0);
> + assert(ptr != (void *)-1);
> + *ptrOut = ptr;
> +}
> +
> +void setup_single_address_sealable(int size, void **ptrOut, bool sealable)
> +{
> + void *ptr;
> + unsigned long mapflags = MAP_ANONYMOUS | MAP_PRIVATE;
> +
> + if (sealable)
> + mapflags |= MAP_SEALABLE;
> +
> + ptr = mmap(NULL, size, PROT_READ, mapflags, -1, 0);
> + assert(ptr != (void *)-1);
> + *ptrOut = ptr;
> +}
> +
> +void setup_single_address_rw_sealable(int size, void **ptrOut, bool sealable)
> +{
> + void *ptr;
> + unsigned long mapflags = MAP_ANONYMOUS | MAP_PRIVATE;
> +
> + if (sealable)
> + mapflags |= MAP_SEALABLE;
> +
> + ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, mapflags, -1, 0);
> + assert(ptr != (void *)-1);
> + *ptrOut = ptr;
> +}
> +
> +void clean_single_address(void *ptr, int size)
> +{
> + int ret;
> +
> + ret = munmap(ptr, size);
> + assert(!ret);
> +}
> +
> +void seal_mprotect_single_address(void *ptr, int size)
> +{
> + int ret;
> +
> + ret = sys_mseal(ptr, size, MM_SEAL_PROT_PKEY);
> + assert(!ret);
> +}
> +
> +void seal_discard_ro_anon_single_address(void *ptr, int size)
> +{
> + int ret;
> +
> + ret = sys_mseal(ptr, size, MM_SEAL_DISCARD_RO_ANON);
> + assert(!ret);
> +}
> +
> +static void test_seal_addseals(void)
> +{
> + LOG_TEST_ENTER();
> + int ret;
> + void *ptr;
> + unsigned long page_size = getpagesize();
> + unsigned long size = 4 * page_size;
> +
> + setup_single_address(size, &ptr);
> +
> + /* adding seal one by one */
> +
> + ret = sys_mseal(ptr, size, MM_SEAL_BASE);
> + assert(!ret);
> + ret = sys_mseal(ptr, size, MM_SEAL_PROT_PKEY);
> + assert(!ret);
> + ret = sys_mseal(ptr, size, MM_SEAL_SEAL);
> + assert(!ret);
> +}
> +
> +static void test_seal_addseals_combined(void)
> +{
> + LOG_TEST_ENTER();
> + int ret;
> + void *ptr;
> + unsigned long page_size = getpagesize();
> + unsigned long size = 4 * page_size;
> +
> + setup_single_address(size, &ptr);
> +
> + ret = sys_mseal(ptr, size, MM_SEAL_PROT_PKEY);
> + assert(!ret);
> +
> + /* adding multiple seals */
> + ret = sys_mseal(ptr, size,
> + MM_SEAL_PROT_PKEY | MM_SEAL_BASE|
> + MM_SEAL_SEAL);
> + assert(!ret);
> +
> + /* not adding more seal type, so ok. */
> + ret = sys_mseal(ptr, size, MM_SEAL_BASE);
> + assert(!ret);
> +
> + /* not adding more seal type, so ok. */
> + ret = sys_mseal(ptr, size, MM_SEAL_SEAL);
> + assert(!ret);
> +}
> +
> +static void test_seal_addseals_reject(void)
> +{
> + LOG_TEST_ENTER();
> + int ret;
> + void *ptr;
> + unsigned long page_size = getpagesize();
> + unsigned long size = 4 * page_size;
> +
> + setup_single_address(size, &ptr);
> +
> + ret = sys_mseal(ptr, size, MM_SEAL_BASE | MM_SEAL_SEAL);
> + assert(!ret);
> +
> + /* MM_SEAL_SEAL is set, so not allow new seal type . */
> + ret = sys_mseal(ptr, size,
> + MM_SEAL_PROT_PKEY | MM_SEAL_BASE | MM_SEAL_SEAL);
> + assert(ret < 0);
> +}
> +
> +static void test_seal_unmapped_start(void)
> +{
> + LOG_TEST_ENTER();
> + int ret;
> + void *ptr;
> + unsigned long page_size = getpagesize();
> + unsigned long size = 4 * page_size;
> +
> + setup_single_address(size, &ptr);
> +
> + // munmap 2 pages from ptr.
Don't use different commenting styles in one file. Use /* */ for comments.

> + ret = sys_munmap(ptr, 2 * page_size);
> + assert(!ret);
> +
> + // mprotect will fail because 2 pages from ptr are unmapped.
> + ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
> + assert(ret < 0);
> +
> + // mseal will fail because 2 pages from ptr are unmapped.
> + ret = sys_mseal(ptr, size, MM_SEAL_SEAL);
> + assert(ret < 0);
> +
> + ret = sys_mseal(ptr + 2 * page_size, 2 * page_size, MM_SEAL_SEAL);
> + assert(!ret);
> +}
> +

Next message: Mike Rapoport: "Re: [REGRESSION] Platforms supporting SGX fail to kexec due to 96c6b8f212a ("memblock: report failures when memblock_can_resize is not set")"
Previous message: Alexandre Ghiti: "Re: [PATCH 4/4] riscv: enable HAVE_FAST_GUP if MMU"
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