- linux-morello - op-lists.linaro.org

by Kevin Brodsky

Hi, The morello/next branch has been rebased from v6.4 to v6.7. Make sure to reset/rebase any local branch tracking next. The final 6.4-based commit has been tagged morello-last-6.4. Note that morello.rst has moved under Documentation/arch/arm64, following the documentation reorganisation merged upstream in 6.5. There should be no other user-visible change following this rebase, aside from upstream changes between 6.4 and 6.7. The rest of this email provides a detailed changelog for developers. Cheers, Kevin -------------- Noteworthy changes: - "fs/binfmt_elf: Add additional Aux vector entries" has been slightly adapted following changes to load_elf_interp() [1]. This revealed an issue with the original patch, where the file size (p_filesz) of segments was considered instead of the memory size (p_memsz). Because we are concerned with the entirety of memory mapped for the executable/interpreter, we should rather consider p_memsz, which may be greater than p_filesz (the leftover is zero-padded / zero-mapped). The calculation of both exec_load_info and interp_load_info has been modified accordingly. - io_uring: * New patch "io_uring: Use full pointers for IORING_SETUP_NO_MMAP" [2] following the introduction of that flag in [3]. * Adaptations following the addition of getsockopt/setsockopt [4] (patch 9-10): new struct io_uring_sqe::optval member. A new patch "io_uring/cmd: Convert compat64 pointers for OP_{G,S}ETSOCKOPT" [5] takes care of the compat64 conversion, as it cannot realistically be done upfront. * Straightforward adaptations (replacing u64_to_user_ptr() with a cast and using io_user_data_is_same() instead of direct comparison) to the following additions: - waitid operation [6] - futex operations [7] * "io_uring: Implement compat versions of uAPI structs and handle them" adapted following [8] (patch 3-4), and additions to uapi structs reflected in linux/io_uring_compat.h. - BPF: * "bpf: compat64: add handler and convert bpf_attr in", "bpf: compat64: handle bpf_{btf,prog,link}_info" and "bpf: use user pointer types in uAPI structs" extended to cover uapi additions since 6.4. The handling of those is straightforward, albeit with a trick to handle BPF_LINK_TYPE_PERF_EVENT in convert_compat_link_info_in(), following [9]. - New commit "fs/proc: Update pagemap ioctl handler for PCuABI" to adapt the new PAGEMAP_SCAN ioctl handler [10]. These are minimal changes; the struct passed to the ioctl should be adapted too. Created issue #64 to track this [11]. - Due to the refactoring and additional macros introduced by [12], the permission split between private and shared mappings introduced in "arm64: morello: Enable access to capabilities in memory" became more difficult to implement fully. Since this permission split is introduced in a more proper and less invasive manner in "arm64: morello: Explicitly add VM_*_CAPS to private user mappings", the split was removed from the original commit, to simplify further rebasing. It should remain functionally correct, beside granting tag access to shared mappings (unlikely to be an issue when bisecting). This simplification also made the following commit unnecessary, and it has now been dropped: "arm64: Refactor PAGE_* definitions" Minor changes: - Added missing declarations in "arm64: add syscall wrapper for compat tasks in purecap", aligning with [13]. - Switched "arm64: morello: ptrace: Add request for reading a capability in memory" to using get_user_page_vma_remote(), following [14]. - "net: Modify ioctl to use user_uintptr_t" is now smaller (several hunks disappeared) as struct proto's ioctl callback no longer manipulates user pointers [15]. - "arm64: vdso: Build a pure-capability vDSO" adapted for the new vdso_install approach [16]. - "futex: Implement PCuABI for futex_waitv syscall" now amends the new futex_requeue syscall introduced in [17] too (simply dropping some u64_to_user_ptr()). - Added an explicit definition of struct sched_param to "kselftests/arm64: morello: Clean-up header files", as [18] removed it from the uapi header. - Added a new commit "tools/include: Add __kernel_uintptr_t to types.h" as arm64 kselftests include tools/include since [19], shadowing the uapi linux/types.h. Notes: - "arm64: morello: Handle capability faults": SEGV_CAPTAGERR conflicts with the new x86-specific (CET) SEGV_CPERR. Its value is left unchanged (10) to avoid a uapi change, which doesn't seem justified as it is currently trivial to disambiguate the two codes (one is x86-only, the other Morello-only). Dropped: - The following patches were posted [20] and merged upstream: * "fcntl: Cast commands with int args explicitly" * "fs: Pass argument to fcntl_setlease as int" * "pipe: Pass argument of pipe_fcntl as int" * "dnotify: Pass argument of fcntl_dirnotify as int" * "NFSv4: Fix nfs4_proc_setlease definition" [1] https://lore.kernel.org/all/20230929031716.it.155-kees@kernel.org/ [2] https://op-lists.linaro.org/archives/list/linux-morello@op-lists.linaro.org… [3] https://lore.kernel.org/all/20230513141643.1037620-1-axboe@kernel.dk/ [4] https://lore.kernel.org/all/20231016134750.1381153-1-leitao@debian.org/ [5] https://op-lists.linaro.org/archives/list/linux-morello@op-lists.linaro.org… [6] https://lore.kernel.org/lkml/20230909151124.1229695-1-axboe@kernel.dk/ [7] https://lore.kernel.org/lkml/20230928172517.961093-1-axboe@kernel.dk/ [8] https://lore.kernel.org/all/447aa1b2968978c99e655ba88db536e903df0fe9.169291… [9] https://lore.kernel.org/all/20230709025630.3735-9-laoar.shao@gmail.com/ [10] https://lore.kernel.org/all/20230821141518.870589-1-usama.anjum@collabora.c… [11] https://git.morello-project.org/morello/kernel/linux/-/issues/64 [12] https://lore.kernel.org/all/20230606145859.697944-1-joey.gouly@arm.com/ [13] https://lore.kernel.org/all/20230516160642.523862-4-arnd@kernel.org/ [14] https://lore.kernel.org/all/cover.1684350871.git.lstoakes@gmail.com/ [15] https://lore.kernel.org/all/20230609152800.830401-1-leitao@debian.org/ [16] https://lore.kernel.org/lkml/20231014105436.2119702-1-masahiroy@kernel.org/ [17] https://lore.kernel.org/all/20230921105248.511860556@noisy.programming.kick… [18] https://lore.kernel.org/all/20230808030357.1213829-1-kolyshkin@gmail.com/ [19] https://lore.kernel.org/all/20230728-arm64-signal-memcpy-fix-v4-4-0c1290db5… [20] https://lore.kernel.org/linux-fsdevel/20230414152459.816046-1-Luca.Vizzarro…

9 months, 3 weeks

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[MORELLO-SDK] Morello Linux 1.7.0

by Vincenzo Frascino

Hi All, I am glad to inform you on the availability of a new version of our SDK and base rootfs images for Morello (1.7.0). After months of hard work we are happy to share with you what we put together. Honoring our motto "Let Linux developers focus on the porting of their own application", we feel that this is another steps in the right direction. [Morello SDK] In less than 10 minutes you should be able to setup a docker container with everything you need to build an application for Morello. - Documentation: https://sdk.morello-project.org/ - Code repository: https://git.morello-project.org/morello/morello-sdk New in 1.7.0: - GDB support with Capabilities. - Support for vDSO in musl. - Initial support for compartments (limited demo of basic cases) [1]. - New versions for compilers and C libraries. [1] https://git.morello-project.org/morello/morello-examples If you want to try a demo of the SDK that runs on a Morello FVP (for more information on what is an FVP: www.morello-project.org) please have a look below: [Morello Linux] In less than 10 minutes you should be able to setup a docker container with everything you need to build and boot into a Morello Debian environment. - Documentation: https://linux.morello-project.org/ - Code repository: https://git.morello-project.org/morello/morello-linux Note: The documentation covers the instructions for Linux but if you know what you are doing and are familiar with docker no one stops you from running our solution on Windows or Mac. New in 1.7.0: - Updated Kernel ABI with initial security support. - Support for vDSO in kernel and C library. - New versions for compilers and C libraries. - Basic Compartment Demos. - Bug fixing and polishing of existing features. Note: This release does not include a new version of the Android environment. Further Android releases are now deprecated. Ongoing releases will focus on the Morello Linux Environment. Are we done with it? No, by any mean. This is just the beginning and we need your help and collaboration to make sure that we improve our solution to meet developers needs: your needs! So why don't you try it and let us know your thoughts? Thanks and Regards, Vincenzo

9 months, 4 weeks

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[PATCH 00/21] Introduce mm reservation interface for PCuABI

by Amit Daniel Kachhap

Hi All, This patch series introduces the mm reservation interface to manage the owning capability of the allocated addresses. This series adds reservation details in the VMA structure and different capability/reservation constraint checks. Looking for feedback regarding API names, directory structure etc. Details about several rules implemented can be found in PCuABI spec here [1]. Changes in this v1 as compared with RFC v2: 1) Added mm specific purecap flag instead of vma specific. 2) Enabled vma merge/expansion with reservation limit checks. 3) Modified get_unmapped_area() to add overlap checks for fixed address. 4) Some code fixes and cleanups as suggested by Kevin. Future works: 1) Users of vm_mmap/vm_munmap() i.e. filesystems, loaders, vdso, exec stack to be modified to preserve capability addresses. Some of these work in progress are hosted in [3] for reference. 2) Cover remaining memory addressing syscalls. Testing: 1) All tests by Chaitanya in v3 selftests [2] passes. 2) Purecap/Compat Busybox boot passes after adding [WIP] patches present in [3]. The whole series can be found here [3]. [1]: https://git.morello-project.org/morello/kernel/linux/-/wikis/Morello-pure-c… [2]: https://git.morello-project.org/chaitanya_prakash/linux.git review/purecap_mmap_testcases_v3 [3]: https://git.morello-project.org/amitdaniel/linux.git review/purecap_mm_reservation_v1 Thanks, Amit Daniel Amit Daniel Kachhap (21): uapi: errno.h: Introduce PCuABI memory reservation error mm: Add MMF_PCUABI_RESERVE mm flag mm: Add capability reservation interfaces in vma for PCuABI mm/cap_addr_mgmt: Add capability constraint helpers for PCuABI mm,fs: Use address as user_uintptr_t in generic get_unmapped_area() mm/mmap: Modify unmapped address space management code for PCuABI mm: Add PCuABI reservation details during vma operation mm/mmap: Add reservation constraints in mmap/munmap parameters mm/mremap: Add reservation constraints in mremap syscall mm/mprotect: Add the PCuABI reservation constraints mm/madvise: Add the PCuABI reservation constraints mm/mlock: Add the PCuABI reservation constraints mm/msync: Add the PCuABI reservation constraints uapi: mman-common.h: Macros for maximum capability permissions mm/cap_addr_mgmt: Add capability permission helpers for PCuABI mm/cap_addr_mgmt: Reduce the maximum protection check impact mm/mmap: Disable MAP_GROWSDOWN mapping flag for PCuABI mm/mmap: Add capability permission constraints for PCuABI mm/mremap: Add capability permission constraints for PCuABI mm/mprotect: Add capability permission constraints for PCuABI mm/mincore: Add PCuABI reservation/capability constraints arch/arm64/include/asm/cap_addr_mgmt.h | 22 ++ drivers/char/mem.c | 2 +- fs/hugetlbfs/inode.c | 2 +- fs/proc/inode.c | 4 +- fs/ramfs/file-mmu.c | 2 +- include/linux/cap_addr_mgmt.h | 268 +++++++++++++++++++++++++ include/linux/cheri.h | 3 + include/linux/fs.h | 2 +- include/linux/huge_mm.h | 2 +- include/linux/mm.h | 39 +++- include/linux/mm_types.h | 7 +- include/linux/proc_fs.h | 2 +- include/linux/sched/coredump.h | 2 + include/linux/sched/mm.h | 8 +- include/linux/shmem_fs.h | 2 +- include/uapi/asm-generic/errno.h | 2 + include/uapi/asm-generic/mman-common.h | 6 + io_uring/advise.c | 2 +- io_uring/io_uring.c | 2 +- ipc/shm.c | 2 +- kernel/fork.c | 3 + mm/Makefile | 2 +- mm/cap_addr_mgmt.c | 261 ++++++++++++++++++++++++ mm/damon/vaddr.c | 2 +- mm/huge_memory.c | 2 +- mm/madvise.c | 29 ++- mm/mincore.c | 46 ++++- mm/mlock.c | 38 +++- mm/mmap.c | 250 ++++++++++++++++++++--- mm/mprotect.c | 29 ++- mm/mremap.c | 96 +++++++-- mm/msync.c | 16 +- mm/shmem.c | 4 +- mm/util.c | 12 +- 34 files changed, 1056 insertions(+), 115 deletions(-) create mode 100644 arch/arm64/include/asm/cap_addr_mgmt.h create mode 100644 include/linux/cap_addr_mgmt.h create mode 100644 mm/cap_addr_mgmt.c -- 2.25.1

10 months

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[PATCH v4] uaccess_testing: Testing of capability enforcement in uaccess

by Akram Ahmad

Add tests for capability enforcement via the standard copy routines (copy_{to, from}_user, {get, put}_user), futex operations and the explicit uaccess checks used in iov_iter via readv and writev. Signed-off-by: Akram Ahmad <Akram.Ahmad(a)arm.com> --- Hi everyone, This is v4 of the uaccess kselftest patch and introduces the following: - Simplification of the futex test to only use one futex - Move FUTEX_WAKE_OP description to futex test - Various minor corrections V3 introduced the following changes: - Corrections to function prototypes to remove void * in favour of the actual struct pointer types and other minor corrections. - Correction to the futex test, which now tests for a correctly enforced uaccess routine when used in an atomic operation. - Reintroduction of the out-of-bounds checking in tests. V2 introduced the following changes: - More concise formatting changes - Corrections to various mistakes in tests - Addition of a strlen_user() test - Fixed futex test The review branch can be found at: https://git.morello-project.org/arkamnite/linux/-/commits/morello/uaccess_v4 The related issue can also be found at: https://git.morello-project.org/morello/kernel/linux/-/issues/58 Many thanks, Akram --- .../testing/selftests/arm64/morello/Makefile | 2 +- .../testing/selftests/arm64/morello/uaccess.c | 262 ++++++++++++++++++ 2 files changed, 263 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/arm64/morello/uaccess.c diff --git a/tools/testing/selftests/arm64/morello/Makefile b/tools/testing/selftests/arm64/morello/Makefile index ecfa6fc5e989..7b794d3e436c 100644 --- a/tools/testing/selftests/arm64/morello/Makefile +++ b/tools/testing/selftests/arm64/morello/Makefile @@ -17,7 +17,7 @@ CFLAGS += $(CLANG_FLAGS) $(CFLAGS_PURECAP) $(CFLAGS_COMMON) LDFLAGS += $(CLANG_LDFLAGS) $(CLANG_FLAGS) -nostdlib -static SRCS := $(wildcard *.c) $(wildcard *.S) -PROGS := bootstrap clone exit mmap read_write sched signal +PROGS := bootstrap clone exit mmap read_write sched signal uaccess DEPS := $(wildcard *.h) # these are the final executables diff --git a/tools/testing/selftests/arm64/morello/uaccess.c b/tools/testing/selftests/arm64/morello/uaccess.c new file mode 100644 index 000000000000..ee2847472bc2 --- /dev/null +++ b/tools/testing/selftests/arm64/morello/uaccess.c @@ -0,0 +1,262 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2023 Arm Limited + +#include <stdint.h> +#include <stddef.h> +#include <stdbool.h> + +#include <asm/fcntl.h> +#include <asm-generic/errno-base.h> +#include <cheriintrin.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/futex.h> +#include <linux/mman.h> +#include <linux/signal.h> +#include <linux/sysinfo.h> +#include <linux/socket.h> +#include <linux/time.h> +#include <linux/uio.h> + +#include "freestanding.h" + +#define MSG_LEN 16 + +static const char file[] = "/my_file.txt"; + +static inline int fsopen(const char *string) +{ + return syscall(__NR_fsopen, string); +} + + +static inline int futex_wake_op(uint32_t *uaddr, uint32_t *uaddr2, uint32_t val3) +{ + return syscall(__NR_futex, uaddr, FUTEX_WAKE_OP, 1, 1, + uaddr2, val3); +} + +typedef unsigned short sa_family_t; + +struct sockaddr { + sa_family_t sa_family; + char sa_data[14]; +}; + +static int getsockname(int socket, struct sockaddr *sockaddr, int *socklen) +{ + return syscall(__NR_getsockname, socket, sockaddr, socklen); +} + +static int open_file(void) +{ + return syscall(__NR_openat, 0, file, O_RDWR | O_CREAT, 0666); +} + +static inline int readv(int fd, struct iovec *iov, int iovcnt) +{ + return syscall(__NR_readv, fd, iov, iovcnt); +} + +static inline int writev(int fd, struct iovec *iov, int iovcnt) +{ + return syscall(__NR_writev, fd, iov, iovcnt); +} + +static inline int sigaction(int sig, struct sigaction *old, struct sigaction *new) +{ + return syscall(__NR_rt_sigaction, sig, old, new, sizeof(sigset_t)); +} + +static inline int sysinfo(struct sysinfo *ptr) +{ + return syscall(__NR_sysinfo, ptr); +} + +TEST(test_copy_to_user) +{ + struct sysinfo my_sysinfo; + + ASSERT_EQ(sysinfo(&my_sysinfo), 0); + + ASSERT_EQ(sysinfo(&my_sysinfo + sizeof(struct sysinfo)), -EFAULT); + + ASSERT_EQ(sysinfo(cheri_tag_clear(&my_sysinfo)), -EFAULT); + + ASSERT_EQ(sysinfo(cheri_perms_and(&my_sysinfo, 0)), -EFAULT); +} + +/* + * sigaction() tests both copy_to_user and copy_from_user by copying + * into and from a pointer to struct sigaction. The resulting action + * in this case is a no-op, but this does not affect the validity of + * the test. sigaction attempts to copy the new action from user space + * and the old action to user space, if the arguments is valid in either + * case. + */ +TEST(test_copy_user) +{ + struct sigaction act; + + ASSERT_EQ(sigaction(SIGSEGV, NULL, &act), 0); + ASSERT_EQ(sigaction(SIGSEGV, &act, NULL), 0); + + ASSERT_EQ(sigaction(SIGSEGV, NULL, &act + sizeof(struct sigaction)), -EFAULT); + ASSERT_EQ(sigaction(SIGSEGV, &act + sizeof(struct sigaction), NULL), -EFAULT); + + ASSERT_EQ(sigaction(SIGSEGV, NULL, cheri_tag_clear(&act)), -EFAULT); + ASSERT_EQ(sigaction(SIGSEGV, cheri_tag_clear(&act), NULL), -EFAULT); + + ASSERT_EQ(sigaction(SIGSEGV, NULL, cheri_perms_and(&act, 0)), -EFAULT); + ASSERT_EQ(sigaction(SIGSEGV, cheri_perms_and(&act, 0), NULL), -EFAULT); +} + +/* + * getsockname(2) uses both get_user and put_user to copy the addrlen argument + * from and to user space respectively. getsockname(2) calls move_addr_to_user + * to copy an address to user space. move_addr_to_user also uses copy_to_user; + * if copy_to_user is successful, but either of get_user or put_user fail then + * getsockname(2) will return -EFAULT appropriately. + */ +TEST(test_get_put_user) +{ + struct sockaddr sa; + int sa_len = sizeof(sa); + int my_socket; + + // socket(AF_INET, SOCK_STREAM, 0) + my_socket = syscall(__NR_socket, 2, 1, 0); + + // The socket must be successfully opened before proceeding. + ASSERT_GE(my_socket, 0); + + ASSERT_EQ(getsockname(my_socket, &sa, &sa_len), 0); + ASSERT_EQ(getsockname(my_socket, &sa, &sa_len + sizeof(struct sockaddr)), -EFAULT); + ASSERT_EQ(getsockname(my_socket, &sa, cheri_tag_clear(&sa_len)), -EFAULT); + ASSERT_EQ(getsockname(my_socket, &sa, cheri_perms_and(&sa_len, 0)), -EFAULT); + close(my_socket); +} + +/* + * The FUTEX_WAKE_OP operation in the futex(2) syscall is used to handle more + * than one futex at the same time. This is an atomic operation that attempts + * to read, modify and write a value at a second uaddr (uaddr2) and also wake + * up waiters on the futex words at uaddr1 and uaddr2. uaddr1 and uaddr2 are + * provided via capabilities, and so this futex tests the case of an atomic + * uaccess operation. + * + * When using FUTEX_WAKE_OP, val3 is an encoding of both the operation as + * well as the comparison to be performed on the futex word at uaddr2. If val3 + * is set to 0, this represents an operation of FUTEX_OP_SET and a comparison + * FUTEX_OP_CMP_EQ, where both oparg and comparg are 0. + */ +TEST(test_futex) +{ + static struct futex_waitv waitv; + uint32_t futex = 0; + + waitv.uaddr = (uintptr_t)&futex; + waitv.flags = FUTEX_32 | FUTEX_PRIVATE_FLAG; + waitv.val = futex; + waitv.__reserved = 0; + + ASSERT_GE(futex_wake_op(&futex, &futex, 0), 0); + ASSERT_EQ(futex_wake_op(&futex, &futex + sizeof(uint32_t), 0), -EFAULT); + ASSERT_EQ(futex_wake_op(&futex, cheri_tag_clear(&futex), 0), -EFAULT); + ASSERT_EQ(futex_wake_op(&futex, cheri_perms_and(&futex, 0), 0), + -EFAULT); +} + +/* + * Test explicit accesses used in iov_iter via readv and writev. Both + * syscalls use explicit checking on the iov_base field of struct iovec, + * so the metadata of the capability provided for iov_base is modified as + * per the needs of each individual test. + */ +TEST(test_explicit_iov_iter) +{ + char buf0[2]; + char buf1[4]; + char buf2[6]; + const char *write_buf0 = "Hello I am the first char buffer!\n"; + const char *write_buf1 = "Hello, I am the second char buffer.\n"; + const char *write_buf2 = "Hello, I am the third and final char buffer.\n"; + struct iovec iov[3]; + int iovcnt; + int fd; + + fd = open_file(); + ASSERT_NE(fd, -1); + + iov[0].iov_base = buf0; + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + ASSERT_GE(readv(fd, iov, iovcnt), 0); + + iov[0].iov_base = buf0 + sizeof(iov) * 100; + ASSERT_EQ(readv(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = cheri_tag_clear(buf0); + ASSERT_EQ(readv(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = cheri_perms_and(buf0, 0); + ASSERT_EQ(readv(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = (void *)write_buf0; + iov[0].iov_len = strlen(write_buf0); + iov[1].iov_base = (void *)write_buf1; + iov[1].iov_len = strlen(write_buf1); + iov[2].iov_base = (void *)write_buf2; + iov[2].iov_len = strlen(write_buf2); + + ASSERT_GE(writev(fd, iov, iovcnt), 0); + + iov[0].iov_base = (void *)write_buf0 + sizeof(iov) * 100; + ASSERT_EQ(writev(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = (void *)cheri_tag_clear(write_buf0); + ASSERT_EQ(writev(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = (void *)cheri_perms_and(write_buf0, 0); + ASSERT_EQ(writev(fd, iov, iovcnt), -EFAULT); + + close(fd); +} + +/* + * strlen_user() explicitly inspects an input capability, the behaviour + * of which must also be verified within these tests. The fsopen() syscall + * makes use of strlen_user() by duplicating a string (representing the name + * of a filesystem) with the strndup_user() function. strlen_user() can + * therefore be tested with a call to fsopen(). + */ +TEST(test_strlen_user) +{ + const char *fsname = "my_nonexistent_filesystem"; + + // strndup_user() will still be called, so fsopen() fails after this. + ASSERT_EQ(fsopen(fsname), -ENODEV); + + ASSERT_EQ(fsopen(fsname + strlen(fsname) * 10), -EFAULT); + + ASSERT_EQ(fsopen(cheri_tag_clear(fsname)), -EFAULT); + + ASSERT_EQ(fsopen(cheri_perms_and(fsname, 0)), -EFAULT); +} + +int main(void) +{ + test_copy_to_user(); + test_copy_user(); + test_get_put_user(); + test_futex(); + test_explicit_iov_iter(); + test_strlen_user(); + return 0; +} -- 2.34.1

10 months, 1 week

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[PATCH v3] uaccess_testing: Testing of capability enforcement in uaccess

by Akram Ahmad

Add tests for capability enforcement via the standard copy routines (copy_{to, from}_user, {get, put}_user), futex operations and the explicit uaccess checks used in iov_iter via readv and writev. Signed-off-by: Akram Ahmad <Akram.Ahmad(a)arm.com> --- Hi everyone, This is v3 of the uaccess kselftest patch. The main changes from V2 to V3 are: - Corrections to function prototypes to remove void * in favour of the actual struct pointer types and other minor corrections. - Correction to the futex test, which now tests for a correctly enforced uaccess routine when used in an atomic operation. - Reintroduction of the out-of-bounds checking in tests. V2 introduced the following changes: - More concise formatting changes - Corrections to various mistakes in tests - Addition of a strlen_user() test - Fixed futex test The review branch can be found at: https://git.morello-project.org/arkamnite/linux/-/commits/morello%2Fuaccess… The related issue can also be found at: https://git.morello-project.org/morello/kernel/linux/-/issues/58 Many thanks, Akram --- .../testing/selftests/arm64/morello/Makefile | 2 +- .../testing/selftests/arm64/morello/uaccess.c | 271 ++++++++++++++++++ 2 files changed, 272 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/arm64/morello/uaccess.c diff --git a/tools/testing/selftests/arm64/morello/Makefile b/tools/testing/selftests/arm64/morello/Makefile index ecfa6fc5e989..7b794d3e436c 100644 --- a/tools/testing/selftests/arm64/morello/Makefile +++ b/tools/testing/selftests/arm64/morello/Makefile @@ -17,7 +17,7 @@ CFLAGS += $(CLANG_FLAGS) $(CFLAGS_PURECAP) $(CFLAGS_COMMON) LDFLAGS += $(CLANG_LDFLAGS) $(CLANG_FLAGS) -nostdlib -static SRCS := $(wildcard *.c) $(wildcard *.S) -PROGS := bootstrap clone exit mmap read_write sched signal +PROGS := bootstrap clone exit mmap read_write sched signal uaccess DEPS := $(wildcard *.h) # these are the final executables diff --git a/tools/testing/selftests/arm64/morello/uaccess.c b/tools/testing/selftests/arm64/morello/uaccess.c new file mode 100644 index 000000000000..d1624f61adcd --- /dev/null +++ b/tools/testing/selftests/arm64/morello/uaccess.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2023 Arm Limited + +#include <stdint.h> +#include <stddef.h> +#include <stdbool.h> + +#include <asm/fcntl.h> +#include <asm-generic/errno-base.h> +#include <cheriintrin.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/futex.h> +#include <linux/mman.h> +#include <linux/signal.h> +#include <linux/sysinfo.h> +#include <linux/socket.h> +#include <linux/time.h> +#include <linux/uio.h> + +#include "freestanding.h" + +#define MSG_LEN 16 +#define NR_FUTEXES 5 + +static const char file[] = "/my_file.txt"; + +static inline int fsopen(const char *string) +{ + return syscall(__NR_fsopen, string); +} + +/* + * FUTEX_WAKE_OP is an operation used to handle more than one futex at the same + * time. When using FUTEX_WAKE_OP, val3 is an encoding of both the operation as + * well as the comparison to be performed on the futex word at uaddr2. If val3 + * is set to 0, this represents an operation of FUTEX_OP_SET and a comparison + * FUTEX_OP_CMP_EQ, where both oparg and comparg are 0. + */ +static inline int futex_wake(uint32_t *uaddr, uint32_t *uaddr2, uint32_t val3, + const struct timespec *timeout) +{ + return syscall(__NR_futex, uaddr, FUTEX_WAKE_OP, NR_FUTEXES, timeout, + uaddr2, val3); +} + +typedef unsigned short sa_family_t; + +struct sockaddr { + sa_family_t sa_family; + char sa_data[14]; +}; + +static int getsockname(int socket, struct sockaddr *sockaddr, int *socklen) +{ + return syscall(__NR_getsockname, socket, sockaddr, socklen); +} + +static int open_file(void) +{ + return syscall(__NR_openat, 0, file, O_RDWR | O_CREAT, 0666); +} + +static inline int readv(int fd, struct iovec *iov, int iovcnt) +{ + return syscall(__NR_readv, fd, iov, iovcnt); +} + +static inline int writev(int fd, struct iovec *iov, int iovcnt) +{ + return syscall(__NR_writev, fd, iov, iovcnt); +} + +static inline int sigaction(int sig, struct sigaction *old, struct sigaction *new) +{ + return syscall(__NR_rt_sigaction, sig, old, new, sizeof(sigset_t)); +} + +static inline int sysinfo(struct sysinfo *ptr) +{ + return syscall(__NR_sysinfo, ptr); +} + +TEST(test_copy_to_user) +{ + struct sysinfo my_sysinfo; + + ASSERT_EQ(sysinfo(&my_sysinfo), 0); + + ASSERT_EQ(sysinfo(&my_sysinfo + sizeof(struct sysinfo) * 100), -EFAULT); + + ASSERT_EQ(sysinfo(cheri_tag_clear(&my_sysinfo)), -EFAULT); + + ASSERT_EQ(sysinfo(cheri_perms_and(&my_sysinfo, 0)), -EFAULT); +} + +/* + * sigaction() tests both copy_to_user and copy_from_user by copying + * into and from a pointer to struct sigaction. The resulting action + * in this case is a no-op, but this does not affect the validity of + * the test. sigaction attempts to copy the new action from user space + * and the old action to user space, if the arguments is valid in either + * case. + */ +TEST(test_copy_user) +{ + struct sigaction act; + + ASSERT_EQ(sigaction(SIGSEGV, NULL, &act), 0); + ASSERT_EQ(sigaction(SIGSEGV, &act, NULL), 0); + + ASSERT_EQ(sigaction(SIGSEGV, NULL, &act + sizeof(struct sigaction) * 100), -EFAULT); + ASSERT_EQ(sigaction(SIGSEGV, &act + sizeof(struct sigaction) * 100, NULL), -EFAULT); + + ASSERT_EQ(sigaction(SIGSEGV, NULL, cheri_tag_clear(&act)), -EFAULT); + ASSERT_EQ(sigaction(SIGSEGV, cheri_tag_clear(&act), NULL), -EFAULT); + + ASSERT_EQ(sigaction(SIGSEGV, NULL, cheri_perms_and(&act, 0)), -EFAULT); + ASSERT_EQ(sigaction(SIGSEGV, cheri_perms_and(&act, 0), NULL), -EFAULT); +} + +/* + * getsockname(2) uses both get_user and put_user to copy the addrlen argument + * from and to user space respectively. getsockname(2) calls move_addr_to_user + * to copy an address to user space. move_addr_to_user also uses copy_to_user; + * if copy_to_user is successful, but either of get_user or put_user fail then + * getsockname(2) will return -EFAULT appropriately. + */ +TEST(test_get_put_user) +{ + struct sockaddr sa; + int sa_len = sizeof(sa); + int my_socket; + + // socket(AF_INET, SOCK_STREAM, 0) + my_socket = syscall(__NR_socket, 2, 1, 0); + + // The socket must be successfully opened before proceeding. + ASSERT_GE(my_socket, 0); + + ASSERT_EQ(getsockname(my_socket, &sa, &sa_len), 0) + ASSERT_EQ(getsockname(my_socket, &sa, &sa_len + sizeof(struct sockaddr) * 100), -EFAULT) + ASSERT_EQ(getsockname(my_socket, &sa, cheri_tag_clear(&sa_len)), -EFAULT) + ASSERT_EQ(getsockname(my_socket, &sa, cheri_perms_and(&sa_len, 0)), -EFAULT) + close(my_socket); +} + +/* + * The FUTEX_WAKE_OP operation in the futex(2) syscall is used to handle more + * than one futex at the same time. This is an atomic operation that attempts + * to read, modify and write a value at a second uaddr (uaddr2) and also wake + * up waiters on the futex words at uaddr1 and uaddr2. uaddr1 and uaddr2 are + * provided via capabilities, and so this futex tests the case of an atomic + * uaccess operation. + */ +TEST(test_futex) +{ + static struct futex_waitv waitv[NR_FUTEXES]; + uint32_t futexes[NR_FUTEXES] = {0}; + struct timespec to = {.tv_sec = 0, .tv_nsec = 500000000}; + + for (int i = 0; i < NR_FUTEXES; i++) { + waitv[i].uaddr = (uintptr_t)&futexes[i]; + waitv[i].flags = FUTEX_32 | FUTEX_PRIVATE_FLAG; + waitv[i].val = futexes[i]; + waitv[i].__reserved = 0; + } + + ASSERT_GE(futex_wake(&futexes[0], &futexes[0], 0, &to), 0); + ASSERT_EQ(futex_wake(&futexes[0], + &futexes[0] + sizeof(uint32_t) * NR_FUTEXES, 0, + &to), + -EFAULT); + ASSERT_EQ(futex_wake(&futexes[0], cheri_tag_clear(&futexes[0]), 0, &to), + -EFAULT); + ASSERT_EQ(futex_wake(&futexes[0], cheri_perms_and(&futexes[0], 0), 0, + &to), + -EFAULT); +} + +/* + * Test explicit accesses used in iov_iter via readv and writev. Both + * syscalls use explicit checking on the iov_base field of struct iovec, + * so the metadata of the capability provided for iov_base is modified as + * per the needs of each individual test. + */ +TEST(test_explicit_iov_iter) +{ + char buf0[2]; + char buf1[4]; + char buf2[6]; + char *write_buf0 = "Hello I am the first char buffer!\n"; + char *write_buf1 = "Hello, I am the second char buffer.\n"; + char *write_buf2 = "Hello, I am the third and final char buffer.\n"; + struct iovec iov[3]; + int iovcnt; + static int fd; + + fd = open_file(); + ASSERT_NE(fd, -1); + + iov[0].iov_base = buf0; + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + ASSERT_GE(readv(fd, iov, iovcnt), 0); + + iov[0].iov_base = buf0 + sizeof(iov) * 100; + ASSERT_EQ(readv(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = cheri_tag_clear(buf0); + ASSERT_EQ(readv(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = cheri_perms_and(buf0, 0); + ASSERT_EQ(readv(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = write_buf0; + iov[0].iov_len = strlen(write_buf0); + iov[1].iov_base = write_buf1; + iov[1].iov_len = strlen(write_buf1); + iov[2].iov_base = write_buf2; + iov[2].iov_len = strlen(write_buf2); + + ASSERT_GE(writev(fd, iov, iovcnt), 0); + + iov[0].iov_base = write_buf0 + sizeof(iov) * 100; + ASSERT_EQ(writev(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = cheri_tag_clear(write_buf0); + ASSERT_EQ(writev(fd, iov, iovcnt), -EFAULT); + + iov[0].iov_base = cheri_perms_and(write_buf0, 0); + ASSERT_EQ(writev(fd, iov, iovcnt), -EFAULT); +} + +/* + * strlen_user() explicitly inspects an input capability, the behaviour + * of which must also be verified within these tests. The fsopen() syscall + * makes use of strlen_user() by duplicating a string (representing the name + * of a filesystem) with the strndup_user() function. strlen_user() can + * therefore be tested with a call to fsopen(). + */ +TEST(test_strlen_user) +{ + const char *fsname = "my_nonexistent_filesystem"; + + // strndup_user() will still be called, so fsopen() fails after this. + ASSERT_EQ(fsopen(fsname), -ENODEV); + + ASSERT_EQ(fsopen(fsname + strlen(fsname) * 10), -EFAULT); + + ASSERT_EQ(fsopen(cheri_tag_clear(fsname)), -EFAULT); + + ASSERT_EQ(fsopen(cheri_perms_and(fsname, 0)), -EFAULT); +} + +int main(void) +{ + test_copy_to_user(); + test_copy_user(); + test_get_put_user(); + test_futex(); + test_explicit_iov_iter(); + test_strlen_user(); + return 0; +} -- 2.34.1

10 months, 1 week

2
1
0 0

[PATCH 00/12] Switch to capability-based uaccess

by Kevin Brodsky

Hi, This series switches all uaccess routines to operate directly on the user-provided capability pointer in PCuABI, instead of making the access via the extracted 64-bit address. This means that all forms of uaccess now enforce the capability metadata, through the use of capability-based loads and stores, and will fail with -EFAULT following a failed (hardware) capability check. The impacted routines are: - *get_user* (including get_user_ptr) - *put_user* (including put_user_ptr) - *copy_from_user* (including copy_from_user_with_ptr) - *copy_to_user* (including copy_to_user_with_ptr) (Note that futex operations are already checked thanks to Luca's work [1].) Enabling capability checks in uaccess exposed a variety of issues, both in the kernel and in userspace. This series addresses the fallout in the kernel before making the switch: - Patch 1-3 overhaul strnlen_user() to prevent it from reading beyond the bounds of the user pointer, while leaving its implementation unchanged in !PCuABI. - Patch 4-6 fixes various capability propagation issues (surprisingly few of those!). - Patch 7 fixes a bug in a Morello kselftest, detected through capability checking in copy_from_user(). Finally, the switch to capability-based accesses is made: - Patch 8-10 switch {get,put}_user and variants. - Patch 11-12 switch copy_{from,to}_user and variants. After this series, the Morello kselftests and Musl tests still pass, and so do the liburing tests, however the LTP syscalls suite doesn't because of various issues in LTP itself. I have addressed a number of them upstream [2] (series already merged), and will post the remaining fixes to linux-morello-ltp. Because this precise uaccess checking cannot be achieved with most existing sanitisers or hardware memory safety mechanisms, further bugs are likely to be identified in low-level libraries and test suites running in purecap (I have spotted a couple in the Bionic tests). Issue: https://git.morello-project.org/morello/kernel/linux/-/issues/5 Review branch: https://git.morello-project.org/kbrodsky-arm/linux/-/commits/morello/checke… Cheers, Kevin [1] https://op-lists.linaro.org/archives/list/linux-morello@op-lists.linaro.org… [2] https://lore.kernel.org/ltp/20231023135647.2157030-1-kevin.brodsky@arm.com/ Kevin Brodsky (12): linux/user_ptr.h: Introduce user_ptr_{base,limit} lib: Refactor do_strnlen_user() lib: Make strnlen_user() PCuABI-friendly block: Eliminate invalid user pointer casts tty: Convert another ioctl helper to take arg as user_uintptr_t seccomp: Preserve pointers when reading sock_fprog from userspace kselftests/arm64: morello: Fix message size in mmap test arm64: morello: Implement user capability accessors inline arm64: uaccess: Move macros from futex.h to uaccess.h arm64: uaccess: Switch to capability-based {get,put}_user in PCuABI arm64: lib: Simplify copy_*_user register allocation arm64: lib: Switch to capability-based copy_*_user in PCuABI Documentation/core-api/user_ptr.rst | 13 ++ arch/arm64/include/asm/assembler.h | 8 + arch/arm64/include/asm/futex.h | 20 +-- arch/arm64/include/asm/gpr-num.h | 6 +- arch/arm64/include/asm/morello.h | 4 - arch/arm64/include/asm/uaccess.h | 49 +++++- arch/arm64/lib/copy_from_user.S | 33 +++- arch/arm64/lib/copy_template.S | 14 +- arch/arm64/lib/copy_to_user.S | 17 +- arch/arm64/lib/morello.S | 23 --- block/blk-zoned.c | 6 +- block/ioctl.c | 22 +-- drivers/tty/tty_ioctl.c | 2 +- include/linux/blkdev.h | 8 +- include/linux/tty.h | 2 +- include/linux/user_ptr.h | 44 +++++ kernel/seccomp.c | 2 +- lib/strnlen_user.c | 163 +++++++++++++++---- tools/testing/selftests/arm64/morello/mmap.c | 2 +- 19 files changed, 319 insertions(+), 119 deletions(-) -- 2.38.1

10 months, 2 weeks

3
24
0 0

[PATCH v2] uaccess_testing: Testing of capability enforcement in uaccess

by Akram Ahmad

Add tests for capability enforcement via the standard copy routines (copy_{to, from}_user, {get, put}_user), futex operations and the explicit uaccess checks used in iov_iter via readv and writev. Signed-off-by: Akram Ahmad <Akram.Ahmad(a)arm.com> --- Hi everyone, This is V2 of the uaccess kselftest patch. The main changes are: - More concise formatting changes - Corrections to various mistakes in tests - Addition of a strlen_user() test case One of the most important fixes is the fixed futex test. It turns out that whilst optimisation was causing some varying results, the overall problem was to do with a mistake in the use of the syscall. I've decided to allow the syscall to timeout in the case of a valid input capability, as I feel this tests the explicit uaccess check sufficiently, but I am not sure if this is the ideal method. Many thanks, Akram --- .../testing/selftests/arm64/morello/Makefile | 2 +- .../testing/selftests/arm64/morello/uaccess.c | 294 ++++++++++++++++++ 2 files changed, 295 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/arm64/morello/uaccess.c diff --git a/tools/testing/selftests/arm64/morello/Makefile b/tools/testing/selftests/arm64/morello/Makefile index ecfa6fc5e989..7b794d3e436c 100644 --- a/tools/testing/selftests/arm64/morello/Makefile +++ b/tools/testing/selftests/arm64/morello/Makefile @@ -17,7 +17,7 @@ CFLAGS += $(CLANG_FLAGS) $(CFLAGS_PURECAP) $(CFLAGS_COMMON) LDFLAGS += $(CLANG_LDFLAGS) $(CLANG_FLAGS) -nostdlib -static SRCS := $(wildcard *.c) $(wildcard *.S) -PROGS := bootstrap clone exit mmap read_write sched signal +PROGS := bootstrap clone exit mmap read_write sched signal uaccess DEPS := $(wildcard *.h) # these are the final executables diff --git a/tools/testing/selftests/arm64/morello/uaccess.c b/tools/testing/selftests/arm64/morello/uaccess.c new file mode 100644 index 000000000000..e3c935df948a --- /dev/null +++ b/tools/testing/selftests/arm64/morello/uaccess.c @@ -0,0 +1,294 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2023 Arm Limited + +#include <stdint.h> +#include <stddef.h> +#include <stdbool.h> + +#include <asm/fcntl.h> +#include <asm-generic/errno-base.h> +#include <cheriintrin.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/futex.h> +#include <linux/mman.h> +#include <linux/signal.h> +#include <linux/sysinfo.h> +#include <linux/socket.h> +#include <linux/time.h> +#include <linux/uio.h> + +#include "freestanding.h" + +#define MSG_LEN 16 +#define NR_FUTEXES 1 + +static struct futex_waitv waitv[NR_FUTEXES]; +uint32_t futexes[NR_FUTEXES] = {1}; + +static const char file[] = "/my_file.txt"; +static int fd; + +static inline int fsopen(void *string) +{ + return syscall(__NR_fsopen, string); +} + +static inline int futex_waitv(struct futex_waitv *waiters, unsigned long nr_waiters, + unsigned long flags, struct timespec *timo, clockid_t clockid) +{ + return syscall(__NR_futex_waitv, waiters, nr_waiters, flags, timo, clockid); +} + +static int getsockname(int socket, void *sockaddr, int *socklen) +{ + return syscall(__NR_getsockname, socket, sockaddr, socklen); +} + +static int open_file(void) +{ + return syscall(__NR_openat, 0, file, O_RDWR | O_CREAT, 0666); +} + +static inline int readv(int fd, struct iovec *iov, int iovcnt) +{ + return syscall(__NR_readv, fd, iov, iovcnt); +} + +static inline int writev(int fd, struct iovec *iov, int iovcnt) +{ + return syscall(__NR_writev, fd, iov, iovcnt); +} + +static inline int sigaction(int sig, void *old, void *new) +{ + return syscall(__NR_rt_sigaction, sig, old, new, sizeof(sigset_t)); +} + +static inline int sysinfo(void *ptr) +{ + return syscall(__NR_sysinfo, ptr); +} + +TEST(test_copy_to_user) +{ + struct sysinfo my_sysinfo; + + // Ensure that valid capabilities are successfully copied. + ASSERT_EQ(sysinfo(&my_sysinfo), 0); + + // Test copying a capability which has an invalid tag. + ASSERT_EQ(sysinfo(cheri_tag_clear(&my_sysinfo)), -EFAULT); + + // Test copying a capability which has invalid permissions. + ASSERT_EQ(sysinfo(cheri_perms_and(&my_sysinfo, 0)), -EFAULT); +} + +/* + * sigaction() tests both copy_to_user and copy_from_user by copying + * into and from a pointer to struct sigaction. The resulting action + * in this case is a no-op, but this does not affect the validity of + * the test. sigaction attempts to copy the new action from user space + * and the old action to user space, if the arguments is valid in either + * case. + */ +TEST(test_copy_user) +{ + struct sigaction act; + + // Check valid capabilities are successfully copied. + ASSERT_EQ(sigaction(SIGSEGV, NULL, &act), 0); + ASSERT_EQ(sigaction(SIGSEGV, &act, NULL), 0); + + /* + * Capabilities with a cleared tag must not be successfully copied + * from nor into user space. + */ + ASSERT_EQ(sigaction(SIGSEGV, NULL, cheri_tag_clear(&act)), -EFAULT); + ASSERT_EQ(sigaction(SIGSEGV, cheri_tag_clear(&act), NULL), -EFAULT); + + /* + * Capabilities with invalid permissions (simulated here with 0) must + * not be successfully copied to or from user space. + */ + ASSERT_EQ(sigaction(SIGSEGV, NULL, cheri_perms_and(&act, 0)), -EFAULT); + ASSERT_EQ(sigaction(SIGSEGV, cheri_perms_and(&act, 0), NULL), -EFAULT); +} + +typedef unsigned short sa_family_t; + +struct sockaddr { + sa_family_t sa_family; + char sa_data[14]; +}; + +/* + * getsockname(2) uses both get_user and put_user to copy the addrlen argument + * from and to user space respectively. If copy_to_user works successfully, + * getsockname(2) will return -EFAULT if either get_user or put_user fail. + */ +TEST(test_get_put_user) +{ + struct sockaddr sa; + int sa_len = sizeof(sa); + int my_socket; + + // socket(AF_INET, SOCK_STREAM, 0) + my_socket = syscall(__NR_socket, 2, 1, 0); + + // The socket must be successfully opened before proceeding. + ASSERT_GE(my_socket, 0); + + ASSERT_EQ(getsockname(my_socket, &sa, &sa_len), 0) + goto cleanup; + // Test with cleared capability tag. + ASSERT_EQ(getsockname(my_socket, &sa, cheri_tag_clear(&sa_len)), -EFAULT) + goto cleanup; + // Test with invalid capability permissions. + ASSERT_EQ(getsockname(my_socket, &sa, cheri_perms_and(&sa_len, 0)), -EFAULT) + goto cleanup; + + /* + * If any of the getsockname syscalls failed, then the socket is + * still open and must be closed before the test exits. + */ +cleanup: + ASSERT_EQ(close(my_socket), 0); +} + +/* + * The futex_waitv syscall explicitly checks the uaddr field of the individual + * futex waiters which is provided by a capability. This capability enforcement + * is therefore tested here; in the case where the capability is valid, the + * syscall should return -ETIMEDOUT as the futex waiter requires another thread + * to signal that it should wake up using futex_wake(). futex_wait() is not + * called in this thread, thus causing a timeout to occur. + */ +TEST(test_futex) +{ + struct timespec to = {.tv_sec = 0, .tv_nsec = 500000000}; + int res; + + // Test with valid capabilities. + for (int i = 0; i < NR_FUTEXES; i++) { + waitv[i].uaddr = (uintptr_t)&futexes[i]; + waitv[i].flags = FUTEX_32 | FUTEX_PRIVATE_FLAG; + waitv[i].val = futexes[i]; + waitv[i].__reserved = 0; + } + + res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC); + ASSERT_EQ(res, -ETIMEDOUT); + + for (int i = 0; i < NR_FUTEXES; i++) + waitv[i].uaddr = (uintptr_t)cheri_tag_clear(&futexes[i]); + + + res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC); + ASSERT_EQ(res, -EFAULT); + + for (int i = 0; i < NR_FUTEXES; i++) + waitv[i].uaddr = (uintptr_t)cheri_perms_and(&futexes[i], 0); + + + res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC); + ASSERT_EQ(res, -EFAULT); +} + +/* + * Test explicit accesses used in iov_iter via readv and writev. Both + * syscalls use explicit checking on the iov_base field of struct iovec, + * so the metadata of the capability provided for iov_base is modified as + * per the needs of each individual test. + */ +TEST(test_explicit_iov_iter) +{ + char buf0[2]; + char buf1[4]; + char buf2[6]; + char *write_buf0 = "Hello I am the first char buffer!\n"; + char *write_buf1 = "Hello, I am the second char buffer.\n"; + char *write_buf2 = "Hello, I am the third and final char buffer.\n"; + struct iovec iov[3]; + int iovcnt; + + fd = open_file(); + ASSERT_NE(fd, -1); + + // Set up buffers for reading. + iov[0].iov_base = buf0; + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + // Make sure readv works as expected with intact buf0. + ASSERT_GE(readv(fd, iov, iovcnt), 0) goto cleanup; + + // Clear the tag for the pointer to buf0. + iov[0].iov_base = cheri_tag_clear(buf0); + ASSERT_EQ(readv(fd, iov, iovcnt), -EFAULT) goto cleanup; + + // Clear permissions, but restore the tag for buf0. + iov[0].iov_base = buf0; + iov[0].iov_base = cheri_perms_and(buf0, 0); + ASSERT_EQ(readv(fd, iov, iovcnt), -EFAULT) goto cleanup; + + // Set up buffers for writing. + iov[0].iov_base = write_buf0; + iov[0].iov_len = sizeof(write_buf0); + iov[1].iov_base = write_buf1; + iov[1].iov_len = sizeof(write_buf1); + iov[2].iov_base = write_buf2; + iov[2].iov_len = sizeof(write_buf2); + + // Make sure writev works as expected for buf0. + ASSERT_GE(writev(fd, iov, iovcnt), 0) goto cleanup; + + // Clear the tag for the pointer to buf0. + iov[0].iov_base = cheri_tag_clear(write_buf0); + ASSERT_EQ(writev(fd, iov, iovcnt), -EFAULT) goto cleanup; + + // Clear permissions, but restore the tag for buf0. + iov[0].iov_base = write_buf0; + iov[0].iov_base = cheri_perms_and(write_buf0, 0); + ASSERT_EQ(writev(fd, iov, iovcnt), -EFAULT) goto cleanup; + +cleanup: + close(fd); +} + +/* + * strlen_user() explicitly inspects an input capability, the behaviour + * of which must also be verified within these tests. The fsopen() syscall + * makes use of strlen_user() by duplicating a string (representing the name + * of a filesystem) with the strndup_user() function. strlen_user() can + * therefore be tested with a call to fsopen(). + */ +TEST(test_strlen_user) +{ + char *fsname = "my_nonexistent_filesystem"; + + // strndup_user() will still be called, so fsopen() fails after this. + ASSERT_EQ(fsopen(&fsname), -ENODEV); + + // Clear the tag for the input capability to strndup_user(). + ASSERT_EQ(fsopen(cheri_tag_clear(&fsname)), -EFAULT); + + // Clear the permissions for the input capability to strndup_user(). + ASSERT_EQ(fsopen(cheri_perms_and(&fsname, 0)), -EFAULT); +} + +int main(void) +{ + test_copy_to_user(); + test_copy_user(); + test_get_put_user(); + test_futex(); + test_explicit_iov_iter(); + test_strlen_user(); + return 0; +} -- 2.34.1

10 months, 2 weeks

2
2
0 0

[PATCH RFC v2 00/19] Introduce mm reservation interface for PCuABI

by Amit Daniel Kachhap

Hi All, This patch series introduces the mm reservation interface to manage the owning capability of the allocated addresses. As compared to the RFC v1, this series adds reservation details in the VMA structure. Looking for feedback regarding interface names, interface directory structure etc. Patch [1-11] manages capability bounds via reservation interface. Patch [12-19] adds support for managing capability permissions. Details about several rules implemented can be found in PCuABI spec here [1]. Changes in RFC v2: 1) Removed separate maple tree structures for the reservation interface and modified the vma structure to add the reservation details. As most of the mmap/munmap operations happen per-vma so this reduced the code churnings. However this approach will increase time-complexity of syscalls which operate across vma's such as mlock, madvise etc. get_unmapped_area() which generated free unmapped virtual address may now need more iterations. 2) Added Cheri base representability and length representability modifications. Now get_unmapped_area() will generate CHERI representable addresses. 3) Added new PCuABI changes for mincore() syscall. 4) Added changes for compat64. Future works: 1) Users of vm_mmap/vm_munmap() i.e. filesystems, loaders, kexec etc to be modified to preserve capability addresses. 2) Cover remaining memory addressing syscalls. Testing: 1) All tests by Chaitanya in v4 selftests [2] passes. 2) Purecap/Compat Busybox boot passes after adding [WIP] patches present in [3]. The whole series can be found here [3]. [1]: https://git.morello-project.org/morello/kernel/linux/-/wikis/Morello-pure-c… [2]: https://git.morello-project.org/chaitanya_prakash/linux.git review/purecap_mmap_testcases [3]: https://git.morello-project.org/amitdaniel/linux.git review/purecap_mm_reservation_v2 Thanks, Amit Daniel Amit Daniel Kachhap (19): uapi: errno.h: Introduce PCuABI memory reservation error arm64: morello: Add VM_PCUABI_RESERVE flags mm: Add capability reservation interfaces in vma for PCuABI mm/cap_addr_mgmt: Add capability bound helpers for PCuABI mm/mmap: Modify unmapped address space management code for PCuABI mm/mmap: Use the PCuABI reservations in mmap/munmap mm/mremap: Add the PCuABI reservation interfaces mm/mprotect: Add the PCuABI reservation interfaces mm/madvise: Add the PCuABI reservation interfaces mm/mlock: Add the PCuABI reservation interfaces mm/msync: Add the PCuABI reservation interfaces uapi: mman-common.h: Macros for maximum capability permissions mm/cap_addr_mgmt: Add capability permission helpers for PCuABI mm/cap_addr_mgmt: Reduce the maximum protection check impact mm/mmap: Disable MAP_GROWSDOWN mapping flag for PCuABI mm/mmap: Add capability permission constraints for PCuABI mm/mremap: Add capability permission constraints for PCuABI mm/mprotect: Add capability permission constraints for PCuABI mm/mincore: Add capability constraints for PCuABI arch/arm64/include/asm/cap_addr_mgmt.h | 22 ++ include/linux/cap_addr_mgmt.h | 168 +++++++++++++ include/linux/cheri.h | 3 + include/linux/mm.h | 29 ++- include/linux/mm_types.h | 5 + include/uapi/asm-generic/errno.h | 2 + include/uapi/asm-generic/mman-common.h | 6 + io_uring/advise.c | 2 +- mm/Makefile | 2 +- mm/cap_addr_mgmt.c | 314 +++++++++++++++++++++++++ mm/damon/vaddr.c | 2 +- mm/madvise.c | 27 ++- mm/mincore.c | 46 +++- mm/mlock.c | 38 ++- mm/mmap.c | 182 ++++++++++++-- mm/mprotect.c | 21 +- mm/mremap.c | 109 +++++++-- mm/msync.c | 15 +- mm/util.c | 10 +- 19 files changed, 919 insertions(+), 84 deletions(-) create mode 100644 arch/arm64/include/asm/cap_addr_mgmt.h create mode 100644 include/linux/cap_addr_mgmt.h create mode 100644 mm/cap_addr_mgmt.c -- 2.25.1

11 months, 1 week

2
32
0 0

[PATCH] uaccess_testing: Testing of capability enforcement in uaccess

by Akram Ahmad

Add tests for capability enforcement via the standard copy routines (copy_{to, from}_user, {get, put}_user), futex operations and the explicit uaccess checks used in iov_iter via readv and writev. Signed-off-by: Akram Ahmad <Akram.Ahmad(a)arm.com> --- Hi everyone, This patch extends kselftests with tests for various uaccess routines. Broadly speaking, this tests the standard uaccess routines, futex operations, and iov_iter (the latter is implemented by testing readv and writev syscalls). The tests currently examine the effects of passing a capability with a cleared tag, invalid permissions, and an invalid base address offset. These are tested separately from one another, and I would especially appreciate any comments on how this could be improved if needed (particularly on the futex test). Thank you and happy holidays! Akram [1] The branch for this patch: https://git.morello-project.org/arkamnite/linux/-/commits/morello%2Fuaccess [2] The issue ticket for this patch: https://git.morello-project.org/morello/kernel/linux/-/issues/58 tools/testing/selftests/Makefile | 1 + .../testing/selftests/arm64/morello/Makefile | 2 +- .../testing/selftests/arm64/morello/uaccess.c | 491 ++++++++++++++++++ 3 files changed, 493 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/arm64/morello/uaccess.c diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 90a62cf75008..82abe4ddbb29 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -86,6 +86,7 @@ TARGETS += timers endif TARGETS += tmpfs TARGETS += tpm2 +TARGETS += uaccess TARGETS += user TARGETS += vDSO TARGETS += mm diff --git a/tools/testing/selftests/arm64/morello/Makefile b/tools/testing/selftests/arm64/morello/Makefile index ecfa6fc5e989..7b794d3e436c 100644 --- a/tools/testing/selftests/arm64/morello/Makefile +++ b/tools/testing/selftests/arm64/morello/Makefile @@ -17,7 +17,7 @@ CFLAGS += $(CLANG_FLAGS) $(CFLAGS_PURECAP) $(CFLAGS_COMMON) LDFLAGS += $(CLANG_LDFLAGS) $(CLANG_FLAGS) -nostdlib -static SRCS := $(wildcard *.c) $(wildcard *.S) -PROGS := bootstrap clone exit mmap read_write sched signal +PROGS := bootstrap clone exit mmap read_write sched signal uaccess DEPS := $(wildcard *.h) # these are the final executables diff --git a/tools/testing/selftests/arm64/morello/uaccess.c b/tools/testing/selftests/arm64/morello/uaccess.c new file mode 100644 index 000000000000..66d93137b819 --- /dev/null +++ b/tools/testing/selftests/arm64/morello/uaccess.c @@ -0,0 +1,491 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2023 Arm Limited + +#include <stdint.h> +#include <stddef.h> +#include <stdbool.h> + +#include <asm/fcntl.h> +#include <asm-generic/errno-base.h> +#include <cheriintrin.h> +#include <linux/fs.h> +#include <linux/futex.h> +#include <linux/mman.h> +#include <linux/sysinfo.h> +#include <linux/socket.h> +#include <linux/time.h> +#include <linux/uio.h> + +#include "freestanding.h" + +#define FILE_PERM 0666 +#define MSG_LEN 16 +#define NR_FUTEXES 2 + +static struct futex_waitv waitv[NR_FUTEXES]; +uint32_t futexes[NR_FUTEXES] = {1}; + +static const char file[] = "/my_file.txt"; +static int fd; +static int my_socket; + +static int open_file(void) +{ + return syscall(__NR_openat, 0, file, O_RDWR | O_CREAT, 0666); +} + +static int close_file(int __fd) +{ + return syscall(__NR_close, __fd); +} + +static __always_inline +void copy_to_user1(void) +{ + int result; + struct sysinfo my_sysinfo; + struct sysinfo *p_si = &my_sysinfo; + struct sysinfo my_sysinfo2; + struct sysinfo *p_si2 = &my_sysinfo2 + 10 * sizeof(struct sysinfo); + + result = syscall(__NR_sysinfo, p_si); + TH_LOG("%s: sysinfo with valid capability", __func__); + ASSERT_EQ(result, 0); + + TH_LOG("%s: sysinfo with invalid capability offset", __func__); + result = syscall(__NR_sysinfo, p_si2); + ASSERT_EQ(result, -EFAULT); +} + +static __always_inline +void copy_to_user2(void) +{ + int result; + struct sysinfo my_sysinfo; + struct sysinfo *cap = &my_sysinfo; + + TH_LOG("%s: sysinfo with cleared capability tag", __func__); + cap = (struct sysinfo *)cheri_tag_clear(cap); + result = syscall(__NR_sysinfo, cap); + ASSERT_EQ(result, -EFAULT); +} + +static __always_inline +void copy_to_user3(void) +{ + int result; + struct sysinfo my_sysinfo; + struct sysinfo *cap = &my_sysinfo; + + TH_LOG("%s: sysinfo with no capability permissions", __func__); + cap = (struct sysinfo *)cheri_perms_and(cap, 0); + result = syscall(__NR_sysinfo, cap); + ASSERT_EQ(result, -EFAULT); +} + +TEST(test_copy_to_user) +{ + copy_to_user1(); + copy_to_user2(); + copy_to_user3(); +} + +static __always_inline +void copy_from_user1(void) +{ + int result; + size_t my_offset = sizeof(int); + size_t *good_p = &my_offset; + size_t *bad_p = &my_offset + sizeof(int); + + /** + * Setup the parameters for our syscall: + * fd_in, fd_out: these can be the same fd. + * off_in: the capability pointing to a buffer for the offset + * off_out: NULL, as we do not need this. + * len: MSG_LEN + */ + fd = open_file(); + + result = syscall(__NR_copy_file_range, fd, good_p, fd, NULL, MSG_LEN, 0); + TH_LOG("%s: copy_file_range with valid capability", __func__); + ASSERT_GE(0, result); + + result = syscall(__NR_copy_file_range, fd, bad_p, fd, NULL, MSG_LEN, 0); + TH_LOG("%s: copy_file_range with invalid capability offset", __func__); + ASSERT_EQ(result, -EFAULT); + close_file(fd); +} + +static __always_inline +void copy_from_user2(void) +{ + int result; + size_t my_offset = sizeof(int); + size_t *good_p = &my_offset; + size_t *bad_p = (size_t *)cheri_tag_clear(good_p); + + fd = open_file(); + + result = syscall(__NR_copy_file_range, fd, bad_p, fd, NULL, MSG_LEN, 0); + TH_LOG("%s: copy_file_range with cleared capability tag", __func__); + ASSERT_EQ(result, -EFAULT); + close_file(fd); +} + +static __always_inline +void copy_from_user3(void) +{ + int result; + size_t my_offset = sizeof(int); + size_t *bad_p = (size_t *)cheri_perms_and(&my_offset, 0); + + fd = open_file(); + + result = syscall(__NR_copy_file_range, fd, bad_p, fd, NULL, MSG_LEN, 0); + TH_LOG("%s: copy_file_range with capability with no permissions", __func__); + ASSERT_EQ(result, -EFAULT); + close_file(fd); +} + +TEST(test_copy_from_user) +{ + copy_from_user1(); + copy_from_user2(); + copy_from_user3(); +} + +typedef unsigned short sa_family_t; + +struct sockaddr { + sa_family_t sa_family; + char sa_data[14]; +}; + +static __always_inline +void get_user1(void) +{ + int result; + struct sockaddr sa; + struct sockaddr sa2; + struct sockaddr *my_sockaddr_ptr = &sa2 + sizeof(int) * 1000; + + // socket(AF_INET, SOCK_STREAM, 0) + my_socket = syscall(__NR_socket, 2, 1, 0); + TH_LOG("%s: socket syscall complete", __func__); + ASSERT_GE(my_socket, 0); + + int sa_len = sizeof(sa); + int *my_len_pointer = &sa_len; + + TH_LOG("%s: getsockname with valid capability", __func__); + result = syscall(__NR_getsockname, my_socket, &sa, &sa_len); + ASSERT_EQ(result, 0); + + sa_len = sizeof(sa2); + TH_LOG("%s: getsockname with invalid capability offset", __func__); + result = syscall(__NR_getsockname, my_socket, my_sockaddr_ptr, my_len_pointer); + ASSERT_EQ(result, -EFAULT); +} + +static __always_inline +void get_user2(void) +{ + int result; + struct sockaddr sa; + int sa_len = sizeof(sa); + struct sockaddr *p_sockaddr = cheri_tag_clear(&sa); + + // socket(AF_INET, SOCK_STREAM, 0) + my_socket = syscall(__NR_socket, 2, 1, 0); + ASSERT_GE(my_socket, 0); + + result = syscall(__NR_getsockname, my_socket, p_sockaddr, &sa_len); + TH_LOG("%s: getsockname with cleared capability tag", __func__); + ASSERT_EQ(result, -EFAULT); +} + +static __always_inline +void get_user3(void) +{ + int result; + struct sockaddr sa; + int sa_len = sizeof(sa); + struct sockaddr *p_sockaddr = cheri_perms_and(&sa, 0); + + // socket(AF_INET, SOCK_STREAM, 0) + my_socket = syscall(__NR_socket, 2, 1, 0); + ASSERT_GE(my_socket, 0); + + result = syscall(__NR_getsockname, my_socket, p_sockaddr, &sa_len); + TH_LOG("%s: getsockname with no capability permissions", __func__); + ASSERT_EQ(result, -EFAULT); +} + +TEST(test_get_user) +{ + get_user1(); + get_user2(); + get_user3(); +} + +static __always_inline +void put_user1(void) +{ + int result; + struct timeval tv; + struct timeval *p_tv = &tv; + + result = syscall(__NR_gettimeofday, p_tv, NULL); + TH_LOG("%s: gettimeofday with valid capability", __func__); + ASSERT_EQ(result, 0); + + p_tv = &tv + sizeof(struct timeval) * 1000; + result = syscall(__NR_gettimeofday, p_tv, NULL); + TH_LOG("%s: gettimeofday with invalid capability offset", __func__); + ASSERT_EQ(result, -EFAULT); +} + +static __always_inline +void put_user2(void) +{ + int result; + struct timeval tv; + struct timeval *p_tv = &tv; + + p_tv = cheri_tag_clear(p_tv); + result = syscall(__NR_gettimeofday, p_tv, NULL); + TH_LOG("%s: gettimeofday with cleared capability tag", __func__); + ASSERT_EQ(result, -EFAULT); +} + +static __always_inline +void put_user3(void) +{ + int result; + struct timeval tv; + struct timeval *p_tv = &tv; + + p_tv = cheri_perms_and(p_tv, 0); + result = syscall(__NR_gettimeofday, p_tv, NULL); + TH_LOG("%s: gettimeofday with capability with no permissions", __func__); + ASSERT_EQ(result, -EFAULT); +} + +TEST(test_put_user) +{ + put_user1(); + put_user2(); + put_user3(); +} + +static inline int futex_waitv(volatile struct futex_waitv *waiters, unsigned long nr_waiters, + unsigned long flags, struct timespec *timo, clockid_t clockid) +{ + return syscall(__NR_futex_waitv, waiters, nr_waiters, flags, timo, clockid); +} + +static __always_inline +void futex1(void) +{ + struct timespec to; + + for (int i = 0; i < NR_FUTEXES; i++) { + waitv[i].uaddr = (uintptr_t)cheri_tag_clear(&futexes[i]); + waitv[i].flags = FUTEX_32 | FUTEX_PRIVATE_FLAG; + waitv[i].val = i; + waitv[i].__reserved = 0; + // This is necessary otherwise the loop is optimised away + TH_LOG("%s: waitv[%d] initialised", __func__, i); + } + + int res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC); + + ASSERT_EQ(res, -EFAULT); +} + +TEST(test_futex) +{ + futex1(); +} + +static __always_inline +void explicit_readv1(void) +{ + ssize_t bytes_read; + char buf0[2]; + char buf1[4]; + char buf2[6]; + struct iovec iov[3]; + int iovcnt; + + iov[0].iov_base = buf0; + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + fd = open_file(); + TH_LOG("%s: readv with valid capability", __func__); + bytes_read = syscall(__NR_readv, fd, iov, iovcnt); + close_file(fd); + ASSERT_GE(bytes_read, 0); +} + +static __always_inline +void explicit_readv2(void) +{ + ssize_t bytes_read; + char buf0[2]; + char buf1[4]; + char buf2[6]; + struct iovec iov[3]; + int iovcnt; + + iov[0].iov_base = buf0; + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + fd = open_file(); + TH_LOG("%s: readv with invalid capability tag", __func__); + bytes_read = syscall(__NR_readv, fd, cheri_tag_clear(iov), iovcnt); + close_file(fd); + ASSERT_EQ(bytes_read, -EFAULT); +} + +static __always_inline +void explicit_readv3(void) +{ + ssize_t bytes_read; + char buf0[2]; + char buf1[4]; + char buf2[6]; + struct iovec iov[3]; + int iovcnt; + + iov[0].iov_base = cheri_perms_and(buf0, 0); + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + fd = open_file(); + TH_LOG("%s: readv with invalid capability permissions", __func__); + bytes_read = syscall(__NR_readv, fd, cheri_perms_and(iov, 0), iovcnt); + close_file(fd); + ASSERT_EQ(bytes_read, -EFAULT); +} + +static __always_inline +void explicit_writev1(void) +{ + ssize_t bytes_written; + char *buf0 = "Hello I am the first char buffer!\n"; + char *buf1 = "Hello, I am the second char buffer.\n"; + char *buf2 = "Hello, I am the third and final char buffer.\n"; + struct iovec iov[3]; + int iovcnt; + + iov[0].iov_base = buf0; + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + fd = open_file(); + TH_LOG("%s: writev with valid capability", __func__); + bytes_written = syscall(__NR_writev, fd, iov, iovcnt); + close_file(fd); + ASSERT_GE(bytes_written, 0); +} + +static __always_inline +void explicit_writev2(void) +{ + ssize_t bytes_written; + char *buf0 = "Hello I am the first char buffer!\n"; + char *buf1 = "Hello, I am the second char buffer.\n"; + char *buf2 = "Hello, I am the third and final char buffer.\n"; + struct iovec iov[3]; + int iovcnt; + + iov[0].iov_base = buf0; + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + fd = open_file(); + TH_LOG("%s: writev with invalid capability tag", __func__); + bytes_written = syscall(__NR_writev, fd, cheri_tag_clear(iov), iovcnt); + close_file(fd); + ASSERT_EQ(bytes_written, -EFAULT); +} + +static __always_inline +void explicit_writev3(void) +{ + ssize_t bytes_written; + char *buf0 = "Hello I am the first char buffer!\n"; + char *buf1 = "Hello, I am the second char buffer.\n"; + char *buf2 = "Hello, I am the third and final char buffer.\n"; + struct iovec iov[3]; + int iovcnt; + + iov[0].iov_base = cheri_perms_and(buf0, 0); + iov[0].iov_len = sizeof(buf0); + iov[1].iov_base = buf1; + iov[1].iov_len = sizeof(buf1); + iov[2].iov_base = buf2; + iov[2].iov_len = sizeof(buf2); + + iovcnt = sizeof(iov) / sizeof(struct iovec); + + fd = open_file(); + TH_LOG("%s: writev with invalid capability permissions", __func__); + bytes_written = syscall(__NR_writev, fd, cheri_perms_and(iov, 0), iovcnt); + close_file(fd); + ASSERT_EQ(bytes_written, -EFAULT); +} + +/* + * Test readv and writev where the array of iovecs is provided + * by a capability. + */ +TEST(test_explicit_iov_iter) +{ + explicit_readv1(); + explicit_readv2(); + explicit_readv3(); + explicit_writev1(); + explicit_writev2(); + explicit_writev3(); +} + +int main(void) +{ + test_copy_to_user(); + test_copy_from_user(); + test_get_user(); + test_put_user(); + test_futex(); + test_explicit_iov_iter(); + return 0; +} -- 2.34.1

11 months, 1 week

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[PATCH] selftests/vDSO: Fix type casts in get_sysinfo_ehdr()

by Aditya Deshpande

Cast the return value of getauxptr() from void* to uintptr_t (which is defined as __uintcap_t in purecap) to address compiler warnings. Remove the unnecessary cast on getauxval(), as uintptr_t is defined as unsigned long in non-purecap anyway. Signed-off-by: Aditya Deshpande <aditya.deshpande(a)arm.com> --- Hi all, This is a minor follow up patch to the vDSO series which fixes a compiler warning about implicit type casts. The current state of the vDSO tests shouldn't cause any issues with the release as: 1. This is just a compiler warning - the test code is still functionally correct. 2. The vDSO selftests are built standalone anyways. Thanks, Aditya --- tools/testing/selftests/vDSO/parse_vdso.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/vDSO/parse_vdso.h b/tools/testing/selftests/vDSO/parse_vdso.h index 54ad67f463cc..9c891a12be7d 100644 --- a/tools/testing/selftests/vDSO/parse_vdso.h +++ b/tools/testing/selftests/vDSO/parse_vdso.h @@ -38,9 +38,9 @@ void vdso_init_from_auxv(void *auxv); static inline uintptr_t get_sysinfo_ehdr() { #ifdef __CHERI_PURE_CAPABILITY__ - return getauxptr(AT_SYSINFO_EHDR); + return (uintptr_t)getauxptr(AT_SYSINFO_EHDR); #else - return (uintptr_t)getauxval(AT_SYSINFO_EHDR); + return getauxval(AT_SYSINFO_EHDR); #endif } -- 2.25.1

11 months, 1 week

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