Add a bunch of test-cases for clone3 syscall, focusing mainly on handling struct clone_args versioning and sizing, alongside the obvious req for respecting capabilities.
Signed-off-by: Beata Michalska beata.michalska@arm.com --- .../testing/selftests/arm64/morello/Makefile | 1 + tools/testing/selftests/arm64/morello/clone.c | 223 +++++++++++++++++- 2 files changed, 223 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/arm64/morello/Makefile b/tools/testing/selftests/arm64/morello/Makefile index 7dbf5b140695..c79e8973dbbf 100644 --- a/tools/testing/selftests/arm64/morello/Makefile +++ b/tools/testing/selftests/arm64/morello/Makefile @@ -38,3 +38,4 @@ $(OUTPUT)/%: $(OUTPUT)/%.o $(OUTPUT)/freestanding_start.o $(OUTPUT)/freestanding $(CC) $^ -o $@ $(LDFLAGS)
$(OUTPUT)/signal: $(OUTPUT)/signal_common.o +$(OUTPUT)/clone: $(OUTPUT)/signal_common.o diff --git a/tools/testing/selftests/arm64/morello/clone.c b/tools/testing/selftests/arm64/morello/clone.c index 8217840ba504..a405b0fd0e4a 100644 --- a/tools/testing/selftests/arm64/morello/clone.c +++ b/tools/testing/selftests/arm64/morello/clone.c @@ -1,15 +1,20 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (C) 2021 Arm Limited +#include "freestanding.h" #include <linux/mman.h> #include <linux/resource.h> #include <linux/wait.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/errno.h> +#include <linux/signal.h> +#include <linux/types.h> +#include <limits.h> #include <cheriintrin.h> -#include "freestanding.h" +#include "signal_common.h"
#define STACK_SIZE 1024*1024 +#define TLS_SIZE 4096
#define in_restricted() \ (!(cheri_perms_get(cheri_pcc_get()) & ARM_CAP_PERMISSION_EXECUTIVE)) @@ -17,6 +22,10 @@
#define MAGIC_NR 0x3562 /* whatever really ..... */
+#ifndef MAX_PID_NS_LEVEL +#define MAX_PID_NS_LEVEL 32 +#endif + /* Cloned thread result */ #define CTR_SUCCESS 1 #define CTR_FAILED -1 @@ -256,6 +265,217 @@ TEST(test_wait_rusage) RUN_WITH_FIXTURE(data, CLONE_TH_RUSAGE, wait_single); }
+#define GET_ERRNO(err) (((err) + MAX_ERRNO) ^ MAX_ERRNO) + +#define CUSTOM_CLONE_STACK_INV BIT(1) + +static struct clone3_fixture { + size_t args_size; + struct clone_args args; + int test_flags; + int e_result; +} clone3_data[] = { + /* BEGIN_SECTION: expected failure */ + /* size of clone_args smaller than CLONE_ARGS_SIZE_VER0 */ + { + .args_size = offsetof(struct clone_args, tls), + .e_result = -EINVAL + }, /* @{0} */ + /* invalid set_tid array size */ + { + .args.set_tid_size = MAX_PID_NS_LEVEL + 1, + .e_result = -EINVAL + }, /* @{1} */ + /* Invalid combination of set_tid & set_tid_size */ + { + .args.set_tid_size = 1, + .e_result = -EINVAL + }, /* @{2} */ + /* Invalid exit_signal */ + { + .args.exit_signal = _NSIG + 1, + .e_result = -EINVAL + }, /* @{3} */ + /* Invalid cgroup number */ + { + .args.flags = CLONE_INTO_CGROUP, + .args.cgroup = (__u64)INT_MAX + 1, + .e_result = -EINVAL + }, /* @{4} */ + /* Invalid size for clone_args with cgroup */ + { + .args_size = offsetof(struct clone_args, cgroup), + .args.flags = CLONE_INTO_CGROUP, + .args.cgroup = 1, + .e_result = -EINVAL + }, /* @{5} */ + /* Invalid stack & stack_size combination */ + { + .args.stack_size = STACK_SIZE, + .test_flags = CUSTOM_CLONE_STACK_INV, + .e_result = -EINVAL + }, /* @{6} */ + { + .test_flags = CUSTOM_CLONE_STACK_INV, + .e_result = -EINVAL + }, /* @{7} */ + /* Invalid set_tid entry */ + { + .args.set_tid = (uintptr_t)&(pid_t){1}, + .args.set_tid_size = 1, + .e_result = -EEXIST + }, /* @{8} */ + + /* END_SECTION: expected failure */ + { + .args.flags = CLONE_PIDFD | CLONE_CHILD_SETTID | + CLONE_CHILD_CLEARTID, + .e_result = 0 + }, /* @{9} */ + { + .args.flags = CLONE_PARENT_SETTID | CLONE_CHILD_SETTID, + .e_result = 0 + }, /* @{10} */ + { + .args.flags = CLONE_SETTLS, + .e_result = 0 + }, /* @{11} */ +}; + +static __attribute__((noinline)) void run_child(struct clone_args *args) +{ + static __thread int tls_data; + + if (args->flags & CLONE_CHILD_SETTID) { + pid_t current_pid = getpid(); + + ASSERT_EQ(current_pid, *(pid_t *)args->child_tid); + } + + if (args->flags & CLONE_SETTLS && args->tls) { + ptraddr_t base_addr = cheri_address_get(args->tls); + ptraddr_t ref_addr = cheri_address_get(&tls_data); + size_t length = cheri_length_get(args->tls); + + ASSERT_TRUE(cheri_tag_get(&tls_data)); + ASSERT_TRUE(ref_addr >= base_addr && ref_addr < base_addr + length); + } + + if (args->flags & CLONE_PIDFD) { + sigset_t set; + + ASSERT_EQ(sigemptyset(&set), 0); + ASSERT_EQ(sigaddset(&set, SIGUSR1), 0); + ASSERT_EQ(sigprocmask(SIG_BLOCK, &set, NULL), 0); + + /* Suspend utill parent kicks things back in */ + ASSERT_EQ(syscall(__NR_kill, getpid(), SIGSTOP), 0); + + /* Wait for a signal */ + ASSERT_EQ(rt_sigtimedwait(&set, NULL, 0, sizeof(set)), + SIGUSR1); + } + syscall(__NR_exit, 0); +} + +static inline __attribute__((always_inline)) +void run_clone3(struct clone3_fixture *data) +{ + struct clone_args *args = &(data->args); + int pidfd, parent_tid = 0, child_tid = 0; + siginfo_t wait_si; + int result; + pid_t pid; + void *tls; + + args->pidfd = (uintcap_t)&pidfd; + args->parent_tid = (uintcap_t)&parent_tid; + args->child_tid = (uintcap_t)&child_tid; + + if (!args->exit_signal) + args->exit_signal = SIGCHLD; + + if (!args->stack_size) { + args->stack = (uintcap_t) mmap_verified(NULL, STACK_SIZE, + PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, + -1, 0, STACK_REQ_PERMS); + ASSERT_NE(args->stack, 0); + args->stack_size = + data->test_flags & CUSTOM_CLONE_STACK_INV ? 0 : STACK_SIZE; + } + + if (!data->args_size) + data->args_size = sizeof(struct clone_args); + + if (data->e_result) { + result = syscall(__NR_clone3, args, data->args_size); + ASSERT_EQ(result, data->e_result) { + TH_LOG("Expected: %d while %d was received", + GET_ERRNO(data->e_result), GET_ERRNO(result)); + } + if (args->stack) + munmap((void *)args->stack, STACK_SIZE); + return; + } + + args->flags |= CLONE_VM; + + if (args->flags & CLONE_SETTLS) { + tls = mmap_verified(NULL, TLS_SIZE, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0, + CAP_LOAD_PERMS | CAP_STORE_PERMS); + + ASSERT_NE(tls, NULL); + args->tls = (uintcap_t)cheri_bounds_set(tls, TLS_SIZE); + } + + pid = syscall(__NR_clone3, args, data->args_size); + + ASSERT_GE(pid, 0); + if (!pid) + run_child(args); + + if (args->flags & CLONE_PIDFD) { + /* Make sure the child here gets a chance to block the signal */ + result = waitid(P_PID, pid, &wait_si, WSTOPPED, NULL); + ASSERT_EQ(result, 0); + result = syscall(__NR_kill, pid, SIGCONT); + ASSERT_EQ(result, 0); + /* Signal handling is not the test target here: valid pidfd is */ + result = syscall(__NR_pidfd_send_signal, pidfd, SIGUSR1, NULL, 0); + ASSERT_EQ(result, 0); + } + + result = waitid(P_PID, pid, &wait_si, WEXITED, NULL); + ASSERT_EQ(result, 0); + + /* child_tid set once the thread gets scheduled */ + if (args->flags & CLONE_PARENT_SETTID && args->flags & CLONE_CHILD_SETTID + && !(args->flags & CLONE_CHILD_CLEARTID)) { + ASSERT_EQ(parent_tid, child_tid); + ASSERT_NE(parent_tid, 0); + } + + if (args->flags & CLONE_CHILD_CLEARTID) + ASSERT_EQ(child_tid, 0); + + munmap((void *)args->stack, STACK_SIZE); + if (args->flags & CLONE_SETTLS) + /* unmap TLS with a capability cached prior to setting the bounds */ + munmap(tls, TLS_SIZE); +} + +TEST(test_clone3) +{ + int ncount = sizeof(clone3_data)/sizeof(clone3_data[0]); + + for (int i = 0; i < ncount; ++i) { + TH_LOG("Validating clone3 @{%d}", i); + run_clone3(&clone3_data[i]); + } +} + void run_restricted(uintcap_t entry_point) { void *new_stack = allocate_mem_raw(STACK_SIZE); @@ -290,5 +510,6 @@ int main(void) run_restricted((uintcap_t)test_clone_tls_restricted); test_wait_raw(); test_wait_rusage(); + test_clone3(); return 0; }