The syscall ABI is inconsistent on aarch64-compat, so at least we should
document it in the seccomp_bpf tests.
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
tools/testing/selftests/seccomp/seccomp_bpf.c | 53 +++++++++++++++++----------
1 file changed, 33 insertions(+), 20 deletions(-)
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 770f47adf295..fe278551ea78 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -19,15 +19,16 @@
#include <linux/prctl.h>
#include <linux/ptrace.h>
#include <linux/seccomp.h>
-#include <poll.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <stddef.h>
#include <stdbool.h>
#include <string.h>
+#include <time.h>
#include <linux/elf.h>
#include <sys/uio.h>
+#include <sys/utsname.h>
#define _GNU_SOURCE
#include <unistd.h>
@@ -2005,20 +2006,25 @@ TEST(syscall_restart)
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0),
- BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_poll, 4, 0),
+ BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 4, 0),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
/* Allow __NR_write for easy logging. */
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
- BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), /* poll */
- BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), /* restart */
+ /* The nanosleep jump target. */
+ BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
+ /* The restart_syscall jump target. */
+ BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
+#if defined(__arm__)
+ struct utsname utsbuf;
+#endif
ASSERT_EQ(0, pipe(pipefd));
@@ -2027,10 +2033,7 @@ TEST(syscall_restart)
if (child_pid == 0) {
/* Child uses EXPECT not ASSERT to deliver status correctly. */
char buf = ' ';
- struct pollfd fds = {
- .fd = pipefd[0],
- .events = POLLIN,
- };
+ struct timespec timeout = { };
/* Attach parent as tracer and stop. */
EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
@@ -2054,10 +2057,11 @@ TEST(syscall_restart)
TH_LOG("Failed to get sync data from read()");
}
- /* Start poll to be interrupted. */
+ /* Start nanosleep to be interrupted. */
+ timeout.tv_sec = 1;
errno = 0;
- EXPECT_EQ(1, poll(&fds, 1, -1)) {
- TH_LOG("Call to poll() failed (errno %d)", errno);
+ EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
+ TH_LOG("Call to nanosleep() failed (errno %d)", errno);
}
/* Read final sync from parent. */
@@ -2082,14 +2086,14 @@ TEST(syscall_restart)
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
ASSERT_EQ(1, write(pipefd[1], ".", 1));
- /* Wait for poll() to start. */
+ /* Wait for nanosleep() to start. */
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
ASSERT_EQ(true, WIFSTOPPED(status));
ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
ASSERT_EQ(0x100, msg);
- EXPECT_EQ(__NR_poll, get_syscall(_metadata, child_pid));
+ EXPECT_EQ(__NR_nanosleep, get_syscall(_metadata, child_pid));
/* Might as well check siginfo for sanity while we're here. */
ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
@@ -2100,7 +2104,7 @@ TEST(syscall_restart)
/* Verify signal delivery came from child (seccomp-triggered). */
EXPECT_EQ(child_pid, info.si_pid);
- /* Interrupt poll with SIGSTOP (which we'll need to handle). */
+ /* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
ASSERT_EQ(0, kill(child_pid, SIGSTOP));
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
@@ -2110,7 +2114,7 @@ TEST(syscall_restart)
ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
EXPECT_EQ(getpid(), info.si_pid);
- /* Restart poll with SIGCONT, which triggers restart_syscall. */
+ /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
ASSERT_EQ(0, kill(child_pid, SIGCONT));
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
@@ -2124,16 +2128,25 @@ TEST(syscall_restart)
ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
+
ASSERT_EQ(0x200, msg);
ret = get_syscall(_metadata, child_pid);
#if defined(__arm__)
- /* FIXME: ARM does not expose true syscall in registers. */
- EXPECT_EQ(__NR_poll, ret);
-#else
- EXPECT_EQ(__NR_restart_syscall, ret);
+ /*
+ * FIXME:
+ * - native ARM registers do NOT expose true syscall.
+ * - compat ARM registers on ARM64 DO expose true syscall.
+ */
+ ASSERT_EQ(0, uname(&utsbuf));
+ if (strncmp(utsbuf.machine, "arm", 3) == 0) {
+ EXPECT_EQ(__NR_nanosleep, ret);
+ } else
#endif
+ {
+ EXPECT_EQ(__NR_restart_syscall, ret);
+ }
- /* Write again to end poll. */
+ /* Write again to end test. */
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
ASSERT_EQ(1, write(pipefd[1], "!", 1));
EXPECT_EQ(0, close(pipefd[1]));
--
1.9.1
--
Kees Cook
Chrome OS Security
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