Remove support for systems without PTRACE_SETOPTIONS
Assume that the kernel is v2.5.46 or newer, i.e. PTRACE_SETOPTIONS
and PTRACE_O_TRACESYSGOOD|PTRACE_O_TRACEEXEC|PTRACE_O_TRACECLONE
are universally available.
This change removes all code that implemented post-execve SIGTRAP
handling and fork/vfork/clone->CLONE_PTRACE substitution.
* defs.h (TCB_BPTSET, TCB_WAITEXECVE): Remove macros.
(need_fork_exec_workarounds, setbpt, clearbpt): Remove declarations.
* strace.c (need_fork_exec_workarounds,
test_ptrace_setoptions_followfork, test_ptrace_setoptions_for_all):
Remove.
(syscall_trap_sig): Set to (SIGTRAP | 0x80).
(ptrace_setoptions): Set to (PTRACE_O_TRACESYSGOOD | PTRACE_O_TRACEEXEC).
(detach): Do not test for TCB_BPTSET.
(init): Do not call test_ptrace_setoptions_followfork and
test_ptrace_setoptions_for_all. Do not test for TCB_BPTSET.
* syscall.c (syscall_fixup_on_sysenter, internal_fork, internal_exec,
syscall_fixup_for_fork_exec, syscall_fixup_on_sysexit): Remove.
(trace_syscall_entering): Do not test for TCB_WAITEXECVE. Do not call
syscall_fixup_on_sysenter and syscall_fixup_for_fork_exec.
(trace_syscall_exiting): Do not call syscall_fixup_on_sysexit and
syscall_fixup_for_fork_exec.
[IA64] (ia64_ia32mode): Make static.
* linux/ia64/arch_regs.h (ia64_ia32mode): Remove declaration.
* util.c: Do not include "syscall.h".
(arg_setup, get_arg0, get_arg1, set_arg0, set_arg1, restore_arg0,
restore_arg1, arg_finish_change, change_syscall, setbpt, clearbpt):
Remove.
* tests/ptrace_setoptions.test: Remove.
* tests/Makefile.am (TESTS): Remove it.
diff --git a/strace.c b/strace.c
index 0e131a1..fccf4ad 100644
--- a/strace.c
+++ b/strace.c
@@ -74,18 +74,17 @@
# define fork() vfork()
#endif
+const unsigned int syscall_trap_sig = SIGTRAP | 0x80;
+
cflag_t cflag = CFLAG_NONE;
unsigned int followfork = 0;
-unsigned int ptrace_setoptions = 0;
+unsigned int ptrace_setoptions = PTRACE_O_TRACESYSGOOD | PTRACE_O_TRACEEXEC;
unsigned int xflag = 0;
-bool need_fork_exec_workarounds = 0;
bool debug_flag = 0;
bool Tflag = 0;
bool iflag = 0;
bool count_wallclock = 0;
unsigned int qflag = 0;
-/* Which WSTOPSIG(status) value marks syscall traps? */
-static unsigned int syscall_trap_sig = SIGTRAP;
static unsigned int tflag = 0;
static bool rflag = 0;
static bool print_pid_pfx = 0;
@@ -347,7 +346,7 @@
int r;
if (!use_seize)
return ptrace(PTRACE_ATTACH, pid, 0L, 0L);
- r = ptrace(PTRACE_SEIZE, pid, 0L, (unsigned long)ptrace_setoptions);
+ r = ptrace(PTRACE_SEIZE, pid, 0L, (unsigned long) ptrace_setoptions);
if (r)
return r;
r = ptrace(PTRACE_INTERRUPT, pid, 0L, 0L);
@@ -766,9 +765,6 @@
int error;
int status;
- if (tcp->flags & TCB_BPTSET)
- clearbpt(tcp);
-
/*
* Linux wrongly insists the child be stopped
* before detaching. Arghh. We go through hoops
@@ -1321,219 +1317,6 @@
}
}
-/*
- * Test whether the kernel support PTRACE_O_TRACECLONE et al options.
- * First fork a new child, call ptrace with PTRACE_SETOPTIONS on it,
- * and then see which options are supported by the kernel.
- */
-static int
-test_ptrace_setoptions_followfork(void)
-{
- int pid, expected_grandchild = 0, found_grandchild = 0;
- const unsigned int test_options = PTRACE_O_TRACECLONE |
- PTRACE_O_TRACEFORK |
- PTRACE_O_TRACEVFORK;
-
- /* Need fork for test. NOMMU has no forks */
- if (NOMMU_SYSTEM)
- goto worked; /* be bold, and pretend that test succeeded */
-
- pid = fork();
- if (pid < 0)
- perror_msg_and_die("fork");
- if (pid == 0) {
- pid = getpid();
- if (ptrace(PTRACE_TRACEME, 0L, 0L, 0L) < 0)
- perror_msg_and_die("%s: PTRACE_TRACEME doesn't work",
- __func__);
- kill_save_errno(pid, SIGSTOP);
- if (fork() < 0)
- perror_msg_and_die("fork");
- _exit(0);
- }
-
- while (1) {
- int status, tracee_pid;
-
- errno = 0;
- tracee_pid = wait(&status);
- if (tracee_pid <= 0) {
- if (errno == EINTR)
- continue;
- if (errno == ECHILD)
- break;
- kill_save_errno(pid, SIGKILL);
- perror_msg_and_die("%s: unexpected wait result %d",
- __func__, tracee_pid);
- }
- if (WIFEXITED(status)) {
- if (WEXITSTATUS(status)) {
- if (tracee_pid != pid)
- kill_save_errno(pid, SIGKILL);
- error_msg_and_die("%s: unexpected exit status %u",
- __func__, WEXITSTATUS(status));
- }
- continue;
- }
- if (WIFSIGNALED(status)) {
- if (tracee_pid != pid)
- kill_save_errno(pid, SIGKILL);
- error_msg_and_die("%s: unexpected signal %u",
- __func__, WTERMSIG(status));
- }
- if (!WIFSTOPPED(status)) {
- if (tracee_pid != pid)
- kill_save_errno(tracee_pid, SIGKILL);
- kill_save_errno(pid, SIGKILL);
- error_msg_and_die("%s: unexpected wait status %x",
- __func__, status);
- }
- if (tracee_pid != pid) {
- found_grandchild = tracee_pid;
- if (ptrace(PTRACE_CONT, tracee_pid, 0, 0) < 0) {
- kill_save_errno(tracee_pid, SIGKILL);
- kill_save_errno(pid, SIGKILL);
- perror_msg_and_die("PTRACE_CONT doesn't work");
- }
- continue;
- }
- switch (WSTOPSIG(status)) {
- case SIGSTOP:
- if (ptrace(PTRACE_SETOPTIONS, pid, 0, test_options) < 0
- && errno != EINVAL && errno != EIO)
- perror_msg("PTRACE_SETOPTIONS");
- break;
- case SIGTRAP:
- if (status >> 16 == PTRACE_EVENT_FORK) {
- long msg = 0;
-
- if (ptrace(PTRACE_GETEVENTMSG, pid,
- NULL, (long) &msg) == 0)
- expected_grandchild = msg;
- }
- break;
- }
- if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) {
- kill_save_errno(pid, SIGKILL);
- perror_msg_and_die("PTRACE_SYSCALL doesn't work");
- }
- }
- if (expected_grandchild && expected_grandchild == found_grandchild) {
- worked:
- ptrace_setoptions |= test_options;
- if (debug_flag)
- fprintf(stderr, "ptrace_setoptions = %#x\n",
- ptrace_setoptions);
- return 0;
- }
- error_msg("Test for PTRACE_O_TRACECLONE failed, "
- "giving up using this feature.");
- return 1;
-}
-
-/*
- * Test whether the kernel support PTRACE_O_TRACESYSGOOD.
- * First fork a new child, call ptrace(PTRACE_SETOPTIONS) on it,
- * and then see whether it will stop with (SIGTRAP | 0x80).
- *
- * Use of this option enables correct handling of user-generated SIGTRAPs,
- * and SIGTRAPs generated by special instructions such as int3 on x86:
-
-# compile with: gcc -nostartfiles -nostdlib -o int3 int3.S
-_start: .globl _start
- int3
- movl $42, %ebx
- movl $1, %eax
- int $0x80
- */
-static int
-test_ptrace_setoptions_for_all(void)
-{
- const unsigned int test_options = PTRACE_O_TRACESYSGOOD |
- PTRACE_O_TRACEEXEC;
- int pid;
- int it_worked = 0;
-
- /* Need fork for test. NOMMU has no forks */
- if (NOMMU_SYSTEM)
- goto worked; /* be bold, and pretend that test succeeded */
-
- pid = fork();
- if (pid < 0)
- perror_msg_and_die("fork");
-
- if (pid == 0) {
- pid = getpid();
- if (ptrace(PTRACE_TRACEME, 0L, 0L, 0L) < 0)
- /* Note: exits with exitcode 1 */
- perror_msg_and_die("%s: PTRACE_TRACEME doesn't work",
- __func__);
- kill(pid, SIGSTOP);
- _exit(0); /* parent should see entry into this syscall */
- }
-
- while (1) {
- int status, tracee_pid;
-
- errno = 0;
- tracee_pid = wait(&status);
- if (tracee_pid <= 0) {
- if (errno == EINTR)
- continue;
- kill_save_errno(pid, SIGKILL);
- perror_msg_and_die("%s: unexpected wait result %d",
- __func__, tracee_pid);
- }
- if (WIFEXITED(status)) {
- if (WEXITSTATUS(status) == 0)
- break;
- error_msg_and_die("%s: unexpected exit status %u",
- __func__, WEXITSTATUS(status));
- }
- if (WIFSIGNALED(status)) {
- error_msg_and_die("%s: unexpected signal %u",
- __func__, WTERMSIG(status));
- }
- if (!WIFSTOPPED(status)) {
- kill(pid, SIGKILL);
- error_msg_and_die("%s: unexpected wait status %x",
- __func__, status);
- }
- if (WSTOPSIG(status) == SIGSTOP) {
- /*
- * We don't check "options aren't accepted" error.
- * If it happens, we'll never get (SIGTRAP | 0x80),
- * and thus will decide to not use the option.
- * IOW: the outcome of the test will be correct.
- */
- if (ptrace(PTRACE_SETOPTIONS, pid, 0L, test_options) < 0
- && errno != EINVAL && errno != EIO)
- perror_msg("PTRACE_SETOPTIONS");
- }
- if (WSTOPSIG(status) == (SIGTRAP | 0x80)) {
- it_worked = 1;
- }
- if (ptrace(PTRACE_SYSCALL, pid, 0L, 0L) < 0) {
- kill_save_errno(pid, SIGKILL);
- perror_msg_and_die("PTRACE_SYSCALL doesn't work");
- }
- }
-
- if (it_worked) {
- worked:
- syscall_trap_sig = (SIGTRAP | 0x80);
- ptrace_setoptions |= test_options;
- if (debug_flag)
- fprintf(stderr, "ptrace_setoptions = %#x\n",
- ptrace_setoptions);
- return 0;
- }
-
- error_msg("Test for PTRACE_O_TRACESYSGOOD failed, "
- "giving up using this feature.");
- return 1;
-}
-
#if USE_SEIZE
static void
test_ptrace_seize(void)
@@ -1871,14 +1654,12 @@
run_gid = getgid();
}
- /*
- * On any reasonably recent Linux kernel (circa about 2.5.46)
- * need_fork_exec_workarounds should stay 0 after these tests:
- */
- /*need_fork_exec_workarounds = 0; - already is */
if (followfork)
- need_fork_exec_workarounds = test_ptrace_setoptions_followfork();
- need_fork_exec_workarounds |= test_ptrace_setoptions_for_all();
+ ptrace_setoptions |= PTRACE_O_TRACECLONE |
+ PTRACE_O_TRACEFORK |
+ PTRACE_O_TRACEVFORK;
+ if (debug_flag)
+ fprintf(stderr, "ptrace_setoptions = %#x\n", ptrace_setoptions);
test_ptrace_seize();
/* Check if they want to redirect the output. */
@@ -2226,20 +2007,7 @@
tcp->flags &= ~TCB_STARTUP;
- if (tcp->flags & TCB_BPTSET) {
- /*
- * One example is a breakpoint inherited from
- * parent through fork().
- */
- if (clearbpt(tcp) < 0) {
- /* Pretty fatal */
- droptcb(tcp);
- exit_code = 1;
- return false;
- }
- }
-
- if (!use_seize && ptrace_setoptions) {
+ if (!use_seize) {
if (debug_flag)
fprintf(stderr, "setting opts 0x%x on pid %d\n",
ptrace_setoptions, tcp->pid);
@@ -2460,7 +2228,6 @@
/*
* This should be syscall entry or exit.
- * (Or it still can be that pesky post-execve SIGTRAP!)
* Handle it.
*/
if (trace_syscall(tcp) < 0) {