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authorPeter Maydell <peter.maydell@linaro.org>2016-07-18 18:12:24 +0100
committerRiku Voipio <riku.voipio@linaro.org>2016-09-21 14:25:59 +0300
commit0cb581d6bdc5aa808ae1a9789d02657fe531cb39 (patch)
treeaf887432d58b74e680b738bc7190810710f05431
parentce9c139d93db03e464341385976606b7568b768f (diff)
linux-user: report signals being taken in strace output
Native strace reports when the process being traced takes a signal: --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} --- Report something similar when QEMU is doing its internal strace of the guest process and is about to deliver it a signal. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
-rw-r--r--linux-user/qemu.h10
-rw-r--r--linux-user/signal.c4
-rw-r--r--linux-user/strace.c106
3 files changed, 120 insertions, 0 deletions
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 815447f5fc..61808f6f35 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -362,6 +362,16 @@ void print_syscall(int num,
abi_long arg1, abi_long arg2, abi_long arg3,
abi_long arg4, abi_long arg5, abi_long arg6);
void print_syscall_ret(int num, abi_long arg1);
+/**
+ * print_taken_signal:
+ * @target_signum: target signal being taken
+ * @tinfo: target_siginfo_t which will be passed to the guest for the signal
+ *
+ * Print strace output indicating that this signal is being taken by the guest,
+ * in a format similar to:
+ * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
+ */
+void print_taken_signal(int target_signum, const target_siginfo_t *tinfo);
extern int do_strace;
/* signal.c */
diff --git a/linux-user/signal.c b/linux-user/signal.c
index d3ac0e2565..3337f1e563 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -5849,6 +5849,10 @@ static void handle_pending_signal(CPUArchState *cpu_env, int sig,
handler = sa->_sa_handler;
}
+ if (do_strace) {
+ print_taken_signal(sig, &k->info);
+ }
+
if (handler == TARGET_SIG_DFL) {
/* default handler : ignore some signal. The other are job control or fatal */
if (sig == TARGET_SIGTSTP || sig == TARGET_SIGTTIN || sig == TARGET_SIGTTOU) {
diff --git a/linux-user/strace.c b/linux-user/strace.c
index cc10dc4703..1e5136098e 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -154,6 +154,100 @@ print_signal(abi_ulong arg, int last)
gemu_log("%s%s", signal_name, get_comma(last));
}
+static void print_si_code(int arg)
+{
+ const char *codename = NULL;
+
+ switch (arg) {
+ case SI_USER:
+ codename = "SI_USER";
+ break;
+ case SI_KERNEL:
+ codename = "SI_KERNEL";
+ break;
+ case SI_QUEUE:
+ codename = "SI_QUEUE";
+ break;
+ case SI_TIMER:
+ codename = "SI_TIMER";
+ break;
+ case SI_MESGQ:
+ codename = "SI_MESGQ";
+ break;
+ case SI_ASYNCIO:
+ codename = "SI_ASYNCIO";
+ break;
+ case SI_SIGIO:
+ codename = "SI_SIGIO";
+ break;
+ case SI_TKILL:
+ codename = "SI_TKILL";
+ break;
+ default:
+ gemu_log("%d", arg);
+ return;
+ }
+ gemu_log("%s", codename);
+}
+
+static void print_siginfo(const target_siginfo_t *tinfo)
+{
+ /* Print a target_siginfo_t in the format desired for printing
+ * signals being taken. We assume the target_siginfo_t is in the
+ * internal form where the top 16 bits of si_code indicate which
+ * part of the union is valid, rather than in the guest-visible
+ * form where the bottom 16 bits are sign-extended into the top 16.
+ */
+ int si_type = extract32(tinfo->si_code, 16, 16);
+ int si_code = sextract32(tinfo->si_code, 0, 16);
+
+ gemu_log("{si_signo=");
+ print_signal(tinfo->si_signo, 1);
+ gemu_log(", si_code=");
+ print_si_code(si_code);
+
+ switch (si_type) {
+ case QEMU_SI_KILL:
+ gemu_log(", si_pid = %u, si_uid = %u",
+ (unsigned int)tinfo->_sifields._kill._pid,
+ (unsigned int)tinfo->_sifields._kill._uid);
+ break;
+ case QEMU_SI_TIMER:
+ gemu_log(", si_timer1 = %u, si_timer2 = %u",
+ tinfo->_sifields._timer._timer1,
+ tinfo->_sifields._timer._timer2);
+ break;
+ case QEMU_SI_POLL:
+ gemu_log(", si_band = %d, si_fd = %d",
+ tinfo->_sifields._sigpoll._band,
+ tinfo->_sifields._sigpoll._fd);
+ break;
+ case QEMU_SI_FAULT:
+ gemu_log(", si_addr = ");
+ print_pointer(tinfo->_sifields._sigfault._addr, 1);
+ break;
+ case QEMU_SI_CHLD:
+ gemu_log(", si_pid = %u, si_uid = %u, si_status = %d"
+ ", si_utime=" TARGET_ABI_FMT_ld
+ ", si_stime=" TARGET_ABI_FMT_ld,
+ (unsigned int)(tinfo->_sifields._sigchld._pid),
+ (unsigned int)(tinfo->_sifields._sigchld._uid),
+ tinfo->_sifields._sigchld._status,
+ tinfo->_sifields._sigchld._utime,
+ tinfo->_sifields._sigchld._stime);
+ break;
+ case QEMU_SI_RT:
+ gemu_log(", si_pid = %u, si_uid = %u, si_sigval = " TARGET_ABI_FMT_ld,
+ (unsigned int)tinfo->_sifields._rt._pid,
+ (unsigned int)tinfo->_sifields._rt._uid,
+ tinfo->_sifields._rt._sigval.sival_ptr);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ gemu_log("}");
+}
+
static void
print_sockaddr(abi_ulong addr, abi_long addrlen)
{
@@ -2190,3 +2284,15 @@ print_syscall_ret(int num, abi_long ret)
break;
}
}
+
+void print_taken_signal(int target_signum, const target_siginfo_t *tinfo)
+{
+ /* Print the strace output for a signal being taken:
+ * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
+ */
+ gemu_log("--- ");
+ print_signal(target_signum, 1);
+ gemu_log(" ");
+ print_siginfo(tinfo);
+ gemu_log(" ---\n");
+}