From 9d660adc3248b81618e7afc1ddef6c9731e1047f Mon Sep 17 00:00:00 2001
From: Laurent Vivier <laurent@vivier.eu>
Date: Wed, 12 Feb 2020 13:56:55 +0100
Subject: [PATCH 1/5] linux-user: add missing TARGET_SIGRTMIN for hppa
This signal is defined for all other targets and we will need it later
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
[pm: that this was actually an ABI change in the hppa kernel (at kernel
version 3.17, kernel commit 1f25df2eff5b25f52c139d). Before that
SIGRTMIN was 37...
All our other HPPA TARGET_SIG* values are for the updated
ABI following that commit, so using 32 for SIGRTMIN is
the right thing for us.]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20200212125658.644558-2-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
linux-user/hppa/target_signal.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/linux-user/hppa/target_signal.h b/linux-user/hppa/target_signal.h
index ba159ff8d0..c2a0102ed7 100644
--- a/linux-user/hppa/target_signal.h
+++ b/linux-user/hppa/target_signal.h
@@ -34,6 +34,7 @@
#define TARGET_SIGURG 29
#define TARGET_SIGXFSZ 30
#define TARGET_SIGSYS 31
+#define TARGET_SIGRTMIN 32
#define TARGET_SIG_BLOCK 0
#define TARGET_SIG_UNBLOCK 1
From 365510fb860a91dbead7d6c9e5815ef9d4e72062 Mon Sep 17 00:00:00 2001
From: Laurent Vivier <laurent@vivier.eu>
Date: Wed, 12 Feb 2020 13:56:56 +0100
Subject: [PATCH 2/5] linux-user: cleanup signal.c
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
No functional changes. Prepare the field for future fixes.
Remove memset(.., 0, ...) that is useless on a static array
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20200212125658.644558-3-laurent@vivier.eu>
---
linux-user/signal.c | 48 ++++++++++++++++++++++++++-------------------
1 file changed, 28 insertions(+), 20 deletions(-)
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 5ca6d62b15..246315571c 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -66,12 +66,6 @@ static uint8_t host_to_target_signal_table[_NSIG] = {
[SIGPWR] = TARGET_SIGPWR,
[SIGSYS] = TARGET_SIGSYS,
/* next signals stay the same */
- /* Nasty hack: Reverse SIGRTMIN and SIGRTMAX to avoid overlap with
- host libpthread signals. This assumes no one actually uses SIGRTMAX :-/
- To fix this properly we need to do manual signal delivery multiplexed
- over a single host signal. */
- [__SIGRTMIN] = __SIGRTMAX,
- [__SIGRTMAX] = __SIGRTMIN,
};
static uint8_t target_to_host_signal_table[_NSIG];
@@ -480,31 +474,45 @@ static int core_dump_signal(int sig)
}
}
+static void signal_table_init(void)
+{
+ int host_sig, target_sig;
+
+ /*
+ * Nasty hack: Reverse SIGRTMIN and SIGRTMAX to avoid overlap with
+ * host libpthread signals. This assumes no one actually uses SIGRTMAX :-/
+ * To fix this properly we need to do manual signal delivery multiplexed
+ * over a single host signal.
+ */
+ host_to_target_signal_table[__SIGRTMIN] = __SIGRTMAX;
+ host_to_target_signal_table[__SIGRTMAX] = __SIGRTMIN;
+
+ /* generate signal conversion tables */
+ for (host_sig = 1; host_sig < _NSIG; host_sig++) {
+ if (host_to_target_signal_table[host_sig] == 0) {
+ host_to_target_signal_table[host_sig] = host_sig;
+ }
+ }
+ for (host_sig = 1; host_sig < _NSIG; host_sig++) {
+ target_sig = host_to_target_signal_table[host_sig];
+ target_to_host_signal_table[target_sig] = host_sig;
+ }
+}
+
void signal_init(void)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
struct sigaction act;
struct sigaction oact;
- int i, j;
+ int i;
int host_sig;
- /* generate signal conversion tables */
- for(i = 1; i < _NSIG; i++) {
- if (host_to_target_signal_table[i] == 0)
- host_to_target_signal_table[i] = i;
- }
- for(i = 1; i < _NSIG; i++) {
- j = host_to_target_signal_table[i];
- target_to_host_signal_table[j] = i;
- }
+ /* initialize signal conversion tables */
+ signal_table_init();
/* Set the signal mask from the host mask. */
sigprocmask(0, 0, &ts->signal_mask);
- /* set all host signal handlers. ALL signals are blocked during
- the handlers to serialize them. */
- memset(sigact_table, 0, sizeof(sigact_table));
-
sigfillset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
act.sa_sigaction = host_signal_handler;
From 9fcff3a67f2be53de2d9b27c270ba2a4ecba8810 Mon Sep 17 00:00:00 2001
From: Laurent Vivier <laurent@vivier.eu>
Date: Wed, 12 Feb 2020 13:56:57 +0100
Subject: [PATCH 3/5] linux-user: fix TARGET_NSIG and _NSIG uses
Valid signal numbers are between 1 (SIGHUP) and SIGRTMAX.
System includes define _NSIG to SIGRTMAX + 1, but
QEMU (like kernel) defines TARGET_NSIG to TARGET_SIGRTMAX.
Fix all the checks involving the signal range.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20200212125658.644558-4-laurent@vivier.eu>
---
linux-user/signal.c | 52 ++++++++++++++++++++++++++++++++-------------
1 file changed, 37 insertions(+), 15 deletions(-)
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 246315571c..c1e664f97a 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -30,6 +30,15 @@ static struct target_sigaction sigact_table[TARGET_NSIG];
static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc);
+
+/*
+ * System includes define _NSIG as SIGRTMAX + 1,
+ * but qemu (like the kernel) defines TARGET_NSIG as TARGET_SIGRTMAX
+ * and the first signal is SIGHUP defined as 1
+ * Signal number 0 is reserved for use as kill(pid, 0), to test whether
+ * a process exists without sending it a signal.
+ */
+QEMU_BUILD_BUG_ON(__SIGRTMAX + 1 != _NSIG);
static uint8_t host_to_target_signal_table[_NSIG] = {
[SIGHUP] = TARGET_SIGHUP,
[SIGINT] = TARGET_SIGINT,
@@ -67,19 +76,24 @@ static uint8_t host_to_target_signal_table[_NSIG] = {
[SIGSYS] = TARGET_SIGSYS,
/* next signals stay the same */
};
-static uint8_t target_to_host_signal_table[_NSIG];
+static uint8_t target_to_host_signal_table[TARGET_NSIG + 1];
+
+/* valid sig is between 1 and _NSIG - 1 */
int host_to_target_signal(int sig)
{
- if (sig < 0 || sig >= _NSIG)
+ if (sig < 1 || sig >= _NSIG) {
return sig;
+ }
return host_to_target_signal_table[sig];
}
+/* valid sig is between 1 and TARGET_NSIG */
int target_to_host_signal(int sig)
{
- if (sig < 0 || sig >= _NSIG)
+ if (sig < 1 || sig > TARGET_NSIG) {
return sig;
+ }
return target_to_host_signal_table[sig];
}
@@ -100,11 +114,15 @@ static inline int target_sigismember(const target_sigset_t *set, int signum)
void host_to_target_sigset_internal(target_sigset_t *d,
const sigset_t *s)
{
- int i;
+ int host_sig, target_sig;
target_sigemptyset(d);
- for (i = 1; i <= TARGET_NSIG; i++) {
- if (sigismember(s, i)) {
- target_sigaddset(d, host_to_target_signal(i));
+ for (host_sig = 1; host_sig < _NSIG; host_sig++) {
+ target_sig = host_to_target_signal(host_sig);
+ if (target_sig < 1 || target_sig > TARGET_NSIG) {
+ continue;
+ }
+ if (sigismember(s, host_sig)) {
+ target_sigaddset(d, target_sig);
}
}
}
@@ -122,11 +140,15 @@ void host_to_target_sigset(target_sigset_t *d, const sigset_t *s)
void target_to_host_sigset_internal(sigset_t *d,
const target_sigset_t *s)
{
- int i;
+ int host_sig, target_sig;
sigemptyset(d);
- for (i = 1; i <= TARGET_NSIG; i++) {
- if (target_sigismember(s, i)) {
- sigaddset(d, target_to_host_signal(i));
+ for (target_sig = 1; target_sig <= TARGET_NSIG; target_sig++) {
+ host_sig = target_to_host_signal(target_sig);
+ if (host_sig < 1 || host_sig >= _NSIG) {
+ continue;
+ }
+ if (target_sigismember(s, target_sig)) {
+ sigaddset(d, host_sig);
}
}
}
@@ -492,10 +514,10 @@ static void signal_table_init(void)
if (host_to_target_signal_table[host_sig] == 0) {
host_to_target_signal_table[host_sig] = host_sig;
}
- }
- for (host_sig = 1; host_sig < _NSIG; host_sig++) {
target_sig = host_to_target_signal_table[host_sig];
- target_to_host_signal_table[target_sig] = host_sig;
+ if (target_sig <= TARGET_NSIG) {
+ target_to_host_signal_table[target_sig] = host_sig;
+ }
}
}
@@ -518,7 +540,7 @@ void signal_init(void)
act.sa_sigaction = host_signal_handler;
for(i = 1; i <= TARGET_NSIG; i++) {
#ifdef TARGET_GPROF
- if (i == SIGPROF) {
+ if (i == TARGET_SIGPROF) {
continue;
}
#endif
From 6bc024e713fd35eb5fddbe16acd8dc92d27872a9 Mon Sep 17 00:00:00 2001
From: Laurent Vivier <laurent@vivier.eu>
Date: Wed, 12 Feb 2020 13:56:58 +0100
Subject: [PATCH 4/5] linux-user: fix use of SIGRTMIN
Some RT signals can be in use by glibc,
it's why SIGRTMIN (34) is generally greater than __SIGRTMIN (32).
So SIGRTMIN cannot be mapped to TARGET_SIGRTMIN.
Instead of swapping only SIGRTMIN and SIGRTMAX, map all the
range [TARGET_SIGRTMIN ... TARGET_SIGRTMAX - X] to
[__SIGRTMIN + X ... SIGRTMAX ]
(SIGRTMIN is __SIGRTMIN + X).
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Taylor Simson <tsimpson@quicinc.com>
Tested-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200212125658.644558-5-laurent@vivier.eu>
---
linux-user/signal.c | 50 ++++++++++++++++++++++++++++++++++++-----
linux-user/trace-events | 3 +++
2 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/linux-user/signal.c b/linux-user/signal.c
index c1e664f97a..046159dd0c 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -498,18 +498,30 @@ static int core_dump_signal(int sig)
static void signal_table_init(void)
{
- int host_sig, target_sig;
+ int host_sig, target_sig, count;
/*
- * Nasty hack: Reverse SIGRTMIN and SIGRTMAX to avoid overlap with
- * host libpthread signals. This assumes no one actually uses SIGRTMAX :-/
+ * Signals are supported starting from TARGET_SIGRTMIN and going up
+ * until we run out of host realtime signals.
+ * glibc at least uses only the lower 2 rt signals and probably
+ * nobody's using the upper ones.
+ * it's why SIGRTMIN (34) is generally greater than __SIGRTMIN (32)
* To fix this properly we need to do manual signal delivery multiplexed
* over a single host signal.
+ * Attempts for configure "missing" signals via sigaction will be
+ * silently ignored.
*/
- host_to_target_signal_table[__SIGRTMIN] = __SIGRTMAX;
- host_to_target_signal_table[__SIGRTMAX] = __SIGRTMIN;
+ for (host_sig = SIGRTMIN; host_sig <= SIGRTMAX; host_sig++) {
+ target_sig = host_sig - SIGRTMIN + TARGET_SIGRTMIN;
+ if (target_sig <= TARGET_NSIG) {
+ host_to_target_signal_table[host_sig] = target_sig;
+ }
+ }
/* generate signal conversion tables */
+ for (target_sig = 1; target_sig <= TARGET_NSIG; target_sig++) {
+ target_to_host_signal_table[target_sig] = _NSIG; /* poison */
+ }
for (host_sig = 1; host_sig < _NSIG; host_sig++) {
if (host_to_target_signal_table[host_sig] == 0) {
host_to_target_signal_table[host_sig] = host_sig;
@@ -519,6 +531,15 @@ static void signal_table_init(void)
target_to_host_signal_table[target_sig] = host_sig;
}
}
+
+ if (trace_event_get_state_backends(TRACE_SIGNAL_TABLE_INIT)) {
+ for (target_sig = 1, count = 0; target_sig <= TARGET_NSIG; target_sig++) {
+ if (target_to_host_signal_table[target_sig] == _NSIG) {
+ count++;
+ }
+ }
+ trace_signal_table_init(count);
+ }
}
void signal_init(void)
@@ -817,6 +838,8 @@ int do_sigaction(int sig, const struct target_sigaction *act,
int host_sig;
int ret = 0;
+ trace_signal_do_sigaction_guest(sig, TARGET_NSIG);
+
if (sig < 1 || sig > TARGET_NSIG || sig == TARGET_SIGKILL || sig == TARGET_SIGSTOP) {
return -TARGET_EINVAL;
}
@@ -847,6 +870,23 @@ int do_sigaction(int sig, const struct target_sigaction *act,
/* we update the host linux signal state */
host_sig = target_to_host_signal(sig);
+ trace_signal_do_sigaction_host(host_sig, TARGET_NSIG);
+ if (host_sig > SIGRTMAX) {
+ /* we don't have enough host signals to map all target signals */
+ qemu_log_mask(LOG_UNIMP, "Unsupported target signal #%d, ignored\n",
+ sig);
+ /*
+ * we don't return an error here because some programs try to
+ * register an handler for all possible rt signals even if they
+ * don't need it.
+ * An error here can abort them whereas there can be no problem
+ * to not have the signal available later.
+ * This is the case for golang,
+ * See https://github.com/golang/go/issues/33746
+ * So we silently ignore the error.
+ */
+ return 0;
+ }
if (host_sig != SIGSEGV && host_sig != SIGBUS) {
sigfillset(&act1.sa_mask);
act1.sa_flags = SA_SIGINFO;
diff --git a/linux-user/trace-events b/linux-user/trace-events
index f6de1b8bef..0296133dae 100644
--- a/linux-user/trace-events
+++ b/linux-user/trace-events
@@ -1,6 +1,9 @@
# See docs/devel/tracing.txt for syntax documentation.
# signal.c
+signal_table_init(int i) "number of unavailable signals: %d"
+signal_do_sigaction_guest(int sig, int max) "target signal %d (MAX %d)"
+signal_do_sigaction_host(int sig, int max) "host signal %d (MAX %d)"
# */signal.c
user_setup_frame(void *env, uint64_t frame_addr) "env=%p frame_addr=0x%"PRIx64
user_setup_rt_frame(void *env, uint64_t frame_addr) "env=%p frame_addr=0x%"PRIx64
From 6d485a55d0cd8fbb8b4337b298f79ddb0c2a5511 Mon Sep 17 00:00:00 2001
From: Laurent Vivier <laurent@vivier.eu>
Date: Tue, 4 Feb 2020 22:19:01 +0100
Subject: [PATCH 5/5] linux-user: implement TARGET_SO_PEERSEC
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
"The purpose of this option is to allow an application to obtain the
security credentials of a Unix stream socket peer. It is analogous to
SO_PEERCRED (which provides authentication using standard Unix credentials
of pid, uid and gid), and extends this concept to other security
models." -- https://lwn.net/Articles/62370/
Until now it was passed to the kernel with an "int" argument and
fails when it was supported by the host because the parameter is
like a filename: it is always a \0-terminated string with no embedded
\0 characters, but is not guaranteed to be ASCII or UTF-8.
I've tested the option with the following program:
/*
* cc -o getpeercon getpeercon.c
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
int main(void)
{
int fd;
struct sockaddr_in server, addr;
int ret;
socklen_t len;
char buf[256];
fd = socket(PF_INET, SOCK_STREAM, 0);
if (fd == -1) {
perror("socket");
return 1;
}
server.sin_family = AF_INET;
inet_aton("127.0.0.1", &server.sin_addr);
server.sin_port = htons(40390);
connect(fd, (struct sockaddr*)&server, sizeof(server));
len = sizeof(buf);
ret = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, buf, &len);
if (ret == -1) {
perror("getsockopt");
return 1;
}
printf("%d %s\n", len, buf);
return 0;
}
On host:
$ ./getpeercon
33 system_u:object_r:unlabeled_t:s0
With qemu-aarch64/bionic without the patch:
$ ./getpeercon
getsockopt: Numerical result out of range
With the patch:
$ ./getpeercon
33 system_u:object_r:unlabeled_t:s0
Bug: https://bugs.launchpad.net/qemu/+bug/1823790
Reported-by: Matthias Lüscher <lueschem@gmail.com>
Tested-by: Matthias Lüscher <lueschem@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200204211901.1731821-1-laurent@vivier.eu>
---
linux-user/syscall.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index d60142f069..c930577686 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -2344,6 +2344,28 @@ static abi_long do_getsockopt(int sockfd, int level, int optname,
}
break;
}
+ case TARGET_SO_PEERSEC: {
+ char *name;
+
+ if (get_user_u32(len, optlen)) {
+ return -TARGET_EFAULT;
+ }
+ if (len < 0) {
+ return -TARGET_EINVAL;
+ }
+ name = lock_user(VERIFY_WRITE, optval_addr, len, 0);
+ if (!name) {
+ return -TARGET_EFAULT;
+ }
+ lv = len;
+ ret = get_errno(getsockopt(sockfd, level, SO_PEERSEC,
+ name, &lv));
+ if (put_user_u32(lv, optlen)) {
+ ret = -TARGET_EFAULT;
+ }
+ unlock_user(name, optval_addr, lv);
+ break;
+ }
case TARGET_SO_LINGER:
{
struct linger lg;