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[PULL 3/5] linux-user: fix TARGET_NSIG and _NSIG uses
From: |
Laurent Vivier |
Subject: |
[PULL 3/5] linux-user: fix TARGET_NSIG and _NSIG uses |
Date: |
Thu, 13 Feb 2020 13:21:06 +0100 |
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 <address@hidden>
Reviewed-by: Peter Maydell <address@hidden>
Tested-by: Taylor Simpson <address@hidden>
Message-Id: <address@hidden>
---
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 246315571c09..c1e664f97a7c 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
--
2.24.1
- [PULL 0/5] Linux user for 5.0 patches, Laurent Vivier, 2020/02/13
- [PULL 1/5] linux-user: add missing TARGET_SIGRTMIN for hppa, Laurent Vivier, 2020/02/13
- [PULL 3/5] linux-user: fix TARGET_NSIG and _NSIG uses,
Laurent Vivier <=
- [PULL 5/5] linux-user: implement TARGET_SO_PEERSEC, Laurent Vivier, 2020/02/13
- [PULL 2/5] linux-user: cleanup signal.c, Laurent Vivier, 2020/02/13
- [PULL 4/5] linux-user: fix use of SIGRTMIN, Laurent Vivier, 2020/02/13
- Re: [PULL 0/5] Linux user for 5.0 patches, Peter Maydell, 2020/02/14