Implement the meat of the sigaltstack(2) system call with do_sigaltstack.
Signed-off-by: Stacey Son <s...@freebsd.org>
Signed-off-by: Kyle Evans <kev...@freebsd.org>
Signed-off-by: Warner Losh <i...@bsdimp.com>
---
bsd-user/qemu.h | 1 +
bsd-user/signal.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 67 insertions(+)
diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h
index c643d6ba246..fcdea460ed2 100644
--- a/bsd-user/qemu.h
+++ b/bsd-user/qemu.h
@@ -226,6 +226,7 @@ int host_to_target_signal(int sig);
void host_to_target_sigset(target_sigset_t *d, const sigset_t *s);
void target_to_host_sigset(sigset_t *d, const target_sigset_t *s);
long do_sigreturn(CPUArchState *regs, abi_ulong addr);
+abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp);
int do_sigaction(int sig, const struct target_sigaction *act,
struct target_sigaction *oact);
void QEMU_NORETURN force_sig(int target_sig);
diff --git a/bsd-user/signal.c b/bsd-user/signal.c
index f055d1db407..e5e5e28c60c 100644
--- a/bsd-user/signal.c
+++ b/bsd-user/signal.c
@@ -528,6 +528,72 @@ static void host_signal_handler(int host_sig, siginfo_t
*info, void *puc)
cpu_exit(thread_cpu);
}
+/* do_sigaltstack() returns target values and errnos. */
+/* compare to kern/kern_sig.c sys_sigaltstack() and kern_sigaltstack() */
+abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp)
+{
+ int ret;
+ target_stack_t oss;
+
+ if (uoss_addr) {
+ /* Save current signal stack params */
+ oss.ss_sp = tswapl(target_sigaltstack_used.ss_sp);
+ oss.ss_size = tswapl(target_sigaltstack_used.ss_size);
+ oss.ss_flags = tswapl(sas_ss_flags(sp));
+ }
+
+ if (uss_addr) {
+ target_stack_t *uss;
+ target_stack_t ss;
+ size_t minstacksize = TARGET_MINSIGSTKSZ;
+
+ ret = -TARGET_EFAULT;
+ if (!lock_user_struct(VERIFY_READ, uss, uss_addr, 1)) {
+ goto out;
+ }
+ __get_user(ss.ss_sp, &uss->ss_sp);
+ __get_user(ss.ss_size, &uss->ss_size);
+ __get_user(ss.ss_flags, &uss->ss_flags);
+ unlock_user_struct(uss, uss_addr, 0);
+
+ ret = -TARGET_EPERM;
+ if (on_sig_stack(sp)) {
+ goto out;
+ }
+
+ ret = -TARGET_EINVAL;
+ if (ss.ss_flags != TARGET_SS_DISABLE
+ && ss.ss_flags != TARGET_SS_ONSTACK
+ && ss.ss_flags != 0) {
+ goto out;
+ }
+
+ if (ss.ss_flags == TARGET_SS_DISABLE) {
+ ss.ss_size = 0;
+ ss.ss_sp = 0;
+ } else {
+ ret = -TARGET_ENOMEM;
+ if (ss.ss_size < minstacksize) {
+ goto out;
+ }
+ }
+
+ target_sigaltstack_used.ss_sp = ss.ss_sp;
+ target_sigaltstack_used.ss_size = ss.ss_size;
+ }
+
+ if (uoss_addr) {
+ ret = -TARGET_EFAULT;
+ if (copy_to_user(uoss_addr, &oss, sizeof(oss))) {
+ goto out;
+ }
+ }
+
+ ret = 0;
+out:
+ return ret;
+}
+
static int fatal_signal(int sig)
{
--
2.33.1
