diff options
Diffstat (limited to 'arch/um/kernel')
| -rw-r--r-- | arch/um/kernel/skas/stub.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/um/kernel/skas/stub.c b/arch/um/kernel/skas/stub.c index 796fc266d3bb..9041f6b6e28b 100644 --- a/arch/um/kernel/skas/stub.c +++ b/arch/um/kernel/skas/stub.c @@ -5,6 +5,9 @@ #include <sysdep/stub.h> +#include <linux/futex.h> +#include <errno.h> + static __always_inline int syscall_handler(struct stub_data *d) { int i; @@ -57,3 +60,49 @@ stub_syscall_handler(void) trap_myself(); } + +void __section(".__syscall_stub") +stub_signal_interrupt(int sig, siginfo_t *info, void *p) +{ + struct stub_data *d = get_stub_data(); + ucontext_t *uc = p; + long res; + + d->signal = sig; + d->si_offset = (unsigned long)info - (unsigned long)&d->sigstack[0]; + d->mctx_offset = (unsigned long)&uc->uc_mcontext - (unsigned long)&d->sigstack[0]; + +restart_wait: + d->futex = FUTEX_IN_KERN; + do { + res = stub_syscall3(__NR_futex, (unsigned long)&d->futex, + FUTEX_WAKE, 1); + } while (res == -EINTR); + do { + res = stub_syscall4(__NR_futex, (unsigned long)&d->futex, + FUTEX_WAIT, FUTEX_IN_KERN, 0); + } while (res == -EINTR || d->futex == FUTEX_IN_KERN); + + if (res < 0 && res != -EAGAIN) + stub_syscall1(__NR_exit_group, 1); + + /* Try running queued syscalls. */ + if (syscall_handler(d) < 0 || d->restart_wait) { + /* Report SIGSYS if we restart. */ + d->signal = SIGSYS; + d->restart_wait = 0; + goto restart_wait; + } + + /* Restore arch dependent state that is not part of the mcontext */ + stub_seccomp_restore_state(&d->arch_data); + + /* Return so that the host modified mcontext is restored. */ +} + +void __section(".__syscall_stub") +stub_signal_restorer(void) +{ + /* We must not have anything on the stack when doing rt_sigreturn */ + stub_syscall0(__NR_rt_sigreturn); +} |