diff options
Diffstat (limited to 'pkg/sentry/kernel/task_syscall.go')
-rw-r--r-- | pkg/sentry/kernel/task_syscall.go | 69 |
1 files changed, 1 insertions, 68 deletions
diff --git a/pkg/sentry/kernel/task_syscall.go b/pkg/sentry/kernel/task_syscall.go index a5903b0b5..2dbf86547 100644 --- a/pkg/sentry/kernel/task_syscall.go +++ b/pkg/sentry/kernel/task_syscall.go @@ -29,75 +29,8 @@ import ( "gvisor.dev/gvisor/pkg/usermem" ) -// SyscallRestartErrno represents a ERESTART* errno defined in the Linux's kernel -// include/linux/errno.h. These errnos are never returned to userspace -// directly, but are used to communicate the expected behavior of an -// interrupted syscall from the syscall to signal handling. -type SyscallRestartErrno int - -// These numeric values are significant because ptrace syscall exit tracing can -// observe them. -// -// For all of the following errnos, if the syscall is not interrupted by a -// signal delivered to a user handler, the syscall is restarted. -const ( - // ERESTARTSYS is returned by an interrupted syscall to indicate that it - // should be converted to EINTR if interrupted by a signal delivered to a - // user handler without SA_RESTART set, and restarted otherwise. - ERESTARTSYS = SyscallRestartErrno(512) - - // ERESTARTNOINTR is returned by an interrupted syscall to indicate that it - // should always be restarted. - ERESTARTNOINTR = SyscallRestartErrno(513) - - // ERESTARTNOHAND is returned by an interrupted syscall to indicate that it - // should be converted to EINTR if interrupted by a signal delivered to a - // user handler, and restarted otherwise. - ERESTARTNOHAND = SyscallRestartErrno(514) - - // ERESTART_RESTARTBLOCK is returned by an interrupted syscall to indicate - // that it should be restarted using a custom function. The interrupted - // syscall must register a custom restart function by calling - // Task.SetRestartSyscallFn. - ERESTART_RESTARTBLOCK = SyscallRestartErrno(516) -) - var vsyscallCount = metric.MustCreateNewUint64Metric("/kernel/vsyscall_count", false /* sync */, "Number of times vsyscalls were invoked by the application") -// Error implements error.Error. -func (e SyscallRestartErrno) Error() string { - // Descriptions are borrowed from strace. - switch e { - case ERESTARTSYS: - return "to be restarted if SA_RESTART is set" - case ERESTARTNOINTR: - return "to be restarted" - case ERESTARTNOHAND: - return "to be restarted if no handler" - case ERESTART_RESTARTBLOCK: - return "interrupted by signal" - default: - return "(unknown interrupt error)" - } -} - -// SyscallRestartErrnoFromReturn returns the SyscallRestartErrno represented by -// rv, the value in a syscall return register. -func SyscallRestartErrnoFromReturn(rv uintptr) (SyscallRestartErrno, bool) { - switch int(rv) { - case -int(ERESTARTSYS): - return ERESTARTSYS, true - case -int(ERESTARTNOINTR): - return ERESTARTNOINTR, true - case -int(ERESTARTNOHAND): - return ERESTARTNOHAND, true - case -int(ERESTART_RESTARTBLOCK): - return ERESTART_RESTARTBLOCK, true - default: - return 0, false - } -} - // SyscallRestartBlock represents the restart block for a syscall restartable // with a custom function. It encapsulates the state required to restart a // syscall across a S/R. @@ -447,7 +380,7 @@ func ExtractErrno(err error, sysno int) int { return 0 case syscall.Errno: return int(err) - case SyscallRestartErrno: + case syserror.SyscallRestartErrno: return int(err) case *memmap.BusError: // Bus errors may generate SIGBUS, but for syscalls they still |