lxc-attach: Fix lost return codes of spawned processes that are killed

lxc-attach swallows the return codes of processes that are terminated
via a signal, and by default exits with a return code of 0 (i.e.
indicating success) even if the command it tried to execute was
terminated.

This patch fixes it by explicitly checking if the process was terminated
via a signal, and returning an appropriate exit code.

Note that we add 128 to the signal value to generate the exit code
because by convention the exit code is 128 + signal number. e.g. if a
process is killed via signal 9, then the error code is 9 + 128 = 137.

Signed-off-by: Mohammed Ajmal Siddiqui <ajmalsiddiqui21@gmail.com>

diff --git a/src/lxc/tools/lxc_attach.c b/src/lxc/tools/lxc_attach.c
index fa303c7b4f1a008763ebb9bc4b08fa8491033d00..6482b0aeee7b500c579365b23ff403a7f817bdb9 100644 (file)
--- a/src/lxc/tools/lxc_attach.c
+++ b/src/lxc/tools/lxc_attach.c
@@ -399,6 +399,8 @@ int lxc_attach_main(int argc, char *argv[])
        }
        if (WIFEXITED(ret))
                wexit = WEXITSTATUS(ret);
+       else if (WIFSIGNALED(ret))
+               wexit = WTERMSIG(ret) + 128;
 
 out:
        lxc_container_put(c);