3.2.85-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Andrey Ryabinin <[email protected]> commit 70d78fe7c8b640b5acfad56ad341985b3810998a upstream. It could be not possible to freeze coredumping task when it waits for 'core_state->startup' completion, because threads are frozen in get_signal() before they got a chance to complete 'core_state->startup'. Inability to freeze a task during suspend will cause suspend to fail. Also CRIU uses cgroup freezer during dump operation. So with an unfreezable task the CRIU dump will fail because it waits for a transition from 'FREEZING' to 'FROZEN' state which will never happen. Use freezer_do_not_count() to tell freezer to ignore coredumping task while it waits for core_state->startup completion. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Andrey Ryabinin <[email protected]> Acked-by: Pavel Machek <[email protected]> Acked-by: Oleg Nesterov <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Tejun Heo <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: Michal Hocko <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <[email protected]> --- --- a/fs/exec.c +++ b/fs/exec.c @@ -25,6 +25,7 @@ #include <linux/slab.h> #include <linux/file.h> #include <linux/fdtable.h> +#include <linux/freezer.h> #include <linux/mm.h> #include <linux/stat.h> #include <linux/fcntl.h> @@ -1974,8 +1975,11 @@ static int coredump_wait(int exit_code, complete(vfork_done); } - if (core_waiters) + if (core_waiters > 0) { + freezer_do_not_count(); wait_for_completion(&core_state->startup); + freezer_count(); + } fail: return core_waiters; }
