From d94bb8c48f42678a5f1cf0041429b82aa1938540 Mon Sep 17 00:00:00 2001 From: Samuel Mendoza-Jonas Date: Mon, 23 Jan 2017 14:53:32 +1100 Subject: [PATCH] process: Cancel all asynchronous jobs on reinit If an asynchronous job is running over a reinit, the process can return and run its callback function after the reinit. This becomes a problem if the callback function accesses pointers that were only valid before the reinit (eg. device structs). If a reinit is requested explicitly stop all active asynchronous jobs and clear their callback functions before the reinit. Signed-off-by: Samuel Mendoza-Jonas --- discover/device-handler.c | 3 +++ lib/process/process.c | 21 +++++++++++++++++++++ lib/process/process.h | 2 ++ 3 files changed, 26 insertions(+) diff --git a/discover/device-handler.c b/discover/device-handler.c index 78fb159..3cf7edf 100644 --- a/discover/device-handler.c +++ b/discover/device-handler.c @@ -358,6 +358,9 @@ void device_handler_reinit(struct device_handler *handler) handler->pending_boot_is_default = false; } + /* Cancel any remaining async jobs */ + process_stop_async_all(); + /* free unresolved boot options */ list_for_each_entry_safe(&handler->unresolved_boot_options, opt, tmp, list) diff --git a/lib/process/process.c b/lib/process/process.c index 93fd9c9..f7e5b8f 100644 --- a/lib/process/process.c +++ b/lib/process/process.c @@ -440,8 +440,29 @@ int process_run_async(struct process *process) void process_stop_async(struct process *process) { + /* Avoid signalling an old pid */ + if (process->cancelled) + return; + pb_debug("process: sending SIGTERM to pid %d\n", process->pid); kill(process->pid, SIGTERM); + process->cancelled = true; +} + +void process_stop_async_all(void) +{ + struct process_info *procinfo; + struct process *process = NULL; + + pb_debug("process: cancelling all async jobs\n"); + + list_for_each_entry(&procset->async_list, procinfo, async_list) { + process = &procinfo->process; + /* Ignore the process completion - callbacks may use stale data */ + process->exit_cb = NULL; + process->stdout_cb = NULL; + process_stop_async(process); + } } int process_run_simple_argv(void *ctx, const char *argv[]) diff --git a/lib/process/process.h b/lib/process/process.h index 65fdba8..f858b0e 100644 --- a/lib/process/process.h +++ b/lib/process/process.h @@ -45,6 +45,7 @@ struct process { /* post-execution information */ int exit_status; + bool cancelled; }; /* Process management system init. process_init must be called before @@ -77,6 +78,7 @@ int process_run_simple(void *ctx, const char *name, ...) int process_run_async(struct process *process); void process_stop_async(struct process *process); +void process_stop_async_all(void); /* helper function to determine if a process exited cleanly, with a non-zero * exit status */ -- 2.39.2