[tor-commits] [tor/master] subsys: Make the subsystem init order match the module dependencies

[dgoulet at torproject.org]

commit 612b0a41399d0ddf260f4f6dd989fcc97d069fbd
Author: teor <teor at torproject.org>
Date:   Wed Sep 4 15:40:57 2019 +1000

    subsys: Make the subsystem init order match the module dependencies
    
    Fix levels for subsystems that depend on log/err
    * winprocess (security) doesn't use err:
      * call windows process security APIs as early as possible
      * init err after winprocess
      * move wallclock so it's still after err
    * network and time depend on log:
      * make sure that network and time can use logging.
      * init network and time after log
    
    Add comments explaining the module init order.
    
    Fixes bug 31615; bugfix on 0.4.0.1-alpha.
---
 changes/bug31615                 | 5 +++++
 src/lib/err/torerr_sys.c         | 5 ++++-
 src/lib/log/log_sys.c            | 2 ++
 src/lib/net/network_sys.c        | 4 +++-
 src/lib/process/winprocess_sys.c | 2 ++
 src/lib/thread/compat_threads.c  | 2 ++
 src/lib/time/time_sys.c          | 4 +++-
 src/lib/wallclock/approx_time.c  | 4 +++-
 8 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/changes/bug31615 b/changes/bug31615
new file mode 100644
index 000000000..49b13bea9
--- /dev/null
+++ b/changes/bug31615
@@ -0,0 +1,5 @@
+  o Minor bugfixes (subsystems):
+    - Make the subsystem init order match the subsystem module dependencies.
+      Call windows process security APIs as early as possible. Init log before
+      network and time, so that network and time can use logging.
+      Fixes bug 31615; bugfix on 0.4.0.1-alpha.
diff --git a/src/lib/err/torerr_sys.c b/src/lib/err/torerr_sys.c
index 3ab1b3c4e..34f70f1f0 100644
--- a/src/lib/err/torerr_sys.c
+++ b/src/lib/err/torerr_sys.c
@@ -33,7 +33,10 @@ subsys_torerr_shutdown(void)
 
 const subsys_fns_t sys_torerr = {
   .name = "err",
-  .level = -100,
+  /* Low-level error handling is a diagnostic feature, we want it to init
+   * right after windows process security, and shutdown last.
+   * (Security never shuts down.) */
+  .level = -99,
   .supported = true,
   .initialize = subsys_torerr_initialize,
   .shutdown = subsys_torerr_shutdown
diff --git a/src/lib/log/log_sys.c b/src/lib/log/log_sys.c
index d1080f226..826358546 100644
--- a/src/lib/log/log_sys.c
+++ b/src/lib/log/log_sys.c
@@ -29,6 +29,8 @@ subsys_logging_shutdown(void)
 const subsys_fns_t sys_logging = {
   .name = "log",
   .supported = true,
+  /* Logging depends on threads, approx time, raw logging, and security.
+   * Most other lib modules depend on logging. */
   .level = -90,
   .initialize = subsys_logging_initialize,
   .shutdown = subsys_logging_shutdown,
diff --git a/src/lib/net/network_sys.c b/src/lib/net/network_sys.c
index 9dfdb2b45..e0a2625d7 100644
--- a/src/lib/net/network_sys.c
+++ b/src/lib/net/network_sys.c
@@ -37,7 +37,9 @@ subsys_network_shutdown(void)
 
 const subsys_fns_t sys_network = {
   .name = "network",
-  .level = -90,
+  /* Network depends on logging, and a lot of other modules depend on network.
+   */
+  .level = -80,
   .supported = true,
   .initialize = subsys_network_initialize,
   .shutdown = subsys_network_shutdown,
diff --git a/src/lib/process/winprocess_sys.c b/src/lib/process/winprocess_sys.c
index 1266babca..407eeaaee 100644
--- a/src/lib/process/winprocess_sys.c
+++ b/src/lib/process/winprocess_sys.c
@@ -58,6 +58,8 @@ subsys_winprocess_initialize(void)
 
 const subsys_fns_t sys_winprocess = {
   .name = "winprocess",
+  /* HeapEnableTerminationOnCorruption and setdeppolicy() are security
+   * features, we want them to run first. */
   .level = -100,
   .supported = WINPROCESS_SYS_ENABLED,
   .initialize = subsys_winprocess_initialize,
diff --git a/src/lib/thread/compat_threads.c b/src/lib/thread/compat_threads.c
index 35cfeba64..1c4a5c4e3 100644
--- a/src/lib/thread/compat_threads.c
+++ b/src/lib/thread/compat_threads.c
@@ -122,6 +122,8 @@ subsys_threads_initialize(void)
 const subsys_fns_t sys_threads = {
   .name = "threads",
   .supported = true,
+  /* Threads is used by logging, which is a diagnostic feature, we want it to
+   * init right after low-level error handling and approx time. */
   .level = -95,
   .initialize = subsys_threads_initialize,
 };
diff --git a/src/lib/time/time_sys.c b/src/lib/time/time_sys.c
index b3feb7b46..8b9aa2856 100644
--- a/src/lib/time/time_sys.c
+++ b/src/lib/time/time_sys.c
@@ -20,7 +20,9 @@ subsys_time_initialize(void)
 
 const subsys_fns_t sys_time = {
   .name = "time",
-  .level = -90,
+  /* Monotonic time depends on logging, and a lot of other modules depend on
+   * monotonic time. */
+  .level = -80,
   .supported = true,
   .initialize = subsys_time_initialize,
 };
diff --git a/src/lib/wallclock/approx_time.c b/src/lib/wallclock/approx_time.c
index 7b3280402..77eeddaf5 100644
--- a/src/lib/wallclock/approx_time.c
+++ b/src/lib/wallclock/approx_time.c
@@ -54,6 +54,8 @@ subsys_wallclock_initialize(void)
 const subsys_fns_t sys_wallclock = {
   .name = "wallclock",
   .supported = true,
-  .level = -99,
+  /* Approximate time is a diagnostic feature, we want it to init right after
+   * low-level error handling. */
+  .level = -98,
   .initialize = subsys_wallclock_initialize,
 };