From fc3f4453a2bc95549682e23600b22e658cb2d6d7 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Sun, 5 Apr 2020 18:23:30 -0700 Subject: [PATCH] Recompute stack base in forked postmaster children. This is for the benefit of running postgres under the rr debugger. When using rr signal handlers running while a syscall is active use an alternative stack. As e.g. bgworkers are started from within signal handlers, the forked backend then has a different stack base than postmaster. Previously that subsequently lead to those processes triggering spurious "stack depth limit exceeded" errors. Discussion: https://postgr.es/m/20200327182217.ubrrl32lyfhxfwk5@alap3.anarazel.de --- src/backend/postmaster/postmaster.c | 5 ----- src/backend/utils/init/miscinit.c | 9 +++++++++ 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 73d278f3b2..0578e92ba9 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -4900,11 +4900,6 @@ SubPostmasterMain(int argc, char *argv[]) /* Close the postmaster's sockets (as soon as we know them) */ ClosePostmasterPorts(strcmp(argv[1], "--forklog") == 0); - /* - * Set reference point for stack-depth checking - */ - set_stack_base(); - /* * Set up memory area for GSS information. Mirrors the code in ConnCreate * for the non-exec case. diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c index a7b7b12249..6fe25c023a 100644 --- a/src/backend/utils/init/miscinit.c +++ b/src/backend/utils/init/miscinit.c @@ -92,6 +92,15 @@ InitPostmasterChild(void) { IsUnderPostmaster = true; /* we are a postmaster subprocess now */ + /* + * Set reference point for stack-depth checking. We re-do that even in the + * !EXEC_BACKEND case, because there are some edge cases where processes + * are started with an alternative stack (e.g. starting bgworkers when + * running postgres using the rr debugger, as bgworkers are launched from + * signal handlers). + */ + set_stack_base(); + InitProcessGlobals(); /*