Hi, The getrlimit(2) page says the RLIMIT_STACK applies to "the process stack". However, in a multithreaded app, each thread has a stack. And RLIMIT_STACK determines the size of the thread's stack (unless overridden by the program). I verified this through a test program on Linux/i386 and Linux/x86_64. The code which implements this is in - glibc/nptl/nptl-init.c for Linux, - glibc/htl/pt-create.c for the Hurd. Patch attached.
>From 563e660d8cb46b566ea716d250cca4136a0ba88e Mon Sep 17 00:00:00 2001 From: Bruno Haible <bruno@xxxxxxxxx> Date: Sun, 23 May 2021 23:37:12 +0200 Subject: [PATCH] getrlimit.2: RLIMIT_STACK applies to each thread's stack. --- man2/getrlimit.2 | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/man2/getrlimit.2 b/man2/getrlimit.2 index 648fd3c..e8a123a 100644 --- a/man2/getrlimit.2 +++ b/man2/getrlimit.2 @@ -61,7 +61,7 @@ .\" 2008-05-07, mtk / Peter Zijlstra, Added description of RLIMIT_RTTIME .\" 2010-11-06, mtk: Added documentation of prlimit() .\" -.TH GETRLIMIT 2 2021-03-22 "Linux" "Linux Programmer's Manual" +.TH GETRLIMIT 2 2021-05-23 "Linux" "Linux Programmer's Manual" .SH NAME getrlimit, setrlimit, prlimit \- get/set resource limits .SH SYNOPSIS @@ -427,7 +427,7 @@ queued to the process. .\" that was present in kernels <= 2.6.7. MTK Dec 04 .TP .B RLIMIT_STACK -This is the maximum size of the process stack, in bytes. +This is the maximum size of the stack of each thread, in bytes. Upon reaching this limit, a .B SIGSEGV signal is generated. -- 2.7.4
