From f4171dfd70dd4d8dd7740edd87ac1c44d022f378 Mon Sep 17 00:00:00 2001
From: "Kelvin M. Klann" <kmk3.code@protonmail.com>
Date: Mon, 27 Sep 2021 23:53:13 -0300
Subject: [PATCH] Fix wrong limits.h include (should be linux/limits.h)

ARG_MAX and PATH_MAX are defined on POSIX.1-2017's limits.h(0p)[1], on
linux/limits.h and on musl's limits.h, but not on glibc's limits.h (nor
on any of its includes):

    $ grep -F -e ' ARG_MAX' -e ' PATH_MAX' /usr/include/limits.h \
      /usr/include/linux/limits.h /usr/lib/musl/include/limits.h
    /usr/include/linux/limits.h:#define ARG_MAX       131072        /* # bytes of args + environ for exec() */
    /usr/include/linux/limits.h:#define PATH_MAX        4096        /* # chars in a path name including nul */
    /usr/lib/musl/include/limits.h:#define PATH_MAX 4096
    /usr/lib/musl/include/limits.h:#define ARG_MAX 131072

Environment:

    $ grep '^NAME' /etc/os-release
    NAME="Artix Linux"
    $ pacman -Qo /usr/include/limits.h /usr/include/linux/limits.h \
      /usr/lib/musl/include/limits.h
    /usr/include/limits.h is owned by glibc 2.33-5
    /usr/include/linux/limits.h is owned by linux-api-headers 5.12.3-1
    /usr/lib/musl/include/limits.h is owned by musl 1.2.2-1

Files that use the macros:

    $ git grep -Fl -e ARG_MAX -e PATH_MAX -- src
    src/firejail/cmdline.c
    src/firejail/firejail.h
    src/libtrace/libtrace.c
    src/libtracelog/libtracelog.c

Note: No other macro from linux/limits.h appears to be used.

Note2: The build works even without including any limits.h on the files
that this commit changes, so there is probably another include on them
that ends up defining ARG_MAX/PATH_MAX.

Relates to #4578.

[1] https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html
---
 src/libtrace/libtrace.c       | 2 +-
 src/libtracelog/libtracelog.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libtrace/libtrace.c b/src/libtrace/libtrace.c
index d88512b0a86..ae560c6d163 100644
--- a/src/libtrace/libtrace.c
+++ b/src/libtrace/libtrace.c
@@ -23,7 +23,7 @@
 #include <string.h>
 #include <dlfcn.h>
 #include <sys/types.h>
-#include <limits.h>
+#include <linux/limits.h>
 #include <unistd.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
diff --git a/src/libtracelog/libtracelog.c b/src/libtracelog/libtracelog.c
index b946cc88983..734b2e8703c 100644
--- a/src/libtracelog/libtracelog.c
+++ b/src/libtracelog/libtracelog.c
@@ -31,7 +31,7 @@
 #include <sys/stat.h>
 #include <syslog.h>
 #include <dirent.h>
-#include <limits.h>
+#include <linux/limits.h>
 #include "../include/rundefs.h"
 
 //#define DEBUG