https://bugs.gentoo.org/971376
https://github.com/systemd/systemd/pull/41240

From 26fe43d2189cc7eab3b5c710673f04a23627caf0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andreas=20K=2E=20H=C3=BCttel?= <dilfridge@gentoo.org>
Date: Fri, 20 Mar 2026 13:52:17 +0100
Subject: [PATCH] mips: Fix conditional inclusion of <asm/sgidefs.h>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

systemd now has a system call wrapper that does a long series of #ifdef's to
differentiate between architectures and ABIs. This wrapper has two problems.

1. On mips, it needs to differentiate between O32, N32, N64 ABI. It does that
via a code block in src/include/override/sys/generate-syscall.py (and derived
files):

     76 #  elif defined(_MIPS_SIM)
     77 #    if _MIPS_SIM == _MIPS_SIM_ABI32
     78 #      define systemd_NR_{syscall} {nr_mipso32}
     79 #    elif _MIPS_SIM == _MIPS_SIM_NABI32
     80 #      define systemd_NR_{syscall} {nr_mips64n32}
     81 #    elif _MIPS_SIM == _MIPS_SIM_ABI64
     82 #      define systemd_NR_{syscall} {nr_mips64}
     83 #    else
     84 #      error "Unknown MIPS ABI"
     85 #    endif
     86 #  elif defined(__hppa__)

Now the _MIPS_SIM* constants stem from a vendor-specific header file sgidefs.h,
which is included with glibc, but not with musl. It is however always present
in the Linux kernel headers as asm/sgidefs.h ...

2. To work around this, the syscall wrapper already has a block

     47 #ifdef ARCH_MIPS
     48 #include <asm/sgidefs.h>
     49 #endif

Turns out, ARCH_MIPS is defined nowhere in Gentoo, neither on glibc nor on musl.
As a result the code (by accident, probably sgidefs.h is included transitively
somehow) works on glibc, but not on musl.

The simplest fix is to replace line 47 in the generator and the derived file
with

     47 #ifdef __mips__

Two other source code files require a similar fix since they rely on the
constants.

Bug: https://github.com/systemd/systemd/issues/41239
Bug: https://bugs.gentoo.org/971376
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
---
 src/include/override/sys/generate-syscall.py | 2 +-
 src/include/override/sys/syscall.h           | 2 +-
 src/shared/base-filesystem.c                 | 2 +-
 src/shared/seccomp-util.c                    | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/include/override/sys/generate-syscall.py b/src/include/override/sys/generate-syscall.py
index 6f449f9dc1330..1c90ad0e38402 100755
--- a/src/include/override/sys/generate-syscall.py
+++ b/src/include/override/sys/generate-syscall.py
@@ -44,7 +44,7 @@ def parse_syscall_tables(filenames):
 
 #include_next <sys/syscall.h>   /* IWYU pragma: export */
 
-#ifdef ARCH_MIPS
+#ifdef __mips__
 #include <asm/sgidefs.h>
 #endif
 
diff --git a/src/include/override/sys/syscall.h b/src/include/override/sys/syscall.h
index da2f780bed39c..0233f254b421c 100644
--- a/src/include/override/sys/syscall.h
+++ b/src/include/override/sys/syscall.h
@@ -11,7 +11,7 @@
 
 #include_next <sys/syscall.h>   /* IWYU pragma: export */
 
-#ifdef ARCH_MIPS
+#ifdef __mips__
 #include <asm/sgidefs.h>
 #endif
 
diff --git a/src/shared/base-filesystem.c b/src/shared/base-filesystem.c
index bad3b46f3ad3a..9e8856ba48ce6 100644
--- a/src/shared/base-filesystem.c
+++ b/src/shared/base-filesystem.c
@@ -5,7 +5,7 @@
 #include <syslog.h>
 #include <unistd.h>
 
-#ifdef ARCH_MIPS
+#ifdef __mips__
 #include <asm/sgidefs.h>
 #endif
 
diff --git a/src/shared/seccomp-util.c b/src/shared/seccomp-util.c
index d2f7612a53de5..9785fc45d78f3 100644
--- a/src/shared/seccomp-util.c
+++ b/src/shared/seccomp-util.c
@@ -12,7 +12,7 @@
 #include <sys/shm.h>
 #include <sys/stat.h>
 
-#ifdef ARCH_MIPS
+#ifdef __mips__
 #include <asm/sgidefs.h>
 #endif
 
