[compiler-rt] Don't handle Linux-specific shmctl commands in sanitizer

[jrtc27]

Despite being defined in the system headers, these commands are not in
fact part of the FreeBSD system call interface. They exist solely for
the Linuxulator, i.e. running Linux binaries on FreeBSD, and any attempt
to use them from a FreeBSD binary will return EINVAL. The fact we needed
to define _KERNEL (which, as the name implies, means we are compiling
the kernel) to even get the definition of shminfo should have been a
strong indicator that IPC_INFO at least was not a userspace interface.

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Jessica Clarke (jrtc27)

Changes

Defining _KERNEL is a hack that can cause all kinds of breakage if
you're not careful, since the actual environment is not a kernel build,
and so should be avoided. Since FreeBSD 12 (MFC'ed for 11.3) you can
define _WANT_SYSVSHM_INTERNALS to expose shminfo (and various other
things) to userspace, so use that instead.

---

Full diff: https://github.com/llvm/llvm-project/pull/143116.diff

1 Files Affected:

• (modified) compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp (+1-2)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp
index 4940062eeae47..8e83ef9ae61df 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp
@@ -87,9 +87,8 @@
 #include <wchar.h>
 #include <wordexp.h>
 
-#define _KERNEL  // to declare 'shminfo' structure
+#define _WANT_SYSVSHM_INTERNALS  // to declare 'shminfo' structure
 #include <sys/shm.h>
-#undef _KERNEL
 
 #undef IOC_DIRMASK
 

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff HEAD~1 HEAD --extensions h,cpp -- compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.h

View the diff from clang-format here.

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp
index 4c1e00528..252f17efc 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.cpp
@@ -29,23 +29,23 @@
 #include <sys/mtio.h>
 #include <sys/ptrace.h>
 #include <sys/resource.h>
-#include <sys/shm.h>
-#include <sys/signal.h>
-#include <sys/socket.h>
-#include <sys/sockio.h>
-#include <sys/soundcard.h>
-#include <sys/stat.h>
-#include <sys/statvfs.h>
-#include <sys/time.h>
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-W#warnings"
-#include <sys/timeb.h>
-#pragma clang diagnostic pop
-#include <sys/times.h>
-#include <sys/timespec.h>
-#include <sys/types.h>
-#include <sys/ucontext.h>
-#include <sys/utsname.h>
+#  include <sys/shm.h>
+#  include <sys/signal.h>
+#  include <sys/socket.h>
+#  include <sys/sockio.h>
+#  include <sys/soundcard.h>
+#  include <sys/stat.h>
+#  include <sys/statvfs.h>
+#  include <sys/time.h>
+#  pragma clang diagnostic push
+#  pragma clang diagnostic ignored "-W#warnings"
+#  include <sys/timeb.h>
+#  pragma clang diagnostic pop
+#  include <sys/times.h>
+#  include <sys/timespec.h>
+#  include <sys/types.h>
+#  include <sys/ucontext.h>
+#  include <sys/utsname.h>
 //
 #include <arpa/inet.h>
 #include <net/ethernet.h>
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.h
index 382b67ce7..91ca73d29 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_freebsd.h
@@ -422,11 +422,11 @@ typedef void __sanitizer_FILE;
 extern int shmctl_ipc_stat;
 
 // This simplifies generic code
-#define struct_shminfo_sz -1
-#define struct_shm_info_sz -1
-#define shmctl_shm_stat -1
-#define shmctl_ipc_info -1
-#define shmctl_shm_info -1
+#  define struct_shminfo_sz -1
+#  define struct_shm_info_sz -1
+#  define shmctl_shm_stat -1
+#  define shmctl_ipc_info -1
+#  define shmctl_shm_info -1
 
 extern unsigned struct_utmpx_sz;
 

[jrtc27]

Hm, actually, we shouldn't even be trying to handle this (nor some others), they're Linux-specific and only defined so the Linuxulator can use them.

[DimitryAndric]

LGTM