mirror_zfs/config/kernel-objtool.m4
Attila Fülöp b96f1a4b1f
Linux build: silence objtool warnings
After #17401 the Linux build produces some stack related warnings.

Silence them with the `STACK_FRAME_NON_STANDARD` macro.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #17410
2025-06-04 17:40:09 -07:00

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dnl #
dnl # Detect objtool functionality.
dnl #
dnl #
dnl # Kernel 5.10: linux/frame.h was renamed linux/objtool.h
dnl #
AC_DEFUN([ZFS_AC_KERNEL_OBJTOOL_HEADER], [
AC_MSG_CHECKING([whether objtool header is available])
ZFS_LINUX_TRY_COMPILE([
#include <linux/objtool.h>
],[
],[
objtool_header=$LINUX/include/linux/objtool.h
AC_DEFINE(HAVE_KERNEL_OBJTOOL_HEADER, 1,
[kernel has linux/objtool.h])
AC_MSG_RESULT(linux/objtool.h)
],[
objtool_header=$LINUX/include/linux/frame.h
AC_MSG_RESULT(linux/frame.h)
])
])
dnl #
dnl # Check for objtool support.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_SRC_OBJTOOL], [
dnl # 4.6 API for compile-time stack validation
ZFS_LINUX_TEST_SRC([objtool], [
#undef __ASSEMBLY__
#include <asm/ptrace.h>
#include <asm/frame.h>
],[
#if !defined(FRAME_BEGIN)
#error "FRAME_BEGIN is not defined"
#endif
])
dnl # 4.6 API added STACK_FRAME_NON_STANDARD macro
ZFS_LINUX_TEST_SRC([stack_frame_non_standard], [
#ifdef HAVE_KERNEL_OBJTOOL_HEADER
#include <linux/objtool.h>
#else
#include <linux/frame.h>
#endif
],[
#if !defined(STACK_FRAME_NON_STANDARD)
#error "STACK_FRAME_NON_STANDARD is not defined."
#endif
])
])
AC_DEFUN([ZFS_AC_KERNEL_OBJTOOL], [
AC_MSG_CHECKING(
[whether compile-time stack validation (objtool) is available])
ZFS_LINUX_TEST_RESULT([objtool], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_KERNEL_OBJTOOL, 1,
[kernel does stack verification])
AC_MSG_CHECKING([whether STACK_FRAME_NON_STANDARD is defined])
ZFS_LINUX_TEST_RESULT([stack_frame_non_standard], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_STACK_FRAME_NON_STANDARD, 1,
[STACK_FRAME_NON_STANDARD is defined])
dnl # Needed for kernels missing the asm macro. We grep
dnl # for it in the header file since there is currently
dnl # no test to check the result of assembling a file.
AC_MSG_CHECKING(
[whether STACK_FRAME_NON_STANDARD asm macro is defined])
dnl # Escape square brackets.
sp='@<:@@<:@:space:@:>@@:>@'
dotmacro='@<:@.@:>@macro'
regexp="^$sp*$dotmacro$sp+STACK_FRAME_NON_STANDARD$sp"
AS_IF([$EGREP -s -q "$regexp" $objtool_header],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_STACK_FRAME_NON_STANDARD_ASM, 1,
[STACK_FRAME_NON_STANDARD asm macro is defined])
],[
AC_MSG_RESULT(no)
])
],[
AC_MSG_RESULT(no)
])
],[
AC_MSG_RESULT(no)
])
])