tablet/grub
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

configure: Defer check for -mcmodel=large until PIC/PIE checks are done

Browse Source 
On RISC-V, large code model is only compatible with position-depedent
code. However, the configure script checks availability of -mcmodel=large
before determining whether PIC/PIE is enabled, and disable them.

This is problematic with toolchains that enable PIE by default, where
check for -mcmodel=large will always fail with,

  cc1: sorry, unimplemented: code model 'large' with '-fPIC'

and -mcmodel=medany will be silently used instead, causing relocation
failures at runtime with some memory layouts since -mcmodel=medany
requires all data and code to stay within a contiguous 4 GiB range.

Let's defer the check for -mcmodel=large until PIC/PIE is ensured disabled.

Fixes: f1957dc8a334 (RISC-V: Add to build system)

Reported-by: Han Gao <gaohan@iscas.ac.cn>
Signed-off-by: Yao Zi <me@ziyao.cc>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Yao Zi 2025-12-31 09:05:53 +00:00 committed by Daniel Kiper
parent ff1edd9752
commit 1aa0dd0c04
1 changed files with 15 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
configure.ac
View File

@ -1543,21 +1543,6 @@ AC_SUBST(TARGET_LDFLAGS_OLDMAGIC)
LDFLAGS="$TARGET_LDFLAGS"
if test "$target_cpu" = x86_64 || test "$target_cpu" = sparc64 || test "$target_cpu" = riscv64 ; then
# Use large model to support 4G memory
AC_CACHE_CHECK([whether option -mcmodel=large works], grub_cv_cc_mcmodel, [
CFLAGS="$TARGET_CFLAGS -mcmodel=large"
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
[grub_cv_cc_mcmodel=yes],
[grub_cv_cc_mcmodel=no])
])
if test "x$grub_cv_cc_mcmodel" = xyes; then
TARGET_CFLAGS="$TARGET_CFLAGS -mcmodel=large"
elif test "$target_cpu" = sparc64 || test "$target_cpu" = riscv64; then
TARGET_CFLAGS="$TARGET_CFLAGS -mcmodel=medany"
fi
fi
if test "$target_cpu"-"$platform" = x86_64-efi; then
# EFI writes to stack below %rsp, we must not use the red zone
AC_CACHE_CHECK([whether option -mno-red-zone works], grub_cv_cc_no_red_zone, [
@ -1666,6 +1651,21 @@ fi]
CFLAGS="$TARGET_CFLAGS"
if test "$target_cpu" = x86_64 || test "$target_cpu" = sparc64 || test "$target_cpu" = riscv64 ; then
# Use large model to support 4G memory
AC_CACHE_CHECK([whether option -mcmodel=large works], grub_cv_cc_mcmodel, [
CFLAGS="$TARGET_CFLAGS -mcmodel=large"
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
[grub_cv_cc_mcmodel=yes],
[grub_cv_cc_mcmodel=no])
])
if test "x$grub_cv_cc_mcmodel" = xyes; then
TARGET_CFLAGS="$TARGET_CFLAGS -mcmodel=large"
elif test "$target_cpu" = sparc64 || test "$target_cpu" = riscv64; then
TARGET_CFLAGS="$TARGET_CFLAGS -mcmodel=medany"
fi
fi
# Stack smashing protector.
grub_CHECK_STACK_PROTECTOR
AC_ARG_ENABLE([stack-protector],