Changes in / [590cb6d2:71b4444] in mainline

Files:

• kernel/meson.build (modified) (2 diffs)
• meson/arch/arm32/meson.build (modified) (1 diff)
• meson/arch/arm64/meson.build (modified) (2 diffs)
• meson/arch/ia64/meson.build (modified) (1 diff)
• meson/arch/ppc32/meson.build (modified) (1 diff)
• meson/arch/riscv64/meson.build (modified) (1 diff)
• meson/part/compiler_args/meson.build (modified) (2 diffs)
• meson/part/tools/meson.build (modified) (1 diff)

kernel/meson.build

@@ -89 +89 @@
         '-T', meson.current_build_dir() / '_link.ld',
 ]
+# The kernel is built as ELF but then copied as a blob of bytes and
+# the permissions are not relevant anyway (needed for binutils 2.39+).
+kernel_link_args += ldflags_ignore_rwx_segments
 
 if CONFIG_LTO
@@ -101 +104 @@
 kernel_c_args = arch_kernel_c_args + kernel_defs + [
         '-ffreestanding',
-        # TODO: remove this flag
-        cc.get_supported_arguments([ '-Wno-cast-function-type' ]),
+
+        cc.get_supported_arguments([
+                # TODO: remove this flag
+                '-Wno-cast-function-type',
+
+                # When accessing specific memory addresses that are below
+                # normal page size, the compiler may assume that we actually
+                # dereferenced NULL pointer and warns us about that.
+                # But in kernel we often need to access these addresses
+                # directly hence we need to ignore these warnings.
+                #
+                # TODO: might make more sense to disable this selectively
+                # in specific files (or better yet, for specific lines).
+                '--param=min-pagesize=0',
+        ]),
 ]
 

meson/arch/arm32/meson.build

@@ -42 +42 @@
 ]
 
+arch_kernel_c_args = arch_uspace_c_args + [ '-mno-unaligned-access', '-mfpu=vfpv3' ]
+arch_kernel_c_args += cc.get_supported_arguments(['-mgeneral-regs-only' ])
+arch_kernel_link_args = [ '-nostdlib', '-Wl,-z,max-page-size=0x1000' ]
+
 if CONFIG_FPU
-        # This is necessary for kernel too, to allow vmsr insn and fpexc manipulation.
-        # Use vfp32 to allow context save/restore of d16-d31 regs.
-        arch_uspace_c_args += [ '-mfloat-abi=hard' ]
+    # Need to use softfp because our libgcc.a uses it too
+    # softfp - generate code with soft-float calling conventions but allow use
+    # of "hard" float instructions
+    arch_uspace_c_args += [ '-mfloat-abi=softfp' ]
 endif
-
-arch_kernel_c_args = arch_uspace_c_args + [ '-mno-unaligned-access', '-mfpu=vfpv3' ]
-arch_kernel_link_args = [ '-nostdlib', '-Wl,-z,max-page-size=0x1000' ]
 arch_uspace_link_args = [ '-nostdlib', '-lgcc', '-Wl,-z,max-page-size=0x1000' ]
 

meson/arch/arm64/meson.build

@@ -28 +28 @@
 #
 
-arch_uspace_c_args = [ '-D__LE__', '-fno-omit-frame-pointer' ]
+arch_uspace_c_args = [
+        '-D__LE__',
+        '-fno-omit-frame-pointer',
+        cc.get_supported_arguments(['-mno-outline-atomics']),
+]
 arch_kernel_c_args = arch_uspace_c_args + [ '-march=armv8-a+nofp+nosimd', '-mgeneral-regs-only' ]
 arch_kernel_link_args = [ '-nostdlib' ]
@@ -44 +48 @@
 # -mstrict-align option is therefore not needed.
 arch_boot_c_args = arch_uspace_c_args + [ '-fpic', '-fvisibility=hidden', '-fno-function-sections' ]
-arch_boot_link_args = [ '-Wl,-shared', '-Wl,--no-gc-sections' ]
+arch_boot_link_args = [ '-Wl,-shared', '-Wl,--no-gc-sections' ] + ldflags_ignore_rwx_segments
 
 if MACHINE == 'virt'

meson/arch/ia64/meson.build

@@ -38 +38 @@
 arch_uspace_link_args = [ '-nostdlib', '-lgcc' ]
 arch_kernel_link_args = [ '-nostdlib', '-Wl,-EL' ]
-arch_boot_link_args = []
+arch_boot_link_args = ldflags_ignore_rwx_segments
 
 

meson/arch/ppc32/meson.build

@@ -37 +37 @@
 arch_kernel_link_args = [ '-nostdlib', '-Wl,-z,max-page-size=0x1000', '-Wl,--no-check-sections', '-Wl,--no-gc-sections' ]
 arch_uspace_link_args = [ '-nostdlib', '-lgcc', '-Wl,-z,max-page-size=0x1000' ]
-arch_boot_link_args = []
+arch_uspace_link_args += ldflags_ignore_rwx_segments
+arch_boot_link_args = ldflags_ignore_rwx_segments
 
 rd_essential += [

meson/arch/riscv64/meson.build

@@ -33 +33 @@
 arch_kernel_link_args = [ '-nostdlib' ]
 arch_uspace_link_args = [ '-nostdlib', '-lgcc' ]
-arch_boot_link_args = []
+arch_boot_link_args = ldflags_ignore_rwx_segments
 
 rd_essential += [

meson/part/compiler_args/meson.build

@@ -110 +110 @@
 extra_cppflags = extra_common_flags + [
         '-fno-exceptions',
+        '-Wno-misleading-indentation',
         '-frtti',
 ]
@@ -128 +129 @@
         add_project_link_arguments(extra_cflags, language : [ lang ])
 endforeach
+
+# This flag is needed at several places, hence we define it here.
+#
+# For backwards compatibility we try to detect --no-warn-rwx-segments.
+# However, the autodetection done by Meson also results in
+# "cannot find entry symbol _start; defaulting to 00000000004000b0"
+# thus the option is never supported alone. So when detecting we also
+# specify --entry=main so that the stub source provided by Meson is build
+# correctly.
+ldflags_ignore_rwx_segments = []
+if cc.has_link_argument('-Wl,--no-warn-rwx-segments,--entry=main')
+    ldflags_ignore_rwx_segments += ['-Wl,--no-warn-rwx-segments']
+endif

meson/part/tools/meson.build

@@ -61 +61 @@
 endif
 
+# On some distributions (e.g. Arch Linux), genisoimage is actually a symbolic
+# link to mkisofs. However, they do not accept exactly the same options.
+# Thus we check if genisoimage is a symbolic link to mkisofs and if it is so,
+# we switch to mkisofs as that is the native application available.
+fs = import('fs')
 genisoimage = find_program('genisoimage', required: false)
-if genisoimage.found()
+_mkisofs = find_program('mkisofs', required: false)
+if genisoimage.found() and not (fs.is_symlink(genisoimage.full_path()) and _mkisofs.found() and fs.is_samepath(genisoimage.full_path(), _mkisofs.full_path()))
         genisoimage_type = 'genisoimage'
 else
-        genisoimage = find_program('mkisofs', required: false)
+        genisoimage = _mkisofs
         if genisoimage.found()
                 genisoimage_type = 'mkisofs'