Changeset 068dd86 in mainline

Timestamp:

2023-08-04T13:07:34Z (19 months ago)

Author:

Vojtech Horky <vojtech.horky@…>

Branches:

ticket/834-toolchain-update

Children:

24cf6694

Parents:

4dbcdf3

Message:

Support linker without —no-warn-rwx-segments

Files:

• kernel/meson.build (modified) (2 diffs)
• meson/arch/arm64/meson.build (modified) (1 diff)
• 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) (1 diff)

kernel/meson.build

@@ -87 +87 @@
 kernel_link_args = arch_kernel_link_args + [
         '-Wl,--nmagic',
-        # 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+).
-        '-Wl,--no-warn-rwx-segments',
         '-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
@@ -104 +104 @@
 kernel_c_args = arch_kernel_c_args + kernel_defs + [
         '-ffreestanding',
-        # 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',
-        # 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/arm64/meson.build

@@ -44 +44 @@
 # -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,--no-warn-rwx-segments']
+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 = ['-Wl,--no-warn-rwx-segments']
+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_uspace_link_args += ['-Wl,--no-warn-rwx-segments']
-arch_boot_link_args = ['-Wl,--no-warn-rwx-segments']
+arch_uspace_link_args += ldflags_ignore_rwx_segments
+arch_boot_link_args = ldflags_ignore_rwx_segments
 
 

meson/arch/riscv64/meson.build

@@ -33 +33 @@
 arch_kernel_link_args = [ '-nostdlib' ]
 arch_uspace_link_args = [ '-nostdlib', '-lgcc' ]
-arch_boot_link_args = ['-Wl,--no-warn-rwx-segments']
+arch_boot_link_args = ldflags_ignore_rwx_segments
 
 rd_essential += [

meson/part/compiler_args/meson.build

@@ -129 +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