kernel/linux.git/arch/mips/vdso/Makefile, branch linux-7.0.y

mips: Add -std= flag specified in KBUILD_CFLAGS to vdso CFLAGS

2025-04-27T07:37:10+00:00

GCC 15 changed the default C standard dialect from gnu17 to gnu23, which should not have impacted the kernel because it explicitly requests the gnu11 standard in the main Makefile. However, mips/vdso code uses its own CFLAGS without a '-std=' value, which break with this dialect change because of the kernel's own definitions of bool, false, and true conflicting with the C23 reserved keywords. include/linux/stddef.h:11:9: error: cannot use keyword 'false' as enumeration constant 11 | false = 0, | ^~~~~ include/linux/stddef.h:11:9: note: 'false' is a keyword with '-std=c23' onwards include/linux/types.h:35:33: error: 'bool' cannot be defined via 'typedef' 35 | typedef _Bool bool; | ^~~~ include/linux/types.h:35:33: note: 'bool' is a keyword with '-std=c23' onwards Add -std as specified in KBUILD_CFLAGS to the decompressor and purgatory CFLAGS to eliminate these errors and make the C standard version of these areas match the rest of the kernel. Signed-off-by: Khem Raj Cc: stable@vger.kernel.org Signed-off-by: Thomas Bogendoerfer

vdso: Rename included Makefile

2025-02-21T08:54:01+00:00

As the Makefile is included into other Makefiles it can not be used to define objects to be built from the current source directory. However the generic datastore will introduce such a local source file. Rename the included Makefile so it is clear how it is to be used and to make room for a regular Makefile in lib/vdso/. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-4-13a4669dfc8c@linutronix.de

Makefile: remove redundant tool coverage variables

2024-05-14T14:35:48+00:00

Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Tested-by: Roberto Sassu

kbuild: use $(src) instead of $(srctree)/$(src) for source directory

2024-05-09T19:34:52+00:00

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier

vdso: Improve cmd_vdso_check to check all dynamic relocations

2023-03-21T20:15:34+00:00

The actual intention is that no dynamic relocation exists in the VDSO. For this the VDSO build validates that the resulting .so file does not have any relocations which are specified via $(ARCH_REL_TYPE_ABS) per architecture, which is fragile as e.g. ARM64 lacks an entry for R_AARCH64_RELATIVE. Aside of that ARCH_REL_TYPE_ABS is a misnomer as it checks for relative relocations too. However, some GNU ld ports produce unneeded R_*_NONE relocation entries. If a port fails to determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE relocations. E.g. ld's powerpc port recently fixed https://sourceware.org/bugzilla/show_bug.cgi?id=29540). R_*_NONE are generally a no-op in the dynamic loaders. So just ignore them. Remove the ARCH_REL_TYPE_ABS defines and just validate that the resulting .so file does not contain any R_* relocation entries except R_*_NONE. Signed-off-by: Fangrui Song Signed-off-by: Thomas Gleixner Tested-by: Vincenzo Frascino # for aarch64 Reviewed-by: Christophe Leroy Reviewed-by: Vincenzo Frascino # for vDSO, aarch64 Acked-by: Michael Ellerman (powerpc) Link: https://lore.kernel.org/r/20230310190750.3323802-1-maskray@google.com

MIPS: remove CONFIG_MIPS_LD_CAN_LINK_VDSO

2023-01-27T16:14:48+00:00

Given commit e4412739472b ("Documentation: raise minimum supported version of binutils to 2.25"), CONFIG_MIPS_LD_CAN_LINK_VDSO is always 'y'. Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Thomas Bogendoerfer

MIPS: Use "grep -E" instead of "egrep"

2022-11-21T16:56:53+00:00

The latest version of grep claims the egrep is now obsolete so the build now contains warnings that look like: egrep: warning: egrep is obsolescent; using grep -E fix this up by moving the related file to use "grep -E" instead. Here are the steps to install the latest grep: wget http://ftp.gnu.org/gnu/grep/grep-3.8.tar.gz tar xf grep-3.8.tar.gz cd grep-3.8 && ./configure && make sudo make install export PATH=/usr/local/bin:$PATH Signed-off-by: Tiezhu Yang Signed-off-by: Thomas Bogendoerfer

mips: Enable KCSAN

2022-02-07T17:31:57+00:00

This patch enables KCSAN for the 64-bit version. Updated rules for the incompatible compilation units (vdso, boot/compressed). Signed-off-by: Nemanja Rakovic Signed-off-by: Thomas Bogendoerfer

MIPS: VDSO: remove -nostdlib compiler flag

2021-11-09T15:09:37+00:00

The -nostdlib option requests the compiler to not use the standard system startup files or libraries when linking. It is effective only when $(CC) is used as a linker driver. Since commit 2ff906994b6c ("MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO"), $(LD) is directly used, hence -nostdlib is unneeded. Signed-off-by: Masahiro Yamada Signed-off-by: Thomas Bogendoerfer

MIPS: Makefile: Replace -pg with CC_FLAGS_FTRACE

2021-04-21T11:44:35+00:00

This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE makefile variable which architectures can override if a different option should be used for code generation. Signed-off-by: zhaoxiao Signed-off-by: Thomas Bogendoerfer