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linux-stable/arch/loongarch/vdso/Makefile

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LoongArch: Add VDSO and VSYSCALL support Add VDSO and VSYSCALL support (sigreturn, gettimeofday and its friends) for LoongArch. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-05-31 10:04:12 +00:00
# SPDX-License-Identifier: GPL-2.0
# Objects to go into the VDSO.
LoongArch: Add KASAN (Kernel Address Sanitizer) support 1/8 of kernel addresses reserved for shadow memory. But for LoongArch, There are a lot of holes between different segments and valid address space (256T available) is insufficient to map all these segments to kasan shadow memory with the common formula provided by kasan core, saying (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET So LoongArch has a arch-specific mapping formula, different segments are mapped individually, and only limited space lengths of these specific segments are mapped to shadow. At early boot stage the whole shadow region populated with just one physical page (kasan_early_shadow_page). Later, this page is reused as readonly zero shadow for some memory that kasan currently don't track. After mapping the physical memory, pages for shadow memory are allocated and mapped. Functions like memset()/memcpy()/memmove() do a lot of memory accesses. If bad pointer passed to one of these function it is important to be caught. Compiler's instrumentation cannot do this since these functions are written in assembly. KASan replaces memory functions with manually instrumented variants. Original functions declared as weak symbols so strong definitions in mm/kasan/kasan.c could replace them. Original functions have aliases with '__' prefix in names, so we could call non-instrumented variant if needed. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 14:54:16 +00:00
KASAN_SANITIZE := n
LoongArch: vDSO: Disable UBSAN instrumentation The vDSO executes in userspace, so the kernel's UBSAN should not instrument it. Solves these kind of build errors: loongarch64-linux-ld: arch/loongarch/vdso/vgettimeofday.o: in function `vdso_shift_ns': lib/vdso/gettimeofday.c:23:(.text+0x3f8): undefined reference to `__ubsan_handle_shift_out_of_bounds' Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202401310530.lZHCj1Zl-lkp@intel.com/ Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Fangrui Song <maskray@google.com> Cc: loongarch@lists.linux.dev Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-02-06 04:32:05 +00:00
UBSAN_SANITIZE := n
LoongArch: Allow building with kcov coverage Add ARCH_HAS_KCOV and HAVE_GCC_PLUGINS to the LoongArch Kconfig. And also disable instrumentation of vdso. Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 14:53:55 +00:00
KCOV_INSTRUMENT := n
LoongArch: Add ORC stack unwinder support The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is similar in concept to a DWARF unwinder. The difference is that the format of the ORC data is much simpler than DWARF, which in turn allows the ORC unwinder to be much simpler and faster. The ORC data consists of unwind tables which are generated by objtool. After analyzing all the code paths of a .o file, it determines information about the stack state at each instruction address in the file and outputs that information to the .orc_unwind and .orc_unwind_ip sections. The per-object ORC sections are combined at link time and are sorted and post-processed at boot time. The unwinder uses the resulting data to correlate instruction addresses with their stack states at run time. Most of the logic are similar with x86, in order to get ra info before ra is saved into stack, add ra_reg and ra_offset into orc_entry. At the same time, modify some arch-specific code to silence the objtool warnings. Co-developed-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Jinyang He <hejinyang@loongson.cn> Co-developed-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-03-11 14:23:47 +00:00
OBJECT_FILES_NON_STANDARD := y
LoongArch: Allow building with kcov coverage Add ARCH_HAS_KCOV and HAVE_GCC_PLUGINS to the LoongArch Kconfig. And also disable instrumentation of vdso. Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 14:53:55 +00:00
vdso: Improve cmd_vdso_check to check all dynamic relocations 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 <maskray@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for aarch64 Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for vDSO, aarch64 Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Link: https://lore.kernel.org/r/20230310190750.3323802-1-maskray@google.com
2023-03-10 19:07:50 +00:00
# Include the generic Makefile to check the built vdso.
LoongArch: Add VDSO and VSYSCALL support Add VDSO and VSYSCALL support (sigreturn, gettimeofday and its friends) for LoongArch. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-05-31 10:04:12 +00:00
include $(srctree)/lib/vdso/Makefile
LoongArch: Add vDSO syscall __vdso_getcpu() We test 20 million times of getcpu(), the real syscall version take 25 seconds, while the vsyscall version take only 2.4 seconds. Signed-off-by: Rui Wang <wangrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-08-06 07:19:33 +00:00
obj-vdso-y := elf.o vgetcpu.o vgettimeofday.o sigreturn.o
LoongArch: Add VDSO and VSYSCALL support Add VDSO and VSYSCALL support (sigreturn, gettimeofday and its friends) for LoongArch. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-05-31 10:04:12 +00:00
# Common compiler flags between ABIs.
ccflags-vdso := \
$(filter -I%,$(KBUILD_CFLAGS)) \
$(filter -E%,$(KBUILD_CFLAGS)) \
$(filter -march=%,$(KBUILD_CFLAGS)) \
$(filter -m%-float,$(KBUILD_CFLAGS)) \
LoongArch: vDSO: Use CLANG_FLAGS instead of filtering out '--target=' This is a port of commit 76d7fff22be3e ("MIPS: VDSO: Use CLANG_FLAGS instead of filtering out '--target='") to arch/loongarch, for fixing cross-compilation with Clang. Reported-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1787#issuecomment-1608306002 Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29 12:58:43 +00:00
$(CLANG_FLAGS) \
LoongArch: Add VDSO and VSYSCALL support Add VDSO and VSYSCALL support (sigreturn, gettimeofday and its friends) for LoongArch. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-05-31 10:04:12 +00:00
-D__VDSO__
cflags-vdso := $(ccflags-vdso) \
LoongArch: Fix build errors for tinyconfig Building loongarch:tinyconfig fails with the following error. ./arch/loongarch/include/asm/page.h: In function 'pfn_valid': ./arch/loongarch/include/asm/page.h:42:32: error: 'PHYS_OFFSET' undeclared Add the missing include file and fix succeeding vdso errors. Fixes: 09cfefb7fa70 ("LoongArch: Add memory management") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-06 03:03:09 +00:00
-isystem $(shell $(CC) -print-file-name=include) \
LoongArch: Add VDSO and VSYSCALL support Add VDSO and VSYSCALL support (sigreturn, gettimeofday and its friends) for LoongArch. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-05-31 10:04:12 +00:00
$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
LoongArch: Tweak CFLAGS for Clang compatibility Now the arch code is mostly ready for LLVM/Clang consumption, it is time to re-organize the CFLAGS a little to actually enable the LLVM build. Namely, all -G0 switches from CFLAGS are removed, and -mexplicit-relocs and -mdirect-extern-access are now wrapped with cc-option (with the related asm/percpu.h definition guarded against toolchain combos that are known to not work). A build with !RELOCATABLE && !MODULE is confirmed working within a QEMU environment; support for the two features are currently blocked on LLVM/Clang, and will come later. Why -G0 can be removed: In GCC, -G stands for "small data threshold", that instructs the compiler to put data smaller than the specified threshold in a dedicated "small data" section (called .sdata on LoongArch and several other arches). However, benefiting from this would require ABI cooperation, which is not the case for LoongArch; and current GCC behave the same whether -G0 (equal to disabling this optimization) is given or not. So, remove -G0 from CFLAGS altogether for one less thing to care about. This also benefits LLVM/Clang compatibility where the -G switch is not supported. Why -mexplicit-relocs can now be conditionally applied without regressions: Originally -mexplicit-relocs is unconditionally added to CFLAGS in case of CONFIG_AS_HAS_EXPLICIT_RELOCS, because not having it (i.e. old GCC + new binutils) would not work: modules will have R_LARCH_ABS_* relocs inside, but given the rarity of such toolchain combo in the wild, it may not be worthwhile to support it, so support for such relocs in modules were not added back when explicit relocs support was upstreamed, and -mexplicit-relocs is unconditionally added to fail the build early. Now that Clang compatibility is desired, given Clang is behaving like -mexplicit-relocs from day one but without support for the CLI flag, we must ensure the flag is not passed in case of Clang. However, explicit compiler flavor checks can be more brittle than feature detection: in this case what actually matters is support for __attribute__((model)) when building modules. Given neither older GCC nor current Clang support this attribute, probing for the attribute support and #error'ing out would allow proper UX without checking for Clang, and also automatically work when Clang support for the attribute is to be added in the future. Why -mdirect-extern-access is now conditionally applied: This is actually a nice-to-have optimization that can reduce GOT accesses, but not having it is harmless either. Because Clang does not support the option currently, but might do so in the future, conditional application via cc-option ensures compatibility with both current and future Clang versions. Suggested-by: Xi Ruoyao <xry111@xry111.site> # cc-option changes Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29 12:58:43 +00:00
-O2 -g -fno-strict-aliasing -fno-common -fno-builtin \
LoongArch: Add VDSO and VSYSCALL support Add VDSO and VSYSCALL support (sigreturn, gettimeofday and its friends) for LoongArch. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-05-31 10:04:12 +00:00
-fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \
$(call cc-option, -fno-asynchronous-unwind-tables) \
$(call cc-option, -fno-stack-protector)
aflags-vdso := $(ccflags-vdso) \
-D__ASSEMBLY__ -Wa,-gdwarf-2
ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)
endif
# VDSO linker flags.
ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
$(filter -E%,$(KBUILD_CFLAGS)) -nostdlib -shared \
--hash-style=sysv --build-id -T
GCOV_PROFILE := n
#
# Shared build commands.
#
quiet_cmd_vdsold_and_vdso_check = LD $@
cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
quiet_cmd_vdsoas_o_S = AS $@
cmd_vdsoas_o_S = $(CC) $(a_flags) -c -o $@ $<
# Generate VDSO offsets using helper script
gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
quiet_cmd_vdsosym = VDSOSYM $@
cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
$(call if_changed,vdsosym)
#
# Build native VDSO.
#
native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS))
targets += $(obj-vdso-y)
targets += vdso.lds vdso.so.dbg vdso.so
obj-vdso := $(obj-vdso-y:%.o=$(obj)/%.o)
$(obj-vdso): KBUILD_CFLAGS := $(cflags-vdso) $(native-abi)
$(obj-vdso): KBUILD_AFLAGS := $(aflags-vdso) $(native-abi)
$(obj)/vdso.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) $(native-abi)
$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold_and_vdso_check)
$(obj)/vdso.so: OBJCOPYFLAGS := -S
$(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE
$(call if_changed,objcopy)
obj-y += vdso.o
$(obj)/vdso.o : $(obj)/vdso.so