f3d60f2a25
We use the generic C VDSO implementations of a handful of clock-related functions. When kasan is enabled this results in asan stub calls that are unlikely to be resolved by userspace, this just disables KASAN when building the VDSO. Verified the fix on a kernel with KASAN enabled using vDSO selftests. Link: https://lore.kernel.org/lkml/CACT4Y+ZNJBnkKHXUf=tm_yuowvZvHwN=0rmJ=7J+xFd+9r_6pQ@mail.gmail.com/ Tested-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Tested-by: Dmitry Vyukov <dvyukov@google.com> [Palmer: commit text] Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
86 lines
2.8 KiB
Makefile
86 lines
2.8 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0-only
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# Copied from arch/tile/kernel/vdso/Makefile
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# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
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# the inclusion of generic Makefile.
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ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT
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include $(srctree)/lib/vdso/Makefile
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# Symbols present in the vdso
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vdso-syms = rt_sigreturn
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ifdef CONFIG_64BIT
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vdso-syms += vgettimeofday
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endif
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vdso-syms += getcpu
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vdso-syms += flush_icache
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# Files to link into the vdso
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obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
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ccflags-y := -fno-stack-protector
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ifneq ($(c-gettimeofday-y),)
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CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
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endif
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# Build rules
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targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
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obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
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obj-y += vdso.o vdso-syms.o
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CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
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# Disable -pg to prevent insert call site
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CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
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# Disable profiling and instrumentation for VDSO code
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GCOV_PROFILE := n
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KCOV_INSTRUMENT := n
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KASAN_SANITIZE := n
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# Force dependency
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$(obj)/vdso.o: $(obj)/vdso.so
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# link rule for the .so file, .lds has to be first
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SYSCFLAGS_vdso.so.dbg = $(c_flags)
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$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
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$(call if_changed,vdsold)
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SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
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-Wl,--build-id=sha1 -Wl,--hash-style=both
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# We also create a special relocatable object that should mirror the symbol
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# table and layout of the linked DSO. With ld --just-symbols we can then
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# refer to these symbols in the kernel code rather than hand-coded addresses.
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$(obj)/vdso-syms.S: $(obj)/vdso.so FORCE
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$(call if_changed,so2s)
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# strip rule for the .so file
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$(obj)/%.so: OBJCOPYFLAGS := -S
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$(obj)/%.so: $(obj)/%.so.dbg FORCE
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$(call if_changed,objcopy)
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# actual build commands
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# The DSO images are built using a special linker script
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# Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
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# Make sure only to export the intended __vdso_xxx symbol offsets.
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quiet_cmd_vdsold = VDSOLD $@
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cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \
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-Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \
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$(CROSS_COMPILE)objcopy \
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$(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
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rm $@.tmp
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# Extracts symbol offsets from the VDSO, converting them into an assembly file
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# that contains the same symbols at the same offsets.
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quiet_cmd_so2s = SO2S $@
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cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@
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# install commands for the unstripped file
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quiet_cmd_vdso_install = INSTALL $@
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cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
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vdso.so: $(obj)/vdso.so.dbg
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@mkdir -p $(MODLIB)/vdso
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$(call cmd,vdso_install)
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vdso_install: vdso.so
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