From: Guo Ren Date: Tue, 5 Apr 2022 07:13:10 +0000 (+0800) Subject: riscv: compat: vdso: Add COMPAT_VDSO base code implementation X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0715372a06ce17a9ba69bbec306ddf30c4bad99e;p=linux.git riscv: compat: vdso: Add COMPAT_VDSO base code implementation There is no vgettimeofday supported in rv32 that makes simple to generate rv32 vdso code which only needs riscv64 compiler. Other architectures need change compiler or -m (machine parameter) to support vdso32 compiling. If rv32 support vgettimeofday (which cause C compile) in future, we would add CROSS_COMPILE to support that makes more requirement on compiler enviornment. linux-rv64/arch/riscv/kernel/compat_vdso/compat_vdso.so.dbg: file format elf64-littleriscv Disassembly of section .text: 0000000000000800 <__vdso_rt_sigreturn>: 800: 08b00893 li a7,139 804: 00000073 ecall 808: 0000 unimp ... 000000000000080c <__vdso_getcpu>: 80c: 0a800893 li a7,168 810: 00000073 ecall 814: 8082 ret ... 0000000000000818 <__vdso_flush_icache>: 818: 10300893 li a7,259 81c: 00000073 ecall 820: 8082 ret linux-rv32/arch/riscv/kernel/vdso/vdso.so.dbg: file format elf32-littleriscv Disassembly of section .text: 00000800 <__vdso_rt_sigreturn>: 800: 08b00893 li a7,139 804: 00000073 ecall 808: 0000 unimp ... 0000080c <__vdso_getcpu>: 80c: 0a800893 li a7,168 810: 00000073 ecall 814: 8082 ret ... 00000818 <__vdso_flush_icache>: 818: 10300893 li a7,259 81c: 00000073 ecall 820: 8082 ret Finally, reuse all *.S from vdso in compat_vdso that makes implementation clear and readable. Signed-off-by: Guo Ren Signed-off-by: Guo Ren Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20220405071314.3225832-17-guoren@kernel.org Signed-off-by: Palmer Dabbelt --- diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index c6ca1b9cbf712..6a494029b8bd7 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -112,12 +112,17 @@ libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a PHONY += vdso_install vdso_install: $(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso $@ + $(if $(CONFIG_COMPAT),$(Q)$(MAKE) \ + $(build)=arch/riscv/kernel/compat_vdso $@) ifeq ($(KBUILD_EXTMOD),) ifeq ($(CONFIG_MMU),y) prepare: vdso_prepare vdso_prepare: prepare0 $(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso include/generated/vdso-offsets.h + $(if $(CONFIG_COMPAT),$(Q)$(MAKE) \ + $(build)=arch/riscv/kernel/compat_vdso include/generated/compat_vdso-offsets.h) + endif endif diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h index bc6f75f3a199f..af981426fe0ff 100644 --- a/arch/riscv/include/asm/vdso.h +++ b/arch/riscv/include/asm/vdso.h @@ -21,6 +21,15 @@ #define VDSO_SYMBOL(base, name) \ (void __user *)((unsigned long)(base) + __vdso_##name##_offset) + +#ifdef CONFIG_COMPAT +#include + +#define COMPAT_VDSO_SYMBOL(base, name) \ + (void __user *)((unsigned long)(base) + compat__vdso_##name##_offset) + +#endif /* CONFIG_COMPAT */ + #endif /* !__ASSEMBLY__ */ #endif /* CONFIG_MMU */ diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 2fa06d6572bba..fec77d101f9e0 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -70,3 +70,4 @@ obj-$(CONFIG_JUMP_LABEL) += jump_label.o obj-$(CONFIG_EFI) += efi.o obj-$(CONFIG_COMPAT) += compat_syscall_table.o +obj-$(CONFIG_COMPAT) += compat_vdso/ diff --git a/arch/riscv/kernel/compat_vdso/.gitignore b/arch/riscv/kernel/compat_vdso/.gitignore new file mode 100644 index 0000000000000..19d83d846c1e6 --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +compat_vdso.lds diff --git a/arch/riscv/kernel/compat_vdso/Makefile b/arch/riscv/kernel/compat_vdso/Makefile new file mode 100644 index 0000000000000..260daf3236d3a --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/Makefile @@ -0,0 +1,78 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for compat_vdso +# + +# Symbols present in the compat_vdso +compat_vdso-syms = rt_sigreturn +compat_vdso-syms += getcpu +compat_vdso-syms += flush_icache + +COMPAT_CC := $(CC) +COMPAT_LD := $(LD) + +COMPAT_CC_FLAGS := -march=rv32g -mabi=ilp32 +COMPAT_LD_FLAGS := -melf32lriscv + +# Files to link into the compat_vdso +obj-compat_vdso = $(patsubst %, %.o, $(compat_vdso-syms)) note.o + +# Build rules +targets := $(obj-compat_vdso) compat_vdso.so compat_vdso.so.dbg compat_vdso.lds +obj-compat_vdso := $(addprefix $(obj)/, $(obj-compat_vdso)) + +obj-y += compat_vdso.o +CPPFLAGS_compat_vdso.lds += -P -C -U$(ARCH) + +# Disable profiling and instrumentation for VDSO code +GCOV_PROFILE := n +KCOV_INSTRUMENT := n +KASAN_SANITIZE := n +UBSAN_SANITIZE := n + +# Force dependency +$(obj)/compat_vdso.o: $(obj)/compat_vdso.so + +# link rule for the .so file, .lds has to be first +$(obj)/compat_vdso.so.dbg: $(obj)/compat_vdso.lds $(obj-compat_vdso) FORCE + $(call if_changed,compat_vdsold) +LDFLAGS_compat_vdso.so.dbg = -shared -S -soname=linux-compat_vdso.so.1 \ + --build-id=sha1 --hash-style=both --eh-frame-hdr + +$(obj-compat_vdso): %.o: %.S FORCE + $(call if_changed_dep,compat_vdsoas) + +# strip rule for the .so file +$(obj)/%.so: OBJCOPYFLAGS := -S +$(obj)/%.so: $(obj)/%.so.dbg FORCE + $(call if_changed,objcopy) + +# Generate VDSO offsets using helper script +gen-compat_vdsosym := $(srctree)/$(src)/gen_compat_vdso_offsets.sh +quiet_cmd_compat_vdsosym = VDSOSYM $@ + cmd_compat_vdsosym = $(NM) $< | $(gen-compat_vdsosym) | LC_ALL=C sort > $@ + +include/generated/compat_vdso-offsets.h: $(obj)/compat_vdso.so.dbg FORCE + $(call if_changed,compat_vdsosym) + +# actual build commands +# The DSO images are built using a special linker script +# Make sure only to export the intended __compat_vdso_xxx symbol offsets. +quiet_cmd_compat_vdsold = VDSOLD $@ + cmd_compat_vdsold = $(COMPAT_LD) $(ld_flags) $(COMPAT_LD_FLAGS) -T $(filter-out FORCE,$^) -o $@.tmp && \ + $(OBJCOPY) $(patsubst %, -G __compat_vdso_%, $(compat_vdso-syms)) $@.tmp $@ && \ + rm $@.tmp + +# actual build commands +quiet_cmd_compat_vdsoas = VDSOAS $@ + cmd_compat_vdsoas = $(COMPAT_CC) $(a_flags) $(COMPAT_CC_FLAGS) -c -o $@ $< + +# install commands for the unstripped file +quiet_cmd_compat_vdso_install = INSTALL $@ + cmd_compat_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/compat_vdso/$@ + +compat_vdso.so: $(obj)/compat_vdso.so.dbg + @mkdir -p $(MODLIB)/compat_vdso + $(call cmd,compat_vdso_install) + +compat_vdso_install: compat_vdso.so diff --git a/arch/riscv/kernel/compat_vdso/compat_vdso.S b/arch/riscv/kernel/compat_vdso/compat_vdso.S new file mode 100644 index 0000000000000..ffd66237e091e --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/compat_vdso.S @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#define vdso_start compat_vdso_start +#define vdso_end compat_vdso_end + +#define __VDSO_PATH "arch/riscv/kernel/compat_vdso/compat_vdso.so" + +#include "../vdso/vdso.S" diff --git a/arch/riscv/kernel/compat_vdso/compat_vdso.lds.S b/arch/riscv/kernel/compat_vdso/compat_vdso.lds.S new file mode 100644 index 0000000000000..c7c9355d311e3 --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/compat_vdso.lds.S @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include "../vdso/vdso.lds.S" diff --git a/arch/riscv/kernel/compat_vdso/flush_icache.S b/arch/riscv/kernel/compat_vdso/flush_icache.S new file mode 100644 index 0000000000000..523dd8b96045e --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/flush_icache.S @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include "../vdso/flush_icache.S" diff --git a/arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh b/arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh new file mode 100755 index 0000000000000..8ac070c783b37 --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh @@ -0,0 +1,5 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +LC_ALL=C +sed -n -e 's/^[0]\+\(0[0-9a-fA-F]*\) . \(__vdso_[a-zA-Z0-9_]*\)$/\#define compat\2_offset\t0x\1/p' diff --git a/arch/riscv/kernel/compat_vdso/getcpu.S b/arch/riscv/kernel/compat_vdso/getcpu.S new file mode 100644 index 0000000000000..10f463efe2710 --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/getcpu.S @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include "../vdso/getcpu.S" diff --git a/arch/riscv/kernel/compat_vdso/note.S b/arch/riscv/kernel/compat_vdso/note.S new file mode 100644 index 0000000000000..b103129075423 --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/note.S @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include "../vdso/note.S" diff --git a/arch/riscv/kernel/compat_vdso/rt_sigreturn.S b/arch/riscv/kernel/compat_vdso/rt_sigreturn.S new file mode 100644 index 0000000000000..884aada4facc5 --- /dev/null +++ b/arch/riscv/kernel/compat_vdso/rt_sigreturn.S @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include "../vdso/rt_sigreturn.S" diff --git a/arch/riscv/kernel/vdso/vdso.S b/arch/riscv/kernel/vdso/vdso.S index df222245be057..83f1c899e8d82 100644 --- a/arch/riscv/kernel/vdso/vdso.S +++ b/arch/riscv/kernel/vdso/vdso.S @@ -7,12 +7,16 @@ #include #include +#ifndef __VDSO_PATH +#define __VDSO_PATH "arch/riscv/kernel/vdso/vdso.so" +#endif + __PAGE_ALIGNED_DATA .globl vdso_start, vdso_end .balign PAGE_SIZE vdso_start: - .incbin "arch/riscv/kernel/vdso/vdso.so" + .incbin __VDSO_PATH .balign PAGE_SIZE vdso_end: