diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/riscv/kernel/vdso.c | 113 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/.gitignore | 4 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/Makefile | 85 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/flush_icache.S | 22 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/getcpu.S | 18 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/note.S | 12 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/rt_sigreturn.S | 16 | ||||
| -rwxr-xr-x | arch/riscv/kernel/vdso/so2s.sh | 6 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/vdso.S | 19 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/vdso.lds.S | 76 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/vgettimeofday.c | 31 |
11 files changed, 402 insertions, 0 deletions
diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c new file mode 100644 index 000000000..73d45931a --- /dev/null +++ b/arch/riscv/kernel/vdso.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp. + * <benh@kernel.crashing.org> + * Copyright (C) 2012 ARM Limited + * Copyright (C) 2015 Regents of the University of California + */ + +#include <linux/elf.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/binfmts.h> +#include <linux/err.h> +#include <asm/page.h> +#ifdef CONFIG_GENERIC_TIME_VSYSCALL +#include <vdso/datapage.h> +#else +#include <asm/vdso.h> +#endif + +extern char vdso_start[], vdso_end[]; + +static unsigned int vdso_pages; +static struct page **vdso_pagelist; + +/* + * The vDSO data page. + */ +static union { + struct vdso_data data; + u8 page[PAGE_SIZE]; +} vdso_data_store __page_aligned_data; +struct vdso_data *vdso_data = &vdso_data_store.data; + +static int __init vdso_init(void) +{ + unsigned int i; + + vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; + vdso_pagelist = + kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL); + if (unlikely(vdso_pagelist == NULL)) { + pr_err("vdso: pagelist allocation failed\n"); + return -ENOMEM; + } + + for (i = 0; i < vdso_pages; i++) { + struct page *pg; + + pg = virt_to_page(vdso_start + (i << PAGE_SHIFT)); + vdso_pagelist[i] = pg; + } + vdso_pagelist[i] = virt_to_page(vdso_data); + + return 0; +} +arch_initcall(vdso_init); + +int arch_setup_additional_pages(struct linux_binprm *bprm, + int uses_interp) +{ + struct mm_struct *mm = current->mm; + unsigned long vdso_base, vdso_len; + int ret; + + vdso_len = (vdso_pages + 1) << PAGE_SHIFT; + + if (mmap_write_lock_killable(mm)) + return -EINTR; + + vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0); + if (IS_ERR_VALUE(vdso_base)) { + ret = vdso_base; + goto end; + } + + /* + * Put vDSO base into mm struct. We need to do this before calling + * install_special_mapping or the perf counter mmap tracking code + * will fail to recognise it as a vDSO (since arch_vma_name fails). + */ + mm->context.vdso = (void *)vdso_base; + + ret = + install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT, + (VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC), + vdso_pagelist); + + if (unlikely(ret)) { + mm->context.vdso = NULL; + goto end; + } + + vdso_base += (vdso_pages << PAGE_SHIFT); + ret = install_special_mapping(mm, vdso_base, PAGE_SIZE, + (VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]); + + if (unlikely(ret)) + mm->context.vdso = NULL; +end: + mmap_write_unlock(mm); + return ret; +} + +const char *arch_vma_name(struct vm_area_struct *vma) +{ + if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso)) + return "[vdso]"; + if (vma->vm_mm && (vma->vm_start == + (long)vma->vm_mm->context.vdso + PAGE_SIZE)) + return "[vdso_data]"; + return NULL; +} diff --git a/arch/riscv/kernel/vdso/.gitignore b/arch/riscv/kernel/vdso/.gitignore new file mode 100644 index 000000000..3a19def86 --- /dev/null +++ b/arch/riscv/kernel/vdso/.gitignore @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +vdso.lds +*.tmp +vdso-syms.S diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile new file mode 100644 index 000000000..f4ac7ff56 --- /dev/null +++ b/arch/riscv/kernel/vdso/Makefile @@ -0,0 +1,85 @@ +# SPDX-License-Identifier: GPL-2.0-only +# Copied from arch/tile/kernel/vdso/Makefile + +# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before +# the inclusion of generic Makefile. +ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT +include $(srctree)/lib/vdso/Makefile +# Symbols present in the vdso +vdso-syms = rt_sigreturn +ifdef CONFIG_64BIT +vdso-syms += vgettimeofday +endif +vdso-syms += getcpu +vdso-syms += flush_icache + +# Files to link into the vdso +obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o + +ccflags-y := -fno-stack-protector +ccflags-y += -DDISABLE_BRANCH_PROFILING + +ifneq ($(c-gettimeofday-y),) + CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y) +endif + +# Build rules +targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-syms.S +obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) + +obj-y += vdso.o vdso-syms.o +CPPFLAGS_vdso.lds += -P -C -U$(ARCH) +ifneq ($(filter vgettimeofday, $(vdso-syms)),) +CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY +endif + +# Disable -pg to prevent insert call site +CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) + +# Disable profiling and instrumentation for VDSO code +GCOV_PROFILE := n +KCOV_INSTRUMENT := n +KASAN_SANITIZE := n + +# Force dependency +$(obj)/vdso.o: $(obj)/vdso.so + +# link rule for the .so file, .lds has to be first +$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE + $(call if_changed,vdsold) +LDFLAGS_vdso.so.dbg = -shared -s -soname=linux-vdso.so.1 \ + --build-id=sha1 --hash-style=both --eh-frame-hdr + +# We also create a special relocatable object that should mirror the symbol +# table and layout of the linked DSO. With ld --just-symbols we can then +# refer to these symbols in the kernel code rather than hand-coded addresses. +$(obj)/vdso-syms.S: $(obj)/vdso.so FORCE + $(call if_changed,so2s) + +# strip rule for the .so file +$(obj)/%.so: OBJCOPYFLAGS := -S +$(obj)/%.so: $(obj)/%.so.dbg FORCE + $(call if_changed,objcopy) + +# actual build commands +# The DSO images are built using a special linker script +# Make sure only to export the intended __vdso_xxx symbol offsets. +quiet_cmd_vdsold = VDSOLD $@ + cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \ + $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \ + rm $@.tmp + +# Extracts symbol offsets from the VDSO, converting them into an assembly file +# that contains the same symbols at the same offsets. +quiet_cmd_so2s = SO2S $@ + cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@ + +# install commands for the unstripped file +quiet_cmd_vdso_install = INSTALL $@ + cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@ + +vdso.so: $(obj)/vdso.so.dbg + @mkdir -p $(MODLIB)/vdso + $(call cmd,vdso_install) + +vdso_install: vdso.so diff --git a/arch/riscv/kernel/vdso/flush_icache.S b/arch/riscv/kernel/vdso/flush_icache.S new file mode 100644 index 000000000..82f97d67c --- /dev/null +++ b/arch/riscv/kernel/vdso/flush_icache.S @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017 SiFive + */ + +#include <linux/linkage.h> +#include <asm/unistd.h> + + .text +/* int __vdso_flush_icache(void *start, void *end, unsigned long flags); */ +ENTRY(__vdso_flush_icache) + .cfi_startproc +#ifdef CONFIG_SMP + li a7, __NR_riscv_flush_icache + ecall +#else + fence.i + li a0, 0 +#endif + ret + .cfi_endproc +ENDPROC(__vdso_flush_icache) diff --git a/arch/riscv/kernel/vdso/getcpu.S b/arch/riscv/kernel/vdso/getcpu.S new file mode 100644 index 000000000..bb0c05e2f --- /dev/null +++ b/arch/riscv/kernel/vdso/getcpu.S @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017 SiFive + */ + +#include <linux/linkage.h> +#include <asm/unistd.h> + + .text +/* int __vdso_getcpu(unsigned *cpu, unsigned *node, void *unused); */ +ENTRY(__vdso_getcpu) + .cfi_startproc + /* For now, just do the syscall. */ + li a7, __NR_getcpu + ecall + ret + .cfi_endproc +ENDPROC(__vdso_getcpu) diff --git a/arch/riscv/kernel/vdso/note.S b/arch/riscv/kernel/vdso/note.S new file mode 100644 index 000000000..2a956c942 --- /dev/null +++ b/arch/riscv/kernel/vdso/note.S @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. + * Here we can supply some information useful to userland. + */ + +#include <linux/elfnote.h> +#include <linux/version.h> + +ELFNOTE_START(Linux, 0, "a") + .long LINUX_VERSION_CODE +ELFNOTE_END diff --git a/arch/riscv/kernel/vdso/rt_sigreturn.S b/arch/riscv/kernel/vdso/rt_sigreturn.S new file mode 100644 index 000000000..0573705ea --- /dev/null +++ b/arch/riscv/kernel/vdso/rt_sigreturn.S @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2014 Regents of the University of California + */ + +#include <linux/linkage.h> +#include <asm/unistd.h> + + .text +ENTRY(__vdso_rt_sigreturn) + .cfi_startproc + .cfi_signal_frame + li a7, __NR_rt_sigreturn + scall + .cfi_endproc +ENDPROC(__vdso_rt_sigreturn) diff --git a/arch/riscv/kernel/vdso/so2s.sh b/arch/riscv/kernel/vdso/so2s.sh new file mode 100755 index 000000000..e64cb6d94 --- /dev/null +++ b/arch/riscv/kernel/vdso/so2s.sh @@ -0,0 +1,6 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0+ +# Copyright 2020 Palmer Dabbelt <palmerdabbelt@google.com> + +sed 's!\([0-9a-f]*\) T \([a-z0-9_]*\)\(@@LINUX_4.15\)*!.global \2\n.set \2,0x\1!' \ +| grep '^\.' diff --git a/arch/riscv/kernel/vdso/vdso.S b/arch/riscv/kernel/vdso/vdso.S new file mode 100644 index 000000000..df222245b --- /dev/null +++ b/arch/riscv/kernel/vdso/vdso.S @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2014 Regents of the University of California + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <asm/page.h> + + __PAGE_ALIGNED_DATA + + .globl vdso_start, vdso_end + .balign PAGE_SIZE +vdso_start: + .incbin "arch/riscv/kernel/vdso/vdso.so" + .balign PAGE_SIZE +vdso_end: + + .previous diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S new file mode 100644 index 000000000..b3e58402c --- /dev/null +++ b/arch/riscv/kernel/vdso/vdso.lds.S @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012 Regents of the University of California + */ +#include <asm/page.h> + +OUTPUT_ARCH(riscv) + +SECTIONS +{ + PROVIDE(_vdso_data = . + PAGE_SIZE); + . = SIZEOF_HEADERS; + + .hash : { *(.hash) } :text + .gnu.hash : { *(.gnu.hash) } + .dynsym : { *(.dynsym) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + + .note : { *(.note.*) } :text :note + .dynamic : { *(.dynamic) } :text :dynamic + + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr + .eh_frame : { KEEP (*(.eh_frame)) } :text + + .rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) } + + /* + * This linker script is used both with -r and with -shared. + * For the layouts to match, we need to skip more than enough + * space for the dynamic symbol table, etc. If this amount is + * insufficient, ld -shared will error; simply increase it here. + */ + . = 0x800; + .text : { *(.text .text.*) } :text + + .data : { + *(.got.plt) *(.got) + *(.data .data.* .gnu.linkonce.d.*) + *(.dynbss) + *(.bss .bss.* .gnu.linkonce.b.*) + } +} + +/* + * We must supply the ELF program headers explicitly to get just one + * PT_LOAD segment, and set the flags explicitly to make segments read-only. + */ +PHDRS +{ + text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */ + dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ + note PT_NOTE FLAGS(4); /* PF_R */ + eh_frame_hdr PT_GNU_EH_FRAME; +} + +/* + * This controls what symbols we export from the DSO. + */ +VERSION +{ + LINUX_4.15 { + global: + __vdso_rt_sigreturn; +#ifdef HAS_VGETTIMEOFDAY + __vdso_gettimeofday; + __vdso_clock_gettime; + __vdso_clock_getres; +#endif + __vdso_getcpu; + __vdso_flush_icache; + local: *; + }; +} diff --git a/arch/riscv/kernel/vdso/vgettimeofday.c b/arch/riscv/kernel/vdso/vgettimeofday.c new file mode 100644 index 000000000..cc0d80699 --- /dev/null +++ b/arch/riscv/kernel/vdso/vgettimeofday.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copied from arch/arm64/kernel/vdso/vgettimeofday.c + * + * Copyright (C) 2018 ARM Ltd. + * Copyright (C) 2020 SiFive + */ + +#include <linux/time.h> +#include <linux/types.h> + +extern +int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts); +int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +extern +int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz); +int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) +{ + return __cvdso_gettimeofday(tv, tz); +} + +extern +int __vdso_clock_getres(clockid_t clock_id, struct __kernel_timespec *res); +int __vdso_clock_getres(clockid_t clock_id, struct __kernel_timespec *res) +{ + return __cvdso_clock_getres(clock_id, res); +} |