[v7,7/9] ARM: add vdso user-space code

Message ID	1403493118-7597-8-git-send-email-nathan_lynch@mentor.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Nathan Lynch <nathan_lynch@mentor.com> To: <linux-arm-kernel@lists.infradead.org> Subject: [PATCH v7 7/9] ARM: add vdso user-space code Date: Sun, 22 Jun 2014 22:11:56 -0500 Message-ID: <1403493118-7597-8-git-send-email-nathan_lynch@mentor.com> In-Reply-To: <1403493118-7597-1-git-send-email-nathan_lynch@mentor.com> References: <1403493118-7597-1-git-send-email-nathan_lynch@mentor.com> MIME-Version: 1.0 Cc: steve.capper@linaro.org, ard.biesheuvel@linaro.org, will.deacon@arm.com, sboyd@codeaurora.org, keescook@google.com, linux@arm.linux.org.uk Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index 85598b5d1efd..a582bb42dc87 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -24,6 +24,7 @@ #include <asm/memory.h> #include <asm/procinfo.h> #include <asm/suspend.h> +#include <asm/vdso_datapage.h> #include <asm/hardware/cache-l2x0.h> #include <linux/kbuild.h> @@ -200,5 +201,9 @@ int main(void) #endif DEFINE(KVM_VTTBR, offsetof(struct kvm, arch.vttbr)); #endif + BLANK(); +#ifdef CONFIG_VDSO + DEFINE(VDSO_DATA_SIZE, sizeof(union vdso_data_store)); +#endif return 0; } diff --git a/arch/arm/kernel/vdso/.gitignore b/arch/arm/kernel/vdso/.gitignore new file mode 100644 index 000000000000..f8b69d84238e --- /dev/null +++ b/arch/arm/kernel/vdso/.gitignore @@ -0,0 +1 @@ +vdso.lds diff --git a/arch/arm/kernel/vdso/Makefile b/arch/arm/kernel/vdso/Makefile new file mode 100644 index 000000000000..ceb712a7626c --- /dev/null +++ b/arch/arm/kernel/vdso/Makefile @@ -0,0 +1,59 @@ +hostprogs-y := vdsomunge + +obj-vdso := vgettimeofday.o datapage.o + +# Build rules +targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds +obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) + +ccflags-y := -shared -fPIC -fno-common -fno-builtin -fno-stack-protector +ccflags-y += -nostdlib -Wl,-soname=linux-vdso.so.1 \ + $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) + +obj-y += vdso.o +extra-y += vdso.lds +CPPFLAGS_vdso.lds += -P -C -U$(ARCH) + +CFLAGS_REMOVE_vdso.o = -pg + +# Force -O2 to avoid libgcc dependencies +CFLAGS_REMOVE_vgettimeofday.o = -pg -Os +CFLAGS_vgettimeofday.o = -O2 + +# Disable gcov profiling for VDSO code +GCOV_PROFILE := n + +# Force dependency +$(obj)/vdso.o : $(obj)/vdso.so + +# Link rule for the .so file, .lds has to be first +$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) + $(call if_changed,vdsold) + +$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE + $(call if_changed,vdsomunge) + +# Strip rule for the .so file +$(obj)/%.so: OBJCOPYFLAGS := -S +$(obj)/%.so: $(obj)/%.so.dbg FORCE + $(call if_changed,objcopy) + +checkundef = sh $(srctree)/$(src)/checkundef.sh + +# Actual build commands +quiet_cmd_vdsold = VDSOL $@ + cmd_vdsold = $(CC) $(c_flags) -Wl,-T $^ -o $@ && \ + $(checkundef) '$(NM)' $@ + +quiet_cmd_vdsomunge = MUNGE $@ + cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@ + +# 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/arm/kernel/vdso/checkundef.sh b/arch/arm/kernel/vdso/checkundef.sh new file mode 100755 index 000000000000..185c30da202b --- /dev/null +++ b/arch/arm/kernel/vdso/checkundef.sh @@ -0,0 +1,9 @@ +#!/bin/sh +nm="$1" +file="$2" +"$nm" -u "$file" | ( ret=0; while read discard symbol +do + echo "$file: undefined symbol $symbol" + ret=1 +done ; exit $ret ) +exit $? diff --git a/arch/arm/kernel/vdso/datapage.S b/arch/arm/kernel/vdso/datapage.S new file mode 100644 index 000000000000..fbf36d75da06 --- /dev/null +++ b/arch/arm/kernel/vdso/datapage.S @@ -0,0 +1,15 @@ +#include <linux/linkage.h> +#include <asm/asm-offsets.h> + + .align 2 +.L_vdso_data_ptr: + .long _start - . - VDSO_DATA_SIZE + +ENTRY(__get_datapage) + .cfi_startproc + adr r0, .L_vdso_data_ptr + ldr r1, [r0] + add r0, r0, r1 + bx lr + .cfi_endproc +ENDPROC(__get_datapage) diff --git a/arch/arm/kernel/vdso/vdso.S b/arch/arm/kernel/vdso/vdso.S new file mode 100644 index 000000000000..aed16ff84c5f --- /dev/null +++ b/arch/arm/kernel/vdso/vdso.S @@ -0,0 +1,35 @@ +/* + * Adapted from arm64 version. + * + * Copyright (C) 2012 ARM Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * Author: Will Deacon <will.deacon@arm.com> + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <linux/const.h> +#include <asm/page.h> + + __PAGE_ALIGNED_DATA + + .globl vdso_start, vdso_end + .balign PAGE_SIZE +vdso_start: + .incbin "arch/arm/kernel/vdso/vdso.so" + .balign PAGE_SIZE +vdso_end: + + .previous diff --git a/arch/arm/kernel/vdso/vdso.lds.S b/arch/arm/kernel/vdso/vdso.lds.S new file mode 100644 index 000000000000..b509cc12e0eb --- /dev/null +++ b/arch/arm/kernel/vdso/vdso.lds.S @@ -0,0 +1,88 @@ +/* + * Adapted from arm64 version. + * + * GNU linker script for the VDSO library. + * + * Copyright (C) 2012 ARM Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * Author: Will Deacon <will.deacon@arm.com> + * Heavily based on the vDSO linker scripts for other archs. + */ + +#include <linux/const.h> +#include <asm/page.h> +#include <asm/vdso.h> + +OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm") +OUTPUT_ARCH(arm) + +SECTIONS +{ + PROVIDE(_start = .); + + . = VDSO_LBASE + 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 + + + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr + .eh_frame : { KEEP (*(.eh_frame)) } :text + + .dynamic : { *(.dynamic) } :text :dynamic + + .rodata : { *(.rodata*) } :text + + .text : { *(.text*) } :text =0xe7f001f2 + + .got : { *(.got) } + .rel.plt : { *(.rel.plt) } + + /DISCARD/ : { + *(.note.GNU-stack) + *(.data .data.* .gnu.linkonce.d.* .sdata*) + *(.bss .sbss .dynbss .dynsbss) + } +} + +/* + * 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; +} + +VERSION +{ + LINUX_3.17 { + global: + __kernel_clock_getres; + __kernel_clock_gettime; + __kernel_gettimeofday; + local: *; + }; +} diff --git a/arch/arm/kernel/vdso/vdsomunge.c b/arch/arm/kernel/vdso/vdsomunge.c new file mode 100644 index 000000000000..823b84d142bc --- /dev/null +++ b/arch/arm/kernel/vdso/vdsomunge.c @@ -0,0 +1,193 @@ +/* + * Copyright 2014 Mentor Graphics Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * + * vdsomunge - Host program which produces a shared object + * architecturally specified to be usable by both soft- and hard-float + * programs. + * + * The Procedure Call Standard for the ARM Architecture (ARM IHI + * 0042E) says: + * + * 6.4.1 VFP and Base Standard Compatibility + * + * Code compiled for the VFP calling standard is compatible with + * the base standard (and vice-versa) if no floating-point or + * containerized vector arguments or results are used. + * + * And ELF for the ARM Architecture (ARM IHI 0044E) (Table 4-2) says: + * + * If both EF_ARM_ABI_FLOAT_XXXX bits are clear, conformance to the + * base procedure-call standard is implied. + * + * The VDSO is built with -msoft-float, as with the rest of the ARM + * kernel, and uses no floating point arguments or results. The build + * process will produce a shared object that may or may not have the + * EF_ARM_ABI_FLOAT_SOFT flag set (it seems to depend on the binutils + * version; binutils starting with 2.24 appears to set it). The + * EF_ARM_ABI_FLOAT_HARD flag should definitely not be set, and this + * program will error out if it is. + * + * If the soft-float flag is set, this program clears it. That's all + * it does. + */ + +#define _GNU_SOURCE + +#include <byteswap.h> +#include <elf.h> +#include <errno.h> +#include <error.h> +#include <fcntl.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ +#define HOST_ORDER ELFDATA2LSB +#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ +#define HOST_ORDER ELFDATA2MSB +#endif + +static const char *outfile; + +static void cleanup(void) +{ + if (error_message_count > 0 && outfile != NULL) + unlink(outfile); +} + +static Elf32_Word read_elf_word(Elf32_Word word, bool swap) +{ + return swap ? bswap_32(word) : word; +} + +static Elf32_Half read_elf_half(Elf32_Half half, bool swap) +{ + return swap ? bswap_16(half) : half; +} + +static void write_elf_word(Elf32_Word val, Elf32_Word *dst, bool swap) +{ + *dst = swap ? bswap_32(val) : val; +} + +int main(int argc, char **argv) +{ + const Elf32_Ehdr *inhdr; + bool clear_soft_float; + const char *infile; + Elf32_Word e_flags; + const void *inbuf; + struct stat stat; + void *outbuf; + bool swap; + int outfd; + int infd; + + atexit(cleanup); + + if (argc != 3) + error(EXIT_FAILURE, 0, "Usage: %s [infile] [outfile]", argv[0]); + + infile = argv[1]; + outfile = argv[2]; + + infd = open(infile, O_RDONLY); + if (infd < 0) + error(EXIT_FAILURE, errno, "Cannot open %s", infile); + + if (fstat(infd, &stat) != 0) + error(EXIT_FAILURE, errno, "Failed stat for %s", infile); + + inbuf = mmap(NULL, stat.st_size, PROT_READ, MAP_PRIVATE, infd, 0); + if (inbuf == MAP_FAILED) + error(EXIT_FAILURE, errno, "Failed to map %s", infile); + + close(infd); + + inhdr = inbuf; + + if (memcmp(&inhdr->e_ident, ELFMAG, SELFMAG) != 0) + error(EXIT_FAILURE, 0, "Not an ELF file"); + + if (inhdr->e_ident[EI_CLASS] != ELFCLASS32) + error(EXIT_FAILURE, 0, "Unsupported ELF class"); + + swap = inhdr->e_ident[EI_DATA] != HOST_ORDER; + + if (read_elf_half(inhdr->e_type, swap) != ET_DYN) + error(EXIT_FAILURE, 0, "Not a shared object"); + + if (read_elf_half(inhdr->e_machine, swap) != EM_ARM) { + error(EXIT_FAILURE, 0, "Unsupported architecture %#x", + inhdr->e_machine); + } + + e_flags = read_elf_word(inhdr->e_flags, swap); + + if (EF_ARM_EABI_VERSION(e_flags) != EF_ARM_EABI_VER5) { + error(EXIT_FAILURE, 0, "Unsupported EABI version %#x", + EF_ARM_EABI_VERSION(e_flags)); + } + + if (e_flags & EF_ARM_ABI_FLOAT_HARD) + error(EXIT_FAILURE, 0, "Unexpected hard-float flag set in " + "e_flags"); + + clear_soft_float = !!(e_flags & EF_ARM_ABI_FLOAT_SOFT); + + outfd = open(outfile, O_RDWR | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR); + if (outfd < 0) + error(EXIT_FAILURE, errno, "Cannot open %s", outfile); + + if (ftruncate(outfd, stat.st_size) != 0) + error(EXIT_FAILURE, errno, "Cannot truncate %s", outfile); + + outbuf = mmap(NULL, stat.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, + outfd, 0); + if (outbuf == MAP_FAILED) + error(EXIT_FAILURE, errno, "Failed to map %s", outfile); + + close(outfd); + + memcpy(outbuf, inbuf, stat.st_size); + + if (clear_soft_float) { + Elf32_Ehdr *outhdr; + + outhdr = outbuf; + e_flags &= ~EF_ARM_ABI_FLOAT_SOFT; + write_elf_word(e_flags, &outhdr->e_flags, swap); + +#ifdef DEBUG + printf("%s: cleared soft-float bit in ELF header for %s " + "(%#x => %#x)\n", program_invocation_short_name, + outfile, inhdr->e_flags, outhdr->e_flags); +#endif + + } + + if (msync(outbuf, stat.st_size, MS_SYNC) != 0) + error(EXIT_FAILURE, errno, "Failed to sync %s", outfile); + + return EXIT_SUCCESS; +} diff --git a/arch/arm/kernel/vdso/vgettimeofday.c b/arch/arm/kernel/vdso/vgettimeofday.c new file mode 100644 index 000000000000..7fb4c4954f8a --- /dev/null +++ b/arch/arm/kernel/vdso/vgettimeofday.c @@ -0,0 +1,320 @@ +/* + * Copyright 2014 Mentor Graphics Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/compiler.h> +#include <linux/hrtimer.h> +#include <linux/time.h> +#include <asm/arch_timer.h> +#include <asm/barrier.h> +#include <asm/bug.h> +#include <asm/page.h> +#include <asm/unistd.h> +#include <asm/vdso_datapage.h> + +#ifndef CONFIG_AEABI +#error This code depends on AEABI system call conventions +#endif + +extern struct vdso_data *__get_datapage(void); + +static u32 __vdso_read_begin(const struct vdso_data *vdata) +{ + u32 seq; +repeat: + seq = ACCESS_ONCE(vdata->seq_count); + if (seq & 1) { + cpu_relax(); + goto repeat; + } + return seq; +} + +static u32 vdso_read_begin(const struct vdso_data *vdata) +{ + u32 seq = __vdso_read_begin(vdata); + smp_rmb(); + return seq; +} + +static int vdso_read_retry(const struct vdso_data *vdata, u32 start) +{ + smp_rmb(); + return vdata->seq_count != start; +} + +static long clock_gettime_fallback(clockid_t _clkid, struct timespec *_ts) +{ + register struct timespec *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_clock_gettime; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static int do_realtime_coarse(struct timespec *ts, struct vdso_data *vdata) +{ + u32 seq; + + do { + seq = vdso_read_begin(vdata); + + ts->tv_sec = vdata->xtime_coarse_sec; + ts->tv_nsec = vdata->xtime_coarse_nsec; + + } while (vdso_read_retry(vdata, seq)); + + return 0; +} + +static int do_monotonic_coarse(struct timespec *ts, struct vdso_data *vdata) +{ + struct timespec tomono; + u32 seq; + + do { + seq = vdso_read_begin(vdata); + + ts->tv_sec = vdata->xtime_coarse_sec; + ts->tv_nsec = vdata->xtime_coarse_nsec; + + tomono.tv_sec = vdata->wtm_clock_sec; + tomono.tv_nsec = vdata->wtm_clock_nsec; + + } while (vdso_read_retry(vdata, seq)); + + ts->tv_sec += tomono.tv_sec; + timespec_add_ns(ts, tomono.tv_nsec); + + return 0; +} + +#ifdef CONFIG_ARM_ARCH_TIMER + +static u64 get_ns(struct vdso_data *vdata) +{ + u64 cycle_delta; + u64 cycle_now; + u64 nsec; + + cycle_now = arch_counter_get_cntvct(); + + cycle_delta = (cycle_now - vdata->cs_cycle_last) & vdata->cs_mask; + + nsec = (cycle_delta * vdata->cs_mult) + vdata->xtime_clock_snsec; + nsec >>= vdata->cs_shift; + + return nsec; +} + +static int do_realtime(struct timespec *ts, struct vdso_data *vdata) +{ + u64 nsecs; + u32 seq; + + do { + seq = vdso_read_begin(vdata); + + if (vdata->use_syscall) + return -1; + + ts->tv_sec = vdata->xtime_clock_sec; + nsecs = get_ns(vdata); + + } while (vdso_read_retry(vdata, seq)); + + ts->tv_nsec = 0; + timespec_add_ns(ts, nsecs); + + return 0; +} + +static int do_monotonic(struct timespec *ts, struct vdso_data *vdata) +{ + struct timespec tomono; + u64 nsecs; + u32 seq; + + do { + seq = vdso_read_begin(vdata); + + if (vdata->use_syscall) + return -1; + + ts->tv_sec = vdata->xtime_clock_sec; + nsecs = get_ns(vdata); + + tomono.tv_sec = vdata->wtm_clock_sec; + tomono.tv_nsec = vdata->wtm_clock_nsec; + + } while (vdso_read_retry(vdata, seq)); + + ts->tv_sec += tomono.tv_sec; + ts->tv_nsec = 0; + timespec_add_ns(ts, nsecs + tomono.tv_nsec); + + return 0; +} + +#else /* CONFIG_ARM_ARCH_TIMER */ + +static int do_realtime(struct timespec *ts, struct vdso_data *vdata) +{ + return -1; +} + +static int do_monotonic(struct timespec *ts, struct vdso_data *vdata) +{ + return -1; +} + +#endif /* CONFIG_ARM_ARCH_TIMER */ + +int __kernel_clock_gettime(clockid_t clkid, struct timespec *ts) +{ + struct vdso_data *vdata; + int ret = -1; + + vdata = __get_datapage(); + + switch (clkid) { + case CLOCK_REALTIME_COARSE: + ret = do_realtime_coarse(ts, vdata); + break; + case CLOCK_MONOTONIC_COARSE: + ret = do_monotonic_coarse(ts, vdata); + break; + case CLOCK_REALTIME: + ret = do_realtime(ts, vdata); + break; + case CLOCK_MONOTONIC: + ret = do_monotonic(ts, vdata); + break; + default: + break; + } + + if (ret) + ret = clock_gettime_fallback(clkid, ts); + + return ret; +} + +static long clock_getres_fallback(clockid_t _clkid, struct timespec *_ts) +{ + register struct timespec *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_clock_getres; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +int __kernel_clock_getres(clockid_t clkid, struct timespec *ts) +{ + int ret; + + switch (clkid) { + case CLOCK_REALTIME: + case CLOCK_MONOTONIC: + if (ts) { + ts->tv_sec = 0; + ts->tv_nsec = MONOTONIC_RES_NSEC; + } + ret = 0; + break; + case CLOCK_REALTIME_COARSE: + case CLOCK_MONOTONIC_COARSE: + if (ts) { + ts->tv_sec = 0; + ts->tv_nsec = LOW_RES_NSEC; + } + ret = 0; + break; + default: + ret = clock_getres_fallback(clkid, ts); + break; + } + + return ret; +} + +static long gettimeofday_fallback(struct timeval *_tv, struct timezone *_tz) +{ + register struct timezone *tz asm("r1") = _tz; + register struct timeval *tv asm("r0") = _tv; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_gettimeofday; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (tv), "r" (tz), "r" (nr) + : "memory"); + + return ret; +} + +int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz) +{ + struct timespec ts; + struct vdso_data *vdata; + int ret; + + vdata = __get_datapage(); + + ret = do_realtime(&ts, vdata); + if (ret) + return gettimeofday_fallback(tv, tz); + + if (tv) { + tv->tv_sec = ts.tv_sec; + tv->tv_usec = ts.tv_nsec / 1000; + } + if (tz) { + tz->tz_minuteswest = vdata->tz_minuteswest; + tz->tz_dsttime = vdata->tz_dsttime; + } + + return ret; +} + +/* Avoid unresolved references emitted by GCC */ + +void __aeabi_unwind_cpp_pr0(void) +{ +} + +void __aeabi_unwind_cpp_pr1(void) +{ +} + +void __aeabi_unwind_cpp_pr2(void) +{ +}

[v7,7/9] ARM: add vdso user-space code

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