ARM: 8330/1: add VDSO user-space code
Place VDSO-related user-space code in arch/arm/kernel/vdso/.
It is almost completely written in C with some assembly helpers to
load the data page address, sample the counter, and fall back to
system calls when necessary.
The VDSO can service gettimeofday and clock_gettime when
CONFIG_ARM_ARCH_TIMER is enabled and the architected timer is present
(and correctly configured). It reads the CP15-based virtual counter
to compute high-resolution timestamps.
Of particular note is that a post-processing step ("vdsomunge") is
necessary to produce a shared object which is architecturally allowed
to be used by both soft- and hard-float EABI programs.
The 2012 edition of the ARM ABI defines Tag_ABI_VFP_args = 3 "Code is
compatible with both the base and VFP variants; the user did not
permit non-variadic functions to pass FP parameters/results."
Unfortunately current toolchains do not support this tag, which is
ideally what we would use.
The best available option is to ensure that both EF_ARM_ABI_FLOAT_SOFT
and EF_ARM_ABI_FLOAT_HARD are unset in the ELF header's e_flags,
indicating that the shared object is "old" and should be accepted for
backward compatibility's sake. While binutils < 2.24 appear to
produce a vdso.so with both flags clear, 2.24 always sets
EF_ARM_ABI_FLOAT_SOFT, with no way to inhibit this behavior. So we
have to fix things up with a custom post-processing step.
In fact, the VDSO code in glibc does much less validation (including
checking these flags) than the code for handling conventional
file-backed shared libraries, so this is a bit moot unless glibc's
VDSO code becomes more strict.
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Nathan Lynch
Russell King
parent
1713ce7c43
commit
8512287a81
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@ -25,6 +25,7 @@
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#include <asm/memory.h>
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#include <asm/procinfo.h>
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#include <asm/suspend.h>
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#include <asm/vdso_datapage.h>
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#include <asm/hardware/cache-l2x0.h>
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#include <linux/kbuild.h>
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@ -209,6 +210,10 @@ int main(void)
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DEFINE(KVM_VGIC_VCTRL, offsetof(struct kvm, arch.vgic.vctrl_base));
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#endif
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DEFINE(KVM_VTTBR, offsetof(struct kvm, arch.vttbr));
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#endif
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BLANK();
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#ifdef CONFIG_VDSO
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DEFINE(VDSO_DATA_SIZE, sizeof(union vdso_data_store));
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#endif
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return 0;
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}
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@ -0,0 +1 @@
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vdso.lds
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@ -0,0 +1,74 @@
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hostprogs-y := vdsomunge
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obj-vdso := vgettimeofday.o datapage.o
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# Build rules
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targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds
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obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
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ccflags-y := -shared -fPIC -fno-common -fno-builtin -fno-stack-protector
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ccflags-y += -nostdlib -Wl,-soname=linux-vdso.so.1 -DDISABLE_BRANCH_PROFILING
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ccflags-y += -Wl,--no-undefined $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
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obj-y += vdso.o
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extra-y += vdso.lds
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CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
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CFLAGS_REMOVE_vdso.o = -pg
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# Force -O2 to avoid libgcc dependencies
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CFLAGS_REMOVE_vgettimeofday.o = -pg -Os
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CFLAGS_vgettimeofday.o = -O2
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# Disable gcov profiling for VDSO code
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GCOV_PROFILE := n
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# Force dependency
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$(obj)/vdso.o : $(obj)/vdso.so
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# Link rule for the .so file
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$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE
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$(call if_changed,vdsold)
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$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE
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$(call if_changed,vdsomunge)
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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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quiet_cmd_vdsold = VDSO $@
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cmd_vdsold = $(CC) $(c_flags) -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) \
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$(call cc-ldoption, -Wl$(comma)--build-id) \
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-Wl,-Bsymbolic -Wl,-z,max-page-size=4096 \
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-Wl,-z,common-page-size=4096 -o $@
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quiet_cmd_vdsomunge = MUNGE $@
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cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@
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#
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# Install the unstripped copy of vdso.so.dbg. If our toolchain
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# supports build-id, install .build-id links as well.
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#
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# Cribbed from arch/x86/vdso/Makefile.
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#
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quiet_cmd_vdso_install = INSTALL $<
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define cmd_vdso_install
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cp $< "$(MODLIB)/vdso/vdso.so"; \
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if readelf -n $< | grep -q 'Build ID'; then \
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buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
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first=`echo $$buildid | cut -b-2`; \
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last=`echo $$buildid | cut -b3-`; \
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mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
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ln -sf "../../vdso.so" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
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fi
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endef
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$(MODLIB)/vdso: FORCE
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@mkdir -p $(MODLIB)/vdso
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PHONY += vdso_install
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vdso_install: $(obj)/vdso.so.dbg $(MODLIB)/vdso FORCE
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$(call cmd,vdso_install)
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@ -0,0 +1,15 @@
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#include <linux/linkage.h>
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#include <asm/asm-offsets.h>
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.align 2
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.L_vdso_data_ptr:
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.long _start - . - VDSO_DATA_SIZE
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ENTRY(__get_datapage)
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.fnstart
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adr r0, .L_vdso_data_ptr
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ldr r1, [r0]
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add r0, r0, r1
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bx lr
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.fnend
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ENDPROC(__get_datapage)
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@ -0,0 +1,35 @@
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/*
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* Adapted from arm64 version.
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*
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* Copyright (C) 2012 ARM Limited
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Author: Will Deacon <will.deacon@arm.com>
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*/
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#include <linux/init.h>
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#include <linux/linkage.h>
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#include <linux/const.h>
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#include <asm/page.h>
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__PAGE_ALIGNED_DATA
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.globl vdso_start, vdso_end
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.balign PAGE_SIZE
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vdso_start:
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.incbin "arch/arm/vdso/vdso.so"
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.balign PAGE_SIZE
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vdso_end:
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.previous
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@ -0,0 +1,87 @@
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/*
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* Adapted from arm64 version.
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*
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* GNU linker script for the VDSO library.
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*
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* Copyright (C) 2012 ARM Limited
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Author: Will Deacon <will.deacon@arm.com>
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* Heavily based on the vDSO linker scripts for other archs.
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*/
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#include <linux/const.h>
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#include <asm/page.h>
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#include <asm/vdso.h>
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OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")
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OUTPUT_ARCH(arm)
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SECTIONS
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{
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PROVIDE(_start = .);
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. = SIZEOF_HEADERS;
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.hash : { *(.hash) } :text
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.gnu.hash : { *(.gnu.hash) }
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.dynsym : { *(.dynsym) }
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.dynstr : { *(.dynstr) }
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.gnu.version : { *(.gnu.version) }
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.gnu.version_d : { *(.gnu.version_d) }
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.gnu.version_r : { *(.gnu.version_r) }
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.note : { *(.note.*) } :text :note
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.eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
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.eh_frame : { KEEP (*(.eh_frame)) } :text
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.dynamic : { *(.dynamic) } :text :dynamic
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.rodata : { *(.rodata*) } :text
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.text : { *(.text*) } :text =0xe7f001f2
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.got : { *(.got) }
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.rel.plt : { *(.rel.plt) }
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/DISCARD/ : {
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*(.note.GNU-stack)
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*(.data .data.* .gnu.linkonce.d.* .sdata*)
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*(.bss .sbss .dynbss .dynsbss)
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}
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}
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/*
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* We must supply the ELF program headers explicitly to get just one
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* PT_LOAD segment, and set the flags explicitly to make segments read-only.
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*/
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PHDRS
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{
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text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
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dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
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note PT_NOTE FLAGS(4); /* PF_R */
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eh_frame_hdr PT_GNU_EH_FRAME;
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}
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VERSION
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{
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LINUX_2.6 {
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global:
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__vdso_clock_gettime;
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__vdso_gettimeofday;
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local: *;
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};
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}
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@ -0,0 +1,201 @@
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/*
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* Copyright 2015 Mentor Graphics Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; version 2 of the
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* License.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*
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* vdsomunge - Host program which produces a shared object
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* architecturally specified to be usable by both soft- and hard-float
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* programs.
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*
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* The Procedure Call Standard for the ARM Architecture (ARM IHI
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* 0042E) says:
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*
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* 6.4.1 VFP and Base Standard Compatibility
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*
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* Code compiled for the VFP calling standard is compatible with
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* the base standard (and vice-versa) if no floating-point or
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* containerized vector arguments or results are used.
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*
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* And ELF for the ARM Architecture (ARM IHI 0044E) (Table 4-2) says:
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*
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* If both EF_ARM_ABI_FLOAT_XXXX bits are clear, conformance to the
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* base procedure-call standard is implied.
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*
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* The VDSO is built with -msoft-float, as with the rest of the ARM
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* kernel, and uses no floating point arguments or results. The build
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* process will produce a shared object that may or may not have the
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* EF_ARM_ABI_FLOAT_SOFT flag set (it seems to depend on the binutils
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* version; binutils starting with 2.24 appears to set it). The
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* EF_ARM_ABI_FLOAT_HARD flag should definitely not be set, and this
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* program will error out if it is.
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*
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* If the soft-float flag is set, this program clears it. That's all
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* it does.
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*/
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#define _GNU_SOURCE
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#include <byteswap.h>
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#include <elf.h>
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#include <errno.h>
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#include <error.h>
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#include <fcntl.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
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#define HOST_ORDER ELFDATA2LSB
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#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
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#define HOST_ORDER ELFDATA2MSB
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#endif
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/* Some of the ELF constants we'd like to use were added to <elf.h>
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* relatively recently.
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*/
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#ifndef EF_ARM_EABI_VER5
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#define EF_ARM_EABI_VER5 0x05000000
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#endif
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#ifndef EF_ARM_ABI_FLOAT_SOFT
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#define EF_ARM_ABI_FLOAT_SOFT 0x200
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#endif
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#ifndef EF_ARM_ABI_FLOAT_HARD
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#define EF_ARM_ABI_FLOAT_HARD 0x400
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#endif
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static const char *outfile;
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static void cleanup(void)
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{
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if (error_message_count > 0 && outfile != NULL)
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unlink(outfile);
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}
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static Elf32_Word read_elf_word(Elf32_Word word, bool swap)
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{
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return swap ? bswap_32(word) : word;
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}
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static Elf32_Half read_elf_half(Elf32_Half half, bool swap)
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{
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return swap ? bswap_16(half) : half;
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}
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static void write_elf_word(Elf32_Word val, Elf32_Word *dst, bool swap)
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{
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*dst = swap ? bswap_32(val) : val;
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}
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int main(int argc, char **argv)
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{
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const Elf32_Ehdr *inhdr;
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bool clear_soft_float;
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const char *infile;
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Elf32_Word e_flags;
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const void *inbuf;
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struct stat stat;
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void *outbuf;
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bool swap;
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int outfd;
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int infd;
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atexit(cleanup);
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if (argc != 3)
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error(EXIT_FAILURE, 0, "Usage: %s [infile] [outfile]", argv[0]);
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infile = argv[1];
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outfile = argv[2];
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infd = open(infile, O_RDONLY);
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if (infd < 0)
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error(EXIT_FAILURE, errno, "Cannot open %s", infile);
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if (fstat(infd, &stat) != 0)
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error(EXIT_FAILURE, errno, "Failed stat for %s", infile);
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inbuf = mmap(NULL, stat.st_size, PROT_READ, MAP_PRIVATE, infd, 0);
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if (inbuf == MAP_FAILED)
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error(EXIT_FAILURE, errno, "Failed to map %s", infile);
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close(infd);
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inhdr = inbuf;
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if (memcmp(&inhdr->e_ident, ELFMAG, SELFMAG) != 0)
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error(EXIT_FAILURE, 0, "Not an ELF file");
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|
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if (inhdr->e_ident[EI_CLASS] != ELFCLASS32)
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error(EXIT_FAILURE, 0, "Unsupported ELF class");
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swap = inhdr->e_ident[EI_DATA] != HOST_ORDER;
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if (read_elf_half(inhdr->e_type, swap) != ET_DYN)
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error(EXIT_FAILURE, 0, "Not a shared object");
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if (read_elf_half(inhdr->e_machine, swap) != EM_ARM) {
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error(EXIT_FAILURE, 0, "Unsupported architecture %#x",
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inhdr->e_machine);
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}
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e_flags = read_elf_word(inhdr->e_flags, swap);
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|
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if (EF_ARM_EABI_VERSION(e_flags) != EF_ARM_EABI_VER5) {
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error(EXIT_FAILURE, 0, "Unsupported EABI version %#x",
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EF_ARM_EABI_VERSION(e_flags));
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}
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|
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if (e_flags & EF_ARM_ABI_FLOAT_HARD)
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error(EXIT_FAILURE, 0,
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"Unexpected hard-float flag set in e_flags");
|
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|
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clear_soft_float = !!(e_flags & EF_ARM_ABI_FLOAT_SOFT);
|
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|
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outfd = open(outfile, O_RDWR | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
|
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if (outfd < 0)
|
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error(EXIT_FAILURE, errno, "Cannot open %s", outfile);
|
||||
|
||||
if (ftruncate(outfd, stat.st_size) != 0)
|
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error(EXIT_FAILURE, errno, "Cannot truncate %s", outfile);
|
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|
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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);
|
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|
||||
if (clear_soft_float) {
|
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Elf32_Ehdr *outhdr;
|
||||
|
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outhdr = outbuf;
|
||||
e_flags &= ~EF_ARM_ABI_FLOAT_SOFT;
|
||||
write_elf_word(e_flags, &outhdr->e_flags, swap);
|
||||
}
|
||||
|
||||
if (msync(outbuf, stat.st_size, MS_SYNC) != 0)
|
||||
error(EXIT_FAILURE, errno, "Failed to sync %s", outfile);
|
||||
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
|
|
@ -0,0 +1,282 @@
|
|||
/*
|
||||
* Copyright 2015 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 notrace 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 notrace u32 vdso_read_begin(const struct vdso_data *vdata)
|
||||
{
|
||||
u32 seq;
|
||||
|
||||
seq = __vdso_read_begin(vdata);
|
||||
|
||||
smp_rmb(); /* Pairs with smp_wmb in vdso_write_end */
|
||||
return seq;
|
||||
}
|
||||
|
||||
static notrace int vdso_read_retry(const struct vdso_data *vdata, u32 start)
|
||||
{
|
||||
smp_rmb(); /* Pairs with smp_wmb in vdso_write_begin */
|
||||
return vdata->seq_count != start;
|
||||
}
|
||||
|
||||
static notrace 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 notrace 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 notrace 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 notrace 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 notrace int do_realtime(struct timespec *ts, struct vdso_data *vdata)
|
||||
{
|
||||
u64 nsecs;
|
||||
u32 seq;
|
||||
|
||||
do {
|
||||
seq = vdso_read_begin(vdata);
|
||||
|
||||
if (!vdata->tk_is_cntvct)
|
||||
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 notrace 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->tk_is_cntvct)
|
||||
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 notrace int do_realtime(struct timespec *ts, struct vdso_data *vdata)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
static notrace int do_monotonic(struct timespec *ts, struct vdso_data *vdata)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
#endif /* CONFIG_ARM_ARCH_TIMER */
|
||||
|
||||
notrace int __vdso_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 notrace 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;
|
||||
}
|
||||
|
||||
notrace int __vdso_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)
|
||||
{
|
||||
}
|
||||
Loading…
Reference in New Issue