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Add support for usermode (vdso-like) gettimeofday(2) and

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clock_gettime(2) on ARMv7 and ARMv8 systems which have architectural
generic timer hardware. It is similar how the RDTSC timer is used in
userspace on x86.

Fix a permission problem where generic timer access from EL0 (or
userspace on v7) was not properly initialized on APs.

For ARMv7, mark the stack non-executable. The shared page is added for
all arms (including ARMv8 64bit), and the signal trampoline code is
moved to the page.

Reviewed by:	andrew
Discussed with:	emaste, mmel
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D4209
This commit is contained in:
Konstantin Belousov 2015-12-07 12:20:26 +00:00
parent dc15d94fd9
commit 4d22d07a07
18 changed files with 264 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lib/libc/aarch64/sys/Makefile.inc
View File

@ -1,6 +1,6 @@
# $FreeBSD$
SRCS+= trivial-vdso_tc.c
SRCS+= __vdso_gettc.c
#MDASM= ptrace.S
MDASM= brk.S \

74
lib/libc/aarch64/sys/__vdso_gettc.c Normal file
View File

@ -0,0 +1,74 @@
/*-
* Copyright (c) 2015 The FreeBSD Foundation
*
* This software was developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/elf.h>
#include <sys/time.h>
#include <sys/vdso.h>
#include <machine/cpufunc.h>
#include "libc_private.h"
static inline uint64_t
cp15_cntvct_get(void)
{
uint64_t reg;
__asm __volatile("mrs %0, cntvct_el0" : "=r" (reg));
return (reg);
}
static inline uint64_t
cp15_cntpct_get(void)
{
uint64_t reg;
__asm __volatile("mrs %0, cntpct_el0" : "=r" (reg));
return (reg);
}
#pragma weak __vdso_gettc
u_int
__vdso_gettc(const struct vdso_timehands *th)
{
uint64_t val;
__asm __volatile("isb" : : : "memory");
val = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
return (val);
}
#pragma weak __vdso_gettimekeep
int
__vdso_gettimekeep(struct vdso_timekeep **tk)
{
return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
}

2
lib/libc/arm/sys/Makefile.inc
View File

@ -1,6 +1,6 @@
# $FreeBSD$
SRCS+= trivial-vdso_tc.c
SRCS+= __vdso_gettc.c
MDASM= Ovfork.S brk.S cerror.S pipe.S ptrace.S sbrk.S shmat.S sigreturn.S syscall.S

79
lib/libc/arm/sys/__vdso_gettc.c Normal file
View File

@ -0,0 +1,79 @@
/*-
* Copyright (c) 2015 The FreeBSD Foundation
*
* This software was developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/elf.h>
#include <sys/time.h>
#include <sys/vdso.h>
#include <machine/cpufunc.h>
#include "libc_private.h"
static inline uint64_t
cp15_cntvct_get(void)
{
uint64_t reg;
__asm __volatile("mrrc\tp15, 1, %Q0, %R0, c14" : "=r" (reg));
return (reg);
}
static inline uint64_t
cp15_cntpct_get(void)
{
uint64_t reg;
__asm __volatile("mrrc\tp15, 0, %Q0, %R0, c14" : "=r" (reg));
return (reg);
}
#pragma weak __vdso_gettc
u_int
__vdso_gettc(const struct vdso_timehands *th)
{
uint64_t val;
/*
* Userspace gettimeofday() is only enabled on ARMv7 CPUs, but
* libc is compiled for ARMv6. Due to clang issues, .arch
* armv7-a directive does not work.
*/
__asm __volatile(".word\t0xf57ff06f" : : : "memory"); /* isb */
val = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
return (val);
}
#pragma weak __vdso_gettimekeep
int
__vdso_gettimekeep(struct vdso_timekeep **tk)
{
return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk)));
}

10
sys/arm/arm/elf_machdep.c
View File

@ -43,6 +43,7 @@ __FBSDID("$FreeBSD$");
#include <vm/pmap.h>
#include <vm/vm_param.h>
#include <machine/acle-compat.h>
#include <machine/elf.h>
#include <machine/md_var.h>
@ -73,13 +74,20 @@ struct sysentvec elf32_freebsd_sysvec = {
.sv_setregs = exec_setregs,
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_FREEBSD | SV_ILP32,
.sv_flags =
#if __ARM_ARCH >= 6
SV_SHP | SV_TIMEKEEP |
#endif
SV_ABI_FREEBSD | SV_ILP32,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = cpu_fetch_syscall_args,
.sv_syscallnames = syscallnames,
.sv_shared_page_base = SHAREDPAGE,
.sv_shared_page_len = PAGE_SIZE,
.sv_schedtail = NULL,
.sv_thread_detach = NULL,
};
INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
static Elf32_Brandinfo freebsd_brand_info = {
.brand = ELFOSABI_FREEBSD,

37
sys/arm/arm/generic_timer.c
View File

@ -49,10 +49,13 @@ __FBSDID("$FreeBSD$");
#include <sys/rman.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/smp.h>
#include <sys/vdso.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/intr.h>
#include <machine/md_var.h>
#ifdef FDT
#include <dev/fdt/fdt_common.h>
@ -121,6 +124,9 @@ static struct timecounter arm_tmr_timecount = {
#define set_el1(x, val) WRITE_SPECIALREG(x ##_el1, val)
#endif
static uint32_t arm_tmr_fill_vdso_timehands(struct vdso_timehands *vdso_th,
struct timecounter *tc);
static int
get_freq(void)
{
@ -181,17 +187,32 @@ get_ctrl(bool physical)
}
static void
disable_user_access(void)
setup_user_access(void *arg __unused)
{
uint32_t cntkctl;
cntkctl = get_el1(cntkctl);
cntkctl &= ~(GT_CNTKCTL_PL0PTEN | GT_CNTKCTL_PL0VTEN |
GT_CNTKCTL_EVNTEN | GT_CNTKCTL_PL0VCTEN | GT_CNTKCTL_PL0PCTEN);
GT_CNTKCTL_EVNTEN);
if (arm_tmr_sc->physical) {
cntkctl |= GT_CNTKCTL_PL0PCTEN;
cntkctl &= ~GT_CNTKCTL_PL0VCTEN;
} else {
cntkctl |= GT_CNTKCTL_PL0VCTEN;
cntkctl &= ~GT_CNTKCTL_PL0PCTEN;
}
set_el1(cntkctl, cntkctl);
isb();
}
static void
tmr_setup_user_access(void *arg __unused)
{
smp_rendezvous(NULL, setup_user_access, NULL, NULL);
}
SYSINIT(tmr_ua, SI_SUB_SMP, SI_ORDER_SECOND, tmr_setup_user_access, NULL);
static unsigned
arm_tmr_get_timecount(struct timecounter *tc)
{
@ -381,7 +402,7 @@ arm_tmr_attach(device_t dev)
}
}
disable_user_access();
arm_cpu_fill_vdso_timehands = arm_tmr_fill_vdso_timehands;
arm_tmr_timecount.tc_frequency = sc->clkfreq;
tc_init(&arm_tmr_timecount);
@ -485,3 +506,13 @@ DELAY(int usec)
first = last;
}
}
static uint32_t
arm_tmr_fill_vdso_timehands(struct vdso_timehands *vdso_th,
struct timecounter *tc)
{
vdso_th->th_physical = arm_tmr_sc->physical;
bzero(vdso_th->th_res, sizeof(vdso_th->th_res));
return (tc == &arm_tmr_timecount);
}

20
sys/arm/arm/machdep.c
View File

@ -82,6 +82,7 @@ __FBSDID("$FreeBSD$");
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/uio.h>
#include <sys/vdso.h>
#include <vm/vm.h>
#include <vm/pmap.h>
@ -271,6 +272,7 @@ sendsig(catcher, ksi, mask)
struct trapframe *tf;
struct sigframe *fp, frame;
struct sigacts *psp;
struct sysentvec *sysent;
int onstack;
int sig;
int code;
@ -337,7 +339,12 @@ sendsig(catcher, ksi, mask)
tf->tf_r5 = (register_t)&fp->sf_uc;
tf->tf_pc = (register_t)catcher;
tf->tf_usr_sp = (register_t)fp;
tf->tf_usr_lr = (register_t)(PS_STRINGS - *(p->p_sysent->sv_szsigcode));
sysent = p->p_sysent;
if (sysent->sv_sigcode_base != 0)
tf->tf_usr_lr = (register_t)sysent->sv_sigcode_base;
else
tf->tf_usr_lr = (register_t)(sysent->sv_psstrings -
*(sysent->sv_szsigcode));
/* Set the mode to enter in the signal handler */
#if __ARM_ARCH >= 7
if ((register_t)catcher & 1)
@ -1910,3 +1917,14 @@ initarm(struct arm_boot_params *abp)
#endif /* !ARM_NEW_PMAP */
#endif /* FDT */
uint32_t (*arm_cpu_fill_vdso_timehands)(struct vdso_timehands *,
struct timecounter *);
uint32_t
cpu_fill_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc)
{
return (arm_cpu_fill_vdso_timehands != NULL ?
arm_cpu_fill_vdso_timehands(vdso_th, tc) : 0);
}

5
sys/arm/include/md_var.h
View File

@ -45,6 +45,11 @@ extern int (*_arm_bzero)(void *, int, int);
extern int _min_memcpy_size;
extern int _min_bzero_size;
struct vdso_timehands;
struct timecounter;
extern uint32_t (*arm_cpu_fill_vdso_timehands)(struct vdso_timehands *,
struct timecounter *);
#define DST_IS_USER 0x1
#define SRC_IS_USER 0x2
#define IS_PHYSICAL 0x4

3
sys/arm/include/vdso.h
View File

@ -29,6 +29,7 @@
#define _ARM_VDSO_H
#define VDSO_TIMEHANDS_MD \
uint32_t th_res[8];
uint32_t th_physical; \
uint32_t th_res[7];
#endif

3
sys/arm/include/vmparam.h
View File

@ -124,7 +124,8 @@
#endif
#define VM_MAX_ADDRESS VM_MAXUSER_ADDRESS
#define USRSTACK VM_MAXUSER_ADDRESS
#define SHAREDPAGE (VM_MAXUSER_ADDRESS - PAGE_SIZE)
#define USRSTACK SHAREDPAGE
/* initial pagein size of beginning of executable file */
#ifndef VM_INITIAL_PAGEIN

5
sys/arm64/arm64/elf_machdep.c
View File

@ -80,12 +80,15 @@ static struct sysentvec elf64_freebsd_sysvec = {
.sv_setregs = exec_setregs,
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_FREEBSD | SV_LP64,
.sv_flags = SV_SHP | SV_TIMEKEEP | SV_ABI_FREEBSD | SV_LP64,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = cpu_fetch_syscall_args,
.sv_syscallnames = syscallnames,
.sv_shared_page_base = SHAREDPAGE,
.sv_shared_page_len = PAGE_SIZE,
.sv_schedtail = NULL,
};
INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
static Elf64_Brandinfo freebsd_brand_info = {
.brand = ELFOSABI_FREEBSD,

21
sys/arm64/arm64/machdep.c
View File

@ -56,6 +56,7 @@ __FBSDID("$FreeBSD$");
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/ucontext.h>
#include <sys/vdso.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
@ -72,6 +73,7 @@ __FBSDID("$FreeBSD$");
#include <machine/devmap.h>
#include <machine/machdep.h>
#include <machine/metadata.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/reg.h>
#include <machine/vmparam.h>
@ -505,6 +507,7 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
struct trapframe *tf;
struct sigframe *fp, frame;
struct sigacts *psp;
struct sysentvec *sysent;
int code, onstack, sig;
td = curthread;
@ -563,7 +566,12 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
tf->tf_elr = (register_t)catcher;
tf->tf_sp = (register_t)fp;
tf->tf_lr = (register_t)(PS_STRINGS - *(p->p_sysent->sv_szsigcode));
sysent = p->p_sysent;
if (sysent->sv_sigcode_base != 0)
tf->tf_lr = (register_t)sysent->sv_sigcode_base;
else
tf->tf_lr = (register_t)(sysent->sv_psstrings -
*(sysent->sv_szsigcode));
CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_elr,
tf->tf_sp);
@ -875,6 +883,17 @@ initarm(struct arm64_bootparams *abp)
early_boot = 0;
}
uint32_t (*arm_cpu_fill_vdso_timehands)(struct vdso_timehands *,
struct timecounter *);
uint32_t
cpu_fill_vdso_timehands(struct vdso_timehands *vdso_th, struct timecounter *tc)
{
return (arm_cpu_fill_vdso_timehands != NULL ?
arm_cpu_fill_vdso_timehands(vdso_th, tc) : 0);
}
#ifdef DDB
#include <ddb/ddb.h>

5
sys/arm64/include/md_var.h
View File

@ -46,4 +46,9 @@ void dump_add_page(vm_paddr_t);
void dump_drop_page(vm_paddr_t);
int minidumpsys(struct dumperinfo *);
struct vdso_timehands;
struct timecounter;
extern uint32_t (*arm_cpu_fill_vdso_timehands)(struct vdso_timehands *,
struct timecounter *);
#endif /* !_MACHINE_MD_VAR_H_ */

3
sys/arm64/include/vdso.h
View File

@ -29,6 +29,7 @@
#define _MACHINE_VDSO_H_
#define VDSO_TIMEHANDS_MD \
uint32_t th_res[8];
uint32_t th_physical; \
uint32_t th_res[7];
#endif /* !_MACHINE_VDSO_H_ */

3
sys/arm64/include/vmparam.h
View File

@ -194,7 +194,8 @@ extern vm_paddr_t dmap_phys_base;
#define VM_MAXUSER_ADDRESS (VM_MAX_USER_ADDRESS)
#define KERNBASE (VM_MIN_KERNEL_ADDRESS)
#define USRSTACK (VM_MAX_USER_ADDRESS)
#define SHAREDPAGE (VM_MAXUSER_ADDRESS - PAGE_SIZE)
#define USRSTACK SHAREDPAGE
/*
* How many physical pages per kmem arena virtual page.

1
sys/conf/files.arm
View File

@ -110,7 +110,6 @@ font.h optional sc \
no-obj no-implicit-rule before-depend \
clean "font.h ${SC_DFLT_FONT}-8x14 ${SC_DFLT_FONT}-8x16 ${SC_DFLT_FONT}-8x8"
kern/subr_busdma_bufalloc.c standard
kern/subr_dummy_vdso_tc.c standard
kern/subr_sfbuf.c standard
libkern/arm/aeabi_unwind.c standard
libkern/arm/divsi3.S standard

1
sys/conf/files.arm64
View File

@ -79,7 +79,6 @@ dev/vnic/thunder_mdio_fdt.c optional vnic fdt
dev/vnic/thunder_mdio.c optional vnic
dev/vnic/lmac_if.m optional vnic
kern/kern_clocksource.c standard
kern/subr_dummy_vdso_tc.c standard
libkern/bcmp.c standard
libkern/ffs.c standard
libkern/ffsl.c standard

6
sys/kern/imgact_elf.c
View File

@ -80,6 +80,9 @@ __FBSDID("$FreeBSD$");
#include <machine/elf.h>
#include <machine/md_var.h>
#ifdef __arm__
#include <machine/acle-compat.h>
#endif
#define ELF_NOTE_ROUNDSIZE 4
#define OLD_EI_BRAND 8
@ -116,7 +119,8 @@ SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW,
&elf_legacy_coredump, 0, "");
int __elfN(nxstack) =
#if defined(__amd64__) || defined(__powerpc64__) /* both 64 and 32 bit */
#if defined(__amd64__) || defined(__powerpc64__) /* both 64 and 32 bit */ || \
(defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__)
1;
#else
0;