freebsd-dev/sys/compat/ia32/ia32_sysvec.c
John Baldwin 91d5354a2c Locking for the per-process resource limits structure.
- struct plimit includes a mutex to protect a reference count.  The plimit
  structure is treated similarly to struct ucred in that is is always copy
  on write, so having a reference to a structure is sufficient to read from
  it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
  limits from a process to keep the limit structure from changing out from
  under you while reading from it.
- Various global limits that are ints are not protected by a lock since
  int writes are atomic on all the archs we support and thus a lock
  wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
  behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
  either an rlimit, or the current or max individual limit of the specified
  resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
  other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
  (it didn't used the stackgap when it should have) but uses lim_rlimit()
  and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
  but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits.  It
  also no longer uses the stackgap for accessing sysctl's for the
  ibcs2_sysconf() syscall but uses kernel_sysctl() instead.  As a result,
  ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.

Submitted by:	mtm (mostly, I only did a few cleanups and catchups)
Tested on:	i386
Compiled on:	alpha, amd64
2004-02-04 21:52:57 +00:00

306 lines
8.3 KiB
C

/*-
* Copyright (c) 2002 Doug Rabson
* Copyright (c) 2003 Peter Wemm
* All rights reserved.
*
* 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 "opt_compat.h"
#define __ELF_WORD_SIZE 32
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mman.h>
#include <sys/namei.h>
#include <sys/pioctl.h>
#include <sys/proc.h>
#include <sys/procfs.h>
#include <sys/resourcevar.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/imgact_elf.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <compat/freebsd32/freebsd32_util.h>
#include <compat/freebsd32/freebsd32_proto.h>
#include <compat/freebsd32/freebsd32_syscall.h>
#include <compat/ia32/ia32_signal.h>
#ifdef __amd64__
#include <machine/psl.h>
#include <machine/segments.h>
#include <machine/specialreg.h>
#else
#include <i386/include/psl.h>
#include <i386/include/segments.h>
#include <i386/include/specialreg.h>
#endif
#include <machine/frame.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/cpufunc.h>
CTASSERT(sizeof(struct ia32_mcontext) == 640);
CTASSERT(sizeof(struct ia32_ucontext) == 704);
CTASSERT(sizeof(struct ia32_sigframe) == 800);
CTASSERT(sizeof(struct ia32_siginfo) == 64);
#ifdef COMPAT_FREEBSD4
CTASSERT(sizeof(struct ia32_mcontext4) == 260);
CTASSERT(sizeof(struct ia32_ucontext4) == 324);
CTASSERT(sizeof(struct ia32_sigframe4) == 408);
#endif
static register_t *ia32_copyout_strings(struct image_params *imgp);
static void ia32_fixlimits(struct image_params *imgp);
extern struct sysent freebsd32_sysent[];
SYSCTL_NODE(_compat, OID_AUTO, ia32, CTLFLAG_RW, 0, "ia32 mode");
struct sysentvec ia32_freebsd_sysvec = {
FREEBSD32_SYS_MAXSYSCALL,
freebsd32_sysent,
0,
0,
NULL,
0,
NULL,
NULL,
elf32_freebsd_fixup,
ia32_sendsig,
ia32_sigcode,
&sz_ia32_sigcode,
NULL,
"FreeBSD ELF32",
elf32_coredump,
NULL,
MINSIGSTKSZ,
IA32_PAGE_SIZE,
0,
FREEBSD32_USRSTACK,
FREEBSD32_USRSTACK,
FREEBSD32_PS_STRINGS,
VM_PROT_ALL,
ia32_copyout_strings,
ia32_setregs,
ia32_fixlimits
};
static Elf32_Brandinfo ia32_brand_info = {
ELFOSABI_FREEBSD,
EM_386,
"FreeBSD",
NULL,
"/libexec/ld-elf.so.1",
&ia32_freebsd_sysvec,
"/libexec/ld-elf-32.so.1",
};
SYSINIT(ia32, SI_SUB_EXEC, SI_ORDER_ANY,
(sysinit_cfunc_t) elf32_insert_brand_entry,
&ia32_brand_info);
static Elf32_Brandinfo ia32_brand_oinfo = {
ELFOSABI_FREEBSD,
EM_386,
"FreeBSD",
NULL,
"/usr/libexec/ld-elf.so.1",
&ia32_freebsd_sysvec,
"/usr/libexec/ld-elf-32.so.1",
};
SYSINIT(oia32, SI_SUB_EXEC, SI_ORDER_ANY,
(sysinit_cfunc_t) elf32_insert_brand_entry,
&ia32_brand_oinfo);
/* XXX may be freebsd32 MI */
static register_t *
ia32_copyout_strings(struct image_params *imgp)
{
int argc, envc;
u_int32_t *vectp;
char *stringp, *destp;
u_int32_t *stack_base;
struct freebsd32_ps_strings *arginfo;
int szsigcode;
/*
* Calculate string base and vector table pointers.
* Also deal with signal trampoline code for this exec type.
*/
arginfo = (struct freebsd32_ps_strings *)FREEBSD32_PS_STRINGS;
szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
roundup((ARG_MAX - imgp->stringspace), sizeof(char *));
/*
* install sigcode
*/
if (szsigcode)
copyout(imgp->proc->p_sysent->sv_sigcode,
((caddr_t)arginfo - szsigcode), szsigcode);
/*
* If we have a valid auxargs ptr, prepare some room
* on the stack.
*/
if (imgp->auxargs) {
/*
* 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
* lower compatibility.
*/
imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size
: (AT_COUNT * 2);
/*
* The '+ 2' is for the null pointers at the end of each of
* the arg and env vector sets,and imgp->auxarg_size is room
* for argument of Runtime loader.
*/
vectp = (u_int32_t *) (destp - (imgp->argc + imgp->envc + 2 +
imgp->auxarg_size) * sizeof(u_int32_t));
} else
/*
* The '+ 2' is for the null pointers at the end of each of
* the arg and env vector sets
*/
vectp = (u_int32_t *)
(destp - (imgp->argc + imgp->envc + 2) * sizeof(u_int32_t));
/*
* vectp also becomes our initial stack base
*/
stack_base = vectp;
stringp = imgp->stringbase;
argc = imgp->argc;
envc = imgp->envc;
/*
* Copy out strings - arguments and environment.
*/
copyout(stringp, destp, ARG_MAX - imgp->stringspace);
/*
* Fill in "ps_strings" struct for ps, w, etc.
*/
suword32(&arginfo->ps_argvstr, (u_int32_t)(intptr_t)vectp);
suword32(&arginfo->ps_nargvstr, argc);
/*
* Fill in argument portion of vector table.
*/
for (; argc > 0; --argc) {
suword32(vectp++, (u_int32_t)(intptr_t)destp);
while (*stringp++ != 0)
destp++;
destp++;
}
/* a null vector table pointer separates the argp's from the envp's */
suword32(vectp++, 0);
suword32(&arginfo->ps_envstr, (u_int32_t)(intptr_t)vectp);
suword32(&arginfo->ps_nenvstr, envc);
/*
* Fill in environment portion of vector table.
*/
for (; envc > 0; --envc) {
suword32(vectp++, (u_int32_t)(intptr_t)destp);
while (*stringp++ != 0)
destp++;
destp++;
}
/* end of vector table is a null pointer */
suword32(vectp, 0);
return ((register_t *)stack_base);
}
static u_long ia32_maxdsiz = IA32_MAXDSIZ;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxdsiz, CTLFLAG_RW, &ia32_maxdsiz, 0, "");
static u_long ia32_maxssiz = IA32_MAXSSIZ;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxssiz, CTLFLAG_RW, &ia32_maxssiz, 0, "");
static u_long ia32_maxvmem = IA32_MAXVMEM;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxvmem, CTLFLAG_RW, &ia32_maxvmem, 0, "");
static void
ia32_fixlimits(struct image_params *imgp)
{
struct proc *p = imgp->proc;
struct plimit *oldlim, *newlim;
if (ia32_maxdsiz == 0 && ia32_maxssiz == 0 && ia32_maxvmem == 0)
return;
newlim = lim_alloc();
PROC_LOCK(p);
oldlim = p->p_limit;
lim_copy(newlim, oldlim);
if (ia32_maxdsiz != 0) {
if (newlim->pl_rlimit[RLIMIT_DATA].rlim_cur > ia32_maxdsiz)
newlim->pl_rlimit[RLIMIT_DATA].rlim_cur = ia32_maxdsiz;
if (newlim->pl_rlimit[RLIMIT_DATA].rlim_max > ia32_maxdsiz)
newlim->pl_rlimit[RLIMIT_DATA].rlim_max = ia32_maxdsiz;
}
if (ia32_maxssiz != 0) {
if (newlim->pl_rlimit[RLIMIT_STACK].rlim_cur > ia32_maxssiz)
newlim->pl_rlimit[RLIMIT_STACK].rlim_cur = ia32_maxssiz;
if (newlim->pl_rlimit[RLIMIT_STACK].rlim_max > ia32_maxssiz)
newlim->pl_rlimit[RLIMIT_STACK].rlim_max = ia32_maxssiz;
}
if (ia32_maxvmem != 0) {
if (newlim->pl_rlimit[RLIMIT_VMEM].rlim_cur > ia32_maxvmem)
newlim->pl_rlimit[RLIMIT_VMEM].rlim_cur = ia32_maxvmem;
if (newlim->pl_rlimit[RLIMIT_VMEM].rlim_max > ia32_maxvmem)
newlim->pl_rlimit[RLIMIT_VMEM].rlim_max = ia32_maxvmem;
}
p->p_limit = newlim;
PROC_UNLOCK(p);
lim_free(oldlim);
}