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freebsd-nq/sys/amd64/linux32/linux32_sysvec.c
Konstantin Belousov 1b3c32568a Update some comments related to use of amd64 full context switch. 
In exec_linux_setregs(), use locally cached pointer to pcb to set
pcb_full_iret.
In set_regs(), note that full return is needed when code that sets
segment registers is enabled.

MFC after:	1 week
2010-12-07 12:44:33 +00:00

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/*-
* Copyright (c) 2004 Tim J. Robbins
* Copyright (c) 2003 Peter Wemm
* Copyright (c) 2002 Doug Rabson
* Copyright (c) 1998-1999 Andrew Gallatin
* Copyright (c) 1994-1996 Søren Schmidt
* 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
* in this position and unchanged.
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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"
#ifndef COMPAT_FREEBSD32
#error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!"
#endif
#define __ELF_WORD_SIZE 32
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/imgact_elf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/sysctl.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/vnode.h>
#include <sys/eventhandler.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_param.h>
#include <machine/cpu.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/specialreg.h>
#include <amd64/linux32/linux.h>
#include <amd64/linux32/linux32_proto.h>
#include <compat/linux/linux_futex.h>
#include <compat/linux/linux_emul.h>
#include <compat/linux/linux_mib.h>
#include <compat/linux/linux_misc.h>
#include <compat/linux/linux_signal.h>
#include <compat/linux/linux_util.h>
MODULE_VERSION(linux, 1);
MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
#define AUXARGS_ENTRY_32(pos, id, val) \
do { \
suword32(pos++, id); \
suword32(pos++, val); \
} while (0)
#if BYTE_ORDER == LITTLE_ENDIAN
#define SHELLMAGIC 0x2123 /* #! */
#else
#define SHELLMAGIC 0x2321
#endif
/*
* Allow the sendsig functions to use the ldebug() facility
* even though they are not syscalls themselves. Map them
* to syscall 0. This is slightly less bogus than using
* ldebug(sigreturn).
*/
#define LINUX_SYS_linux_rt_sendsig 0
#define LINUX_SYS_linux_sendsig 0
const char *linux_platform = "i686";
static int linux_szplatform;
extern char linux_sigcode[];
extern int linux_szsigcode;
extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
SET_DECLARE(linux_device_handler_set, struct linux_device_handler);
static int elf_linux_fixup(register_t **stack_base,
struct image_params *iparams);
static register_t *linux_copyout_strings(struct image_params *imgp);
static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
static void exec_linux_setregs(struct thread *td,
struct image_params *imgp, u_long stack);
static void linux32_fixlimit(struct rlimit *rl, int which);
static boolean_t linux32_trans_osrel(const Elf_Note *note, int32_t *osrel);
static eventhandler_tag linux_exit_tag;
static eventhandler_tag linux_schedtail_tag;
static eventhandler_tag linux_exec_tag;
/*
* Linux syscalls return negative errno's, we do positive and map them
* Reference:
* FreeBSD: src/sys/sys/errno.h
* Linux: linux-2.6.17.8/include/asm-generic/errno-base.h
* linux-2.6.17.8/include/asm-generic/errno.h
*/
static int bsd_to_linux_errno[ELAST + 1] = {
-0, -1, -2, -3, -4, -5, -6, -7, -8, -9,
-10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
-20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
-30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
-90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
-100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
-110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
-116, -66, -6, -6, -6, -6, -6, -37, -38, -9,
-6, -6, -43, -42, -75,-125, -84, -95, -16, -74,
-72, -67, -71
};
int bsd_to_linux_signal[LINUX_SIGTBLSZ] = {
LINUX_SIGHUP, LINUX_SIGINT, LINUX_SIGQUIT, LINUX_SIGILL,
LINUX_SIGTRAP, LINUX_SIGABRT, 0, LINUX_SIGFPE,
LINUX_SIGKILL, LINUX_SIGBUS, LINUX_SIGSEGV, LINUX_SIGSYS,
LINUX_SIGPIPE, LINUX_SIGALRM, LINUX_SIGTERM, LINUX_SIGURG,
LINUX_SIGSTOP, LINUX_SIGTSTP, LINUX_SIGCONT, LINUX_SIGCHLD,
LINUX_SIGTTIN, LINUX_SIGTTOU, LINUX_SIGIO, LINUX_SIGXCPU,
LINUX_SIGXFSZ, LINUX_SIGVTALRM, LINUX_SIGPROF, LINUX_SIGWINCH,
0, LINUX_SIGUSR1, LINUX_SIGUSR2
};
int linux_to_bsd_signal[LINUX_SIGTBLSZ] = {
SIGHUP, SIGINT, SIGQUIT, SIGILL,
SIGTRAP, SIGABRT, SIGBUS, SIGFPE,
SIGKILL, SIGUSR1, SIGSEGV, SIGUSR2,
SIGPIPE, SIGALRM, SIGTERM, SIGBUS,
SIGCHLD, SIGCONT, SIGSTOP, SIGTSTP,
SIGTTIN, SIGTTOU, SIGURG, SIGXCPU,
SIGXFSZ, SIGVTALRM, SIGPROF, SIGWINCH,
SIGIO, SIGURG, SIGSYS
};
#define LINUX_T_UNKNOWN 255
static int _bsd_to_linux_trapcode[] = {
LINUX_T_UNKNOWN, /* 0 */
6, /* 1 T_PRIVINFLT */
LINUX_T_UNKNOWN, /* 2 */
3, /* 3 T_BPTFLT */
LINUX_T_UNKNOWN, /* 4 */
LINUX_T_UNKNOWN, /* 5 */
16, /* 6 T_ARITHTRAP */
254, /* 7 T_ASTFLT */
LINUX_T_UNKNOWN, /* 8 */
13, /* 9 T_PROTFLT */
1, /* 10 T_TRCTRAP */
LINUX_T_UNKNOWN, /* 11 */
14, /* 12 T_PAGEFLT */
LINUX_T_UNKNOWN, /* 13 */
17, /* 14 T_ALIGNFLT */
LINUX_T_UNKNOWN, /* 15 */
LINUX_T_UNKNOWN, /* 16 */
LINUX_T_UNKNOWN, /* 17 */
0, /* 18 T_DIVIDE */
2, /* 19 T_NMI */
4, /* 20 T_OFLOW */
5, /* 21 T_BOUND */
7, /* 22 T_DNA */
8, /* 23 T_DOUBLEFLT */
9, /* 24 T_FPOPFLT */
10, /* 25 T_TSSFLT */
11, /* 26 T_SEGNPFLT */
12, /* 27 T_STKFLT */
18, /* 28 T_MCHK */
19, /* 29 T_XMMFLT */
15 /* 30 T_RESERVED */
};
#define bsd_to_linux_trapcode(code) \
((code)<sizeof(_bsd_to_linux_trapcode)/sizeof(*_bsd_to_linux_trapcode)? \
_bsd_to_linux_trapcode[(code)]: \
LINUX_T_UNKNOWN)
struct linux32_ps_strings {
u_int32_t ps_argvstr; /* first of 0 or more argument strings */
u_int ps_nargvstr; /* the number of argument strings */
u_int32_t ps_envstr; /* first of 0 or more environment strings */
u_int ps_nenvstr; /* the number of environment strings */
};
/*
* If FreeBSD & Linux have a difference of opinion about what a trap
* means, deal with it here.
*
* MPSAFE
*/
static int
translate_traps(int signal, int trap_code)
{
if (signal != SIGBUS)
return signal;
switch (trap_code) {
case T_PROTFLT:
case T_TSSFLT:
case T_DOUBLEFLT:
case T_PAGEFLT:
return SIGSEGV;
default:
return signal;
}
}
static int
elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
{
Elf32_Auxargs *args;
Elf32_Addr *base;
Elf32_Addr *pos, *uplatform;
struct linux32_ps_strings *arginfo;
arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szsigcode -
linux_szplatform);
KASSERT(curthread->td_proc == imgp->proc,
("unsafe elf_linux_fixup(), should be curproc"));
base = (Elf32_Addr *)*stack_base;
args = (Elf32_Auxargs *)imgp->auxargs;
pos = base + (imgp->args->argc + imgp->args->envc + 2);
AUXARGS_ENTRY_32(pos, LINUX_AT_HWCAP, cpu_feature);
/*
* Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
* as it has appeared in the 2.4.0-rc7 first time.
* Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
* glibc falls back to the hard-coded CLK_TCK value when aux entry
* is not present.
* Also see linux_times() implementation.
*/
if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
AUXARGS_ENTRY_32(pos, LINUX_AT_CLKTCK, stclohz);
AUXARGS_ENTRY_32(pos, AT_PHDR, args->phdr);
AUXARGS_ENTRY_32(pos, AT_PHENT, args->phent);
AUXARGS_ENTRY_32(pos, AT_PHNUM, args->phnum);
AUXARGS_ENTRY_32(pos, AT_PAGESZ, args->pagesz);
AUXARGS_ENTRY_32(pos, AT_FLAGS, args->flags);
AUXARGS_ENTRY_32(pos, AT_ENTRY, args->entry);
AUXARGS_ENTRY_32(pos, AT_BASE, args->base);
AUXARGS_ENTRY_32(pos, LINUX_AT_SECURE, 0);
AUXARGS_ENTRY_32(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
AUXARGS_ENTRY_32(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
AUXARGS_ENTRY_32(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
AUXARGS_ENTRY_32(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
AUXARGS_ENTRY_32(pos, LINUX_AT_PLATFORM, PTROUT(uplatform));
if (args->execfd != -1)
AUXARGS_ENTRY_32(pos, AT_EXECFD, args->execfd);
AUXARGS_ENTRY_32(pos, AT_NULL, 0);
free(imgp->auxargs, M_TEMP);
imgp->auxargs = NULL;
base--;
suword32(base, (uint32_t)imgp->args->argc);
*stack_base = (register_t *)base;
return 0;
}
extern unsigned long linux_sznonrtsigcode;
static void
linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct thread *td = curthread;
struct proc *p = td->td_proc;
struct sigacts *psp;
struct trapframe *regs;
struct l_rt_sigframe *fp, frame;
int oonstack;
int sig;
int code;
sig = ksi->ksi_signo;
code = ksi->ksi_code;
PROC_LOCK_ASSERT(p, MA_OWNED);
psp = p->p_sigacts;
mtx_assert(&psp->ps_mtx, MA_OWNED);
regs = td->td_frame;
oonstack = sigonstack(regs->tf_rsp);
#ifdef DEBUG
if (ldebug(rt_sendsig))
printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
catcher, sig, (void*)mask, code);
#endif
/*
* Allocate space for the signal handler context.
*/
if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct l_rt_sigframe *)(td->td_sigstk.ss_sp +
td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
} else
fp = (struct l_rt_sigframe *)regs->tf_rsp - 1;
mtx_unlock(&psp->ps_mtx);
/*
* Build the argument list for the signal handler.
*/
if (p->p_sysent->sv_sigtbl)
if (sig <= p->p_sysent->sv_sigsize)
sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)];
bzero(&frame, sizeof(frame));
frame.sf_handler = PTROUT(catcher);
frame.sf_sig = sig;
frame.sf_siginfo = PTROUT(&fp->sf_si);
frame.sf_ucontext = PTROUT(&fp->sf_sc);
/* Fill in POSIX parts */
ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
/*
* Build the signal context to be used by sigreturn.
*/
frame.sf_sc.uc_flags = 0; /* XXX ??? */
frame.sf_sc.uc_link = 0; /* XXX ??? */
frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
PROC_UNLOCK(p);
bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__bits[0];
frame.sf_sc.uc_mcontext.sc_edi = regs->tf_rdi;
frame.sf_sc.uc_mcontext.sc_esi = regs->tf_rsi;
frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_rbp;
frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_rbx;
frame.sf_sc.uc_mcontext.sc_edx = regs->tf_rdx;
frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_rcx;
frame.sf_sc.uc_mcontext.sc_eax = regs->tf_rax;
frame.sf_sc.uc_mcontext.sc_eip = regs->tf_rip;
frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
frame.sf_sc.uc_mcontext.sc_gs = regs->tf_gs;
frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_rflags;
frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp;
frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
frame.sf_sc.uc_mcontext.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr;
frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
#ifdef DEBUG
if (ldebug(rt_sendsig))
printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
#endif
if (copyout(&frame, fp, sizeof(frame)) != 0) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
#ifdef DEBUG
if (ldebug(rt_sendsig))
printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
fp, oonstack);
#endif
PROC_LOCK(p);
sigexit(td, SIGILL);
}
/*
* Build context to run handler in.
*/
regs->tf_rsp = PTROUT(fp);
regs->tf_rip = LINUX32_PS_STRINGS - *(p->p_sysent->sv_szsigcode) +
linux_sznonrtsigcode;
regs->tf_rflags &= ~(PSL_T | PSL_D);
regs->tf_cs = _ucode32sel;
regs->tf_ss = _udatasel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _ufssel;
regs->tf_gs = _ugssel;
regs->tf_flags = TF_HASSEGS;
td->td_pcb->pcb_full_iret = 1;
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
}
/*
* Send an interrupt to process.
*
* Stack is set up to allow sigcode stored
* in u. to call routine, followed by kcall
* to sigreturn routine below. After sigreturn
* resets the signal mask, the stack, and the
* frame pointer, it returns to the user
* specified pc, psl.
*/
static void
linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct thread *td = curthread;
struct proc *p = td->td_proc;
struct sigacts *psp;
struct trapframe *regs;
struct l_sigframe *fp, frame;
l_sigset_t lmask;
int oonstack, i;
int sig, code;
sig = ksi->ksi_signo;
code = ksi->ksi_code;
PROC_LOCK_ASSERT(p, MA_OWNED);
psp = p->p_sigacts;
mtx_assert(&psp->ps_mtx, MA_OWNED);
if (SIGISMEMBER(psp->ps_siginfo, sig)) {
/* Signal handler installed with SA_SIGINFO. */
linux_rt_sendsig(catcher, ksi, mask);
return;
}
regs = td->td_frame;
oonstack = sigonstack(regs->tf_rsp);
#ifdef DEBUG
if (ldebug(sendsig))
printf(ARGS(sendsig, "%p, %d, %p, %u"),
catcher, sig, (void*)mask, code);
#endif
/*
* Allocate space for the signal handler context.
*/
if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct l_sigframe *)(td->td_sigstk.ss_sp +
td->td_sigstk.ss_size - sizeof(struct l_sigframe));
} else
fp = (struct l_sigframe *)regs->tf_rsp - 1;
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(p);
/*
* Build the argument list for the signal handler.
*/
if (p->p_sysent->sv_sigtbl)
if (sig <= p->p_sysent->sv_sigsize)
sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)];
bzero(&frame, sizeof(frame));
frame.sf_handler = PTROUT(catcher);
frame.sf_sig = sig;
bsd_to_linux_sigset(mask, &lmask);
/*
* Build the signal context to be used by sigreturn.
*/
frame.sf_sc.sc_mask = lmask.__bits[0];
frame.sf_sc.sc_gs = regs->tf_gs;
frame.sf_sc.sc_fs = regs->tf_fs;
frame.sf_sc.sc_es = regs->tf_es;
frame.sf_sc.sc_ds = regs->tf_ds;
frame.sf_sc.sc_edi = regs->tf_rdi;
frame.sf_sc.sc_esi = regs->tf_rsi;
frame.sf_sc.sc_ebp = regs->tf_rbp;
frame.sf_sc.sc_ebx = regs->tf_rbx;
frame.sf_sc.sc_edx = regs->tf_rdx;
frame.sf_sc.sc_ecx = regs->tf_rcx;
frame.sf_sc.sc_eax = regs->tf_rax;
frame.sf_sc.sc_eip = regs->tf_rip;
frame.sf_sc.sc_cs = regs->tf_cs;
frame.sf_sc.sc_eflags = regs->tf_rflags;
frame.sf_sc.sc_esp_at_signal = regs->tf_rsp;
frame.sf_sc.sc_ss = regs->tf_ss;
frame.sf_sc.sc_err = regs->tf_err;
frame.sf_sc.sc_cr2 = (u_int32_t)(uintptr_t)ksi->ksi_addr;
frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code);
for (i = 0; i < (LINUX_NSIG_WORDS-1); i++)
frame.sf_extramask[i] = lmask.__bits[i+1];
if (copyout(&frame, fp, sizeof(frame)) != 0) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
PROC_LOCK(p);
sigexit(td, SIGILL);
}
/*
* Build context to run handler in.
*/
regs->tf_rsp = PTROUT(fp);
regs->tf_rip = LINUX32_PS_STRINGS - *(p->p_sysent->sv_szsigcode);
regs->tf_rflags &= ~(PSL_T | PSL_D);
regs->tf_cs = _ucode32sel;
regs->tf_ss = _udatasel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _ufssel;
regs->tf_gs = _ugssel;
regs->tf_flags = TF_HASSEGS;
td->td_pcb->pcb_full_iret = 1;
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
}
/*
* System call to cleanup state after a signal
* has been taken. Reset signal mask and
* stack state from context left by sendsig (above).
* Return to previous pc and psl as specified by
* context left by sendsig. Check carefully to
* make sure that the user has not modified the
* psl to gain improper privileges or to cause
* a machine fault.
*/
int
linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
{
struct l_sigframe frame;
struct trapframe *regs;
sigset_t bmask;
l_sigset_t lmask;
int eflags, i;
ksiginfo_t ksi;
regs = td->td_frame;
#ifdef DEBUG
if (ldebug(sigreturn))
printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
#endif
/*
* The trampoline code hands us the sigframe.
* It is unsafe to keep track of it ourselves, in the event that a
* program jumps out of a signal handler.
*/
if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
return (EFAULT);
/*
* Check for security violations.
*/
#define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
eflags = frame.sf_sc.sc_eflags;
/*
* XXX do allow users to change the privileged flag PSL_RF. The
* cpu sets PSL_RF in tf_eflags for faults. Debuggers should
* sometimes set it there too. tf_eflags is kept in the signal
* context during signal handling and there is no other place
* to remember it, so the PSL_RF bit may be corrupted by the
* signal handler without us knowing. Corruption of the PSL_RF
* bit at worst causes one more or one less debugger trap, so
* allowing it is fairly harmless.
*/
if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF))
return(EINVAL);
/*
* Don't allow users to load a valid privileged %cs. Let the
* hardware check for invalid selectors, excess privilege in
* other selectors, invalid %eip's and invalid %esp's.
*/
#define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
if (!CS_SECURE(frame.sf_sc.sc_cs)) {
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = SIGBUS;
ksi.ksi_code = BUS_OBJERR;
ksi.ksi_trapno = T_PROTFLT;
ksi.ksi_addr = (void *)regs->tf_rip;
trapsignal(td, &ksi);
return(EINVAL);
}
lmask.__bits[0] = frame.sf_sc.sc_mask;
for (i = 0; i < (LINUX_NSIG_WORDS-1); i++)
lmask.__bits[i+1] = frame.sf_extramask[i];
linux_to_bsd_sigset(&lmask, &bmask);
kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
/*
* Restore signal context.
*/
regs->tf_rdi = frame.sf_sc.sc_edi;
regs->tf_rsi = frame.sf_sc.sc_esi;
regs->tf_rbp = frame.sf_sc.sc_ebp;
regs->tf_rbx = frame.sf_sc.sc_ebx;
regs->tf_rdx = frame.sf_sc.sc_edx;
regs->tf_rcx = frame.sf_sc.sc_ecx;
regs->tf_rax = frame.sf_sc.sc_eax;
regs->tf_rip = frame.sf_sc.sc_eip;
regs->tf_cs = frame.sf_sc.sc_cs;
regs->tf_ds = frame.sf_sc.sc_ds;
regs->tf_es = frame.sf_sc.sc_es;
regs->tf_fs = frame.sf_sc.sc_fs;
regs->tf_gs = frame.sf_sc.sc_gs;
regs->tf_rflags = eflags;
regs->tf_rsp = frame.sf_sc.sc_esp_at_signal;
regs->tf_ss = frame.sf_sc.sc_ss;
td->td_pcb->pcb_full_iret = 1;
return (EJUSTRETURN);
}
/*
* System call to cleanup state after a signal
* has been taken. Reset signal mask and
* stack state from context left by rt_sendsig (above).
* Return to previous pc and psl as specified by
* context left by sendsig. Check carefully to
* make sure that the user has not modified the
* psl to gain improper privileges or to cause
* a machine fault.
*/
int
linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
{
struct l_ucontext uc;
struct l_sigcontext *context;
sigset_t bmask;
l_stack_t *lss;
stack_t ss;
struct trapframe *regs;
int eflags;
ksiginfo_t ksi;
regs = td->td_frame;
#ifdef DEBUG
if (ldebug(rt_sigreturn))
printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
#endif
/*
* The trampoline code hands us the ucontext.
* It is unsafe to keep track of it ourselves, in the event that a
* program jumps out of a signal handler.
*/
if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
return (EFAULT);
context = &uc.uc_mcontext;
/*
* Check for security violations.
*/
#define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
eflags = context->sc_eflags;
/*
* XXX do allow users to change the privileged flag PSL_RF. The
* cpu sets PSL_RF in tf_eflags for faults. Debuggers should
* sometimes set it there too. tf_eflags is kept in the signal
* context during signal handling and there is no other place
* to remember it, so the PSL_RF bit may be corrupted by the
* signal handler without us knowing. Corruption of the PSL_RF
* bit at worst causes one more or one less debugger trap, so
* allowing it is fairly harmless.
*/
if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF))
return(EINVAL);
/*
* Don't allow users to load a valid privileged %cs. Let the
* hardware check for invalid selectors, excess privilege in
* other selectors, invalid %eip's and invalid %esp's.
*/
#define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
if (!CS_SECURE(context->sc_cs)) {
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = SIGBUS;
ksi.ksi_code = BUS_OBJERR;
ksi.ksi_trapno = T_PROTFLT;
ksi.ksi_addr = (void *)regs->tf_rip;
trapsignal(td, &ksi);
return(EINVAL);
}
linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
/*
* Restore signal context
*/
regs->tf_gs = context->sc_gs;
regs->tf_fs = context->sc_fs;
regs->tf_es = context->sc_es;
regs->tf_ds = context->sc_ds;
regs->tf_rdi = context->sc_edi;
regs->tf_rsi = context->sc_esi;
regs->tf_rbp = context->sc_ebp;
regs->tf_rbx = context->sc_ebx;
regs->tf_rdx = context->sc_edx;
regs->tf_rcx = context->sc_ecx;
regs->tf_rax = context->sc_eax;
regs->tf_rip = context->sc_eip;
regs->tf_cs = context->sc_cs;
regs->tf_rflags = eflags;
regs->tf_rsp = context->sc_esp_at_signal;
regs->tf_ss = context->sc_ss;
td->td_pcb->pcb_full_iret = 1;
/*
* call sigaltstack & ignore results..
*/
lss = &uc.uc_stack;
ss.ss_sp = PTRIN(lss->ss_sp);
ss.ss_size = lss->ss_size;
ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
#ifdef DEBUG
if (ldebug(rt_sigreturn))
printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
#endif
(void)kern_sigaltstack(td, &ss, NULL);
return (EJUSTRETURN);
}
static int
linux32_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
{
struct proc *p;
struct trapframe *frame;
p = td->td_proc;
frame = td->td_frame;
sa->args[0] = frame->tf_rbx;
sa->args[1] = frame->tf_rcx;
sa->args[2] = frame->tf_rdx;
sa->args[3] = frame->tf_rsi;
sa->args[4] = frame->tf_rdi;
sa->args[5] = frame->tf_rbp; /* Unconfirmed */
sa->code = frame->tf_rax;
if (sa->code >= p->p_sysent->sv_size)
sa->callp = &p->p_sysent->sv_table[0];
else
sa->callp = &p->p_sysent->sv_table[sa->code];
sa->narg = sa->callp->sy_narg;
td->td_retval[0] = 0;
td->td_retval[1] = frame->tf_rdx;
return (0);
}
/*
* If a linux binary is exec'ing something, try this image activator
* first. We override standard shell script execution in order to
* be able to modify the interpreter path. We only do this if a linux
* binary is doing the exec, so we do not create an EXEC module for it.
*/
static int exec_linux_imgact_try(struct image_params *iparams);
static int
exec_linux_imgact_try(struct image_params *imgp)
{
const char *head = (const char *)imgp->image_header;
char *rpath;
int error = -1;
/*
* The interpreter for shell scripts run from a linux binary needs
* to be located in /compat/linux if possible in order to recursively
* maintain linux path emulation.
*/
if (((const short *)head)[0] == SHELLMAGIC) {
/*
* Run our normal shell image activator. If it succeeds attempt
* to use the alternate path for the interpreter. If an
* alternate * path is found, use our stringspace to store it.
*/
if ((error = exec_shell_imgact(imgp)) == 0) {
linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc),
imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0,
AT_FDCWD);
if (rpath != NULL)
imgp->args->fname_buf =
imgp->interpreter_name = rpath;
}
}
return (error);
}
/*
* Clear registers on exec
* XXX copied from ia32_signal.c.
*/
static void
exec_linux_setregs(struct thread *td, struct image_params *imgp, u_long stack)
{
struct trapframe *regs = td->td_frame;
struct pcb *pcb = td->td_pcb;
mtx_lock(&dt_lock);
if (td->td_proc->p_md.md_ldt != NULL)
user_ldt_free(td);
else
mtx_unlock(&dt_lock);
critical_enter();
wrmsr(MSR_FSBASE, 0);
wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */
pcb->pcb_fsbase = 0;
pcb->pcb_gsbase = 0;
critical_exit();
pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
bzero((char *)regs, sizeof(struct trapframe));
regs->tf_rip = imgp->entry_addr;
regs->tf_rsp = stack;
regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
regs->tf_gs = _ugssel;
regs->tf_fs = _ufssel;
regs->tf_es = _udatasel;
regs->tf_ds = _udatasel;
regs->tf_ss = _udatasel;
regs->tf_flags = TF_HASSEGS;
regs->tf_cs = _ucode32sel;
regs->tf_rbx = imgp->ps_strings;
load_cr0(rcr0() | CR0_MP | CR0_TS);
fpstate_drop(td);
/* Do full restore on return so that we can change to a different %cs */
pcb->pcb_flags |= PCB_32BIT;
pcb->pcb_flags &= ~PCB_GS32BIT;
pcb->pcb_full_iret = 1;
td->td_retval[1] = 0;
}
/*
* XXX copied from ia32_sysvec.c.
*/
static register_t *
linux_copyout_strings(struct image_params *imgp)
{
int argc, envc;
u_int32_t *vectp;
char *stringp, *destp;
u_int32_t *stack_base;
struct linux32_ps_strings *arginfo;
/*
* Calculate string base and vector table pointers.
* Also deal with signal trampoline code for this exec type.
*/
arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
destp = (caddr_t)arginfo - linux_szsigcode - SPARE_USRSPACE -
linux_szplatform - roundup((ARG_MAX - imgp->args->stringspace),
sizeof(char *));
/*
* install sigcode
*/
copyout(imgp->proc->p_sysent->sv_sigcode,
((caddr_t)arginfo - linux_szsigcode), linux_szsigcode);
/*
* Install LINUX_PLATFORM
*/
copyout(linux_platform, ((caddr_t)arginfo - linux_szsigcode -
linux_szplatform), linux_szplatform);
/*
* 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 :
(LINUX_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->args->argc +
imgp->args->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->args->argc +
imgp->args->envc + 2) * sizeof(u_int32_t));
/*
* vectp also becomes our initial stack base
*/
stack_base = vectp;
stringp = imgp->args->begin_argv;
argc = imgp->args->argc;
envc = imgp->args->envc;
/*
* Copy out strings - arguments and environment.
*/
copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
/*
* Fill in "ps_strings" struct for ps, w, etc.
*/
suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp);
suword32(&arginfo->ps_nargvstr, argc);
/*
* Fill in argument portion of vector table.
*/
for (; argc > 0; --argc) {
suword32(vectp++, (uint32_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, (uint32_t)(intptr_t)vectp);
suword32(&arginfo->ps_nenvstr, envc);
/*
* Fill in environment portion of vector table.
*/
for (; envc > 0; --envc) {
suword32(vectp++, (uint32_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);
}
SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW, 0,
"32-bit Linux emulation");
static u_long linux32_maxdsiz = LINUX32_MAXDSIZ;
SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW,
&linux32_maxdsiz, 0, "");
static u_long linux32_maxssiz = LINUX32_MAXSSIZ;
SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW,
&linux32_maxssiz, 0, "");
static u_long linux32_maxvmem = LINUX32_MAXVMEM;
SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW,
&linux32_maxvmem, 0, "");
static void
linux32_fixlimit(struct rlimit *rl, int which)
{
switch (which) {
case RLIMIT_DATA:
if (linux32_maxdsiz != 0) {
if (rl->rlim_cur > linux32_maxdsiz)
rl->rlim_cur = linux32_maxdsiz;
if (rl->rlim_max > linux32_maxdsiz)
rl->rlim_max = linux32_maxdsiz;
}
break;
case RLIMIT_STACK:
if (linux32_maxssiz != 0) {
if (rl->rlim_cur > linux32_maxssiz)
rl->rlim_cur = linux32_maxssiz;
if (rl->rlim_max > linux32_maxssiz)
rl->rlim_max = linux32_maxssiz;
}
break;
case RLIMIT_VMEM:
if (linux32_maxvmem != 0) {
if (rl->rlim_cur > linux32_maxvmem)
rl->rlim_cur = linux32_maxvmem;
if (rl->rlim_max > linux32_maxvmem)
rl->rlim_max = linux32_maxvmem;
}
break;
}
}
struct sysentvec elf_linux_sysvec = {
.sv_size = LINUX_SYS_MAXSYSCALL,
.sv_table = linux_sysent,
.sv_mask = 0,
.sv_sigsize = LINUX_SIGTBLSZ,
.sv_sigtbl = bsd_to_linux_signal,
.sv_errsize = ELAST + 1,
.sv_errtbl = bsd_to_linux_errno,
.sv_transtrap = translate_traps,
.sv_fixup = elf_linux_fixup,
.sv_sendsig = linux_sendsig,
.sv_sigcode = linux_sigcode,
.sv_szsigcode = &linux_szsigcode,
.sv_prepsyscall = NULL,
.sv_name = "Linux ELF32",
.sv_coredump = elf32_coredump,
.sv_imgact_try = exec_linux_imgact_try,
.sv_minsigstksz = LINUX_MINSIGSTKSZ,
.sv_pagesize = PAGE_SIZE,
.sv_minuser = VM_MIN_ADDRESS,
.sv_maxuser = LINUX32_USRSTACK,
.sv_usrstack = LINUX32_USRSTACK,
.sv_psstrings = LINUX32_PS_STRINGS,
.sv_stackprot = VM_PROT_ALL,
.sv_copyout_strings = linux_copyout_strings,
.sv_setregs = exec_linux_setregs,
.sv_fixlimit = linux32_fixlimit,
.sv_maxssiz = &linux32_maxssiz,
.sv_flags = SV_ABI_LINUX | SV_ILP32 | SV_IA32,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = linux32_fetch_syscall_args,
.sv_syscallnames = NULL,
};
static char GNU_ABI_VENDOR[] = "GNU";
static int GNULINUX_ABI_DESC = 0;
static boolean_t
linux32_trans_osrel(const Elf_Note *note, int32_t *osrel)
{
const Elf32_Word *desc;
uintptr_t p;
p = (uintptr_t)(note + 1);
p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
desc = (const Elf32_Word *)p;
if (desc[0] != GNULINUX_ABI_DESC)
return (FALSE);
/*
* For linux we encode osrel as follows (see linux_mib.c):
* VVVMMMIII (version, major, minor), see linux_mib.c.
*/
*osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
return (TRUE);
}
static Elf_Brandnote linux32_brandnote = {
.hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
.hdr.n_descsz = 16, /* XXX at least 16 */
.hdr.n_type = 1,
.vendor = GNU_ABI_VENDOR,
.flags = BN_TRANSLATE_OSREL,
.trans_osrel = linux32_trans_osrel
};
static Elf32_Brandinfo linux_brand = {
.brand = ELFOSABI_LINUX,
.machine = EM_386,
.compat_3_brand = "Linux",
.emul_path = "/compat/linux",
.interp_path = "/lib/ld-linux.so.1",
.sysvec = &elf_linux_sysvec,
.interp_newpath = NULL,
.brand_note = &linux32_brandnote,
.flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
static Elf32_Brandinfo linux_glibc2brand = {
.brand = ELFOSABI_LINUX,
.machine = EM_386,
.compat_3_brand = "Linux",
.emul_path = "/compat/linux",
.interp_path = "/lib/ld-linux.so.2",
.sysvec = &elf_linux_sysvec,
.interp_newpath = NULL,
.brand_note = &linux32_brandnote,
.flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
Elf32_Brandinfo *linux_brandlist[] = {
&linux_brand,
&linux_glibc2brand,
NULL
};
static int
linux_elf_modevent(module_t mod, int type, void *data)
{
Elf32_Brandinfo **brandinfo;
int error;
struct linux_ioctl_handler **lihp;
struct linux_device_handler **ldhp;
error = 0;
switch(type) {
case MOD_LOAD:
for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
++brandinfo)
if (elf32_insert_brand_entry(*brandinfo) < 0)
error = EINVAL;
if (error == 0) {
SET_FOREACH(lihp, linux_ioctl_handler_set)
linux_ioctl_register_handler(*lihp);
SET_FOREACH(ldhp, linux_device_handler_set)
linux_device_register_handler(*ldhp);
mtx_init(&emul_lock, "emuldata lock", NULL, MTX_DEF);
sx_init(&emul_shared_lock, "emuldata->shared lock");
LIST_INIT(&futex_list);
mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
linux_exit_tag = EVENTHANDLER_REGISTER(process_exit,
linux_proc_exit, NULL, 1000);
linux_schedtail_tag = EVENTHANDLER_REGISTER(schedtail,
linux_schedtail, NULL, 1000);
linux_exec_tag = EVENTHANDLER_REGISTER(process_exec,
linux_proc_exec, NULL, 1000);
linux_szplatform = roundup(strlen(linux_platform) + 1,
sizeof(char *));
linux_osd_jail_register();
stclohz = (stathz ? stathz : hz);
if (bootverbose)
printf("Linux ELF exec handler installed\n");
} else
printf("cannot insert Linux ELF brand handler\n");
break;
case MOD_UNLOAD:
for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
++brandinfo)
if (elf32_brand_inuse(*brandinfo))
error = EBUSY;
if (error == 0) {
for (brandinfo = &linux_brandlist[0];
*brandinfo != NULL; ++brandinfo)
if (elf32_remove_brand_entry(*brandinfo) < 0)
error = EINVAL;
}
if (error == 0) {
SET_FOREACH(lihp, linux_ioctl_handler_set)
linux_ioctl_unregister_handler(*lihp);
SET_FOREACH(ldhp, linux_device_handler_set)
linux_device_unregister_handler(*ldhp);
mtx_destroy(&emul_lock);
sx_destroy(&emul_shared_lock);
mtx_destroy(&futex_mtx);
EVENTHANDLER_DEREGISTER(process_exit, linux_exit_tag);
EVENTHANDLER_DEREGISTER(schedtail, linux_schedtail_tag);
EVENTHANDLER_DEREGISTER(process_exec, linux_exec_tag);
linux_osd_jail_deregister();
if (bootverbose)
printf("Linux ELF exec handler removed\n");
} else
printf("Could not deinstall ELF interpreter entry\n");
break;
default:
return EOPNOTSUPP;
}
return error;
}
static moduledata_t linux_elf_mod = {
"linuxelf",
linux_elf_modevent,
0
};
DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
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