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freebsd-dev/sys/i386/linux/linux_sysvec.c
Konstantin Belousov afe1a68827 Reorganize syscall entry and leave handling. 
Extend struct sysvec with three new elements:
sv_fetch_syscall_args - the method to fetch syscall arguments from
  usermode into struct syscall_args. The structure is machine-depended
  (this might be reconsidered after all architectures are converted).
sv_set_syscall_retval - the method to set a return value for usermode
  from the syscall. It is a generalization of
  cpu_set_syscall_retval(9) to allow ABIs to override the way to set a
  return value.
sv_syscallnames - the table of syscall names.

Use sv_set_syscall_retval in kern_sigsuspend() instead of hardcoding
the call to cpu_set_syscall_retval().

The new functions syscallenter(9) and syscallret(9) are provided that
use sv_*syscall* pointers and contain the common repeated code from
the syscall() implementations for the architecture-specific syscall
trap handlers.

Syscallenter() fetches arguments, calls syscall implementation from
ABI sysent table, and set up return frame. The end of syscall
bookkeeping is done by syscallret().

Take advantage of single place for MI syscall handling code and
implement ptrace_lwpinfo pl_flags PL_FLAG_SCE, PL_FLAG_SCX and
PL_FLAG_EXEC. The SCE and SCX flags notify the debugger that the
thread is stopped at syscall entry or return point respectively.  The
EXEC flag augments SCX and notifies debugger that the process address
space was changed by one of exec(2)-family syscalls.

The i386, amd64, sparc64, sun4v, powerpc and ia64 syscall()s are
changed to use syscallenter()/syscallret(). MIPS and arm are not
converted and use the mostly unchanged syscall() implementation.

Reviewed by:	jhb, marcel, marius, nwhitehorn, stas
Tested by:	marcel (ia64), marius (sparc64), nwhitehorn (powerpc),
	stas (mips)
MFC after:	1 month
2010-05-23 18:32:02 +00:00

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/*-
* 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/imgact_aout.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/signalvar.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/cputypes.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <i386/linux/linux.h>
#include <i386/linux/linux_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");
#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
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 linux_fixup(register_t **stack_base,
struct image_params *iparams);
static int elf_linux_fixup(register_t **stack_base,
struct image_params *iparams);
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 register_t *linux_copyout_strings(struct image_params *imgp);
static boolean_t linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
static int linux_szplatform;
const char *linux_platform;
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)
/*
* 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
linux_fixup(register_t **stack_base, struct image_params *imgp)
{
register_t *argv, *envp;
argv = *stack_base;
envp = *stack_base + (imgp->args->argc + 1);
(*stack_base)--;
**stack_base = (intptr_t)(void *)envp;
(*stack_base)--;
**stack_base = (intptr_t)(void *)argv;
(*stack_base)--;
**stack_base = imgp->args->argc;
return (0);
}
static int
elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
{
struct proc *p;
Elf32_Auxargs *args;
Elf32_Addr *uplatform;
struct ps_strings *arginfo;
register_t *pos;
KASSERT(curthread->td_proc == imgp->proc,
("unsafe elf_linux_fixup(), should be curproc"));
p = imgp->proc;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szsigcode -
linux_szplatform);
args = (Elf32_Auxargs *)imgp->auxargs;
pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
AUXARGS_ENTRY(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(pos, LINUX_AT_CLKTCK, stclohz);
AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
AUXARGS_ENTRY(pos, AT_BASE, args->base);
AUXARGS_ENTRY(pos, LINUX_AT_SECURE, 0);
AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(uplatform));
if (args->execfd != -1)
AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
AUXARGS_ENTRY(pos, AT_NULL, 0);
free(imgp->auxargs, M_TEMP);
imgp->auxargs = NULL;
(*stack_base)--;
**stack_base = (register_t)imgp->args->argc;
return (0);
}
/*
* Copied from kern/kern_exec.c
*/
static register_t *
linux_copyout_strings(struct image_params *imgp)
{
int argc, envc;
char **vectp;
char *stringp, *destp;
register_t *stack_base;
struct ps_strings *arginfo;
struct proc *p;
/*
* Calculate string base and vector table pointers.
* Also deal with signal trampoline code for this exec type.
*/
p = imgp->proc;
arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
destp = (caddr_t)arginfo - linux_szsigcode - SPARE_USRSPACE -
linux_szplatform - roundup((ARG_MAX - imgp->args->stringspace),
sizeof(char *));
/*
* install sigcode
*/
copyout(p->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 = (char **)(destp - (imgp->args->argc +
imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *));
} else {
/*
* The '+ 2' is for the null pointers at the end of each of
* the arg and env vector sets
*/
vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc + 2) *
sizeof(char *));
}
/*
* vectp also becomes our initial stack base
*/
stack_base = (register_t *)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.
*/
suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
suword(&arginfo->ps_nargvstr, argc);
/*
* Fill in argument portion of vector table.
*/
for (; argc > 0; --argc) {
suword(vectp++, (long)(intptr_t)destp);
while (*stringp++ != 0)
destp++;
destp++;
}
/* a null vector table pointer separates the argp's from the envp's */
suword(vectp++, 0);
suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
suword(&arginfo->ps_nenvstr, envc);
/*
* Fill in environment portion of vector table.
*/
for (; envc > 0; --envc) {
suword(vectp++, (long)(intptr_t)destp);
while (*stringp++ != 0)
destp++;
destp++;
}
/* end of vector table is a null pointer */
suword(vectp, 0);
return (stack_base);
}
extern int _ucodesel, _udatasel;
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 sig, code;
int oonstack;
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_esp);
#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_esp - 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 = catcher;
frame.sf_sig = sig;
frame.sf_siginfo = &fp->sf_si;
frame.sf_ucontext = &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 = NULL; /* XXX ??? */
frame.sf_sc.uc_stack.ss_sp = 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_gs = rgs();
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_edi = regs->tf_edi;
frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi;
frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp;
frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx;
frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx;
frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx;
frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax;
frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip;
frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
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 = (register_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%x, 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_esp = (int)fp;
regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode) +
linux_sznonrtsigcode;
regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
regs->tf_cs = _ucodesel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _udatasel;
regs->tf_ss = _udatasel;
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 sig, code;
int oonstack, i;
PROC_LOCK_ASSERT(p, MA_OWNED);
psp = p->p_sigacts;
sig = ksi->ksi_signo;
code = ksi->ksi_code;
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_esp);
#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_esp - 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 = 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 = rgs();
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_edi;
frame.sf_sc.sc_esi = regs->tf_esi;
frame.sf_sc.sc_ebp = regs->tf_ebp;
frame.sf_sc.sc_ebx = regs->tf_ebx;
frame.sf_sc.sc_edx = regs->tf_edx;
frame.sf_sc.sc_ecx = regs->tf_ecx;
frame.sf_sc.sc_eax = regs->tf_eax;
frame.sf_sc.sc_eip = regs->tf_eip;
frame.sf_sc.sc_cs = regs->tf_cs;
frame.sf_sc.sc_eflags = regs->tf_eflags;
frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
frame.sf_sc.sc_ss = regs->tf_ss;
frame.sf_sc.sc_err = regs->tf_err;
frame.sf_sc.sc_cr2 = (register_t)ksi->ksi_addr;
frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno);
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_esp = (int)fp;
regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
regs->tf_cs = _ucodesel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _udatasel;
regs->tf_ss = _udatasel;
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;
l_sigset_t lmask;
sigset_t bmask;
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_eflags & ~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_eip;
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.
*/
/* %gs was restored by the trampoline. */
regs->tf_fs = frame.sf_sc.sc_fs;
regs->tf_es = frame.sf_sc.sc_es;
regs->tf_ds = frame.sf_sc.sc_ds;
regs->tf_edi = frame.sf_sc.sc_edi;
regs->tf_esi = frame.sf_sc.sc_esi;
regs->tf_ebp = frame.sf_sc.sc_ebp;
regs->tf_ebx = frame.sf_sc.sc_ebx;
regs->tf_edx = frame.sf_sc.sc_edx;
regs->tf_ecx = frame.sf_sc.sc_ecx;
regs->tf_eax = frame.sf_sc.sc_eax;
regs->tf_eip = frame.sf_sc.sc_eip;
regs->tf_cs = frame.sf_sc.sc_cs;
regs->tf_eflags = eflags;
regs->tf_esp = frame.sf_sc.sc_esp_at_signal;
regs->tf_ss = frame.sf_sc.sc_ss;
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_eflags & ~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_eip;
trapsignal(td, &ksi);
return(EINVAL);
}
linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
/*
* Restore signal context
*/
/* %gs was restored by the trampoline. */
regs->tf_fs = context->sc_fs;
regs->tf_es = context->sc_es;
regs->tf_ds = context->sc_ds;
regs->tf_edi = context->sc_edi;
regs->tf_esi = context->sc_esi;
regs->tf_ebp = context->sc_ebp;
regs->tf_ebx = context->sc_ebx;
regs->tf_edx = context->sc_edx;
regs->tf_ecx = context->sc_ecx;
regs->tf_eax = context->sc_eax;
regs->tf_eip = context->sc_eip;
regs->tf_cs = context->sc_cs;
regs->tf_eflags = eflags;
regs->tf_esp = context->sc_esp_at_signal;
regs->tf_ss = context->sc_ss;
/*
* call sigaltstack & ignore results..
*/
lss = &uc.uc_stack;
ss.ss_sp = 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%x, 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
linux_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->code = frame->tf_eax;
sa->args[0] = frame->tf_ebx;
sa->args[1] = frame->tf_ecx;
sa->args[2] = frame->tf_edx;
sa->args[3] = frame->tf_esi;
sa->args[4] = frame->tf_edi;
sa->args[5] = frame->tf_ebp; /* Unconfirmed */
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_edx;
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, len;
/*
* 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) {
len = strlen(rpath) + 1;
if (len <= MAXSHELLCMDLEN) {
memcpy(imgp->interpreter_name, rpath, len);
}
free(rpath, M_TEMP);
}
}
}
return(error);
}
/*
* exec_setregs may initialize some registers differently than Linux
* does, thus potentially confusing Linux binaries. If necessary, we
* override the exec_setregs default(s) here.
*/
static void
exec_linux_setregs(struct thread *td, struct image_params *imgp, u_long stack)
{
struct pcb *pcb = td->td_pcb;
exec_setregs(td, imgp, stack);
/* Linux sets %gs to 0, we default to _udatasel */
pcb->pcb_gs = 0;
load_gs(0);
pcb->pcb_initial_npxcw = __LINUX_NPXCW__;
}
static void
linux_get_machine(const char **dst)
{
switch (cpu_class) {
case CPUCLASS_686:
*dst = "i686";
break;
case CPUCLASS_586:
*dst = "i586";
break;
case CPUCLASS_486:
*dst = "i486";
break;
default:
*dst = "i386";
}
}
struct sysentvec 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 = linux_fixup,
.sv_sendsig = linux_sendsig,
.sv_sigcode = linux_sigcode,
.sv_szsigcode = &linux_szsigcode,
.sv_prepsyscall = NULL,
.sv_name = "Linux a.out",
.sv_coredump = NULL,
.sv_imgact_try = exec_linux_imgact_try,
.sv_minsigstksz = LINUX_MINSIGSTKSZ,
.sv_pagesize = PAGE_SIZE,
.sv_minuser = VM_MIN_ADDRESS,
.sv_maxuser = VM_MAXUSER_ADDRESS,
.sv_usrstack = USRSTACK,
.sv_psstrings = PS_STRINGS,
.sv_stackprot = VM_PROT_ALL,
.sv_copyout_strings = exec_copyout_strings,
.sv_setregs = exec_linux_setregs,
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = linux_fetch_syscall_args,
.sv_syscallnames = NULL,
};
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 ELF",
.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 = VM_MAXUSER_ADDRESS,
.sv_usrstack = USRSTACK,
.sv_psstrings = PS_STRINGS,
.sv_stackprot = VM_PROT_ALL,
.sv_copyout_strings = linux_copyout_strings,
.sv_setregs = exec_linux_setregs,
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_LINUX | SV_IA32 | SV_ILP32,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = linux_fetch_syscall_args,
.sv_syscallnames = NULL,
};
static char GNU_ABI_VENDOR[] = "GNU";
static int GNULINUX_ABI_DESC = 0;
static boolean_t
linux_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 linux_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 = linux_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 = &linux_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 = &linux_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_get_machine(&linux_platform);
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(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
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