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8b9d6e94af
freebsd/sys/i386/linux/linux_sysvec.c
Andrew Gallatin 2c4ab9ddfa Make linux_sendsig and linux_sigreturn use all 64 bits of a 
linux_sigset_t by updating the linux_sigframe struct so as to include
linux's "extramask" field.  This field contains the upper 32-bits of
the sigset.  extramask sits behind a linux_fpstate struct, which I've
defined primarily for padding purposes.

While we're here, define LINUX_NSIG in terms of LINUX_NBPW (32) and
LINUX_NSIG_WORDS (2).

This fixes problems where threaded apps would accumulate a large
number of zombies.  This was happening because the exit signal resides
in the upper 32-bits of the sigset and was never getting unmasked by
the manager thread after the first child exited.

PR: 		misc/18530  (may be related, originator not yet contacted)
Reviewed by:	marcel
2000-11-13 20:44:05 +00:00

833 lines
24 KiB
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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 withough 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.
*
* $FreeBSD$
*/
/* XXX we use functions that might not exist. */
#include "opt_compat.h"
#ifndef COMPAT_43
#error "Unable to compile Linux-emulator due to missing COMPAT_43 option!"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/sysproto.h>
#include <sys/sysent.h>
#include <sys/imgact.h>
#include <sys/imgact_aout.h>
#include <sys/imgact_elf.h>
#include <sys/signalvar.h>
#include <sys/malloc.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_page.h>
#include <vm/vm_extern.h>
#include <sys/exec.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <machine/cpu.h>
#include <i386/linux/linux.h>
#include <i386/linux/linux_proto.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
extern char linux_sigcode[];
extern int linux_szsigcode;
extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
extern struct linker_set linux_ioctl_handler_set;
static int linux_fixup __P((register_t **stack_base,
struct image_params *iparams));
static int elf_linux_fixup __P((register_t **stack_base,
struct image_params *iparams));
static void linux_prepsyscall __P((struct trapframe *tf, int *args,
u_int *code, caddr_t *params));
static void linux_sendsig __P((sig_t catcher, int sig, sigset_t *mask,
u_long code));
/*
* Linux syscalls return negative errno's, we do positive and map them
*/
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, -6, -84
};
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, 0,
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, 0
};
/*
* If FreeBSD & Linux have a difference of opinion about what a trap
* means, deal with it here.
*/
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->argc + 1);
(*stack_base)--;
**stack_base = (intptr_t)(void *)envp;
(*stack_base)--;
**stack_base = (intptr_t)(void *)argv;
(*stack_base)--;
**stack_base = imgp->argc;
return 0;
}
static int
elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
{
Elf32_Auxargs *args = (Elf32_Auxargs *)imgp->auxargs;
register_t *pos;
pos = *stack_base + (imgp->argc + imgp->envc + 2);
if (args->trace) {
AUXARGS_ENTRY(pos, AT_DEBUG, 1);
}
if (args->execfd != -1) {
AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
}
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, AT_UID, imgp->proc->p_cred->p_ruid);
AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_cred->p_svuid);
AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_cred->p_rgid);
AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_cred->p_svgid);
AUXARGS_ENTRY(pos, AT_NULL, 0);
free(imgp->auxargs, M_TEMP);
imgp->auxargs = NULL;
(*stack_base)--;
**stack_base = (long)imgp->argc;
return 0;
}
extern int _ucodesel, _udatasel;
extern unsigned long _linux_sznonrtsigcode;
static void
linux_rt_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
{
register struct proc *p = curproc;
register struct trapframe *regs;
struct linux_rt_sigframe *fp, frame;
struct sigacts *psp = p->p_sigacts;
int oonstack;
regs = p->p_md.md_regs;
oonstack = p->p_sigstk.ss_flags & SS_ONSTACK;
#ifdef DEBUG
printf("Linux-emul(%ld): linux_rt_sendsig(%p, %d, %p, %lu)\n",
(long)p->p_pid, catcher, sig, (void*)mask, code);
#endif
/*
* Allocate space for the signal handler context.
*/
if ((p->p_flag & P_ALTSTACK) && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct linux_rt_sigframe *)(p->p_sigstk.ss_sp +
p->p_sigstk.ss_size - sizeof(struct linux_rt_sigframe));
p->p_sigstk.ss_flags |= SS_ONSTACK;
} else {
fp = (struct linux_rt_sigframe *)regs->tf_esp - 1;
}
/*
* grow() will return FALSE if the fp will not fit inside the stack
* and the stack can not be grown. useracc will return FALSE
* if access is denied.
*/
if ((grow_stack (p, (int)fp) == FALSE) ||
!useracc((caddr_t)fp, sizeof (struct linux_rt_sigframe),
VM_PROT_WRITE)) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
SIGACTION(p, SIGILL) = SIG_DFL;
SIGDELSET(p->p_sigignore, SIGILL);
SIGDELSET(p->p_sigcatch, SIGILL);
SIGDELSET(p->p_sigmask, SIGILL);
#ifdef DEBUG
printf("Linux-emul(%ld): linux_rt_sendsig -- bad stack %p, SS_ONSTACK: 0x%x ",
(long)p->p_pid, fp, p->p_sigstk.ss_flags & SS_ONSTACK);
#endif
psignal(p, SIGILL);
return;
}
/*
* 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)];
frame.sf_handler = catcher;
frame.sf_sig = sig;
frame.sf_siginfo = &fp->sf_si;
frame.sf_ucontext = &fp->sf_sc;
/* Fill siginfo structure. */
frame.sf_si.lsi_signo = sig;
frame.sf_si.lsi_code = code;
frame.sf_si.lsi_addr = (void *)regs->tf_err;
/*
* Build the signal context to be used by sigreturn.
*/
frame.sf_sc.uc_mcontext.sc_mask = mask->__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_trapno = code; /* XXX ???? */
/*
* Build the remainder of the ucontext struct 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 = p->p_sigstk.ss_sp;
frame.sf_sc.uc_stack.ss_flags =
bsd_to_linux_sigaltstack(p->p_sigstk.ss_flags);
frame.sf_sc.uc_stack.ss_size = p->p_sigstk.ss_size;
#ifdef DEBUG
printf("Linux-emul(%ld): rt_sendsig flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x\n",
(long)p->p_pid, frame.sf_sc.uc_stack.ss_flags, p->p_sigstk.ss_sp,
p->p_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
#endif
bsd_to_linux_sigset(&p->p_sigmask, &frame.sf_sc.uc_sigmask);
if (copyout(&frame, fp, sizeof(frame)) != 0) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
sigexit(p, SIGILL);
/* NOTREACHED */
}
/*
* 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_VM;
regs->tf_cs = _ucodesel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _udatasel;
load_gs(_udatasel);
regs->tf_ss = _udatasel;
}
/*
* 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, int sig, sigset_t *mask, u_long code)
{
register struct proc *p = curproc;
register struct trapframe *regs;
struct linux_sigframe *fp, frame;
struct sigacts *psp = p->p_sigacts;
int oonstack, i;
regs = p->p_md.md_regs;
oonstack = p->p_sigstk.ss_flags & SS_ONSTACK;
#ifdef DEBUG
printf("Linux-emul(%ld): linux_sendsig(%p, %d, %p, %lu)\n",
(long)p->p_pid, catcher, sig, (void*)mask, code);
#endif
if (SIGISMEMBER(p->p_sigacts->ps_siginfo, sig)) {
/* Signal handler installed with SA_SIGINFO. */
linux_rt_sendsig(catcher, sig, mask, code);
return;
}
/*
* Allocate space for the signal handler context.
*/
if ((p->p_flag & P_ALTSTACK) && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct linux_sigframe *)(p->p_sigstk.ss_sp +
p->p_sigstk.ss_size - sizeof(struct linux_sigframe));
p->p_sigstk.ss_flags |= SS_ONSTACK;
} else {
fp = (struct linux_sigframe *)regs->tf_esp - 1;
}
/*
* grow() will return FALSE if the fp will not fit inside the stack
* and the stack can not be grown. useracc will return FALSE
* if access is denied.
*/
if ((grow_stack (p, (int)fp) == FALSE) ||
!useracc((caddr_t)fp, sizeof (struct linux_sigframe),
VM_PROT_WRITE)) {
/*
* Process has trashed its stack; give it an illegal
* instruction to halt it in its tracks.
*/
SIGACTION(p, SIGILL) = SIG_DFL;
SIGDELSET(p->p_sigignore, SIGILL);
SIGDELSET(p->p_sigcatch, SIGILL);
SIGDELSET(p->p_sigmask, SIGILL);
psignal(p, SIGILL);
return;
}
/*
* 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)];
frame.sf_handler = catcher;
frame.sf_sig = sig;
/*
* Build the signal context to be used by sigreturn.
*/
frame.sf_sc.sc_mask = mask->__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_trapno = code; /* XXX ???? */
bzero(&frame.fpstate, sizeof(struct linux_fpstate));
for (i = 0; i < (LINUX_NSIG_WORDS-1); i++)
frame.extramask[i] = mask->__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.
*/
sigexit(p, SIGILL);
/* NOTREACHED */
}
/*
* 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_VM;
regs->tf_cs = _ucodesel;
regs->tf_ds = _udatasel;
regs->tf_es = _udatasel;
regs->tf_fs = _udatasel;
load_gs(_udatasel);
regs->tf_ss = _udatasel;
}
/*
* 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(p, args)
struct proc *p;
struct linux_sigreturn_args *args;
{
struct linux_sigcontext context;
register struct trapframe *regs;
u_int extramask[LINUX_NSIG_WORDS-1];
u_int *emp;
int eflags, i;
regs = p->p_md.md_regs;
#ifdef DEBUG
printf("Linux-emul(%ld): linux_sigreturn(%p)\n",
(long)p->p_pid, (void *)args->scp);
#endif
/*
* The trampoline code hands us the context.
* It is unsafe to keep track of it ourselves, in the event that a
* program jumps out of a signal handler.
*/
if (copyin((caddr_t)args->scp, &context, sizeof(context)) != 0)
return (EFAULT);
/*
* 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)) {
trapsignal(p, SIGBUS, T_PROTFLT);
return(EINVAL);
}
p->p_sigstk.ss_flags &= ~SS_ONSTACK;
emp = (u_int *)((caddr_t)args->scp + sizeof(context) +
sizeof(struct linux_fpstate));
if (copyin((caddr_t)emp, extramask, sizeof(extramask)) == 0)
for (i = 0; i < (LINUX_NSIG_WORDS-1); i++)
p->p_sigmask.__bits[i+1] = extramask[i];
SIGSETOLD(p->p_sigmask, context.sc_mask);
SIG_CANTMASK(p->p_sigmask);
/*
* 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;
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(p, args)
struct proc *p;
struct linux_rt_sigreturn_args *args;
{
struct sigaltstack_args sasargs;
struct linux_ucontext uc;
struct linux_sigcontext *context;
linux_stack_t *lss;
stack_t *ss;
register struct trapframe *regs;
int eflags;
caddr_t sg = stackgap_init();
regs = p->p_md.md_regs;
#ifdef DEBUG
printf("Linux-emul(%ld): linux_rt_sigreturn(%p)\n",
(long)p->p_pid, (void *)args->ucp);
#endif
/*
* The trampoline code hands us the u_context.
* It is unsafe to keep track of it ourselves, in the event that a
* program jumps out of a signal handler.
*/
if (copyin((caddr_t)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)) {
trapsignal(p, SIGBUS, T_PROTFLT);
return(EINVAL);
}
p->p_sigstk.ss_flags &= ~SS_ONSTACK;
SIGSETOLD(p->p_sigmask, context->sc_mask);
SIG_CANTMASK(p->p_sigmask);
/*
* 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..
*/
ss = stackgap_alloc(&sg, sizeof(stack_t));
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
printf("Linux-emul(%ld): rt_sigret flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x\n",
(long)p->p_pid, ss->ss_flags, ss->ss_sp, ss->ss_size, context->sc_mask);
#endif
sasargs.ss = ss;
sasargs.oss = NULL;
(void) sigaltstack(p, &sasargs);
return (EJUSTRETURN);
}
static void
linux_prepsyscall(struct trapframe *tf, int *args, u_int *code, caddr_t *params)
{
args[0] = tf->tf_ebx;
args[1] = tf->tf_ecx;
args[2] = tf->tf_edx;
args[3] = tf->tf_esi;
args[4] = tf->tf_edi;
*params = NULL; /* no copyin */
}
/*
* 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 __P((struct image_params *iparams));
static int
exec_linux_imgact_try(imgp)
struct image_params *imgp;
{
const char *head = (const char *)imgp->image_header;
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) {
char *rpath = NULL;
linux_emul_find(imgp->proc, NULL, linux_emul_path,
imgp->interpreter_name, &rpath, 0);
if (rpath != imgp->interpreter_name) {
int len = strlen(rpath) + 1;
if (len <= MAXSHELLCMDLEN) {
memcpy(imgp->interpreter_name, rpath, len);
}
free(rpath, M_TEMP);
}
}
}
return(error);
}
struct sysentvec linux_sysvec = {
LINUX_SYS_MAXSYSCALL,
linux_sysent,
0xff,
LINUX_SIGTBLSZ,
bsd_to_linux_signal,
ELAST + 1,
bsd_to_linux_errno,
translate_traps,
linux_fixup,
linux_sendsig,
linux_sigcode,
&linux_szsigcode,
linux_prepsyscall,
"Linux a.out",
aout_coredump,
exec_linux_imgact_try,
LINUX_MINSIGSTKSZ
};
struct sysentvec elf_linux_sysvec = {
LINUX_SYS_MAXSYSCALL,
linux_sysent,
0xff,
LINUX_SIGTBLSZ,
bsd_to_linux_signal,
ELAST + 1,
bsd_to_linux_errno,
translate_traps,
elf_linux_fixup,
linux_sendsig,
linux_sigcode,
&linux_szsigcode,
linux_prepsyscall,
"Linux ELF",
elf_coredump,
exec_linux_imgact_try,
LINUX_MINSIGSTKSZ
};
static Elf32_Brandinfo linux_brand = {
ELFOSABI_LINUX,
"/compat/linux",
"/lib/ld-linux.so.1",
&elf_linux_sysvec
};
static Elf32_Brandinfo linux_glibc2brand = {
ELFOSABI_LINUX,
"/compat/linux",
"/lib/ld-linux.so.2",
&elf_linux_sysvec
};
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;
error = 0;
switch(type) {
case MOD_LOAD:
for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
++brandinfo)
if (elf_insert_brand_entry(*brandinfo) < 0)
error = EINVAL;
if (error)
printf("cannot insert Linux elf brand handler\n");
else {
linux_ioctl_register_handlers(&linux_ioctl_handler_set);
if (bootverbose)
printf("Linux-ELF exec handler installed\n");
}
break;
case MOD_UNLOAD:
linux_ioctl_unregister_handlers(&linux_ioctl_handler_set);
for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
++brandinfo)
if (elf_brand_inuse(*brandinfo))
error = EBUSY;
if (error == 0) {
for (brandinfo = &linux_brandlist[0];
*brandinfo != NULL; ++brandinfo)
if (elf_remove_brand_entry(*brandinfo) < 0)
error = EINVAL;
}
if (error)
printf("Could not deinstall ELF interpreter entry\n");
else if (bootverbose)
printf("Linux-elf exec handler removed\n");
break;
default:
break;
}
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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