2 * Copyright (c) 1994-1996 Søren Schmidt
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software withough specific prior written permission
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 * $FreeBSD: src/sys/i386/linux/linux_sysvec.c,v 1.55.2.9 2002/01/12 11:03:30 bde Exp $
29 * $DragonFly: src/sys/emulation/linux/i386/linux_sysvec.c,v 1.31 2008/04/21 15:47:53 dillon Exp $
32 /* XXX we use functions that might not exist. */
33 #include "opt_compat.h"
36 #error "Unable to compile Linux-emulator due to missing COMPAT_43 option!"
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/imgact.h>
42 #include <sys/imgact_aout.h>
43 #include <sys/imgact_elf.h>
44 #include <sys/kern_syscall.h>
46 #include <sys/malloc.h>
48 #include <sys/signalvar.h>
49 #include <sys/sysent.h>
50 #include <sys/sysproto.h>
53 #include <vm/vm_param.h>
54 #include <vm/vm_page.h>
55 #include <vm/vm_extern.h>
57 #include <sys/kernel.h>
58 #include <sys/module.h>
59 #include <machine/cpu.h>
62 #include "linux_proto.h"
63 #include "../linux_signal.h"
64 #include "../linux_util.h"
66 MODULE_VERSION(linux, 1);
68 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
70 #if BYTE_ORDER == LITTLE_ENDIAN
71 #define SHELLMAGIC 0x2123 /* #! */
73 #define SHELLMAGIC 0x2321
77 * Allow the sendsig functions to use the ldebug() facility
78 * even though they are not syscalls themselves. Map them
79 * to syscall 0. This is slightly less bogus than using
82 #define LINUX_SYS_linux_rt_sendsig 0
83 #define LINUX_SYS_linux_sendsig 0
85 extern char linux_sigcode[];
86 extern int linux_szsigcode;
88 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
90 static int linux_fixup (register_t **stack_base,
91 struct image_params *iparams);
92 static int elf_linux_fixup (register_t **stack_base,
93 struct image_params *iparams);
94 static void linux_prepsyscall (struct trapframe *tf, int *args,
95 u_int *code, caddr_t *params);
96 static void linux_sendsig (sig_t catcher, int sig, sigset_t *mask,
100 * Linux syscalls return negative errno's, we do positive and map them
102 static int bsd_to_linux_errno[ELAST + 1] = {
103 -0, -1, -2, -3, -4, -5, -6, -7, -8, -9,
104 -10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
105 -20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
106 -30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
107 -90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
108 -100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
109 -110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
110 -116, -66, -6, -6, -6, -6, -6, -37, -38, -9,
111 -6, -6, -43, -42, -75, -6, -84
114 int bsd_to_linux_signal[LINUX_SIGTBLSZ] = {
115 LINUX_SIGHUP, LINUX_SIGINT, LINUX_SIGQUIT, LINUX_SIGILL,
116 LINUX_SIGTRAP, LINUX_SIGABRT, 0, LINUX_SIGFPE,
117 LINUX_SIGKILL, LINUX_SIGBUS, LINUX_SIGSEGV, 0,
118 LINUX_SIGPIPE, LINUX_SIGALRM, LINUX_SIGTERM, LINUX_SIGURG,
119 LINUX_SIGSTOP, LINUX_SIGTSTP, LINUX_SIGCONT, LINUX_SIGCHLD,
120 LINUX_SIGTTIN, LINUX_SIGTTOU, LINUX_SIGIO, LINUX_SIGXCPU,
121 LINUX_SIGXFSZ, LINUX_SIGVTALRM, LINUX_SIGPROF, LINUX_SIGWINCH,
122 0, LINUX_SIGUSR1, LINUX_SIGUSR2
125 int linux_to_bsd_signal[LINUX_SIGTBLSZ] = {
126 SIGHUP, SIGINT, SIGQUIT, SIGILL,
127 SIGTRAP, SIGABRT, SIGBUS, SIGFPE,
128 SIGKILL, SIGUSR1, SIGSEGV, SIGUSR2,
129 SIGPIPE, SIGALRM, SIGTERM, SIGBUS,
130 SIGCHLD, SIGCONT, SIGSTOP, SIGTSTP,
131 SIGTTIN, SIGTTOU, SIGURG, SIGXCPU,
132 SIGXFSZ, SIGVTALRM, SIGPROF, SIGWINCH,
136 #define LINUX_T_UNKNOWN 255
137 static int _bsd_to_linux_trapcode[] = {
138 LINUX_T_UNKNOWN, /* 0 */
139 6, /* 1 T_PRIVINFLT */
140 LINUX_T_UNKNOWN, /* 2 */
142 LINUX_T_UNKNOWN, /* 4 */
143 LINUX_T_UNKNOWN, /* 5 */
144 16, /* 6 T_ARITHTRAP */
145 254, /* 7 T_ASTFLT */
146 LINUX_T_UNKNOWN, /* 8 */
147 13, /* 9 T_PROTFLT */
148 1, /* 10 T_TRCTRAP */
149 LINUX_T_UNKNOWN, /* 11 */
150 14, /* 12 T_PAGEFLT */
151 LINUX_T_UNKNOWN, /* 13 */
152 17, /* 14 T_ALIGNFLT */
153 LINUX_T_UNKNOWN, /* 15 */
154 LINUX_T_UNKNOWN, /* 16 */
155 LINUX_T_UNKNOWN, /* 17 */
161 8, /* 23 T_DOUBLEFLT */
162 9, /* 24 T_FPOPFLT */
163 10, /* 25 T_TSSFLT */
164 11, /* 26 T_SEGNPFLT */
165 12, /* 27 T_STKFLT */
167 19, /* 29 T_XMMFLT */
168 15 /* 30 T_RESERVED */
170 #define bsd_to_linux_trapcode(code) \
171 ((code)<sizeof(_bsd_to_linux_trapcode)/sizeof(*_bsd_to_linux_trapcode)? \
172 _bsd_to_linux_trapcode[(code)]: \
176 * If FreeBSD & Linux have a difference of opinion about what a trap
177 * means, deal with it here.
180 translate_traps(int signal, int trap_code)
182 if (signal != SIGBUS)
196 linux_fixup(register_t **stack_base, struct image_params *imgp)
198 register_t *argv, *envp;
201 envp = *stack_base + (imgp->args->argc + 1);
203 **stack_base = (intptr_t)(void *)envp;
205 **stack_base = (intptr_t)(void *)argv;
207 **stack_base = imgp->args->argc;
212 elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
214 Elf32_Auxargs *args = (Elf32_Auxargs *)imgp->auxargs;
217 pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
220 AUXARGS_ENTRY(pos, AT_DEBUG, 1);
222 if (args->execfd != -1) {
223 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
225 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
226 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
227 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
228 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
229 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
230 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
231 AUXARGS_ENTRY(pos, AT_BASE, args->base);
232 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
233 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
234 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
235 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
236 AUXARGS_ENTRY(pos, AT_NULL, 0);
238 kfree(imgp->auxargs, M_TEMP);
239 imgp->auxargs = NULL;
242 **stack_base = (long)imgp->args->argc;
246 extern int _ucodesel, _udatasel;
247 extern unsigned long linux_sznonrtsigcode;
250 linux_rt_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
252 struct proc *p = curproc;
253 struct lwp *lp = curthread->td_lwp;
254 struct trapframe *regs;
255 struct l_rt_sigframe *fp, frame;
258 regs = lp->lwp_md.md_regs;
259 oonstack = lp->lwp_sigstk.ss_flags & SS_ONSTACK;
262 if (ldebug(rt_sendsig))
263 kprintf(ARGS(rt_sendsig, "%p, %d, %p, %lu"),
264 catcher, sig, (void*)mask, code);
267 * Allocate space for the signal handler context.
269 if ((lp->lwp_flag & LWP_ALTSTACK) && !oonstack &&
270 SIGISMEMBER(p->p_sigacts->ps_sigonstack, sig)) {
271 fp = (struct l_rt_sigframe *)(lp->lwp_sigstk.ss_sp +
272 lp->lwp_sigstk.ss_size - sizeof(struct l_rt_sigframe));
273 lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
275 fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
278 * grow() will return FALSE if the fp will not fit inside the stack
279 * and the stack can not be grown. useracc will return FALSE
280 * if access is denied.
282 if ((grow_stack (p, (int)fp) == FALSE) ||
283 !useracc((caddr_t)fp, sizeof (struct l_rt_sigframe),
286 * Process has trashed its stack; give it an illegal
287 * instruction to halt it in its tracks.
289 SIGACTION(p, SIGILL) = SIG_DFL;
290 SIGDELSET(p->p_sigignore, SIGILL);
291 SIGDELSET(p->p_sigcatch, SIGILL);
292 SIGDELSET(lp->lwp_sigmask, SIGILL);
294 if (ldebug(rt_sendsig))
295 kprintf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
298 lwpsignal(p, lp, SIGILL);
303 * Build the argument list for the signal handler.
305 if (p->p_sysent->sv_sigtbl)
306 if (sig <= p->p_sysent->sv_sigsize)
307 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)];
309 frame.sf_handler = catcher;
311 frame.sf_siginfo = &fp->sf_si;
312 frame.sf_ucontext = &fp->sf_sc;
314 /* Fill siginfo structure. */
315 frame.sf_si.lsi_signo = sig;
316 frame.sf_si.lsi_code = code;
317 frame.sf_si.lsi_addr = (void *)regs->tf_err;
320 * Build the signal context to be used by sigreturn.
322 frame.sf_sc.uc_flags = 0; /* XXX ??? */
323 frame.sf_sc.uc_link = NULL; /* XXX ??? */
325 frame.sf_sc.uc_stack.ss_sp = lp->lwp_sigstk.ss_sp;
326 frame.sf_sc.uc_stack.ss_size = lp->lwp_sigstk.ss_size;
327 frame.sf_sc.uc_stack.ss_flags = (lp->lwp_flag & LWP_ALTSTACK)
328 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
330 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
332 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__bits[0];
333 frame.sf_sc.uc_mcontext.sc_gs = regs->tf_gs;
334 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
335 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
336 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
337 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_edi;
338 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi;
339 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp;
340 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx;
341 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx;
342 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx;
343 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax;
344 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip;
345 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
346 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
347 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
348 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
349 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
350 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
353 if (ldebug(rt_sendsig))
354 kprintf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
355 frame.sf_sc.uc_stack.ss_flags, lp->lwp_sigstk.ss_sp,
356 lp->lwp_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
359 if (copyout(&frame, fp, sizeof(frame)) != 0) {
361 * Process has trashed its stack; give it an illegal
362 * instruction to halt it in its tracks.
369 * Build context to run handler in.
371 regs->tf_esp = (int)fp;
372 regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode) +
373 linux_sznonrtsigcode;
376 * i386 abi specifies that the direction flag must be cleared
379 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
381 regs->tf_cs = _ucodesel;
382 regs->tf_ds = _udatasel;
383 regs->tf_es = _udatasel;
384 /* allow %fs and %gs to be inherited by the signal handler */
386 regs->tf_fs = _udatasel;
387 regs->tf_gs = _udatasel;
389 regs->tf_ss = _udatasel;
394 * Send an interrupt to process.
396 * Stack is set up to allow sigcode stored
397 * in u. to call routine, followed by kcall
398 * to sigreturn routine below. After sigreturn
399 * resets the signal mask, the stack, and the
400 * frame pointer, it returns to the user
405 linux_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
407 struct proc *p = curproc;
408 struct lwp *lp = curthread->td_lwp;
409 struct trapframe *regs;
410 struct l_sigframe *fp, frame;
414 if (SIGISMEMBER(p->p_sigacts->ps_siginfo, sig)) {
415 /* Signal handler installed with SA_SIGINFO. */
416 linux_rt_sendsig(catcher, sig, mask, code);
420 regs = lp->lwp_md.md_regs;
421 oonstack = lp->lwp_sigstk.ss_flags & SS_ONSTACK;
425 kprintf(ARGS(sendsig, "%p, %d, %p, %lu"),
426 catcher, sig, (void*)mask, code);
430 * Allocate space for the signal handler context.
432 if ((lp->lwp_flag & LWP_ALTSTACK) && !oonstack &&
433 SIGISMEMBER(p->p_sigacts->ps_sigonstack, sig)) {
434 fp = (struct l_sigframe *)(lp->lwp_sigstk.ss_sp +
435 lp->lwp_sigstk.ss_size - sizeof(struct l_sigframe));
436 lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
438 fp = (struct l_sigframe *)regs->tf_esp - 1;
441 * grow() will return FALSE if the fp will not fit inside the stack
442 * and the stack can not be grown. useracc will return FALSE
443 * if access is denied.
445 if ((grow_stack (p, (int)fp) == FALSE) ||
446 !useracc((caddr_t)fp, sizeof (struct l_sigframe),
449 * Process has trashed its stack; give it an illegal
450 * instruction to halt it in its tracks.
452 SIGACTION(p, SIGILL) = SIG_DFL;
453 SIGDELSET(p->p_sigignore, SIGILL);
454 SIGDELSET(p->p_sigcatch, SIGILL);
455 SIGDELSET(lp->lwp_sigmask, SIGILL);
456 lwpsignal(p, lp, SIGILL);
461 * Build the argument list for the signal handler.
463 if (p->p_sysent->sv_sigtbl)
464 if (sig <= p->p_sysent->sv_sigsize)
465 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)];
467 frame.sf_handler = catcher;
470 bsd_to_linux_sigset(mask, &lmask);
473 * Build the signal context to be used by sigreturn.
475 frame.sf_sc.sc_mask = lmask.__bits[0];
476 frame.sf_sc.sc_gs = regs->tf_gs;
477 frame.sf_sc.sc_fs = regs->tf_fs;
478 frame.sf_sc.sc_es = regs->tf_es;
479 frame.sf_sc.sc_ds = regs->tf_ds;
480 frame.sf_sc.sc_edi = regs->tf_edi;
481 frame.sf_sc.sc_esi = regs->tf_esi;
482 frame.sf_sc.sc_ebp = regs->tf_ebp;
483 frame.sf_sc.sc_ebx = regs->tf_ebx;
484 frame.sf_sc.sc_edx = regs->tf_edx;
485 frame.sf_sc.sc_ecx = regs->tf_ecx;
486 frame.sf_sc.sc_eax = regs->tf_eax;
487 frame.sf_sc.sc_eip = regs->tf_eip;
488 frame.sf_sc.sc_cs = regs->tf_cs;
489 frame.sf_sc.sc_eflags = regs->tf_eflags;
490 frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
491 frame.sf_sc.sc_ss = regs->tf_ss;
492 frame.sf_sc.sc_err = regs->tf_err;
493 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code);
495 bzero(&frame.sf_fpstate, sizeof(struct l_fpstate));
497 for (i = 0; i < (LINUX_NSIG_WORDS-1); i++)
498 frame.sf_extramask[i] = lmask.__bits[i+1];
500 if (copyout(&frame, fp, sizeof(frame)) != 0) {
502 * Process has trashed its stack; give it an illegal
503 * instruction to halt it in its tracks.
510 * Build context to run handler in.
512 regs->tf_esp = (int)fp;
513 regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
516 * i386 abi specifies that the direction flag must be cleared
519 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
521 regs->tf_cs = _ucodesel;
522 regs->tf_ds = _udatasel;
523 regs->tf_es = _udatasel;
524 /* Allow %fs and %gs to be inherited by the signal handler */
526 regs->tf_fs = _udatasel;
527 regs->tf_gs = _udatasel;
529 regs->tf_ss = _udatasel;
533 * System call to cleanup state after a signal
534 * has been taken. Reset signal mask and
535 * stack state from context left by sendsig (above).
536 * Return to previous pc and psl as specified by
537 * context left by sendsig. Check carefully to
538 * make sure that the user has not modified the
539 * psl to gain improper privileges or to cause
543 sys_linux_sigreturn(struct linux_sigreturn_args *args)
545 struct lwp *lp = curthread->td_lwp;
546 struct l_sigframe frame;
547 struct trapframe *regs;
551 regs = lp->lwp_md.md_regs;
554 if (ldebug(sigreturn))
555 kprintf(ARGS(sigreturn, "%p"), (void *)args->sfp);
558 * The trampoline code hands us the sigframe.
559 * It is unsafe to keep track of it ourselves, in the event that a
560 * program jumps out of a signal handler.
562 if (copyin((caddr_t)args->sfp, &frame, sizeof(frame)) != 0)
566 * Check for security violations.
568 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
569 eflags = frame.sf_sc.sc_eflags;
571 * XXX do allow users to change the privileged flag PSL_RF. The
572 * cpu sets PSL_RF in tf_eflags for faults. Debuggers should
573 * sometimes set it there too. tf_eflags is kept in the signal
574 * context during signal handling and there is no other place
575 * to remember it, so the PSL_RF bit may be corrupted by the
576 * signal handler without us knowing. Corruption of the PSL_RF
577 * bit at worst causes one more or one less debugger trap, so
578 * allowing it is fairly harmless.
580 if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) {
585 * Don't allow users to load a valid privileged %cs. Let the
586 * hardware check for invalid selectors, excess privilege in
587 * other selectors, invalid %eip's and invalid %esp's.
589 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
590 if (!CS_SECURE(frame.sf_sc.sc_cs)) {
591 trapsignal(lp, SIGBUS, T_PROTFLT);
595 lp->lwp_sigstk.ss_flags &= ~SS_ONSTACK;
596 lmask.__bits[0] = frame.sf_sc.sc_mask;
597 for (i = 0; i < (LINUX_NSIG_WORDS-1); i++)
598 lmask.__bits[i+1] = frame.sf_extramask[i];
599 linux_to_bsd_sigset(&lmask, &lp->lwp_sigmask);
600 SIG_CANTMASK(lp->lwp_sigmask);
603 * Restore signal context.
605 /* %gs was restored by the trampoline. */
606 regs->tf_fs = frame.sf_sc.sc_fs;
607 regs->tf_es = frame.sf_sc.sc_es;
608 regs->tf_ds = frame.sf_sc.sc_ds;
609 regs->tf_edi = frame.sf_sc.sc_edi;
610 regs->tf_esi = frame.sf_sc.sc_esi;
611 regs->tf_ebp = frame.sf_sc.sc_ebp;
612 regs->tf_ebx = frame.sf_sc.sc_ebx;
613 regs->tf_edx = frame.sf_sc.sc_edx;
614 regs->tf_ecx = frame.sf_sc.sc_ecx;
615 regs->tf_eax = frame.sf_sc.sc_eax;
616 regs->tf_eip = frame.sf_sc.sc_eip;
617 regs->tf_cs = frame.sf_sc.sc_cs;
618 regs->tf_eflags = eflags;
619 regs->tf_esp = frame.sf_sc.sc_esp_at_signal;
620 regs->tf_ss = frame.sf_sc.sc_ss;
622 return (EJUSTRETURN);
626 * System call to cleanup state after a signal
627 * has been taken. Reset signal mask and
628 * stack state from context left by rt_sendsig (above).
629 * Return to previous pc and psl as specified by
630 * context left by sendsig. Check carefully to
631 * make sure that the user has not modified the
632 * psl to gain improper privileges or to cause
636 sys_linux_rt_sigreturn(struct linux_rt_sigreturn_args *args)
638 struct lwp *lp = curthread->td_lwp;
639 struct l_ucontext uc;
640 struct l_sigcontext *context;
643 struct trapframe *regs;
646 regs = lp->lwp_md.md_regs;
649 if (ldebug(rt_sigreturn))
650 kprintf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
653 * The trampoline code hands us the ucontext.
654 * It is unsafe to keep track of it ourselves, in the event that a
655 * program jumps out of a signal handler.
657 if (copyin((caddr_t)args->ucp, &uc, sizeof(uc)) != 0)
660 context = &uc.uc_mcontext;
663 * Check for security violations.
665 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
666 eflags = context->sc_eflags;
668 * XXX do allow users to change the privileged flag PSL_RF. The
669 * cpu sets PSL_RF in tf_eflags for faults. Debuggers should
670 * sometimes set it there too. tf_eflags is kept in the signal
671 * context during signal handling and there is no other place
672 * to remember it, so the PSL_RF bit may be corrupted by the
673 * signal handler without us knowing. Corruption of the PSL_RF
674 * bit at worst causes one more or one less debugger trap, so
675 * allowing it is fairly harmless.
677 if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) {
682 * Don't allow users to load a valid privileged %cs. Let the
683 * hardware check for invalid selectors, excess privilege in
684 * other selectors, invalid %eip's and invalid %esp's.
686 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
687 if (!CS_SECURE(context->sc_cs)) {
688 trapsignal(lp, SIGBUS, T_PROTFLT);
692 lp->lwp_sigstk.ss_flags &= ~SS_ONSTACK;
693 linux_to_bsd_sigset(&uc.uc_sigmask, &lp->lwp_sigmask);
694 SIG_CANTMASK(lp->lwp_sigmask);
697 * Restore signal context
699 /* %gs was restored by the trampoline. */
700 regs->tf_fs = context->sc_fs;
701 regs->tf_es = context->sc_es;
702 regs->tf_ds = context->sc_ds;
703 regs->tf_edi = context->sc_edi;
704 regs->tf_esi = context->sc_esi;
705 regs->tf_ebp = context->sc_ebp;
706 regs->tf_ebx = context->sc_ebx;
707 regs->tf_edx = context->sc_edx;
708 regs->tf_ecx = context->sc_ecx;
709 regs->tf_eax = context->sc_eax;
710 regs->tf_eip = context->sc_eip;
711 regs->tf_cs = context->sc_cs;
712 regs->tf_eflags = eflags;
713 regs->tf_esp = context->sc_esp_at_signal;
714 regs->tf_ss = context->sc_ss;
717 * call sigaltstack & ignore results..
720 ss.ss_sp = lss->ss_sp;
721 ss.ss_size = lss->ss_size;
722 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
725 if (ldebug(rt_sigreturn))
726 kprintf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
727 ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
729 kern_sigaltstack(&ss, NULL);
731 return (EJUSTRETURN);
740 linux_prepsyscall(struct trapframe *tf, int *args, u_int *code, caddr_t *params)
742 args[0] = tf->tf_ebx;
743 args[1] = tf->tf_ecx;
744 args[2] = tf->tf_edx;
745 args[3] = tf->tf_esi;
746 args[4] = tf->tf_edi;
747 args[5] = tf->tf_ebp;
748 *params = NULL; /* no copyin */
752 * If a linux binary is exec'ing something, try this image activator
753 * first. We override standard shell script execution in order to
754 * be able to modify the interpreter path. We only do this if a linux
755 * binary is doing the exec, so we do not create an EXEC module for it.
757 static int exec_linux_imgact_try (struct image_params *iparams);
760 exec_linux_imgact_try(struct image_params *imgp)
762 const char *head = (const char *)imgp->image_header;
766 * The interpreter for shell scripts run from a linux binary needs
767 * to be located in /compat/linux if possible in order to recursively
768 * maintain linux path emulation.
770 if (((const short *)head)[0] == SHELLMAGIC) {
772 * Run our normal shell image activator. If it succeeds attempt
773 * to use the alternate path for the interpreter. If an alternate
774 * path is found, use our stringspace to store it.
776 if ((error = exec_shell_imgact(imgp)) == 0) {
777 linux_translate_path(imgp->interpreter_name,
784 struct sysentvec linux_sysvec = {
785 LINUX_SYS_MAXSYSCALL,
800 exec_linux_imgact_try,
804 struct sysentvec elf_linux_sysvec = {
805 LINUX_SYS_MAXSYSCALL,
820 exec_linux_imgact_try,
824 static int linux_match_abi_note(const Elf_Note *abi_note);
825 static int linux_match_suse_note(const Elf_Note *abi_note);
827 static Elf32_Brandinfo linux_brand = {
830 linux_match_abi_note,
832 "/lib/ld-linux.so.1",
836 static Elf32_Brandinfo linux_glibc2brand = {
839 linux_match_abi_note,
841 "/lib/ld-linux.so.2",
845 static Elf32_Brandinfo linux_suse_brand = {
848 linux_match_suse_note,
850 "/lib/ld-linux.so.2",
854 Elf32_Brandinfo *linux_brandlist[] = {
862 linux_match_abi_note(const Elf_Note *abi_note)
864 const char *abi_name = (const char *)
865 ((const uint8_t *)abi_note + sizeof(*abi_note));
866 const uint32_t *descr = (const uint32_t *)
867 ((const uint8_t *)abi_name + abi_note->n_namesz);
869 if (abi_note->n_namesz != sizeof("GNU"))
871 if (memcmp(abi_name, "GNU", sizeof("GNU")))
873 if (abi_note->n_descsz < sizeof(uint32_t))
882 linux_match_suse_note(const Elf_Note *abi_note)
884 const char *abi_name = (const char *)
885 ((const uint8_t *)abi_note + sizeof(*abi_note));
887 if (abi_note->n_namesz != sizeof("SuSE"))
889 if (memcmp(abi_name, "SuSE", sizeof("SuSE")))
896 linux_elf_modevent(module_t mod, int type, void *data)
898 Elf32_Brandinfo **brandinfo;
905 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
907 if (elf_insert_brand_entry(*brandinfo) < 0)
911 kprintf("Linux ELF exec handler installed\n");
913 kprintf("cannot insert Linux ELF brand handler\n");
916 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
918 if (elf_brand_inuse(*brandinfo))
921 for (brandinfo = &linux_brandlist[0];
922 *brandinfo != NULL; ++brandinfo)
923 if (elf_remove_brand_entry(*brandinfo) < 0)
928 kprintf("Linux ELF exec handler removed\n");
930 kprintf("Could not deinstall ELF interpreter entry\n");
938 static moduledata_t linux_elf_mod = {
944 DECLARE_MODULE(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);