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 without 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 $
31 /* XXX we use functions that might not exist. */
32 #include "opt_compat.h"
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/imgact.h>
37 #include <sys/imgact_aout.h>
38 #include <sys/imgact_elf.h>
39 #include <sys/kern_syscall.h>
41 #include <sys/malloc.h>
43 #include <sys/signalvar.h>
44 #include <sys/sysent.h>
45 #include <sys/sysproto.h>
46 #include <sys/eventhandler.h>
49 #include <vm/vm_param.h>
50 #include <vm/vm_page.h>
51 #include <vm/vm_extern.h>
53 #include <sys/kernel.h>
54 #include <sys/module.h>
55 #include <machine/cpu.h>
58 #include "linux_proto.h"
59 #include "../linux_signal.h"
60 #include "../linux_util.h"
61 #include "../linux_futex.h"
62 #include "../linux_emuldata.h"
64 MODULE_VERSION(linux, 1);
66 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
68 #if BYTE_ORDER == LITTLE_ENDIAN
69 #define SHELLMAGIC 0x2123 /* #! */
71 #define SHELLMAGIC 0x2321
75 * Allow the sendsig functions to use the ldebug() facility
76 * even though they are not syscalls themselves. Map them
77 * to syscall 0. This is slightly less bogus than using
80 #define LINUX_SYS_linux_rt_sendsig 0
81 #define LINUX_SYS_linux_sendsig 0
83 extern char linux_sigcode[];
84 extern int linux_szsigcode;
86 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL];
88 static int linux_fixup (register_t **stack_base,
89 struct image_params *iparams);
90 static int elf_linux_fixup (register_t **stack_base,
91 struct image_params *iparams);
92 static void linux_prepsyscall (struct trapframe *tf, int *args,
93 u_int *code, caddr_t *params);
94 static void linux_sendsig (sig_t catcher, int sig, sigset_t *mask,
96 static boolean_t linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
98 static eventhandler_tag linux_exec_tag;
99 static eventhandler_tag linux_exit_tag;
102 * Linux syscalls return negative errno's, we do positive and map them
104 static int bsd_to_linux_errno[ELAST + 1] = {
105 -0, -1, -2, -3, -4, -5, -6, -7, -8, -9,
106 -10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
107 -20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
108 -30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
109 -90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
110 -100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
111 -110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
112 -116, -66, -6, -6, -6, -6, -6, -37, -38, -9,
113 -6, -6, -43, -42, -75, -6, -84
116 int bsd_to_linux_signal[LINUX_SIGTBLSZ] = {
117 LINUX_SIGHUP, LINUX_SIGINT, LINUX_SIGQUIT, LINUX_SIGILL,
118 LINUX_SIGTRAP, LINUX_SIGABRT, 0, LINUX_SIGFPE,
119 LINUX_SIGKILL, LINUX_SIGBUS, LINUX_SIGSEGV, LINUX_SIGSYS,
120 LINUX_SIGPIPE, LINUX_SIGALRM, LINUX_SIGTERM, LINUX_SIGURG,
121 LINUX_SIGSTOP, LINUX_SIGTSTP, LINUX_SIGCONT, LINUX_SIGCHLD,
122 LINUX_SIGTTIN, LINUX_SIGTTOU, LINUX_SIGIO, LINUX_SIGXCPU,
123 LINUX_SIGXFSZ, LINUX_SIGVTALRM, LINUX_SIGPROF, LINUX_SIGWINCH,
124 0, LINUX_SIGUSR1, LINUX_SIGUSR2
127 int linux_to_bsd_signal[LINUX_SIGTBLSZ] = {
128 SIGHUP, SIGINT, SIGQUIT, SIGILL,
129 SIGTRAP, SIGABRT, SIGBUS, SIGFPE,
130 SIGKILL, SIGUSR1, SIGSEGV, SIGUSR2,
131 SIGPIPE, SIGALRM, SIGTERM, SIGBUS,
132 SIGCHLD, SIGCONT, SIGSTOP, SIGTSTP,
133 SIGTTIN, SIGTTOU, SIGURG, SIGXCPU,
134 SIGXFSZ, SIGVTALRM, SIGPROF, SIGWINCH,
135 SIGIO, SIGURG, SIGSYS
138 #define LINUX_T_UNKNOWN 255
139 static int _bsd_to_linux_trapcode[] = {
140 LINUX_T_UNKNOWN, /* 0 */
141 6, /* 1 T_PRIVINFLT */
142 LINUX_T_UNKNOWN, /* 2 */
144 LINUX_T_UNKNOWN, /* 4 */
145 LINUX_T_UNKNOWN, /* 5 */
146 16, /* 6 T_ARITHTRAP */
147 254, /* 7 T_ASTFLT */
148 LINUX_T_UNKNOWN, /* 8 */
149 13, /* 9 T_PROTFLT */
150 1, /* 10 T_TRCTRAP */
151 LINUX_T_UNKNOWN, /* 11 */
152 14, /* 12 T_PAGEFLT */
153 LINUX_T_UNKNOWN, /* 13 */
154 17, /* 14 T_ALIGNFLT */
155 LINUX_T_UNKNOWN, /* 15 */
156 LINUX_T_UNKNOWN, /* 16 */
157 LINUX_T_UNKNOWN, /* 17 */
163 8, /* 23 T_DOUBLEFLT */
164 9, /* 24 T_FPOPFLT */
165 10, /* 25 T_TSSFLT */
166 11, /* 26 T_SEGNPFLT */
167 12, /* 27 T_STKFLT */
169 19, /* 29 T_XMMFLT */
170 15 /* 30 T_RESERVED */
172 #define bsd_to_linux_trapcode(code) \
173 ((code)<NELEM(_bsd_to_linux_trapcode)? \
174 _bsd_to_linux_trapcode[(code)]: \
178 * If FreeBSD & Linux have a difference of opinion about what a trap
179 * means, deal with it here.
182 translate_traps(int signal, int trap_code)
184 if (signal != SIGBUS)
198 linux_fixup(register_t **stack_base, struct image_params *imgp)
200 register_t *argv, *envp;
203 envp = *stack_base + (imgp->args->argc + 1);
205 **stack_base = (intptr_t)(void *)envp;
207 **stack_base = (intptr_t)(void *)argv;
209 **stack_base = imgp->args->argc;
214 elf_linux_fixup(register_t **stack_base, struct image_params *imgp)
216 Elf32_Auxargs *args = (Elf32_Auxargs *)imgp->auxargs;
219 pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
221 if (args->execfd != -1) {
222 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
224 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
225 AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
226 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
227 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
228 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
229 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
230 AUXARGS_ENTRY(pos, AT_BASE, args->base);
231 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
232 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
233 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
234 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
235 AUXARGS_ENTRY(pos, AT_NULL, 0);
237 kfree(imgp->auxargs, M_TEMP);
238 imgp->auxargs = NULL;
241 **stack_base = (long)imgp->args->argc;
245 extern int _ucodesel, _udatasel;
246 extern unsigned long linux_sznonrtsigcode;
249 linux_rt_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
251 struct proc *p = curproc;
252 struct lwp *lp = curthread->td_lwp;
253 struct trapframe *regs;
254 struct l_rt_sigframe *fp, frame;
257 regs = lp->lwp_md.md_regs;
258 oonstack = lp->lwp_sigstk.ss_flags & SS_ONSTACK;
261 if (ldebug(rt_sendsig))
262 kprintf(ARGS(rt_sendsig, "%p, %d, %p, %lu"),
263 catcher, sig, (void*)mask, code);
266 * Allocate space for the signal handler context.
268 if ((lp->lwp_flags & LWP_ALTSTACK) && !oonstack &&
269 SIGISMEMBER(p->p_sigacts->ps_sigonstack, sig)) {
270 fp = (struct l_rt_sigframe *)(lp->lwp_sigstk.ss_sp +
271 lp->lwp_sigstk.ss_size - sizeof(struct l_rt_sigframe));
272 lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
274 fp = (struct l_rt_sigframe *)regs->tf_esp - 1;
277 * grow() will return FALSE if the fp will not fit inside the stack
278 * and the stack can not be grown. useracc will return FALSE
279 * if access is denied.
281 if ((vm_map_growstack(p, (vm_offset_t)fp) != KERN_SUCCESS) ||
282 !useracc((caddr_t)fp, sizeof (struct l_rt_sigframe),
285 * Process has trashed its stack; give it an illegal
286 * instruction to halt it in its tracks.
288 SIGACTION(p, SIGILL) = SIG_DFL;
289 SIGDELSET(p->p_sigignore, SIGILL);
290 SIGDELSET(p->p_sigcatch, SIGILL);
291 SIGDELSET(lp->lwp_sigmask, SIGILL);
293 if (ldebug(rt_sendsig))
294 kprintf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
297 lwpsignal(p, lp, SIGILL);
302 * Build the argument list for the signal handler.
304 if (p->p_sysent->sv_sigtbl)
305 if (sig <= p->p_sysent->sv_sigsize)
306 sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)];
308 frame.sf_handler = catcher;
310 frame.sf_siginfo = &fp->sf_si;
311 frame.sf_ucontext = &fp->sf_sc;
313 /* Fill siginfo structure. */
314 frame.sf_si.lsi_signo = sig;
315 frame.sf_si.lsi_code = code;
316 frame.sf_si.lsi_addr = (void *)regs->tf_err;
319 * Build the signal context to be used by sigreturn.
321 frame.sf_sc.uc_flags = 0; /* XXX ??? */
322 frame.sf_sc.uc_link = NULL; /* XXX ??? */
324 frame.sf_sc.uc_stack.ss_sp = lp->lwp_sigstk.ss_sp;
325 frame.sf_sc.uc_stack.ss_size = lp->lwp_sigstk.ss_size;
326 frame.sf_sc.uc_stack.ss_flags = (lp->lwp_flags & LWP_ALTSTACK)
327 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
329 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
331 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__bits[0];
332 frame.sf_sc.uc_mcontext.sc_gs = regs->tf_gs;
333 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs;
334 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es;
335 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds;
336 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_edi;
337 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi;
338 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp;
339 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx;
340 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx;
341 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx;
342 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax;
343 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip;
344 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs;
345 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags;
346 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp;
347 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss;
348 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err;
349 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
352 if (ldebug(rt_sendsig))
353 kprintf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
354 frame.sf_sc.uc_stack.ss_flags, lp->lwp_sigstk.ss_sp,
355 lp->lwp_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
358 if (copyout(&frame, fp, sizeof(frame)) != 0) {
360 * Process has trashed its stack; give it an illegal
361 * instruction to halt it in its tracks.
368 * Build context to run handler in.
370 regs->tf_esp = (int)fp;
371 regs->tf_eip = PS_STRINGS - *(p->p_sysent->sv_szsigcode) +
372 linux_sznonrtsigcode;
375 * i386 abi specifies that the direction flag must be cleared
378 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D);
380 regs->tf_cs = _ucodesel;
381 regs->tf_ds = _udatasel;
382 regs->tf_es = _udatasel;
383 /* allow %fs and %gs to be inherited by the signal handler */
385 regs->tf_fs = _udatasel;
386 regs->tf_gs = _udatasel;
388 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_flags & 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 ((vm_map_growstack(p, (vm_offset_t)fp) != KERN_SUCCESS) ||
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;
534 * System call to cleanup state after a signal
535 * has been taken. Reset signal mask and
536 * stack state from context left by sendsig (above).
537 * Return to previous pc and psl as specified by
538 * context left by sendsig. Check carefully to
539 * make sure that the user has not modified the
540 * psl to gain improper privileges or to cause
546 sys_linux_sigreturn(struct linux_sigreturn_args *args)
548 struct lwp *lp = curthread->td_lwp;
549 struct l_sigframe frame;
550 struct trapframe *regs;
554 regs = lp->lwp_md.md_regs;
557 if (ldebug(sigreturn))
558 kprintf(ARGS(sigreturn, "%p"), (void *)args->sfp);
561 * The trampoline code hands us the sigframe.
562 * It is unsafe to keep track of it ourselves, in the event that a
563 * program jumps out of a signal handler.
565 if (copyin((caddr_t)args->sfp, &frame, sizeof(frame)) != 0)
569 * Check for security violations.
571 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
572 eflags = frame.sf_sc.sc_eflags;
574 * XXX do allow users to change the privileged flag PSL_RF. The
575 * cpu sets PSL_RF in tf_eflags for faults. Debuggers should
576 * sometimes set it there too. tf_eflags is kept in the signal
577 * context during signal handling and there is no other place
578 * to remember it, so the PSL_RF bit may be corrupted by the
579 * signal handler without us knowing. Corruption of the PSL_RF
580 * bit at worst causes one more or one less debugger trap, so
581 * allowing it is fairly harmless.
583 if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) {
588 * Don't allow users to load a valid privileged %cs. Let the
589 * hardware check for invalid selectors, excess privilege in
590 * other selectors, invalid %eip's and invalid %esp's.
592 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
593 if (!CS_SECURE(frame.sf_sc.sc_cs)) {
594 trapsignal(lp, SIGBUS, T_PROTFLT);
598 lp->lwp_sigstk.ss_flags &= ~SS_ONSTACK;
599 lmask.__bits[0] = frame.sf_sc.sc_mask;
600 for (i = 0; i < (LINUX_NSIG_WORDS-1); i++)
601 lmask.__bits[i+1] = frame.sf_extramask[i];
602 linux_to_bsd_sigset(&lmask, &lp->lwp_sigmask);
603 SIG_CANTMASK(lp->lwp_sigmask);
606 * Restore signal context.
608 /* %gs was restored by the trampoline. */
609 regs->tf_fs = frame.sf_sc.sc_fs;
610 regs->tf_es = frame.sf_sc.sc_es;
611 regs->tf_ds = frame.sf_sc.sc_ds;
612 regs->tf_edi = frame.sf_sc.sc_edi;
613 regs->tf_esi = frame.sf_sc.sc_esi;
614 regs->tf_ebp = frame.sf_sc.sc_ebp;
615 regs->tf_ebx = frame.sf_sc.sc_ebx;
616 regs->tf_edx = frame.sf_sc.sc_edx;
617 regs->tf_ecx = frame.sf_sc.sc_ecx;
618 regs->tf_eax = frame.sf_sc.sc_eax;
619 regs->tf_eip = frame.sf_sc.sc_eip;
620 regs->tf_cs = frame.sf_sc.sc_cs;
621 regs->tf_eflags = eflags;
622 regs->tf_esp = frame.sf_sc.sc_esp_at_signal;
623 regs->tf_ss = frame.sf_sc.sc_ss;
626 return (EJUSTRETURN);
630 * System call to cleanup state after a signal
631 * has been taken. Reset signal mask and
632 * stack state from context left by rt_sendsig (above).
633 * Return to previous pc and psl as specified by
634 * context left by sendsig. Check carefully to
635 * make sure that the user has not modified the
636 * psl to gain improper privileges or to cause
642 sys_linux_rt_sigreturn(struct linux_rt_sigreturn_args *args)
644 struct lwp *lp = curthread->td_lwp;
645 struct l_ucontext uc;
646 struct l_sigcontext *context;
649 struct trapframe *regs;
652 regs = lp->lwp_md.md_regs;
655 if (ldebug(rt_sigreturn))
656 kprintf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
659 * The trampoline code hands us the ucontext.
660 * It is unsafe to keep track of it ourselves, in the event that a
661 * program jumps out of a signal handler.
663 if (copyin((caddr_t)args->ucp, &uc, sizeof(uc)) != 0)
666 context = &uc.uc_mcontext;
669 * Check for security violations.
671 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
672 eflags = context->sc_eflags;
674 * XXX do allow users to change the privileged flag PSL_RF. The
675 * cpu sets PSL_RF in tf_eflags for faults. Debuggers should
676 * sometimes set it there too. tf_eflags is kept in the signal
677 * context during signal handling and there is no other place
678 * to remember it, so the PSL_RF bit may be corrupted by the
679 * signal handler without us knowing. Corruption of the PSL_RF
680 * bit at worst causes one more or one less debugger trap, so
681 * allowing it is fairly harmless.
683 if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) {
688 * Don't allow users to load a valid privileged %cs. Let the
689 * hardware check for invalid selectors, excess privilege in
690 * other selectors, invalid %eip's and invalid %esp's.
692 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
693 if (!CS_SECURE(context->sc_cs)) {
694 trapsignal(lp, SIGBUS, T_PROTFLT);
698 lp->lwp_sigstk.ss_flags &= ~SS_ONSTACK;
699 linux_to_bsd_sigset(&uc.uc_sigmask, &lp->lwp_sigmask);
700 SIG_CANTMASK(lp->lwp_sigmask);
703 * Restore signal context
705 /* %gs was restored by the trampoline. */
706 regs->tf_fs = context->sc_fs;
707 regs->tf_es = context->sc_es;
708 regs->tf_ds = context->sc_ds;
709 regs->tf_edi = context->sc_edi;
710 regs->tf_esi = context->sc_esi;
711 regs->tf_ebp = context->sc_ebp;
712 regs->tf_ebx = context->sc_ebx;
713 regs->tf_edx = context->sc_edx;
714 regs->tf_ecx = context->sc_ecx;
715 regs->tf_eax = context->sc_eax;
716 regs->tf_eip = context->sc_eip;
717 regs->tf_cs = context->sc_cs;
718 regs->tf_eflags = eflags;
719 regs->tf_esp = context->sc_esp_at_signal;
720 regs->tf_ss = context->sc_ss;
723 * call sigaltstack & ignore results..
726 ss.ss_sp = lss->ss_sp;
727 ss.ss_size = lss->ss_size;
728 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
731 if (ldebug(rt_sigreturn))
732 kprintf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%x, mask: 0x%x"),
733 ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
735 kern_sigaltstack(&ss, NULL);
738 return (EJUSTRETURN);
747 linux_prepsyscall(struct trapframe *tf, int *args, u_int *code, caddr_t *params)
749 args[0] = tf->tf_ebx;
750 args[1] = tf->tf_ecx;
751 args[2] = tf->tf_edx;
752 args[3] = tf->tf_esi;
753 args[4] = tf->tf_edi;
754 args[5] = tf->tf_ebp;
755 *params = NULL; /* no copyin */
759 * If a linux binary is exec'ing something, try this image activator
760 * first. We override standard shell script execution in order to
761 * be able to modify the interpreter path. We only do this if a linux
762 * binary is doing the exec, so we do not create an EXEC module for it.
764 static int exec_linux_imgact_try (struct image_params *iparams);
767 exec_linux_imgact_try(struct image_params *imgp)
769 const char *head = (const char *)imgp->image_header;
773 * The interpreter for shell scripts run from a linux binary needs
774 * to be located in /compat/linux if possible in order to recursively
775 * maintain linux path emulation.
777 if (((const short *)head)[0] == SHELLMAGIC) {
779 * Run our normal shell image activator. If it succeeds attempt
780 * to use the alternate path for the interpreter. If an alternate
781 * path is found, use our stringspace to store it.
783 if ((error = exec_shell_imgact(imgp)) == 0) {
784 linux_translate_path(imgp->interpreter_name,
791 struct sysentvec linux_sysvec = {
792 .sv_size = LINUX_SYS_MAXSYSCALL,
793 .sv_table = linux_sysent,
794 .sv_mask = 0xffffffff,
795 .sv_sigsize = LINUX_SIGTBLSZ,
796 .sv_sigtbl = bsd_to_linux_signal,
797 .sv_errsize = ELAST + 1,
798 .sv_errtbl = bsd_to_linux_errno,
799 .sv_transtrap = translate_traps,
800 .sv_fixup = linux_fixup,
801 .sv_sendsig = linux_sendsig,
802 .sv_sigcode = linux_sigcode,
803 .sv_szsigcode = &linux_szsigcode,
804 .sv_prepsyscall = linux_prepsyscall,
805 .sv_name = "Linux a.out",
807 .sv_imgact_try = exec_linux_imgact_try,
808 .sv_minsigstksz = LINUX_MINSIGSTKSZ
811 struct sysentvec elf_linux_sysvec = {
812 .sv_size = LINUX_SYS_MAXSYSCALL,
813 .sv_table = linux_sysent,
814 .sv_mask = 0xffffffff,
815 .sv_sigsize = LINUX_SIGTBLSZ,
816 .sv_sigtbl = bsd_to_linux_signal,
817 .sv_errsize = ELAST + 1,
818 .sv_errtbl = bsd_to_linux_errno,
819 .sv_transtrap = translate_traps,
820 .sv_fixup = elf_linux_fixup,
821 .sv_sendsig = linux_sendsig,
822 .sv_sigcode = linux_sigcode,
823 .sv_szsigcode = &linux_szsigcode,
824 .sv_prepsyscall = linux_prepsyscall,
825 .sv_name = "Linux ELF32",
826 .sv_coredump = elf32_coredump,
827 .sv_imgact_try = exec_linux_imgact_try,
828 .sv_minsigstksz = LINUX_MINSIGSTKSZ
831 static const char GNU_ABI_VENDOR[] = "GNU";
832 static const char SUSE_ABI_VENDOR[] = "SuSE";
833 static int GNULINUX_ABI_DESC = 0;
836 linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
838 const Elf32_Word *desc;
841 p = (uintptr_t)(note + 1);
842 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
844 desc = (const Elf32_Word *)p;
845 if (desc[0] != GNULINUX_ABI_DESC)
848 * For Linux we encode osrel as follows:
849 * VVVMMMIII (version, major, minor)
851 *osrel = desc[1] * 1000000 +
858 static Elf_Brandnote linux32_generic_brandnote = {
859 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR),
862 .vendor = GNU_ABI_VENDOR,
863 .flags = BN_TRANSLATE_OSREL,
864 .trans_osrel = linux_trans_osrel,
867 static Elf_Brandnote linux32_suse_brandnote = {
868 .hdr.n_namesz = sizeof(SUSE_ABI_VENDOR),
871 .vendor = SUSE_ABI_VENDOR,
872 .flags = BN_TRANSLATE_OSREL,
873 .trans_osrel = linux_trans_osrel,
876 static Elf32_Brandinfo linux32_brand = {
877 .brand = ELFOSABI_LINUX,
879 .compat_3_brand = "Linux",
880 .emul_path = "/compat/linux",
881 .interp_path = "/lib/ld-linux.so.1",
882 .sysvec = &elf_linux_sysvec,
883 .interp_newpath = NULL,
884 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
885 .brand_note = &linux32_generic_brandnote,
888 static Elf32_Brandinfo linux32_glibc2_brand = {
889 .brand = ELFOSABI_LINUX,
891 .compat_3_brand = "Linux",
892 .emul_path = "/compat/linux",
893 .interp_path = "/lib/ld-linux.so.2",
894 .sysvec = &elf_linux_sysvec,
895 .interp_newpath = NULL,
896 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
897 .brand_note = &linux32_generic_brandnote,
900 static Elf32_Brandinfo linux32_suse_brand = {
901 .brand = ELFOSABI_LINUX,
903 .compat_3_brand = "Linux",
904 .emul_path = "/compat/linux",
905 .interp_path = "/lib/ld-linux.so.2",
906 .sysvec = &elf_linux_sysvec,
907 .interp_newpath = NULL,
908 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
909 .brand_note = &linux32_suse_brandnote,
912 Elf32_Brandinfo *linux_brandlist[] = {
914 &linux32_glibc2_brand,
920 linux_elf_modevent(module_t mod, int type, void *data)
922 Elf32_Brandinfo **brandinfo;
929 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
931 if (elf32_insert_brand_entry(*brandinfo) < 0)
935 kprintf("Linux ELF exec handler installed\n");
937 kprintf("cannot insert Linux ELF brand handler\n");
940 lockinit(&futex_mtx, "linftxs", 0, LK_CANRECURSE);
941 linux_exec_tag = EVENTHANDLER_REGISTER(process_exec, linux_proc_transition,
943 linux_exit_tag = EVENTHANDLER_REGISTER(process_exit, emuldata_exit,
947 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
949 if (elf32_brand_inuse(*brandinfo))
952 for (brandinfo = &linux_brandlist[0];
953 *brandinfo != NULL; ++brandinfo)
954 if (elf32_remove_brand_entry(*brandinfo) < 0)
959 kprintf("Linux ELF exec handler removed\n");
961 kprintf("Could not deinstall ELF interpreter entry\n");
963 EVENTHANDLER_DEREGISTER(process_exec, linux_exec_tag);
964 EVENTHANDLER_DEREGISTER(process_exit, linux_exit_tag);
965 lockuninit(&futex_mtx);
974 static moduledata_t linux_elf_mod = {
980 DECLARE_MODULE(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);