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core_elf32.c revision 1.36
      1 /*	$NetBSD: core_elf32.c,v 1.36 2012/01/27 19:48:40 para Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2001 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed for the NetBSD Project by
     20  *	Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 /*
     39  * core_elf32.c/core_elf64.c: Support for the Elf32/Elf64 core file format.
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(1, "$NetBSD: core_elf32.c,v 1.36 2012/01/27 19:48:40 para Exp $");
     44 
     45 #ifdef _KERNEL_OPT
     46 #include "opt_coredump.h"
     47 #endif
     48 
     49 #ifndef ELFSIZE
     50 #define	ELFSIZE		32
     51 #endif
     52 
     53 #include <sys/param.h>
     54 #include <sys/systm.h>
     55 #include <sys/proc.h>
     56 #include <sys/vnode.h>
     57 #include <sys/exec.h>
     58 #include <sys/exec_elf.h>
     59 #include <sys/ptrace.h>
     60 #include <sys/kmem.h>
     61 #include <sys/kauth.h>
     62 
     63 #include <machine/reg.h>
     64 
     65 #include <uvm/uvm_extern.h>
     66 
     67 #ifdef COREDUMP
     68 
     69 struct countsegs_state {
     70 	int	npsections;
     71 };
     72 
     73 static int	ELFNAMEEND(coredump_countsegs)(struct proc *, void *,
     74 		    struct uvm_coredump_state *);
     75 
     76 struct writesegs_state {
     77 	Elf_Phdr *psections;
     78 	off_t	secoff;
     79 };
     80 
     81 static int	ELFNAMEEND(coredump_writeseghdrs)(struct proc *, void *,
     82 		    struct uvm_coredump_state *);
     83 
     84 static int	ELFNAMEEND(coredump_notes)(struct proc *, struct lwp *, void *,
     85 		    size_t *);
     86 static int	ELFNAMEEND(coredump_note)(struct proc *, struct lwp *, void *,
     87 		    size_t *);
     88 
     89 #define	ELFROUNDSIZE	4	/* XXX Should it be sizeof(Elf_Word)? */
     90 #define	elfround(x)	roundup((x), ELFROUNDSIZE)
     91 
     92 #define elf_process_read_regs	CONCAT(process_read_regs, ELFSIZE)
     93 #ifdef __HAVE_PROCESS_XFPREGS
     94 #define elf_process_read_xfpregs CONCAT(process_read_xfpregs, ELFSIZE)
     95 #else
     96 #define elf_process_read_fpregs	CONCAT(process_read_fpregs, ELFSIZE)
     97 #endif
     98 #define elf_reg			CONCAT(process_reg, ELFSIZE)
     99 #define elf_fpreg		CONCAT(process_fpreg, ELFSIZE)
    100 
    101 int
    102 ELFNAMEEND(coredump)(struct lwp *l, void *cookie)
    103 {
    104 	struct proc *p;
    105 	Elf_Ehdr ehdr;
    106 	Elf_Phdr phdr, *psections;
    107 	size_t psectionssize;
    108 	struct countsegs_state cs;
    109 	struct writesegs_state ws;
    110 	off_t notestart, secstart, offset;
    111 	size_t notesize;
    112 	int error, i;
    113 
    114 	psections = NULL;
    115 	p = l->l_proc;
    116 	/*
    117 	 * We have to make a total of 3 passes across the map:
    118 	 *
    119 	 *	1. Count the number of map entries (the number of
    120 	 *	   PT_LOAD sections).
    121 	 *
    122 	 *	2. Write the P-section headers.
    123 	 *
    124 	 *	3. Write the P-sections.
    125 	 */
    126 
    127 	/* Pass 1: count the entries. */
    128 	cs.npsections = 0;
    129 	error = uvm_coredump_walkmap(p, NULL,
    130 	    ELFNAMEEND(coredump_countsegs), &cs);
    131 	if (error)
    132 		goto out;
    133 
    134 	/* Count the PT_NOTE section. */
    135 	cs.npsections++;
    136 
    137 	/* Get the size of the notes. */
    138 	error = ELFNAMEEND(coredump_notes)(p, l, NULL, &notesize);
    139 	if (error)
    140 		goto out;
    141 
    142 	memset(&ehdr.e_ident[EI_PAD], 0, sizeof(ehdr.e_ident) - EI_PAD);
    143 	memcpy(ehdr.e_ident, ELFMAG, SELFMAG);
    144 #if ELFSIZE == 32
    145 	ehdr.e_ident[EI_CLASS] = ELFCLASS32;
    146 #elif ELFSIZE == 64
    147 	ehdr.e_ident[EI_CLASS] = ELFCLASS64;
    148 #endif
    149 	ehdr.e_ident[EI_DATA] = ELFDEFNNAME(MACHDEP_ENDIANNESS);
    150 	ehdr.e_ident[EI_VERSION] = EV_CURRENT;
    151 	/* XXX Should be the OSABI/ABI version of the executable. */
    152 	ehdr.e_ident[EI_OSABI] = ELFOSABI_SYSV;
    153 	ehdr.e_ident[EI_ABIVERSION] = 0;
    154 
    155 	ehdr.e_type = ET_CORE;
    156 	/* XXX This should be the e_machine of the executable. */
    157 	ehdr.e_machine = ELFDEFNNAME(MACHDEP_ID);
    158 	ehdr.e_version = EV_CURRENT;
    159 	ehdr.e_entry = 0;
    160 	ehdr.e_phoff = sizeof(ehdr);
    161 	ehdr.e_shoff = 0;
    162 	ehdr.e_flags = 0;
    163 	ehdr.e_ehsize = sizeof(ehdr);
    164 	ehdr.e_phentsize = sizeof(Elf_Phdr);
    165 	ehdr.e_phnum = cs.npsections;
    166 	ehdr.e_shentsize = 0;
    167 	ehdr.e_shnum = 0;
    168 	ehdr.e_shstrndx = 0;
    169 
    170 #ifdef ELF_MD_COREDUMP_SETUP
    171 	ELF_MD_COREDUMP_SETUP(l, &ehdr);
    172 #endif
    173 
    174 	/* Write out the ELF header. */
    175 	error = coredump_write(cookie, UIO_SYSSPACE, &ehdr, sizeof(ehdr));
    176 	if (error)
    177 		goto out;
    178 
    179 	offset = sizeof(ehdr);
    180 
    181 	notestart = offset + sizeof(phdr) * cs.npsections;
    182 	secstart = notestart + notesize;
    183 
    184 	psectionssize = cs.npsections * sizeof(Elf_Phdr);
    185 	psections = kmem_zalloc(psectionssize, KM_SLEEP);
    186 
    187 	/* Pass 2: now write the P-section headers. */
    188 	ws.secoff = secstart;
    189 	ws.psections = psections;
    190 	error = uvm_coredump_walkmap(p, cookie,
    191 	    ELFNAMEEND(coredump_writeseghdrs), &ws);
    192 	if (error)
    193 		goto out;
    194 
    195 	/* Write out the PT_NOTE header. */
    196 	ws.psections->p_type = PT_NOTE;
    197 	ws.psections->p_offset = notestart;
    198 	ws.psections->p_vaddr = 0;
    199 	ws.psections->p_paddr = 0;
    200 	ws.psections->p_filesz = notesize;
    201 	ws.psections->p_memsz = 0;
    202 	ws.psections->p_flags = PF_R;
    203 	ws.psections->p_align = ELFROUNDSIZE;
    204 
    205 	error = coredump_write(cookie, UIO_SYSSPACE, psections,
    206 	    cs.npsections * sizeof(Elf_Phdr));
    207 	if (error)
    208 		goto out;
    209 
    210 #ifdef DIAGNOSTIC
    211 	offset += cs.npsections * sizeof(Elf_Phdr);
    212 	if (offset != notestart)
    213 		panic("coredump: offset %lld != notestart %lld",
    214 		    (long long) offset, (long long) notestart);
    215 #endif
    216 
    217 	/* Write out the notes. */
    218 	error = ELFNAMEEND(coredump_notes)(p, l, cookie, &notesize);
    219 	if (error)
    220 		goto out;
    221 
    222 #ifdef DIAGNOSTIC
    223 	offset += notesize;
    224 	if (offset != secstart)
    225 		panic("coredump: offset %lld != secstart %lld",
    226 		    (long long) offset, (long long) secstart);
    227 #endif
    228 
    229 	/* Pass 3: finally, write the sections themselves. */
    230 	for (i = 0; i < cs.npsections - 1; i++) {
    231 		if (psections[i].p_filesz == 0)
    232 			continue;
    233 
    234 #ifdef DIAGNOSTIC
    235 		if (offset != psections[i].p_offset)
    236 			panic("coredump: offset %lld != p_offset[%d] %lld",
    237 			    (long long) offset, i,
    238 			    (long long) psections[i].p_filesz);
    239 #endif
    240 
    241 		error = coredump_write(cookie, UIO_USERSPACE,
    242 		    (void *)(vaddr_t)psections[i].p_vaddr,
    243 		    psections[i].p_filesz);
    244 		if (error)
    245 			goto out;
    246 
    247 #ifdef DIAGNOSTIC
    248 		offset += psections[i].p_filesz;
    249 #endif
    250 	}
    251 
    252   out:
    253 	if (psections)
    254 		kmem_free(psections, psectionssize);
    255 	return (error);
    256 }
    257 
    258 static int
    259 ELFNAMEEND(coredump_countsegs)(struct proc *p, void *iocookie,
    260     struct uvm_coredump_state *us)
    261 {
    262 	struct countsegs_state *cs = us->cookie;
    263 
    264 	cs->npsections++;
    265 	return (0);
    266 }
    267 
    268 static int
    269 ELFNAMEEND(coredump_writeseghdrs)(struct proc *p, void *iocookie,
    270     struct uvm_coredump_state *us)
    271 {
    272 	struct writesegs_state *ws = us->cookie;
    273 	Elf_Phdr phdr;
    274 	vsize_t size, realsize;
    275 	vaddr_t end;
    276 	int error;
    277 
    278 	size = us->end - us->start;
    279 	realsize = us->realend - us->start;
    280 	end = us->realend;
    281 
    282 	while (realsize > 0) {
    283 		long buf[1024 / sizeof(long)];
    284 		size_t slen = realsize > sizeof(buf) ? sizeof(buf) : realsize;
    285 		const long *ep;
    286 		int i;
    287 
    288 		end -= slen;
    289 		if ((error = copyin_proc(p, (void *)end, buf, slen)) != 0)
    290 			return error;
    291 
    292 		ep = (const long *) &buf[slen / sizeof(buf[0])];
    293 		for (i = 0, ep--; buf <= ep; ep--, i++) {
    294 			if (*ep)
    295 				break;
    296 		}
    297 		realsize -= i * sizeof(buf[0]);
    298 		if (i * sizeof(buf[0]) < slen)
    299 			break;
    300 	}
    301 
    302 	phdr.p_type = PT_LOAD;
    303 	phdr.p_offset = ws->secoff;
    304 	phdr.p_vaddr = us->start;
    305 	phdr.p_paddr = 0;
    306 	phdr.p_filesz = realsize;
    307 	phdr.p_memsz = size;
    308 	phdr.p_flags = 0;
    309 	if (us->prot & VM_PROT_READ)
    310 		phdr.p_flags |= PF_R;
    311 	if (us->prot & VM_PROT_WRITE)
    312 		phdr.p_flags |= PF_W;
    313 	if (us->prot & VM_PROT_EXECUTE)
    314 		phdr.p_flags |= PF_X;
    315 	phdr.p_align = PAGE_SIZE;
    316 
    317 	ws->secoff += phdr.p_filesz;
    318 	*ws->psections++ = phdr;
    319 
    320 	return (0);
    321 }
    322 
    323 static int
    324 ELFNAMEEND(coredump_notes)(struct proc *p, struct lwp *l,
    325     void *iocookie, size_t *sizep)
    326 {
    327 	struct netbsd_elfcore_procinfo cpi;
    328 	Elf_Nhdr nhdr;
    329 	size_t size, notesize;
    330 	int error;
    331 	struct lwp *l0;
    332 	sigset_t ss1, ss2;
    333 
    334 	size = 0;
    335 
    336 	/* First, write an elfcore_procinfo. */
    337 	notesize = sizeof(nhdr) + elfround(sizeof(ELF_NOTE_NETBSD_CORE_NAME)) +
    338 	    elfround(sizeof(cpi));
    339 	if (iocookie) {
    340 		cpi.cpi_version = NETBSD_ELFCORE_PROCINFO_VERSION;
    341 		cpi.cpi_cpisize = sizeof(cpi);
    342 		cpi.cpi_signo = p->p_sigctx.ps_signo;
    343 		cpi.cpi_sigcode = p->p_sigctx.ps_code;
    344 		cpi.cpi_siglwp = p->p_sigctx.ps_lwp;
    345 
    346 		/*
    347 		 * XXX This should be per-LWP.
    348 		 */
    349 		ss1 = p->p_sigpend.sp_set;
    350 		sigemptyset(&ss2);
    351 		LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
    352 			sigplusset(&l0->l_sigpend.sp_set, &ss1);
    353 			sigplusset(&l0->l_sigmask, &ss2);
    354 		}
    355 		memcpy(&cpi.cpi_sigpend, &ss1, sizeof(cpi.cpi_sigpend));
    356 		memcpy(&cpi.cpi_sigmask, &ss2, sizeof(cpi.cpi_sigmask));
    357 		memcpy(&cpi.cpi_sigignore, &p->p_sigctx.ps_sigignore,
    358 		    sizeof(cpi.cpi_sigignore));
    359 		memcpy(&cpi.cpi_sigcatch, &p->p_sigctx.ps_sigcatch,
    360 		    sizeof(cpi.cpi_sigcatch));
    361 
    362 		cpi.cpi_pid = p->p_pid;
    363 		mutex_enter(proc_lock);
    364 		cpi.cpi_ppid = p->p_pptr->p_pid;
    365 		cpi.cpi_pgrp = p->p_pgid;
    366 		cpi.cpi_sid = p->p_session->s_sid;
    367 		mutex_exit(proc_lock);
    368 
    369 		cpi.cpi_ruid = kauth_cred_getuid(l->l_cred);
    370 		cpi.cpi_euid = kauth_cred_geteuid(l->l_cred);
    371 		cpi.cpi_svuid = kauth_cred_getsvuid(l->l_cred);
    372 
    373 		cpi.cpi_rgid = kauth_cred_getgid(l->l_cred);
    374 		cpi.cpi_egid = kauth_cred_getegid(l->l_cred);
    375 		cpi.cpi_svgid = kauth_cred_getsvgid(l->l_cred);
    376 
    377 		cpi.cpi_nlwps = p->p_nlwps;
    378 		(void)strncpy(cpi.cpi_name, p->p_comm, sizeof(cpi.cpi_name));
    379 		cpi.cpi_name[sizeof(cpi.cpi_name) - 1] = '\0';
    380 
    381 		nhdr.n_namesz = sizeof(ELF_NOTE_NETBSD_CORE_NAME);
    382 		nhdr.n_descsz = sizeof(cpi);
    383 		nhdr.n_type = ELF_NOTE_NETBSD_CORE_PROCINFO;
    384 
    385 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
    386 		    ELF_NOTE_NETBSD_CORE_NAME "\0\0\0", &cpi);
    387 		if (error)
    388 			return (error);
    389 	}
    390 
    391 	size += notesize;
    392 
    393 	/* XXX Add hook for machdep per-proc notes. */
    394 
    395 	/*
    396 	 * Now write the register info for the thread that caused the
    397 	 * coredump.
    398 	 */
    399 	error = ELFNAMEEND(coredump_note)(p, l, iocookie, &notesize);
    400 	if (error)
    401 		return (error);
    402 	size += notesize;
    403 
    404 	/*
    405 	 * Now, for each LWP, write the register info and any other
    406 	 * per-LWP notes.  Since we're dumping core, we don't bother
    407 	 * locking.
    408 	 */
    409 	LIST_FOREACH(l0, &p->p_lwps, l_sibling) {
    410 		if (l0 == l)		/* we've taken care of this thread */
    411 			continue;
    412 		error = ELFNAMEEND(coredump_note)(p, l0, iocookie, &notesize);
    413 		if (error)
    414 			return (error);
    415 		size += notesize;
    416 	}
    417 
    418 	*sizep = size;
    419 	return (0);
    420 }
    421 
    422 static int
    423 ELFNAMEEND(coredump_note)(struct proc *p, struct lwp *l, void *iocookie,
    424     size_t *sizep)
    425 {
    426 	Elf_Nhdr nhdr;
    427 	int size, notesize, error;
    428 	int namesize;
    429 	char name[64+ELFROUNDSIZE];
    430 	elf_reg intreg;
    431 #ifdef PT_GETFPREGS
    432 	elf_fpreg freg;
    433 #endif
    434 
    435 	size = 0;
    436 
    437 	snprintf(name, sizeof(name)-ELFROUNDSIZE, "%s@%d",
    438 	    ELF_NOTE_NETBSD_CORE_NAME, l->l_lid);
    439 	namesize = strlen(name) + 1;
    440 	memset(name + namesize, 0, elfround(namesize) - namesize);
    441 
    442 	notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(intreg));
    443 	if (iocookie) {
    444 		error = elf_process_read_regs(l, &intreg);
    445 		if (error)
    446 			return (error);
    447 
    448 		nhdr.n_namesz = namesize;
    449 		nhdr.n_descsz = sizeof(intreg);
    450 		nhdr.n_type = PT_GETREGS;
    451 
    452 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
    453 		    name, &intreg);
    454 		if (error)
    455 			return (error);
    456 
    457 	}
    458 	size += notesize;
    459 
    460 #ifdef PT_GETFPREGS
    461 	notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(freg));
    462 	if (iocookie) {
    463 		size_t freglen = sizeof(freg);
    464 #ifdef __HAVE_PROCESS_XFPREGS
    465 		error = elf_process_read_xfpregs(l, &freg, &freglen);
    466 #else
    467 		error = elf_process_read_fpregs(l, &freg);
    468 #endif
    469 		if (error)
    470 			return (error);
    471 
    472 		nhdr.n_namesz = namesize;
    473 		nhdr.n_descsz = freglen;
    474 		nhdr.n_type = PT_GETFPREGS;
    475 
    476 		error = ELFNAMEEND(coredump_writenote)(p, iocookie, &nhdr,
    477 		    name, &freg);
    478 		if (error)
    479 			return (error);
    480 	}
    481 	size += notesize;
    482 #endif
    483 	*sizep = size;
    484 	/* XXX Add hook for machdep per-LWP notes. */
    485 	return (0);
    486 }
    487 
    488 int
    489 ELFNAMEEND(coredump_writenote)(struct proc *p, void *cookie, Elf_Nhdr *nhdr,
    490     const char *name, void *data)
    491 {
    492 	int error;
    493 
    494 	error = coredump_write(cookie, UIO_SYSSPACE, nhdr, sizeof(*nhdr));
    495 	if (error)
    496 		return error;
    497 
    498 	error = coredump_write(cookie, UIO_SYSSPACE, name,
    499 	    elfround(nhdr->n_namesz));
    500 	if (error)
    501 		return error;
    502 
    503 	return coredump_write(cookie, UIO_SYSSPACE, data, nhdr->n_descsz);
    504 }
    505 
    506 #else	/* COREDUMP */
    507 
    508 int
    509 ELFNAMEEND(coredump)(struct lwp *l, void *cookie)
    510 {
    511 
    512 	return ENOSYS;
    513 }
    514 
    515 #endif	/* COREDUMP */
    516