freebsd-dev/sys/kern/kern_dump.c
Mark Johnston bdb9ab0dd9 Factor out duplicated code from dumpsys() on each architecture into generic
code in sys/kern/kern_dump.c. Most dumpsys() implementations are nearly
identical and simply redefine a number of constants and helper subroutines;
a generic implementation will make it easier to implement features around
kernel core dumps. This change does not alter any minidump code and should
have no functional impact.

PR:		193873
Differential Revision:	https://reviews.freebsd.org/D904
Submitted by:	Conrad Meyer <conrad.meyer@isilon.com>
Reviewed by:	jhibbits (earlier version)
Sponsored by:	EMC / Isilon Storage Division
2015-01-07 01:01:39 +00:00

394 lines
9.0 KiB
C

/*-
* Copyright (c) 2002 Marcel Moolenaar
* 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.
* 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.
*
* 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 "opt_watchdog.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/kerneldump.h>
#ifdef SW_WATCHDOG
#include <sys/watchdog.h>
#endif
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <machine/dump.h>
#include <machine/elf.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
CTASSERT(sizeof(struct kerneldumpheader) == 512);
/*
* Don't touch the first SIZEOF_METADATA bytes on the dump device. This
* is to protect us from metadata and to protect metadata from us.
*/
#define SIZEOF_METADATA (64*1024)
#define MD_ALIGN(x) (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
#define DEV_ALIGN(x) (((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
off_t dumplo;
/* Handle buffered writes. */
static char buffer[DEV_BSIZE];
static size_t fragsz;
struct dump_pa dump_map[DUMPSYS_MD_PA_NPAIRS];
void
dumpsys_gen_pa_init(void)
{
#if !defined(__sparc__) && !defined(__powerpc__)
int n, idx;
bzero(dump_map, sizeof(dump_map));
for (n = 0; n < sizeof(dump_map) / sizeof(dump_map[0]); n++) {
idx = n * 2;
if (dump_avail[idx] == 0 && dump_avail[idx + 1] == 0)
break;
dump_map[n].pa_start = dump_avail[idx];
dump_map[n].pa_size = dump_avail[idx + 1] - dump_avail[idx];
}
#endif
}
struct dump_pa *
dumpsys_gen_pa_next(struct dump_pa *mdp)
{
if (mdp == NULL)
return (&dump_map[0]);
mdp++;
if (mdp->pa_size == 0)
mdp = NULL;
return (mdp);
}
void
dumpsys_gen_wbinv_all(void)
{
}
void
dumpsys_gen_unmap_chunk(vm_paddr_t pa __unused, size_t chunk __unused,
void *va __unused)
{
}
int
dumpsys_gen_write_aux_headers(struct dumperinfo *di)
{
return (0);
}
int
dumpsys_buf_write(struct dumperinfo *di, char *ptr, size_t sz)
{
size_t len;
int error;
while (sz) {
len = DEV_BSIZE - fragsz;
if (len > sz)
len = sz;
bcopy(ptr, buffer + fragsz, len);
fragsz += len;
ptr += len;
sz -= len;
if (fragsz == DEV_BSIZE) {
error = dump_write(di, buffer, 0, dumplo,
DEV_BSIZE);
if (error)
return (error);
dumplo += DEV_BSIZE;
fragsz = 0;
}
}
return (0);
}
int
dumpsys_buf_flush(struct dumperinfo *di)
{
int error;
if (fragsz == 0)
return (0);
error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
dumplo += DEV_BSIZE;
fragsz = 0;
return (error);
}
CTASSERT(PAGE_SHIFT < 20);
#define PG2MB(pgs) ((pgs + (1 << (20 - PAGE_SHIFT)) - 1) >> (20 - PAGE_SHIFT))
int
dumpsys_cb_dumpdata(struct dump_pa *mdp, int seqnr, void *arg)
{
struct dumperinfo *di = (struct dumperinfo*)arg;
vm_paddr_t pa;
void *va;
uint64_t pgs;
size_t counter, sz, chunk;
int c, error;
u_int maxdumppgs;
error = 0; /* catch case in which chunk size is 0 */
counter = 0; /* Update twiddle every 16MB */
va = 0;
pgs = mdp->pa_size / PAGE_SIZE;
pa = mdp->pa_start;
maxdumppgs = min(di->maxiosize / PAGE_SIZE, MAXDUMPPGS);
if (maxdumppgs == 0) /* seatbelt */
maxdumppgs = 1;
printf(" chunk %d: %juMB (%ju pages)", seqnr, (uintmax_t)PG2MB(pgs),
(uintmax_t)pgs);
dumpsys_wbinv_all();
while (pgs) {
chunk = pgs;
if (chunk > maxdumppgs)
chunk = maxdumppgs;
sz = chunk << PAGE_SHIFT;
counter += sz;
if (counter >> 24) {
printf(" %ju", (uintmax_t)PG2MB(pgs));
counter &= (1 << 24) - 1;
}
dumpsys_map_chunk(pa, chunk, &va);
#ifdef SW_WATCHDOG
wdog_kern_pat(WD_LASTVAL);
#endif
error = dump_write(di, va, 0, dumplo, sz);
dumpsys_unmap_chunk(pa, chunk, va);
if (error)
break;
dumplo += sz;
pgs -= chunk;
pa += sz;
/* Check for user abort. */
c = cncheckc();
if (c == 0x03)
return (ECANCELED);
if (c != -1)
printf(" (CTRL-C to abort) ");
}
printf(" ... %s\n", (error) ? "fail" : "ok");
return (error);
}
int
dumpsys_foreach_chunk(dumpsys_callback_t cb, void *arg)
{
struct dump_pa *mdp;
int error, seqnr;
seqnr = 0;
mdp = dumpsys_pa_next(NULL);
while (mdp != NULL) {
error = (*cb)(mdp, seqnr++, arg);
if (error)
return (-error);
mdp = dumpsys_pa_next(mdp);
}
return (seqnr);
}
static off_t fileofs;
static int
cb_dumphdr(struct dump_pa *mdp, int seqnr, void *arg)
{
struct dumperinfo *di = (struct dumperinfo*)arg;
Elf_Phdr phdr;
uint64_t size;
int error;
size = mdp->pa_size;
bzero(&phdr, sizeof(phdr));
phdr.p_type = PT_LOAD;
phdr.p_flags = PF_R; /* XXX */
phdr.p_offset = fileofs;
#ifdef __powerpc__
phdr.p_vaddr = (do_minidump? mdp->pa_start : ~0L);
phdr.p_paddr = (do_minidump? ~0L : mdp->pa_start);
#else
phdr.p_vaddr = mdp->pa_start;
phdr.p_paddr = mdp->pa_start;
#endif
phdr.p_filesz = size;
phdr.p_memsz = size;
phdr.p_align = PAGE_SIZE;
error = dumpsys_buf_write(di, (char*)&phdr, sizeof(phdr));
fileofs += phdr.p_filesz;
return (error);
}
static int
cb_size(struct dump_pa *mdp, int seqnr, void *arg)
{
uint64_t *sz;
sz = (uint64_t *)arg;
*sz += (uint64_t)mdp->pa_size;
return (0);
}
int
dumpsys_generic(struct dumperinfo *di)
{
static struct kerneldumpheader kdh;
Elf_Ehdr ehdr;
uint64_t dumpsize;
off_t hdrgap;
size_t hdrsz;
int error;
#ifndef __powerpc__
if (do_minidump)
return (minidumpsys(di));
#endif
bzero(&ehdr, sizeof(ehdr));
ehdr.e_ident[EI_MAG0] = ELFMAG0;
ehdr.e_ident[EI_MAG1] = ELFMAG1;
ehdr.e_ident[EI_MAG2] = ELFMAG2;
ehdr.e_ident[EI_MAG3] = ELFMAG3;
ehdr.e_ident[EI_CLASS] = ELF_CLASS;
#if BYTE_ORDER == LITTLE_ENDIAN
ehdr.e_ident[EI_DATA] = ELFDATA2LSB;
#else
ehdr.e_ident[EI_DATA] = ELFDATA2MSB;
#endif
ehdr.e_ident[EI_VERSION] = EV_CURRENT;
ehdr.e_ident[EI_OSABI] = ELFOSABI_STANDALONE; /* XXX big picture? */
ehdr.e_type = ET_CORE;
ehdr.e_machine = EM_VALUE;
ehdr.e_phoff = sizeof(ehdr);
ehdr.e_flags = 0;
ehdr.e_ehsize = sizeof(ehdr);
ehdr.e_phentsize = sizeof(Elf_Phdr);
ehdr.e_shentsize = sizeof(Elf_Shdr);
dumpsys_pa_init();
/* Calculate dump size. */
dumpsize = 0L;
ehdr.e_phnum = dumpsys_foreach_chunk(cb_size, &dumpsize) +
DUMPSYS_NUM_AUX_HDRS;
hdrsz = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
fileofs = MD_ALIGN(hdrsz);
dumpsize += fileofs;
hdrgap = fileofs - DEV_ALIGN(hdrsz);
/* Determine dump offset on device. */
if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
error = ENOSPC;
goto fail;
}
dumplo = di->mediaoffset + di->mediasize - dumpsize;
dumplo -= sizeof(kdh) * 2;
mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_ARCH_VERSION, dumpsize,
di->blocksize);
printf("Dumping %ju MB (%d chunks)\n", (uintmax_t)dumpsize >> 20,
ehdr.e_phnum - DUMPSYS_NUM_AUX_HDRS);
/* Dump leader */
error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
if (error)
goto fail;
dumplo += sizeof(kdh);
/* Dump ELF header */
error = dumpsys_buf_write(di, (char*)&ehdr, sizeof(ehdr));
if (error)
goto fail;
/* Dump program headers */
error = dumpsys_foreach_chunk(cb_dumphdr, di);
if (error < 0)
goto fail;
error = dumpsys_write_aux_headers(di);
if (error < 0)
goto fail;
dumpsys_buf_flush(di);
/*
* All headers are written using blocked I/O, so we know the
* current offset is (still) block aligned. Skip the alignement
* in the file to have the segment contents aligned at page
* boundary. We cannot use MD_ALIGN on dumplo, because we don't
* care and may very well be unaligned within the dump device.
*/
dumplo += hdrgap;
/* Dump memory chunks (updates dumplo) */
error = dumpsys_foreach_chunk(dumpsys_cb_dumpdata, di);
if (error < 0)
goto fail;
/* Dump trailer */
error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
if (error)
goto fail;
/* Signal completion, signoff and exit stage left. */
dump_write(di, NULL, 0, 0, 0);
printf("\nDump complete\n");
return (0);
fail:
if (error < 0)
error = -error;
if (error == ECANCELED)
printf("\nDump aborted\n");
else if (error == ENOSPC)
printf("\nDump failed. Partition too small.\n");
else
printf("\n** DUMP FAILED (ERROR %d) **\n", error);
return (error);
}