| db_textdump.c (174921) | db_textdump.c (175199) |
|---|---|
| 1/*- 2 * Copyright (c) 2007 Robert N. M. Watson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 11 unchanged lines hidden (view full) --- 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27/*- | 1/*- 2 * Copyright (c) 2007 Robert N. M. Watson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 11 unchanged lines hidden (view full) --- 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27/*- |
| 28 * Kernel text-dump support: allow a series of text files to be written to 29 * the dump partition for later recovery, including captured DDB output, the 30 * kernel configuration, message buffer, panic message, etc. This allows for 31 * a more compact representation of critical debugging information than 32 * traditional binary dumps, as well as allowing dump information to be used 33 * without access to kernel symbols, source code, etc. | 28 * Kernel text-dump support: write a series of text files to the dump 29 * partition for later recovery, including captured DDB output, kernel 30 * configuration, message buffer, and panic message. This allows for a more 31 * compact representation of critical debugging information than traditional 32 * binary dumps, as well as allowing dump information to be used without 33 * access to kernel symbols, source code, etc. |
| 34 * 35 * Storage Layout 36 * -------------- 37 * 38 * Crash dumps are aligned to the end of the dump or swap partition in order 39 * to minimize the chances of swap duing fsck eating into the dump. However, 40 * unlike a memory dump, we don't know the size of the textdump a priori, so 41 * can't just write it out sequentially in order from a known starting point 42 * calculated with respect to the end of the partition. In order to address 43 * this, we actually write out the textdump in reverse block order, allowing 44 * us to directly align it to the end of the partition and then write out the 45 * dump header and trailer before and after it once done. savecore(8) must 46 * know to reverse the order of the blocks in order to produce a readable 47 * file. 48 * | 34 * 35 * Storage Layout 36 * -------------- 37 * 38 * Crash dumps are aligned to the end of the dump or swap partition in order 39 * to minimize the chances of swap duing fsck eating into the dump. However, 40 * unlike a memory dump, we don't know the size of the textdump a priori, so 41 * can't just write it out sequentially in order from a known starting point 42 * calculated with respect to the end of the partition. In order to address 43 * this, we actually write out the textdump in reverse block order, allowing 44 * us to directly align it to the end of the partition and then write out the 45 * dump header and trailer before and after it once done. savecore(8) must 46 * know to reverse the order of the blocks in order to produce a readable 47 * file. 48 * |
| 49 * Data is written out in the 'tar' file format, as it provides the facility 50 * to write data incrementally as a stream without reference to previous 51 * files. | 49 * Data is written out in the ustar file format so that we can write data 50 * incrementally as a stream without reference to previous files. |
| 52 * 53 * TODO 54 * ---- 55 * 56 * - Allow subsytems to register to submit files for inclusion in the text 57 * dump in a generic way. 58 */ 59 60#include <sys/cdefs.h> | 51 * 52 * TODO 53 * ---- 54 * 55 * - Allow subsytems to register to submit files for inclusion in the text 56 * dump in a generic way. 57 */ 58 59#include <sys/cdefs.h> |
| 61__FBSDID("$FreeBSD: head/sys/ddb/db_textdump.c 174921 2007-12-26 11:32:33Z rwatson $"); | 60__FBSDID("$FreeBSD: head/sys/ddb/db_textdump.c 175199 2008-01-10 00:26:47Z rwatson $"); |
| 62 63#include "opt_config.h" 64 65#include <sys/param.h> 66#include <sys/conf.h> 67#include <sys/kernel.h> 68#include <sys/kerneldump.h> 69#include <sys/msgbuf.h> --- 126 unchanged lines hidden (view full) --- 196 strncpy(kdh->hostname, hostname, sizeof(kdh->hostname)); 197 strncpy(kdh->versionstring, version, sizeof(kdh->versionstring)); 198 if (panicstr != NULL) 199 strncpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring)); 200 kdh->parity = kerneldump_parity(kdh); 201} 202 203/* | 61 62#include "opt_config.h" 63 64#include <sys/param.h> 65#include <sys/conf.h> 66#include <sys/kernel.h> 67#include <sys/kerneldump.h> 68#include <sys/msgbuf.h> --- 126 unchanged lines hidden (view full) --- 195 strncpy(kdh->hostname, hostname, sizeof(kdh->hostname)); 196 strncpy(kdh->versionstring, version, sizeof(kdh->versionstring)); 197 if (panicstr != NULL) 198 strncpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring)); 199 kdh->parity = kerneldump_parity(kdh); 200} 201 202/* |
| 204 * Calculate and fill in the checksum for a tar header. | 203 * Calculate and fill in the checksum for a ustar header. |
| 205 */ 206static void 207ustar_checksum(struct ustar_header *uhp) 208{ 209 u_int sum; 210 int i; 211 212 for (i = 0; i < sizeof(uhp->uh_sum); i++) --- 51 unchanged lines hidden (view full) --- 264 di->mediaoffset, TEXTDUMP_BLOCKSIZE); 265 return (textdump_error); 266} 267 268/* 269 * Interfaces to save and restore the dump offset, so that printers can go 270 * back to rewrite a header if required, while avoiding their knowing about 271 * the global layout of the blocks. | 204 */ 205static void 206ustar_checksum(struct ustar_header *uhp) 207{ 208 u_int sum; 209 int i; 210 211 for (i = 0; i < sizeof(uhp->uh_sum); i++) --- 51 unchanged lines hidden (view full) --- 263 di->mediaoffset, TEXTDUMP_BLOCKSIZE); 264 return (textdump_error); 265} 266 267/* 268 * Interfaces to save and restore the dump offset, so that printers can go 269 * back to rewrite a header if required, while avoiding their knowing about 270 * the global layout of the blocks. |
| 271 * 272 * If we ever want to support writing textdumps to tape or other 273 * stream-oriented target, we'll need to remove this. |
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| 272 */ 273void 274textdump_saveoff(off_t *offsetp) 275{ 276 277 *offsetp = textdump_offset; 278} 279 --- 276 unchanged lines hidden --- | 274 */ 275void 276textdump_saveoff(off_t *offsetp) 277{ 278 279 *offsetp = textdump_offset; 280} 281 --- 276 unchanged lines hidden --- |