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author | Alfred Perlstein <alfred@FreeBSD.org> | 2010-03-02 06:58:58 +0000 |
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committer | Alfred Perlstein <alfred@FreeBSD.org> | 2010-03-02 06:58:58 +0000 |
commit | e7228204343ac61d2316e74891e3606361a23f6e (patch) | |
tree | f83c2f2fdc768503cc062e89b74034f42a21dc98 /sys/kern/kern_gzio.c | |
parent | 24179b01409038c958cdeb06e602d9878d06db1b (diff) | |
download | src-e7228204343ac61d2316e74891e3606361a23f6e.tar.gz src-e7228204343ac61d2316e74891e3606361a23f6e.zip |
Merge projects/enhanced_coredumps (r204346) into HEAD:
Enhanced process coredump routines.
This brings in the following features:
1) Limit number of cores per process via the %I coredump formatter.
Example:
if corefilename is set to %N.%I.core AND num_cores = 3, then
if a process "rpd" cores, then the corefile will be named
"rpd.0.core", however if it cores again, then the kernel will
generate "rpd.1.core" until we hit the limit of "num_cores".
this is useful to get several corefiles, but also prevent filling
the machine with corefiles.
2) Encode machine hostname in core dump name via %H.
3) Compress coredumps, useful for embedded platforms with limited space.
A sysctl kern.compress_user_cores is made available if turned on.
To enable compressed coredumps, the following config options need to be set:
options COMPRESS_USER_CORES
device zlib # brings in the zlib requirements.
device gzio # brings in the kernel vnode gzip output module.
4) Eventhandlers are fired to indicate coredumps in progress.
5) The imgact sv_coredump routine has grown a flag to pass in more
state, currently this is used only for passing a flag down to compress
the coredump or not.
Note that the gzio facility can be used for generic output of gzip'd
streams via vnodes.
Obtained from: Juniper Networks
Reviewed by: kan
Notes
Notes:
svn path=/head/; revision=204552
Diffstat (limited to 'sys/kern/kern_gzio.c')
-rw-r--r-- | sys/kern/kern_gzio.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/sys/kern/kern_gzio.c b/sys/kern/kern_gzio.c new file mode 100644 index 000000000000..1f9c387dffad --- /dev/null +++ b/sys/kern/kern_gzio.c @@ -0,0 +1,406 @@ +/* + * $Id: kern_gzio.c,v 1.6 2008-10-18 22:54:45 lbazinet Exp $ + * + * core_gzip.c -- gzip routines used in compressing user process cores + * + * This file is derived from src/lib/libz/gzio.c in FreeBSD. + */ + +/* gzio.c -- IO on .gz files + * Copyright (C) 1995-1998 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + * + */ + +/* @(#) $FreeBSD$ */ + +#include <sys/param.h> +#include <sys/proc.h> +#include <sys/malloc.h> +#include <sys/vnode.h> +#include <sys/syslog.h> +#include <sys/endian.h> +#include <net/zutil.h> +#include <sys/libkern.h> + +#include <sys/vnode.h> +#include <sys/mount.h> + +#define GZ_HEADER_LEN 10 + +#ifndef Z_BUFSIZE +# ifdef MAXSEG_64K +# define Z_BUFSIZE 4096 /* minimize memory usage for 16-bit DOS */ +# else +# define Z_BUFSIZE 16384 +# endif +#endif +#ifndef Z_PRINTF_BUFSIZE +# define Z_PRINTF_BUFSIZE 4096 +#endif + +#define ALLOC(size) malloc(size, M_TEMP, M_WAITOK | M_ZERO) +#define TRYFREE(p) {if (p) free(p, M_TEMP);} + +static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */ + +/* gzip flag byte */ +#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ +#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */ +#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ +#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ +#define COMMENT 0x10 /* bit 4 set: file comment present */ +#define RESERVED 0xE0 /* bits 5..7: reserved */ + +typedef struct gz_stream { + z_stream stream; + int z_err; /* error code for last stream operation */ + int z_eof; /* set if end of input file */ + struct vnode *file; /* vnode pointer of .gz file */ + Byte *inbuf; /* input buffer */ + Byte *outbuf; /* output buffer */ + uLong crc; /* crc32 of uncompressed data */ + char *msg; /* error message */ + char *path; /* path name for debugging only */ + int transparent; /* 1 if input file is not a .gz file */ + char mode; /* 'w' or 'r' */ + long startpos; /* start of compressed data in file (header skipped) */ + off_t outoff; /* current offset in output file */ + int flags; +} gz_stream; + + +local int do_flush OF((gzFile file, int flush)); +local int destroy OF((gz_stream *s)); +local void putU32 OF((gz_stream *file, uint32_t x)); +local void *gz_alloc OF((void *notused, u_int items, u_int size)); +local void gz_free OF((void *notused, void *ptr)); + +/* =========================================================================== + Opens a gzip (.gz) file for reading or writing. The mode parameter + is as in fopen ("rb" or "wb"). The file is given either by file descriptor + or path name (if fd == -1). + gz_open return NULL if the file could not be opened or if there was + insufficient memory to allocate the (de)compression state; errno + can be checked to distinguish the two cases (if errno is zero, the + zlib error is Z_MEM_ERROR). +*/ +gzFile gz_open (path, mode, vp) + const char *path; + const char *mode; + struct vnode *vp; +{ + int err; + int level = Z_DEFAULT_COMPRESSION; /* compression level */ + int strategy = Z_DEFAULT_STRATEGY; /* compression strategy */ + const char *p = mode; + gz_stream *s; + char fmode[80]; /* copy of mode, without the compression level */ + char *m = fmode; + int resid; + int error; + char buf[GZ_HEADER_LEN + 1]; + + if (!path || !mode) return Z_NULL; + + s = (gz_stream *)ALLOC(sizeof(gz_stream)); + if (!s) return Z_NULL; + + s->stream.zalloc = (alloc_func)gz_alloc; + s->stream.zfree = (free_func)gz_free; + s->stream.opaque = (voidpf)0; + s->stream.next_in = s->inbuf = Z_NULL; + s->stream.next_out = s->outbuf = Z_NULL; + s->stream.avail_in = s->stream.avail_out = 0; + s->file = NULL; + s->z_err = Z_OK; + s->z_eof = 0; + s->crc = 0; + s->msg = NULL; + s->transparent = 0; + s->outoff = 0; + s->flags = 0; + + s->path = (char*)ALLOC(strlen(path)+1); + if (s->path == NULL) { + return destroy(s), (gzFile)Z_NULL; + } + strcpy(s->path, path); /* do this early for debugging */ + + s->mode = '\0'; + do { + if (*p == 'r') s->mode = 'r'; + if (*p == 'w' || *p == 'a') s->mode = 'w'; + if (*p >= '0' && *p <= '9') { + level = *p - '0'; + } else if (*p == 'f') { + strategy = Z_FILTERED; + } else if (*p == 'h') { + strategy = Z_HUFFMAN_ONLY; + } else { + *m++ = *p; /* copy the mode */ + } + } while (*p++ && m != fmode + sizeof(fmode)); + + if (s->mode != 'w') { + log(LOG_ERR, "gz_open: mode is not w (%c)\n", s->mode); + return destroy(s), (gzFile)Z_NULL; + } + + err = deflateInit2(&(s->stream), level, + Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, strategy); + /* windowBits is passed < 0 to suppress zlib header */ + + s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE); + if (err != Z_OK || s->outbuf == Z_NULL) { + return destroy(s), (gzFile)Z_NULL; + } + + s->stream.avail_out = Z_BUFSIZE; + s->file = vp; + + /* Write a very simple .gz header: + */ + snprintf(buf, sizeof(buf), "%c%c%c%c%c%c%c%c%c%c", gz_magic[0], + gz_magic[1], Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/, + 0 /*xflags*/, OS_CODE); + + if ((error = vn_rdwr(UIO_WRITE, s->file, buf, GZ_HEADER_LEN, s->outoff, + UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, curproc->p_ucred, + NOCRED, &resid, curthread))) { + s->outoff += GZ_HEADER_LEN - resid; + return destroy(s), (gzFile)Z_NULL; + } + s->outoff += GZ_HEADER_LEN; + s->startpos = 10L; + + return (gzFile)s; +} + + + /* =========================================================================== + * Cleanup then free the given gz_stream. Return a zlib error code. + Try freeing in the reverse order of allocations. + */ +local int destroy (s) + gz_stream *s; +{ + int err = Z_OK; + + if (!s) return Z_STREAM_ERROR; + + TRYFREE(s->msg); + + if (s->stream.state != NULL) { + if (s->mode == 'w') { + err = deflateEnd(&(s->stream)); + } + } + if (s->z_err < 0) err = s->z_err; + + TRYFREE(s->inbuf); + TRYFREE(s->outbuf); + TRYFREE(s->path); + TRYFREE(s); + return err; +} + + +/* =========================================================================== + Writes the given number of uncompressed bytes into the compressed file. + gzwrite returns the number of bytes actually written (0 in case of error). +*/ +int ZEXPORT gzwrite (file, buf, len) + gzFile file; + const voidp buf; + unsigned len; +{ + gz_stream *s = (gz_stream*)file; + off_t curoff; + size_t resid; + int error; + int vfslocked; + + if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR; + + s->stream.next_in = (Bytef*)buf; + s->stream.avail_in = len; + + curoff = s->outoff; + while (s->stream.avail_in != 0) { + + if (s->stream.avail_out == 0) { + + s->stream.next_out = s->outbuf; + vfslocked = VFS_LOCK_GIANT(s->file->v_mount); + error = vn_rdwr_inchunks(UIO_WRITE, s->file, s->outbuf, Z_BUFSIZE, + curoff, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, + curproc->p_ucred, NOCRED, &resid, curthread); + VFS_UNLOCK_GIANT(vfslocked); + if (error) { + log(LOG_ERR, "gzwrite: vn_rdwr return %d\n", error); + curoff += Z_BUFSIZE - resid; + s->z_err = Z_ERRNO; + break; + } + curoff += Z_BUFSIZE; + s->stream.avail_out = Z_BUFSIZE; + } + s->z_err = deflate(&(s->stream), Z_NO_FLUSH); + if (s->z_err != Z_OK) { + log(LOG_ERR, + "gzwrite: deflate returned error %d\n", s->z_err); + break; + } + } + + s->crc = ~crc32_raw(buf, len, ~s->crc); + s->outoff = curoff; + + return (int)(len - s->stream.avail_in); +} + + +/* =========================================================================== + Flushes all pending output into the compressed file. The parameter + flush is as in the deflate() function. +*/ +local int do_flush (file, flush) + gzFile file; + int flush; +{ + uInt len; + int done = 0; + gz_stream *s = (gz_stream*)file; + off_t curoff = s->outoff; + size_t resid; + int vfslocked = 0; + int error; + + if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR; + + if (s->stream.avail_in) { + log(LOG_WARNING, "do_flush: avail_in non-zero on entry\n"); + } + + s->stream.avail_in = 0; /* should be zero already anyway */ + + for (;;) { + len = Z_BUFSIZE - s->stream.avail_out; + + if (len != 0) { + vfslocked = VFS_LOCK_GIANT(s->file->v_mount); + error = vn_rdwr_inchunks(UIO_WRITE, s->file, s->outbuf, len, curoff, + UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, curproc->p_ucred, + NOCRED, &resid, curthread); + VFS_UNLOCK_GIANT(vfslocked); + if (error) { + s->z_err = Z_ERRNO; + s->outoff = curoff + len - resid; + return Z_ERRNO; + } + s->stream.next_out = s->outbuf; + s->stream.avail_out = Z_BUFSIZE; + curoff += len; + } + if (done) break; + s->z_err = deflate(&(s->stream), flush); + + /* Ignore the second of two consecutive flushes: */ + if (len == 0 && s->z_err == Z_BUF_ERROR) s->z_err = Z_OK; + + /* deflate has finished flushing only when it hasn't used up + * all the available space in the output buffer: + */ + done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END); + + if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break; + } + s->outoff = curoff; + + return s->z_err == Z_STREAM_END ? Z_OK : s->z_err; +} + +int ZEXPORT gzflush (file, flush) + gzFile file; + int flush; +{ + gz_stream *s = (gz_stream*)file; + int err = do_flush (file, flush); + + if (err) return err; + return s->z_err == Z_STREAM_END ? Z_OK : s->z_err; +} + + +/* =========================================================================== + Outputs a long in LSB order to the given file +*/ +local void putU32 (s, x) + gz_stream *s; + uint32_t x; +{ + uint32_t xx; + off_t curoff = s->outoff; + int resid; + +#if BYTE_ORDER == BIG_ENDIAN + xx = bswap32(x); +#else + xx = x; +#endif + vn_rdwr(UIO_WRITE, s->file, (caddr_t)&xx, sizeof(xx), curoff, + UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, curproc->p_ucred, + NOCRED, &resid, curthread); + s->outoff += sizeof(xx) - resid; +} + + +/* =========================================================================== + Flushes all pending output if necessary, closes the compressed file + and deallocates all the (de)compression state. +*/ +int ZEXPORT gzclose (file) + gzFile file; +{ + int err; + gz_stream *s = (gz_stream*)file; + + if (s == NULL) return Z_STREAM_ERROR; + + if (s->mode == 'w') { + err = do_flush (file, Z_FINISH); + if (err != Z_OK) { + log(LOG_ERR, "gzclose: do_flush failed (err %d)\n", err); + return destroy((gz_stream*)file); + } +#if 0 + printf("gzclose: putting crc: %lld total: %lld\n", + (long long)s->crc, (long long)s->stream.total_in); + printf("sizeof uLong = %d\n", (int)sizeof(uLong)); +#endif + putU32 (s, s->crc); + putU32 (s, (uint32_t) s->stream.total_in); + } + return destroy((gz_stream*)file); +} + +/* + * Space allocation and freeing routines for use by zlib routines when called + * from gzip modules. + */ +static void * +gz_alloc(void *notused __unused, u_int items, u_int size) +{ + void *ptr; + + MALLOC(ptr, void *, items * size, M_TEMP, M_NOWAIT | M_ZERO); + return ptr; +} + +static void +gz_free(void *opaque __unused, void *ptr) +{ + FREE(ptr, M_TEMP); +} + |