From 30d65dbfe3add7f010a075991dc0bfeaebb7d9e1 Mon Sep 17 00:00:00 2001 From: Alain Knaff Date: Sun, 4 Jan 2009 22:46:17 +0100 Subject: bzip2/lzma: config and initramfs support for bzip2/lzma decompression Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff Signed-off-by: H. Peter Anvin --- init/do_mounts_rd.c | 182 +++++++++++++++++++--------------------------------- 1 file changed, 65 insertions(+), 117 deletions(-) (limited to 'init/do_mounts_rd.c') diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c index a7c748fa977a..dcaeb1f90b32 100644 --- a/init/do_mounts_rd.c +++ b/init/do_mounts_rd.c @@ -10,6 +10,12 @@ #include "do_mounts.h" +#include + +#include +#include +#include + int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */ static int __init prompt_ramdisk(char *str) @@ -28,7 +34,7 @@ static int __init ramdisk_start_setup(char *str) } __setup("ramdisk_start=", ramdisk_start_setup); -static int __init crd_load(int in_fd, int out_fd); +static int __init crd_load(int in_fd, int out_fd, decompress_fn deco); /* * This routine tries to find a RAM disk image to load, and returns the @@ -44,7 +50,7 @@ static int __init crd_load(int in_fd, int out_fd); * gzip */ static int __init -identify_ramdisk_image(int fd, int start_block) +identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) { const int size = 512; struct minix_super_block *minixsb; @@ -70,6 +76,7 @@ identify_ramdisk_image(int fd, int start_block) sys_lseek(fd, start_block * BLOCK_SIZE, 0); sys_read(fd, buf, size); +#ifdef CONFIG_RD_GZIP /* * If it matches the gzip magic numbers, return 0 */ @@ -77,9 +84,39 @@ identify_ramdisk_image(int fd, int start_block) printk(KERN_NOTICE "RAMDISK: Compressed image found at block %d\n", start_block); + *decompressor = gunzip; + nblocks = 0; + goto done; + } +#endif + +#ifdef CONFIG_RD_BZIP2 + /* + * If it matches the bzip2 magic numbers, return -1 + */ + if (buf[0] == 0x42 && (buf[1] == 0x5a)) { + printk(KERN_NOTICE + "RAMDISK: Bzipped image found at block %d\n", + start_block); + *decompressor = bunzip2; + nblocks = 0; + goto done; + } +#endif + +#ifdef CONFIG_RD_LZMA + /* + * If it matches the lzma magic numbers, return -1 + */ + if (buf[0] == 0x5d && (buf[1] == 0x00)) { + printk(KERN_NOTICE + "RAMDISK: Lzma image found at block %d\n", + start_block); + *decompressor = unlzma; nblocks = 0; goto done; } +#endif /* romfs is at block zero too */ if (romfsb->word0 == ROMSB_WORD0 && @@ -143,6 +180,7 @@ int __init rd_load_image(char *from) int nblocks, i, disk; char *buf = NULL; unsigned short rotate = 0; + decompress_fn decompressor = NULL; #if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES) char rotator[4] = { '|' , '/' , '-' , '\\' }; #endif @@ -155,12 +193,12 @@ int __init rd_load_image(char *from) if (in_fd < 0) goto noclose_input; - nblocks = identify_ramdisk_image(in_fd, rd_image_start); + nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor); if (nblocks < 0) goto done; if (nblocks == 0) { - if (crd_load(in_fd, out_fd) == 0) + if (crd_load(in_fd, out_fd, decompressor) == 0) goto successful_load; goto done; } @@ -259,138 +297,48 @@ int __init rd_load_disk(int n) return rd_load_image("/dev/root"); } -/* - * gzip declarations - */ - -#define OF(args) args - -#ifndef memzero -#define memzero(s, n) memset ((s), 0, (n)) -#endif - -typedef unsigned char uch; -typedef unsigned short ush; -typedef unsigned long ulg; - -#define INBUFSIZ 4096 -#define WSIZE 0x8000 /* window size--must be a power of two, and */ - /* at least 32K for zip's deflate method */ - -static uch *inbuf; -static uch *window; - -static unsigned insize; /* valid bytes in inbuf */ -static unsigned inptr; /* index of next byte to be processed in inbuf */ -static unsigned outcnt; /* bytes in output buffer */ static int exit_code; -static int unzip_error; -static long bytes_out; +static int decompress_error; static int crd_infd, crd_outfd; -#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf()) - -/* Diagnostic functions (stubbed out) */ -#define Assert(cond,msg) -#define Trace(x) -#define Tracev(x) -#define Tracevv(x) -#define Tracec(c,x) -#define Tracecv(c,x) - -#define STATIC static -#define INIT __init - -static int __init fill_inbuf(void); -static void __init flush_window(void); -static void __init error(char *m); - -#define NO_INFLATE_MALLOC - -#include "../lib/inflate.c" - -/* =========================================================================== - * Fill the input buffer. This is called only when the buffer is empty - * and at least one byte is really needed. - * Returning -1 does not guarantee that gunzip() will ever return. - */ -static int __init fill_inbuf(void) +static int __init compr_fill(void *buf, unsigned int len) { - if (exit_code) return -1; - - insize = sys_read(crd_infd, inbuf, INBUFSIZ); - if (insize == 0) { - error("RAMDISK: ran out of compressed data"); - return -1; - } - - inptr = 1; - - return inbuf[0]; + int r = sys_read(crd_infd, buf, len); + if (r < 0) + printk(KERN_ERR "RAMDISK: error while reading compressed data"); + else if (r == 0) + printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); + return r; } -/* =========================================================================== - * Write the output window window[0..outcnt-1] and update crc and bytes_out. - * (Used for the decompressed data only.) - */ -static void __init flush_window(void) +static int __init compr_flush(void *window, unsigned int outcnt) { - ulg c = crc; /* temporary variable */ - unsigned n, written; - uch *in, ch; - - written = sys_write(crd_outfd, window, outcnt); - if (written != outcnt && unzip_error == 0) { - printk(KERN_ERR "RAMDISK: incomplete write (%d != %d) %ld\n", - written, outcnt, bytes_out); - unzip_error = 1; - } - in = window; - for (n = 0; n < outcnt; n++) { - ch = *in++; - c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); - } - crc = c; - bytes_out += (ulg)outcnt; - outcnt = 0; + int written = sys_write(crd_outfd, window, outcnt); + if (written != outcnt) { + if (decompress_error == 0) + printk(KERN_ERR + "RAMDISK: incomplete write (%d != %d)\n", + written, outcnt); + decompress_error = 1; + return -1; + } + return outcnt; } static void __init error(char *x) { printk(KERN_ERR "%s\n", x); exit_code = 1; - unzip_error = 1; + decompress_error = 1; } -static int __init crd_load(int in_fd, int out_fd) +static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) { int result; - - insize = 0; /* valid bytes in inbuf */ - inptr = 0; /* index of next byte to be processed in inbuf */ - outcnt = 0; /* bytes in output buffer */ - exit_code = 0; - bytes_out = 0; - crc = (ulg)0xffffffffL; /* shift register contents */ - crd_infd = in_fd; crd_outfd = out_fd; - inbuf = kmalloc(INBUFSIZ, GFP_KERNEL); - if (!inbuf) { - printk(KERN_ERR "RAMDISK: Couldn't allocate gzip buffer\n"); - return -1; - } - window = kmalloc(WSIZE, GFP_KERNEL); - if (!window) { - printk(KERN_ERR "RAMDISK: Couldn't allocate gzip window\n"); - kfree(inbuf); - return -1; - } - makecrc(); - result = gunzip(); - if (unzip_error) + result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); + if (decompress_error) result = 1; - kfree(inbuf); - kfree(window); return result; } -- cgit v1.2.2 From b172fd882d201cf8aa67cddd9c1a023421fd4956 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Sun, 4 Jan 2009 14:42:52 -0800 Subject: bzip2/lzma: use a table to search for initramfs compression formats Impact: Code simplification Instead of open-coding testing for initramfs compression formats, use a table. Signed-off-by: H. Peter Anvin --- init/do_mounts_rd.c | 82 +++++++++++++++++++++++------------------------------ 1 file changed, 35 insertions(+), 47 deletions(-) (limited to 'init/do_mounts_rd.c') diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c index dcaeb1f90b32..9c9d7dbcf9ca 100644 --- a/init/do_mounts_rd.c +++ b/init/do_mounts_rd.c @@ -43,13 +43,31 @@ static int __init crd_load(int in_fd, int out_fd, decompress_fn deco); * numbers could not be found. * * We currently check for the following magic numbers: - * minix - * ext2 + * minix + * ext2 * romfs * cramfs - * gzip + * gzip */ -static int __init +static const struct compress_format { + unsigned char magic[2]; + const char *name; + decompress_fn decompressor; +} compressed_formats[] = { +#ifdef CONFIG_RD_GZIP + { {037, 0213}, "gzip", gunzip }, + { {037, 0236}, "gzip", gunzip }, +#endif +#ifdef CONFIG_RD_BZIP2 + { {0x42, 0x5a}, "bzip2", bunzip2 }, +#endif +#ifdef CONFIG_RD_LZMA + { {0x5d, 0x00}, "lzma", unlzma }, +#endif + { {0, 0}, NULL, NULL } +}; + +static int __init identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) { const int size = 512; @@ -59,6 +77,7 @@ identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) struct cramfs_super *cramfsb; int nblocks = -1; unsigned char *buf; + const struct compress_format *cf; buf = kmalloc(size, GFP_KERNEL); if (!buf) @@ -71,52 +90,21 @@ identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) memset(buf, 0xe5, size); /* - * Read block 0 to test for gzipped kernel + * Read block 0 to test for compressed kernel */ sys_lseek(fd, start_block * BLOCK_SIZE, 0); sys_read(fd, buf, size); -#ifdef CONFIG_RD_GZIP - /* - * If it matches the gzip magic numbers, return 0 - */ - if (buf[0] == 037 && ((buf[1] == 0213) || (buf[1] == 0236))) { - printk(KERN_NOTICE - "RAMDISK: Compressed image found at block %d\n", - start_block); - *decompressor = gunzip; - nblocks = 0; - goto done; - } -#endif - -#ifdef CONFIG_RD_BZIP2 - /* - * If it matches the bzip2 magic numbers, return -1 - */ - if (buf[0] == 0x42 && (buf[1] == 0x5a)) { - printk(KERN_NOTICE - "RAMDISK: Bzipped image found at block %d\n", - start_block); - *decompressor = bunzip2; - nblocks = 0; - goto done; - } -#endif - -#ifdef CONFIG_RD_LZMA - /* - * If it matches the lzma magic numbers, return -1 - */ - if (buf[0] == 0x5d && (buf[1] == 0x00)) { - printk(KERN_NOTICE - "RAMDISK: Lzma image found at block %d\n", - start_block); - *decompressor = unlzma; - nblocks = 0; - goto done; + for (cf = compressed_formats; cf->decompressor; cf++) { + if (buf[0] == cf->magic[0] && buf[1] == cf->magic[1]) { + printk(KERN_NOTICE + "RAMDISK: %s image found at block %d\n", + cf->name, start_block); + *decompressor = cf->decompressor; + nblocks = 0; + goto done; + } } -#endif /* romfs is at block zero too */ if (romfsb->word0 == ROMSB_WORD0 && @@ -165,7 +153,7 @@ identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) printk(KERN_NOTICE "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", start_block); - + done: sys_lseek(fd, start_block * BLOCK_SIZE, 0); kfree(buf); @@ -224,7 +212,7 @@ int __init rd_load_image(char *from) nblocks, rd_blocks); goto done; } - + /* * OK, time to copy in the data */ -- cgit v1.2.2 From 889c92d21db40be0b7d22a59395060237895bb85 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Thu, 8 Jan 2009 15:14:17 -0800 Subject: bzip2/lzma: centralize format detection Centralize the compression format detection to a common routine in the lib directory, and use it for both initramfs and initrd. Signed-off-by: H. Peter Anvin --- init/do_mounts_rd.c | 38 +++++++------------------------------- 1 file changed, 7 insertions(+), 31 deletions(-) (limited to 'init/do_mounts_rd.c') diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c index 9c9d7dbcf9ca..a06ed4f92e0e 100644 --- a/init/do_mounts_rd.c +++ b/init/do_mounts_rd.c @@ -12,9 +12,6 @@ #include -#include -#include -#include int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */ @@ -49,24 +46,6 @@ static int __init crd_load(int in_fd, int out_fd, decompress_fn deco); * cramfs * gzip */ -static const struct compress_format { - unsigned char magic[2]; - const char *name; - decompress_fn decompressor; -} compressed_formats[] = { -#ifdef CONFIG_RD_GZIP - { {037, 0213}, "gzip", gunzip }, - { {037, 0236}, "gzip", gunzip }, -#endif -#ifdef CONFIG_RD_BZIP2 - { {0x42, 0x5a}, "bzip2", bunzip2 }, -#endif -#ifdef CONFIG_RD_LZMA - { {0x5d, 0x00}, "lzma", unlzma }, -#endif - { {0, 0}, NULL, NULL } -}; - static int __init identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) { @@ -77,7 +56,7 @@ identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) struct cramfs_super *cramfsb; int nblocks = -1; unsigned char *buf; - const struct compress_format *cf; + const char *compress_name; buf = kmalloc(size, GFP_KERNEL); if (!buf) @@ -95,15 +74,12 @@ identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) sys_lseek(fd, start_block * BLOCK_SIZE, 0); sys_read(fd, buf, size); - for (cf = compressed_formats; cf->decompressor; cf++) { - if (buf[0] == cf->magic[0] && buf[1] == cf->magic[1]) { - printk(KERN_NOTICE - "RAMDISK: %s image found at block %d\n", - cf->name, start_block); - *decompressor = cf->decompressor; - nblocks = 0; - goto done; - } + *decompressor = decompress_method(buf, size, &compress_name); + if (*decompressor) { + printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n", + compress_name, start_block); + nblocks = 0; + goto done; } /* romfs is at block zero too */ -- cgit v1.2.2 From 23a22d57a8962479ca630c9542e62d6f86fdf927 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 12 Jan 2009 14:24:04 -0800 Subject: bzip2/lzma: comprehensible error messages for missing decompressor Instead of failing to identify a compressed image with a decompressor that we don't have compiled in, identify it and fail with a comprehensible panic message. Signed-off-by: H. Peter Anvin --- init/do_mounts_rd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'init/do_mounts_rd.c') diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c index a015e267fd17..91d0cfca5071 100644 --- a/init/do_mounts_rd.c +++ b/init/do_mounts_rd.c @@ -79,9 +79,12 @@ identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) sys_read(fd, buf, size); *decompressor = decompress_method(buf, size, &compress_name); - if (*decompressor) { + if (compress_name) { printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n", compress_name, start_block); + if (!*decompressor) + printk(KERN_CRIT "RAMDISK: %s decompressor not configured!\n", + compress_name); nblocks = 0; goto done; } -- cgit v1.2.2 From 73310a169aebe257efdd35a763cce1c7658f40c9 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 14 Jan 2009 11:28:35 -0800 Subject: init: make initrd/initramfs decompression failure a KERN_EMERG event Impact: More consistent behaviour, avoid policy in the kernel Upgrade/downgrade initrd/initramfs decompression failure from inconsistently a panic or a KERN_ALERT message to a KERN_EMERG event. It is, however, possible do design a system which can recover from this (using the kernel builtin code and/or the internal initramfs), which means this is policy, not a technical necessity. A good way to handle this would be to have a panic-level=X option, to force a panic on a printk above a certain level. That is a separate patch, however. Signed-off-by: H. Peter Anvin --- init/do_mounts_rd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'init/do_mounts_rd.c') diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c index 91d0cfca5071..027a402708de 100644 --- a/init/do_mounts_rd.c +++ b/init/do_mounts_rd.c @@ -83,7 +83,8 @@ identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n", compress_name, start_block); if (!*decompressor) - printk(KERN_CRIT "RAMDISK: %s decompressor not configured!\n", + printk(KERN_EMERG + "RAMDISK: %s decompressor not configured!\n", compress_name); nblocks = 0; goto done; -- cgit v1.2.2