On Thu, Aug 13, 2009 at 09:47:27AM +0200, Chris Lalancette wrote:
> All,
> Recent upstream kernels can be compressed using either gzip, bzip2, or
> LZMA. However, the PV kernel loader in Xen currently only understands gzip,
> and
> will fail on the other two types. The attached patch implements kernel
> decompression for gzip, bzip2, and LZMA so that kernels compressed with any of
> these methods can be launched. Note that the patch is still a little bit
> rough,
> but I thought I would post it to get feedback about what I'm doing wrong.
> I developed this against the RHEL-5 version of the xen tools, but a quick
> look through xen-unstable shows that this should apply pretty easily to the
> current code.
>
Attached are two patches:
- Patch by Chris modified to apply to Xen 3.4.1 (only a small Makefile change)
- Patch by me to fix compilation with gcc 4.4.0.
-- Pasi
> Signed-off-by: Chris Lalancette <clalance@xxxxxxxxxx>
> diff -urp xen-3.1.0-src/tools/libxc/Makefile
> xen-3.1.0-src.working/tools/libxc/Makefile
> --- xen-3.1.0-src/tools/libxc/Makefile 2009-08-13 03:03:55.000000000
> -0400
> +++ xen-3.1.0-src.working/tools/libxc/Makefile 2009-08-12
> 11:56:38.000000000 -0400
> @@ -161,7 +161,7 @@ libxenguest.so.$(MAJOR): libxenguest.so.
> ln -sf $< $@
>
> libxenguest.so.$(MAJOR).$(MINOR): $(GUEST_PIC_OBJS) libxenctrl.so
> - $(CC) $(CFLAGS) $(LDFLAGS) -Wl,$(SONAME_LDFLAG)
> -Wl,libxenguest.so.$(MAJOR) $(SHLIB_CFLAGS) -o $@ $(GUEST_PIC_OBJS) -lz
> -lxenctrl -lpthread
> + $(CC) $(CFLAGS) $(LDFLAGS) -Wl,$(SONAME_LDFLAG)
> -Wl,libxenguest.so.$(MAJOR) $(SHLIB_CFLAGS) -o $@ $(GUEST_PIC_OBJS) -lz
> -llzma -lbz2 -lxenctrl -lpthread
>
> -include $(DEPS)
>
> diff -urp xen-3.1.0-src/tools/libxc/xc_dom_bzimageloader.c
> xen-3.1.0-src.working/tools/libxc/xc_dom_bzimageloader.c
> --- xen-3.1.0-src/tools/libxc/xc_dom_bzimageloader.c 2009-08-13
> 03:03:55.000000000 -0400
> +++ xen-3.1.0-src.working/tools/libxc/xc_dom_bzimageloader.c 2009-08-13
> 03:06:19.000000000 -0400
> @@ -11,15 +11,208 @@
> * written 2006 by Gerd Hoffmann <kraxel@xxxxxxx>.
> * written 2007 by Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
> * written 2008 by Ian Campbell <ijc@xxxxxxxxxxxxxx>
> + * written 2009 by Chris Lalancette <clalance@xxxxxxxxxx>
> *
> */
> #include <stdio.h>
> #include <stdlib.h>
> #include <inttypes.h>
> +#include <bzlib.h>
> +#include <lzma.h>
>
> #include "xg_private.h"
> #include "xc_dom.h"
>
> +static inline uint64_t physmem(void)
> +{
> + uint64_t ret = 0;
> +
> + const long pagesize = sysconf(_SC_PAGESIZE);
> + const long pages = sysconf(_SC_PHYS_PAGES);
> + if (pagesize != -1 || pages != -1)
> + // According to docs, pagesize * pages can overflow.
> + // Simple case is 32-bit box with 4 GiB or more RAM,
> + // which may report exactly 4 GiB of RAM, and "long"
> + // being 32-bit will overflow. Casting to uint64_t
> + // hopefully avoids overflows in the near future.
> + ret = (uint64_t)(pagesize) * (uint64_t)(pages);
> +
> + return ret;
> +}
> +
> +static int xc_try_bzip2_decode(struct xc_dom_image *dom, void **blob, size_t
> *size)
> +{
> + bz_stream stream;
> + int ret;
> + char *out_buf;
> + int retval = -1;
> + int outsize;
> + uint64_t total;
> +
> + stream.bzalloc = NULL;
> + stream.bzfree = NULL;
> + stream.opaque = NULL;
> +
> + ret = BZ2_bzDecompressInit(&stream, 0, 0);
> + if (ret != BZ_OK) {
> + xc_dom_printf("Error initting bz2 stream\n");
> + return -1;
> + }
> +
> + /* sigh. We don't know up-front how much memory we are going to need
> + * for the output buffer. Allocate the output buffer to be equal
> + * the input buffer to start, and we'll realloc as needed.
> + */
> + outsize = dom->kernel_size;
> + out_buf = malloc(outsize);
> + if (out_buf == NULL) {
> + xc_dom_printf("Failed to alloc memory\n");
> + goto bzip2_cleanup;
> + }
> +
> + stream.next_in = dom->kernel_blob;
> + stream.avail_in = dom->kernel_size;
> +
> + stream.next_out = out_buf;
> + stream.avail_out = dom->kernel_size;
> +
> + while (1) {
> + ret = BZ2_bzDecompress(&stream);
> + if (stream.avail_out == 0 || ret != BZ_OK) {
> + out_buf = realloc(out_buf, outsize * 2);
> + if (out_buf == NULL) {
> + xc_dom_printf("Failed to realloc memory\n");
> + break;
> + }
> +
> + stream.next_out = out_buf + outsize;
> + stream.avail_out = (outsize * 2) - outsize;
> + outsize *= 2;
> + }
> +
> + if (ret != BZ_OK) {
> + if (ret == BZ_STREAM_END) {
> + xc_dom_printf("Saw data stream end\n");
> + retval = 0;
> + break;
> + }
> + xc_dom_printf("BZIP error\n");
> + }
> + }
> +
> + total = (stream.total_out_hi32 << 31) | stream.total_out_lo32;
> +
> + xc_dom_printf("%s: BZIP2 decompress OK, 0x%zx -> 0x%lx\n", __FUNCTION__,
> *size, total);
> +
> + *blob = out_buf;
> + *size = total;
> +
> +bzip2_cleanup:
> + BZ2_bzDecompressEnd(&stream);
> +
> + return retval;
> +}
> +
> +static int xc_try_lzma_decode(struct xc_dom_image *dom, void **blob, size_t
> *size)
> +{
> + lzma_stream stream = LZMA_STREAM_INIT;
> + lzma_ret ret;
> + lzma_action action = LZMA_RUN;
> + unsigned char *out_buf;
> + int retval = -1;
> + int outsize;
> + const char *msg;
> +
> + ret = lzma_alone_decoder(&stream, physmem() / 3);
> + if (ret != LZMA_OK) {
> + xc_dom_printf("Failed to init lzma stream decoder\n");
> + return -1;
> + }
> +
> + /* sigh. We don't know up-front how much memory we are going to need
> + * for the output buffer. Allocate the output buffer to be equal
> + * the input buffer to start, and we'll realloc as needed.
> + */
> + outsize = dom->kernel_size;
> + out_buf = malloc(outsize);
> + if (out_buf == NULL) {
> + xc_dom_printf("Failed to alloc memory\n");
> + goto lzma_cleanup;
> + }
> +
> + stream.next_in = dom->kernel_blob;
> + stream.avail_in = dom->kernel_size;
> +
> + stream.next_out = out_buf;
> + stream.avail_out = dom->kernel_size;
> +
> + while (1) {
> + ret = lzma_code(&stream, action);
> + if (stream.avail_out == 0 || ret != LZMA_OK) {
> + out_buf = realloc(out_buf, outsize * 2);
> + if (out_buf == NULL) {
> + xc_dom_printf("Failed to realloc memory\n");
> + break;
> + }
> +
> + stream.next_out = out_buf + outsize;
> + stream.avail_out = (outsize * 2) - outsize;
> + outsize *= 2;
> + }
> +
> + if (ret != LZMA_OK) {
> + if (ret == LZMA_STREAM_END) {
> + xc_dom_printf("Saw data stream end\n");
> + retval = 0;
> + break;
> + }
> +
> + switch (ret) {
> + case LZMA_MEM_ERROR:
> + msg = strerror(ENOMEM);
> + break;
> +
> + case LZMA_MEMLIMIT_ERROR:
> + msg = "Memory usage limit reached";
> + break;
> +
> + case LZMA_FORMAT_ERROR:
> + msg = "File format not recognized";
> + break;
> +
> + case LZMA_OPTIONS_ERROR:
> + // FIXME: Better message?
> + msg = "Unsupported compression options";
> + break;
> +
> + case LZMA_DATA_ERROR:
> + msg = "File is corrupt";
> + break;
> +
> + case LZMA_BUF_ERROR:
> + msg = "Unexpected end of input";
> + break;
> +
> + default:
> + msg = "Internal program error (bug)";
> + break;
> + }
> + xc_dom_printf("%s: LZMA decompression error %s\n", __FUNCTION__,
> msg);
> + break;
> + }
> + }
> +
> + xc_dom_printf("%s: LZMA decompress OK, 0x%zx -> 0x%zx\n", __FUNCTION__,
> *size, stream.total_out);
> +
> + *blob = out_buf;
> + *size = stream.total_out;
> +
> + lzma_cleanup:
> + lzma_end(&stream);
> +
> + return retval;
> +}
> +
> struct setup_header {
> uint8_t _pad0[0x1f1]; /* skip uninteresting stuff */
> uint8_t setup_sects;
> @@ -70,22 +263,22 @@ static unsigned int payload_offset(struc
> return off;
> }
>
> -static int check_bzimage_kernel(struct xc_dom_image *dom, int verbose)
> +static int xc_dom_probe_bzimage_kernel(struct xc_dom_image *dom)
> {
> struct setup_header *hdr;
> + int ret;
>
> if ( dom->kernel_blob == NULL )
> {
> - if ( verbose )
> - xc_dom_panic(XC_INTERNAL_ERROR, "%s: no kernel image loaded\n",
> - __FUNCTION__);
> + xc_dom_panic(XC_INTERNAL_ERROR, "%s: no kernel image loaded\n",
> + __FUNCTION__);
> return -EINVAL;
> }
> +
> if ( dom->kernel_size < sizeof(struct setup_header) )
> {
> - if ( verbose )
> - xc_dom_panic(XC_INTERNAL_ERROR, "%s: kernel image too small\n",
> - __FUNCTION__);
> + xc_dom_panic(XC_INTERNAL_ERROR, "%s: kernel image too small\n",
> + __FUNCTION__);
> return -EINVAL;
> }
>
> @@ -93,39 +286,54 @@ static int check_bzimage_kernel(struct x
>
> if ( memcmp(&hdr->header, HDR_MAGIC, HDR_MAGIC_SZ) != 0 )
> {
> - if ( verbose )
> - xc_dom_panic(XC_INVALID_KERNEL, "%s: kernel is not a bzImage\n",
> - __FUNCTION__);
> + xc_dom_panic(XC_INVALID_KERNEL, "%s: kernel is not a bzImage\n",
> + __FUNCTION__);
> return -EINVAL;
> }
>
> if ( hdr->version < VERSION(2,8) )
> {
> - if ( verbose )
> - xc_dom_panic(XC_INVALID_KERNEL, "%s: boot protocol too old
> (%04x)\n",
> - __FUNCTION__, hdr->version);
> + xc_dom_panic(XC_INVALID_KERNEL, "%s: boot protocol too old (%04x)\n",
> + __FUNCTION__, hdr->version);
> return -EINVAL;
> }
>
> dom->kernel_blob = dom->kernel_blob + payload_offset(hdr);
> dom->kernel_size = hdr->payload_length;
>
> - if ( xc_dom_try_gunzip(dom, &dom->kernel_blob, &dom->kernel_size) == -1 )
> - {
> - if ( verbose )
> - xc_dom_panic(XC_INVALID_KERNEL, "%s: unable to decompress
> kernel\n",
> + if (memcmp(dom->kernel_blob, "\037\213", 2) == 0) {
> + ret = xc_dom_try_gunzip(dom, &dom->kernel_blob, &dom->kernel_size);
> + if (ret == -1) {
> + xc_dom_panic(XC_INVALID_KERNEL, "%s: unable to gzip decompress
> kernel\n",
> + __FUNCTION__);
> + return -EINVAL;
> + }
> + }
> + else if (memcmp(dom->kernel_blob, "\102\132\150", 3) == 0) {
> + ret = xc_try_bzip2_decode(dom, &dom->kernel_blob, &dom->kernel_size);
> + if (ret < 0) {
> + xc_dom_panic(XC_INVALID_KERNEL, "%s unable to BZIP2 decompress
> kernel",
> + __FUNCTION__);
> + return -EINVAL;
> + }
> + }
> + else if (memcmp(dom->kernel_blob, "\135\000", 2) == 0) {
> + ret = xc_try_lzma_decode(dom, &dom->kernel_blob, &dom->kernel_size);
> + if (ret < 0) {
> + xc_dom_panic(XC_INVALID_KERNEL, "%s unable to LZMA decompress
> kernel\n",
> __FUNCTION__);
> + return -EINVAL;
> + }
> + }
> + else {
> + xc_dom_panic(XC_INVALID_KERNEL, "%s: unknown compression format\n",
> + __FUNCTION__);
> return -EINVAL;
> }
>
> return elf_loader.probe(dom);
> }
>
> -static int xc_dom_probe_bzimage_kernel(struct xc_dom_image *dom)
> -{
> - return check_bzimage_kernel(dom, 0);
> -}
> -
> static int xc_dom_parse_bzimage_kernel(struct xc_dom_image *dom)
> {
> return elf_loader.parser(dom);
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
xen-loader-bzip2-lzma-xen34-fixed.patch
Description: Text Data
xen-loader-bzip2-lzma-xen34-fixed-compilefix-gcc440.patch
Description: Text Data
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