Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright 2021 Google LLC. */
#include <linux/init.h>#include <linux/highmem.h>#include <linux/kobject.h>#include <linux/mm.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/sysfs.h>#include <linux/vmalloc.h>
#include "internal.h"
static int module_extend_max_pages(struct load_info *info, unsigned int extent){ struct page **new_pages; unsigned int new_max = info->max_pages + extent;
new_pages = kvrealloc(info->pages, size_mul(new_max, sizeof(*info->pages)), GFP_KERNEL); if (!new_pages) return -ENOMEM;
info->pages = new_pages; info->max_pages = new_max;
return 0;}
static struct page *module_get_next_page(struct load_info *info){ struct page *page; int error;
if (info->max_pages == info->used_pages) { error = module_extend_max_pages(info, info->used_pages); if (error) return ERR_PTR(error); }
page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); if (!page) return ERR_PTR(-ENOMEM);
info->pages[info->used_pages++] = page; return page;}
#if defined(CONFIG_MODULE_COMPRESS_GZIP)#include <linux/zlib.h>#define MODULE_COMPRESSION gzip#define MODULE_DECOMPRESS_FN module_gzip_decompress
/* * Calculate length of the header which consists of signature, header * flags, time stamp and operating system ID (10 bytes total), plus * an optional filename. */static size_t module_gzip_header_len(const u8 *buf, size_t size){ const u8 signature[] = { 0x1f, 0x8b, 0x08 }; size_t len = 10;
if (size < len || memcmp(buf, signature, sizeof(signature))) return 0;
if (buf[3] & 0x08) { do { /* * If we can't find the end of the file name we must * be dealing with a corrupted file. */ if (len == size) return 0; } while (buf[len++] != '\0'); }
return len;}
static ssize_t module_gzip_decompress(struct load_info *info, const void *buf, size_t size){ struct z_stream_s s = { 0 }; size_t new_size = 0; size_t gzip_hdr_len; ssize_t retval; int rc;
gzip_hdr_len = module_gzip_header_len(buf, size); if (!gzip_hdr_len) { pr_err("not a gzip compressed module\n"); return -EINVAL; }
s.next_in = buf + gzip_hdr_len; s.avail_in = size - gzip_hdr_len;
s.workspace = kvmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); if (!s.workspace) return -ENOMEM;
rc = zlib_inflateInit2(&s, -MAX_WBITS); if (rc != Z_OK) { pr_err("failed to initialize decompressor: %d\n", rc); retval = -EINVAL; goto out; }
do { struct page *page = module_get_next_page(info);
if (IS_ERR(page)) { retval = PTR_ERR(page); goto out_inflate_end; }
s.next_out = kmap_local_page(page); s.avail_out = PAGE_SIZE; rc = zlib_inflate(&s, 0); kunmap_local(s.next_out);
new_size += PAGE_SIZE - s.avail_out; } while (rc == Z_OK);
if (rc != Z_STREAM_END) { pr_err("decompression failed with status %d\n", rc); retval = -EINVAL; goto out_inflate_end; }
retval = new_size;
out_inflate_end: zlib_inflateEnd(&s);out: kvfree(s.workspace); return retval;}#elif defined(CONFIG_MODULE_COMPRESS_XZ)#include <linux/xz.h>#define MODULE_COMPRESSION xz#define MODULE_DECOMPRESS_FN module_xz_decompress
static ssize_t module_xz_decompress(struct load_info *info, const void *buf, size_t size){ static const u8 signature[] = { 0xfd, '7', 'z', 'X', 'Z', 0 }; struct xz_dec *xz_dec; struct xz_buf xz_buf; enum xz_ret xz_ret; size_t new_size = 0; ssize_t retval;
if (size < sizeof(signature) || memcmp(buf, signature, sizeof(signature))) { pr_err("not an xz compressed module\n"); return -EINVAL; }
xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1); if (!xz_dec) return -ENOMEM;
xz_buf.in_size = size; xz_buf.in = buf; xz_buf.in_pos = 0;
do { struct page *page = module_get_next_page(info);
if (IS_ERR(page)) { retval = PTR_ERR(page); goto out; }
xz_buf.out = kmap_local_page(page); xz_buf.out_pos = 0; xz_buf.out_size = PAGE_SIZE; xz_ret = xz_dec_run(xz_dec, &xz_buf); kunmap_local(xz_buf.out);
new_size += xz_buf.out_pos; } while (xz_buf.out_pos == PAGE_SIZE && xz_ret == XZ_OK);
if (xz_ret != XZ_STREAM_END) { pr_err("decompression failed with status %d\n", xz_ret); retval = -EINVAL; goto out; }
retval = new_size;
out: xz_dec_end(xz_dec); return retval;}#elif defined(CONFIG_MODULE_COMPRESS_ZSTD)#include <linux/zstd.h>#define MODULE_COMPRESSION zstd#define MODULE_DECOMPRESS_FN module_zstd_decompress
static ssize_t module_zstd_decompress(struct load_info *info, const void *buf, size_t size){ static const u8 signature[] = { 0x28, 0xb5, 0x2f, 0xfd }; ZSTD_outBuffer zstd_dec; ZSTD_inBuffer zstd_buf; zstd_frame_header header; size_t wksp_size; void *wksp = NULL; ZSTD_DStream *dstream; size_t ret; size_t new_size = 0; int retval;
if (size < sizeof(signature) || memcmp(buf, signature, sizeof(signature))) { pr_err("not a zstd compressed module\n"); return -EINVAL; }
zstd_buf.src = buf; zstd_buf.pos = 0; zstd_buf.size = size;
ret = zstd_get_frame_header(&header, zstd_buf.src, zstd_buf.size); if (ret != 0) { pr_err("ZSTD-compressed data has an incomplete frame header\n"); retval = -EINVAL; goto out; } if (header.windowSize > (1 << ZSTD_WINDOWLOG_MAX)) { pr_err("ZSTD-compressed data has too large a window size\n"); retval = -EINVAL; goto out; }
wksp_size = zstd_dstream_workspace_bound(header.windowSize); wksp = kvmalloc(wksp_size, GFP_KERNEL); if (!wksp) { retval = -ENOMEM; goto out; }
dstream = zstd_init_dstream(header.windowSize, wksp, wksp_size); if (!dstream) { pr_err("Can't initialize ZSTD stream\n"); retval = -ENOMEM; goto out; }
do { struct page *page = module_get_next_page(info);
if (IS_ERR(page)) { retval = PTR_ERR(page); goto out; }
zstd_dec.dst = kmap_local_page(page); zstd_dec.pos = 0; zstd_dec.size = PAGE_SIZE;
ret = zstd_decompress_stream(dstream, &zstd_dec, &zstd_buf); kunmap_local(zstd_dec.dst); retval = zstd_get_error_code(ret); if (retval) break;
new_size += zstd_dec.pos; } while (zstd_dec.pos == PAGE_SIZE && ret != 0);
if (retval) { pr_err("ZSTD-decompression failed with status %d\n", retval); retval = -EINVAL; goto out; }
retval = new_size;
out: kvfree(wksp); return retval;}#else#error "Unexpected configuration for CONFIG_MODULE_DECOMPRESS"#endif
int module_decompress(struct load_info *info, const void *buf, size_t size){ unsigned int n_pages; ssize_t data_size; int error;
#if defined(CONFIG_MODULE_STATS) info->compressed_len = size;#endif
/* * Start with number of pages twice as big as needed for * compressed data. */ n_pages = DIV_ROUND_UP(size, PAGE_SIZE) * 2; error = module_extend_max_pages(info, n_pages); if (error) return error;
data_size = MODULE_DECOMPRESS_FN(info, buf, size); if (data_size < 0) { error = data_size; goto err; }
info->hdr = vmap(info->pages, info->used_pages, VM_MAP, PAGE_KERNEL); if (!info->hdr) { error = -ENOMEM; goto err; }
info->len = data_size; return 0;
err: module_decompress_cleanup(info); return error;}
void module_decompress_cleanup(struct load_info *info){ int i;
if (info->hdr) vunmap(info->hdr);
for (i = 0; i < info->used_pages; i++) __free_page(info->pages[i]);
kvfree(info->pages);
info->pages = NULL; info->max_pages = info->used_pages = 0;}
#ifdef CONFIG_SYSFSstatic ssize_t compression_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf){ return sysfs_emit(buf, __stringify(MODULE_COMPRESSION) "\n");}
static struct kobj_attribute module_compression_attr = __ATTR_RO(compression);
static int __init module_decompress_sysfs_init(void){ int error;
error = sysfs_create_file(&module_kset->kobj, &module_compression_attr.attr); if (error) pr_warn("Failed to create 'compression' attribute");
return 0;}late_initcall(module_decompress_sysfs_init);#endif